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authorZeng Chi <zengchi@kylinos.cn>2026-09-21 18:24:42 +0800
committerSean Christopherson <seanjc@google.com>2026-09-22 08:36:16 -0700
commit119e9db233ad0f4cbd4cfb9f9385a7bca378b37d (patch)
tree660d50d4139cb750fbde1ae3432452c20726c99d /arch/x86/coco
downloadlinux-stable-119e9db233ad0f4cbd4cfb9f9385a7bca378b37d.tar.gz
linux-stable-119e9db233ad0f4cbd4cfb9f9385a7bca378b37d.zip
KVM: Don't pre-reserve xarray entries when storing empty/NULL attributesgrafted
Skip the xarray reservation loop when clearing all memory attributes, as storing NULL only erases the entry and never needs to allocate, so no reservation (and no cleanup of a failed one) is required in that case. Suggested-by: Sean Christopherson <seanjc@google.com> Cc: David Ballesteros <davimaba.v@proton.me> Signed-off-by: Zeng Chi <zengchi@kylinos.cn> Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com [sean: split to separate patch] Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'arch/x86/coco')
-rw-r--r--arch/x86/coco/Makefile9
-rw-r--r--arch/x86/coco/core.c249
-rw-r--r--arch/x86/coco/sev/Makefile12
-rw-r--r--arch/x86/coco/sev/core.c2040
-rw-r--r--arch/x86/coco/sev/internal.h122
-rw-r--r--arch/x86/coco/sev/noinstr.c191
-rw-r--r--arch/x86/coco/sev/svsm.c356
-rw-r--r--arch/x86/coco/sev/vc-handle.c1089
-rw-r--r--arch/x86/coco/sev/vc-shared.c656
-rw-r--r--arch/x86/coco/tdx/Makefile3
-rw-r--r--arch/x86/coco/tdx/debug.c69
-rw-r--r--arch/x86/coco/tdx/tdcall.S63
-rw-r--r--arch/x86/coco/tdx/tdx-shared.c91
-rw-r--r--arch/x86/coco/tdx/tdx.c1195
14 files changed, 6145 insertions, 0 deletions
diff --git a/arch/x86/coco/Makefile b/arch/x86/coco/Makefile
new file mode 100644
index 000000000..eabdc7486
--- /dev/null
+++ b/arch/x86/coco/Makefile
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0
+CFLAGS_REMOVE_core.o = -pg
+KASAN_SANITIZE_core.o := n
+CFLAGS_core.o += -fno-stack-protector
+
+obj-y += core.o
+
+obj-$(CONFIG_INTEL_TDX_GUEST) += tdx/
+obj-$(CONFIG_AMD_MEM_ENCRYPT) += sev/
diff --git a/arch/x86/coco/core.c b/arch/x86/coco/core.c
new file mode 100644
index 000000000..989ca9f72
--- /dev/null
+++ b/arch/x86/coco/core.c
@@ -0,0 +1,249 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Confidential Computing Platform Capability checks
+ *
+ * Copyright (C) 2021 Advanced Micro Devices, Inc.
+ * Copyright (C) 2024 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ *
+ * Author: Tom Lendacky <thomas.lendacky@amd.com>
+ */
+
+#include <linux/export.h>
+#include <linux/cc_platform.h>
+#include <linux/string.h>
+#include <linux/random.h>
+
+#include <asm/archrandom.h>
+#include <asm/coco.h>
+#include <asm/processor.h>
+
+enum cc_vendor cc_vendor __ro_after_init = CC_VENDOR_NONE;
+SYM_PIC_ALIAS(cc_vendor);
+u64 cc_mask __ro_after_init;
+SYM_PIC_ALIAS(cc_mask);
+
+static struct cc_attr_flags {
+ __u64 host_sev_snp : 1,
+ __resv : 63;
+} cc_flags;
+
+static bool noinstr intel_cc_platform_has(enum cc_attr attr)
+{
+ switch (attr) {
+ case CC_ATTR_GUEST_UNROLL_STRING_IO:
+ case CC_ATTR_GUEST_MEM_ENCRYPT:
+ case CC_ATTR_MEM_ENCRYPT:
+ return true;
+ default:
+ return false;
+ }
+}
+
+/*
+ * Handle the SEV-SNP vTOM case where sme_me_mask is zero, and
+ * the other levels of SME/SEV functionality, including C-bit
+ * based SEV-SNP, are not enabled.
+ */
+static __maybe_unused __always_inline bool amd_cc_platform_vtom(enum cc_attr attr)
+{
+ switch (attr) {
+ case CC_ATTR_GUEST_MEM_ENCRYPT:
+ case CC_ATTR_MEM_ENCRYPT:
+ return true;
+ default:
+ return false;
+ }
+}
+
+/*
+ * SME and SEV are very similar but they are not the same, so there are
+ * times that the kernel will need to distinguish between SME and SEV. The
+ * cc_platform_has() function is used for this. When a distinction isn't
+ * needed, the CC_ATTR_MEM_ENCRYPT attribute can be used.
+ *
+ * The trampoline code is a good example for this requirement. Before
+ * paging is activated, SME will access all memory as decrypted, but SEV
+ * will access all memory as encrypted. So, when APs are being brought
+ * up under SME the trampoline area cannot be encrypted, whereas under SEV
+ * the trampoline area must be encrypted.
+ */
+static bool noinstr amd_cc_platform_has(enum cc_attr attr)
+{
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+
+ if (sev_status & MSR_AMD64_SNP_VTOM)
+ return amd_cc_platform_vtom(attr);
+
+ switch (attr) {
+ case CC_ATTR_MEM_ENCRYPT:
+ return sme_me_mask;
+
+ case CC_ATTR_HOST_MEM_ENCRYPT:
+ return sme_me_mask && !(sev_status & MSR_AMD64_SEV_ENABLED);
+
+ case CC_ATTR_GUEST_MEM_ENCRYPT:
+ return sev_status & MSR_AMD64_SEV_ENABLED;
+
+ case CC_ATTR_GUEST_STATE_ENCRYPT:
+ return sev_status & MSR_AMD64_SEV_ES_ENABLED;
+
+ /*
+ * With SEV, the rep string I/O instructions need to be unrolled
+ * but SEV-ES supports them through the #VC handler.
+ */
+ case CC_ATTR_GUEST_UNROLL_STRING_IO:
+ return (sev_status & MSR_AMD64_SEV_ENABLED) &&
+ !(sev_status & MSR_AMD64_SEV_ES_ENABLED);
+
+ case CC_ATTR_GUEST_SEV_SNP:
+ return sev_status & MSR_AMD64_SEV_SNP_ENABLED;
+
+ case CC_ATTR_GUEST_SNP_SECURE_TSC:
+ return sev_status & MSR_AMD64_SNP_SECURE_TSC;
+
+ case CC_ATTR_HOST_SEV_SNP:
+ return cc_flags.host_sev_snp;
+
+ case CC_ATTR_SNP_SECURE_AVIC:
+ return sev_status & MSR_AMD64_SNP_SECURE_AVIC;
+
+ default:
+ return false;
+ }
+#else
+ return false;
+#endif
+}
+
+bool noinstr cc_platform_has(enum cc_attr attr)
+{
+ switch (cc_vendor) {
+ case CC_VENDOR_AMD:
+ return amd_cc_platform_has(attr);
+ case CC_VENDOR_INTEL:
+ return intel_cc_platform_has(attr);
+ default:
+ return false;
+ }
+}
+EXPORT_SYMBOL_GPL(cc_platform_has);
+
+u64 cc_mkenc(u64 val)
+{
+ /*
+ * Both AMD and Intel use a bit in the page table to indicate
+ * encryption status of the page.
+ *
+ * - for AMD, bit *set* means the page is encrypted
+ * - for AMD with vTOM and for Intel, *clear* means encrypted
+ */
+ switch (cc_vendor) {
+ case CC_VENDOR_AMD:
+ if (sev_status & MSR_AMD64_SNP_VTOM)
+ return val & ~cc_mask;
+ else
+ return val | cc_mask;
+ case CC_VENDOR_INTEL:
+ return val & ~cc_mask;
+ default:
+ return val;
+ }
+}
+
+u64 cc_mkdec(u64 val)
+{
+ /* See comment in cc_mkenc() */
+ switch (cc_vendor) {
+ case CC_VENDOR_AMD:
+ if (sev_status & MSR_AMD64_SNP_VTOM)
+ return val | cc_mask;
+ else
+ return val & ~cc_mask;
+ case CC_VENDOR_INTEL:
+ return val | cc_mask;
+ default:
+ return val;
+ }
+}
+EXPORT_SYMBOL_GPL(cc_mkdec);
+
+static void amd_cc_platform_clear(enum cc_attr attr)
+{
+ switch (attr) {
+ case CC_ATTR_HOST_SEV_SNP:
+ cc_flags.host_sev_snp = 0;
+ break;
+ default:
+ break;
+ }
+}
+
+void cc_platform_clear(enum cc_attr attr)
+{
+ switch (cc_vendor) {
+ case CC_VENDOR_AMD:
+ amd_cc_platform_clear(attr);
+ break;
+ default:
+ break;
+ }
+}
+
+static void amd_cc_platform_set(enum cc_attr attr)
+{
+ switch (attr) {
+ case CC_ATTR_HOST_SEV_SNP:
+ cc_flags.host_sev_snp = 1;
+ break;
+ default:
+ break;
+ }
+}
+
+void cc_platform_set(enum cc_attr attr)
+{
+ switch (cc_vendor) {
+ case CC_VENDOR_AMD:
+ amd_cc_platform_set(attr);
+ break;
+ default:
+ break;
+ }
+}
+
+__init void cc_random_init(void)
+{
+ /*
+ * The seed is 32 bytes (in units of longs), which is 256 bits, which
+ * is the security level that the RNG is targeting.
+ */
+ unsigned long rng_seed[32 / sizeof(long)];
+ size_t i, longs;
+
+ if (!cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
+ return;
+
+ /*
+ * Since the CoCo threat model includes the host, the only reliable
+ * source of entropy that can be neither observed nor manipulated is
+ * RDRAND. Usually, RDRAND failure is considered tolerable, but since
+ * CoCo guests have no other unobservable source of entropy, it's
+ * important to at least ensure the RNG gets some initial random seeds.
+ */
+ for (i = 0; i < ARRAY_SIZE(rng_seed); i += longs) {
+ longs = arch_get_random_longs(&rng_seed[i], ARRAY_SIZE(rng_seed) - i);
+
+ /*
+ * A zero return value means that the guest doesn't have RDRAND
+ * or the CPU is physically broken, and in both cases that
+ * means most crypto inside of the CoCo instance will be
+ * broken, defeating the purpose of CoCo in the first place. So
+ * just panic here because it's absolutely unsafe to continue
+ * executing.
+ */
+ if (longs == 0)
+ panic("RDRAND is defective.");
+ }
+ add_device_randomness(rng_seed, sizeof(rng_seed));
+ memzero_explicit(rng_seed, sizeof(rng_seed));
+}
diff --git a/arch/x86/coco/sev/Makefile b/arch/x86/coco/sev/Makefile
new file mode 100644
index 000000000..3111a2ee6
--- /dev/null
+++ b/arch/x86/coco/sev/Makefile
@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-y += core.o noinstr.o vc-handle.o svsm.o
+
+# Clang 14 and older may fail to respect __no_sanitize_undefined when inlining
+UBSAN_SANITIZE_noinstr.o := n
+
+# GCC may fail to respect __no_sanitize_address or __no_kcsan when inlining
+KASAN_SANITIZE_noinstr.o := n
+KCSAN_SANITIZE_noinstr.o := n
+
+GCOV_PROFILE_noinstr.o := n
diff --git a/arch/x86/coco/sev/core.c b/arch/x86/coco/sev/core.c
new file mode 100644
index 000000000..cc292d7c6
--- /dev/null
+++ b/arch/x86/coco/sev/core.c
@@ -0,0 +1,2040 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AMD Memory Encryption Support
+ *
+ * Copyright (C) 2019 SUSE
+ *
+ * Author: Joerg Roedel <jroedel@suse.de>
+ */
+
+#define pr_fmt(fmt) "SEV: " fmt
+
+#include <linux/sched/debug.h> /* For show_regs() */
+#include <linux/percpu-defs.h>
+#include <linux/cc_platform.h>
+#include <linux/printk.h>
+#include <linux/mm_types.h>
+#include <linux/set_memory.h>
+#include <linux/memblock.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/cpumask.h>
+#include <linux/efi.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/psp-sev.h>
+#include <linux/dmi.h>
+#include <uapi/linux/sev-guest.h>
+#include <crypto/aes-gcm.h>
+
+#include <asm/init.h>
+#include <asm/cpu_entry_area.h>
+#include <asm/stacktrace.h>
+#include <asm/sev.h>
+#include <asm/insn-eval.h>
+#include <asm/fpu/xcr.h>
+#include <asm/processor.h>
+#include <asm/realmode.h>
+#include <asm/setup.h>
+#include <asm/traps.h>
+#include <asm/svm.h>
+#include <asm/smp.h>
+#include <asm/cpu.h>
+#include <asm/apic.h>
+#include <asm/cpuid/api.h>
+#include <asm/cmdline.h>
+#include <asm/msr.h>
+
+#include "internal.h"
+
+/* Bitmap of SEV features supported by the hypervisor */
+u64 sev_hv_features __ro_after_init;
+SYM_PIC_ALIAS(sev_hv_features);
+
+/* Secrets page physical address from the CC blob */
+u64 sev_secrets_pa __ro_after_init;
+SYM_PIC_ALIAS(sev_secrets_pa);
+
+/* AP INIT values as documented in the APM2 section "Processor Initialization State" */
+#define AP_INIT_CS_LIMIT 0xffff
+#define AP_INIT_DS_LIMIT 0xffff
+#define AP_INIT_LDTR_LIMIT 0xffff
+#define AP_INIT_GDTR_LIMIT 0xffff
+#define AP_INIT_IDTR_LIMIT 0xffff
+#define AP_INIT_TR_LIMIT 0xffff
+#define AP_INIT_RFLAGS_DEFAULT 0x2
+#define AP_INIT_DR6_DEFAULT 0xffff0ff0
+#define AP_INIT_GPAT_DEFAULT 0x0007040600070406ULL
+#define AP_INIT_XCR0_DEFAULT 0x1
+#define AP_INIT_X87_FTW_DEFAULT 0x5555
+#define AP_INIT_X87_FCW_DEFAULT 0x0040
+#define AP_INIT_CR0_DEFAULT 0x60000010
+#define AP_INIT_MXCSR_DEFAULT 0x1f80
+
+static const char * const sev_status_feat_names[] = {
+ [MSR_AMD64_SEV_ENABLED_BIT] = "SEV",
+ [MSR_AMD64_SEV_ES_ENABLED_BIT] = "SEV-ES",
+ [MSR_AMD64_SEV_SNP_ENABLED_BIT] = "SEV-SNP",
+ [MSR_AMD64_SNP_VTOM_BIT] = "vTom",
+ [MSR_AMD64_SNP_REFLECT_VC_BIT] = "ReflectVC",
+ [MSR_AMD64_SNP_RESTRICTED_INJ_BIT] = "RI",
+ [MSR_AMD64_SNP_ALT_INJ_BIT] = "AI",
+ [MSR_AMD64_SNP_DEBUG_SWAP_BIT] = "DebugSwap",
+ [MSR_AMD64_SNP_PREVENT_HOST_IBS_BIT] = "NoHostIBS",
+ [MSR_AMD64_SNP_BTB_ISOLATION_BIT] = "BTBIsol",
+ [MSR_AMD64_SNP_VMPL_SSS_BIT] = "VmplSSS",
+ [MSR_AMD64_SNP_SECURE_TSC_BIT] = "SecureTSC",
+ [MSR_AMD64_SNP_VMGEXIT_PARAM_BIT] = "VMGExitParam",
+ [MSR_AMD64_SNP_IBS_VIRT_BIT] = "IBSVirt",
+ [MSR_AMD64_SNP_VMSA_REG_PROT_BIT] = "VMSARegProt",
+ [MSR_AMD64_SNP_SMT_PROT_BIT] = "SMTProt",
+ [MSR_AMD64_SNP_SECURE_AVIC_BIT] = "SecureAVIC",
+ [MSR_AMD64_SNP_IBPB_ON_ENTRY_BIT] = "IBPBOnEntry",
+};
+
+/*
+ * For Secure TSC guests, the BSP fetches TSC_INFO using SNP guest messaging and
+ * initializes snp_tsc_scale and snp_tsc_offset. These values are replicated
+ * across the APs VMSA fields (TSC_SCALE and TSC_OFFSET).
+ */
+static u64 snp_tsc_scale __ro_after_init;
+static u64 snp_tsc_offset __ro_after_init;
+static unsigned long snp_tsc_freq_khz __ro_after_init;
+
+DEFINE_PER_CPU(struct sev_es_runtime_data*, runtime_data);
+DEFINE_PER_CPU(struct sev_es_save_area *, sev_vmsa);
+
+/*
+ * SVSM related information:
+ * When running under an SVSM, the VMPL that Linux is executing at must be
+ * non-zero. The VMPL is therefore used to indicate the presence of an SVSM.
+ */
+u8 snp_vmpl __ro_after_init;
+EXPORT_SYMBOL_GPL(snp_vmpl);
+SYM_PIC_ALIAS(snp_vmpl);
+
+/*
+ * Since feature negotiation related variables are set early in the boot
+ * process they must reside in the .data section so as not to be zeroed
+ * out when the .bss section is later cleared.
+ *
+ * GHCB protocol version negotiated with the hypervisor.
+ */
+u16 ghcb_version __ro_after_init;
+SYM_PIC_ALIAS(ghcb_version);
+
+/* For early boot hypervisor communication in SEV-ES enabled guests */
+static struct ghcb boot_ghcb_page __bss_decrypted __aligned(PAGE_SIZE);
+
+/*
+ * Needs to be in the .data section because we need it NULL before bss is
+ * cleared
+ */
+struct ghcb *boot_ghcb __section(".data");
+
+static u64 __init get_snp_jump_table_addr(void)
+{
+ struct snp_secrets_page *secrets;
+ void __iomem *mem;
+ u64 addr;
+
+ mem = ioremap_encrypted(sev_secrets_pa, PAGE_SIZE);
+ if (!mem) {
+ pr_err("Unable to locate AP jump table address: failed to map the SNP secrets page.\n");
+ return 0;
+ }
+
+ secrets = (__force struct snp_secrets_page *)mem;
+
+ addr = secrets->os_area.ap_jump_table_pa;
+ iounmap(mem);
+
+ return addr;
+}
+
+static u64 __init get_jump_table_addr(void)
+{
+ struct ghcb_state state;
+ unsigned long flags;
+ struct ghcb *ghcb;
+ u64 ret = 0;
+
+ if (cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
+ return get_snp_jump_table_addr();
+
+ local_irq_save(flags);
+
+ ghcb = __sev_get_ghcb(&state);
+
+ vc_ghcb_invalidate(ghcb);
+ ghcb_set_sw_exit_code(ghcb, SVM_VMGEXIT_AP_JUMP_TABLE);
+ ghcb_set_sw_exit_info_1(ghcb, SVM_VMGEXIT_GET_AP_JUMP_TABLE);
+ ghcb_set_sw_exit_info_2(ghcb, 0);
+
+ sev_es_wr_ghcb_msr(__pa(ghcb));
+ VMGEXIT();
+
+ if (ghcb_sw_exit_info_1_is_valid(ghcb) &&
+ ghcb_sw_exit_info_2_is_valid(ghcb))
+ ret = ghcb->save.sw_exit_info_2;
+
+ __sev_put_ghcb(&state);
+
+ local_irq_restore(flags);
+
+ return ret;
+}
+
+static void pval_pages(struct snp_psc_desc *desc)
+{
+ struct psc_entry *e;
+ unsigned long vaddr;
+ unsigned int size;
+ unsigned int i;
+ bool validate;
+ u64 pfn;
+ int rc;
+
+ for (i = 0; i <= desc->hdr.end_entry; i++) {
+ e = &desc->entries[i];
+
+ pfn = e->gfn;
+ vaddr = (unsigned long)pfn_to_kaddr(pfn);
+ size = e->pagesize ? RMP_PG_SIZE_2M : RMP_PG_SIZE_4K;
+ validate = e->operation == SNP_PAGE_STATE_PRIVATE;
+
+ rc = pvalidate(vaddr, size, validate);
+ if (!rc)
+ continue;
+
+ if (rc == PVALIDATE_FAIL_SIZEMISMATCH && size == RMP_PG_SIZE_2M) {
+ unsigned long vaddr_end = vaddr + PMD_SIZE;
+
+ for (; vaddr < vaddr_end; vaddr += PAGE_SIZE, pfn++) {
+ rc = pvalidate(vaddr, RMP_PG_SIZE_4K, validate);
+ if (rc)
+ __pval_terminate(pfn, validate, RMP_PG_SIZE_4K, rc, 0);
+ }
+ } else {
+ __pval_terminate(pfn, validate, size, rc, 0);
+ }
+ }
+}
+
+static void pvalidate_pages(struct snp_psc_desc *desc)
+{
+ struct psc_entry *e;
+ unsigned int i;
+
+ if (snp_vmpl)
+ svsm_pval_pages(desc);
+ else
+ pval_pages(desc);
+
+ /*
+ * If not affected by the cache-coherency vulnerability there is no need
+ * to perform the cache eviction mitigation.
+ */
+ if (cpu_feature_enabled(X86_FEATURE_COHERENCY_SFW_NO))
+ return;
+
+ for (i = 0; i <= desc->hdr.end_entry; i++) {
+ e = &desc->entries[i];
+
+ /*
+ * If validating memory (making it private) perform the cache
+ * eviction mitigation.
+ */
+ if (e->operation == SNP_PAGE_STATE_PRIVATE)
+ sev_evict_cache(pfn_to_kaddr(e->gfn), e->pagesize ? 512 : 1);
+ }
+}
+
+static int vmgexit_psc(struct ghcb *ghcb, struct snp_psc_desc *desc)
+{
+ int cur_entry, end_entry, ret = 0;
+ struct snp_psc_desc *data;
+ struct es_em_ctxt ctxt;
+
+ vc_ghcb_invalidate(ghcb);
+
+ /* Copy the input desc into GHCB shared buffer */
+ data = (struct snp_psc_desc *)ghcb->shared_buffer;
+ memcpy(ghcb->shared_buffer, desc, min_t(int, GHCB_SHARED_BUF_SIZE, sizeof(*desc)));
+
+ /*
+ * As per the GHCB specification, the hypervisor can resume the guest
+ * before processing all the entries. Check whether all the entries
+ * are processed. If not, then keep retrying. Note, the hypervisor
+ * will update the data memory directly to indicate the status, so
+ * reference the data->hdr everywhere.
+ *
+ * The strategy here is to wait for the hypervisor to change the page
+ * state in the RMP table before guest accesses the memory pages. If the
+ * page state change was not successful, then later memory access will
+ * result in a crash.
+ */
+ cur_entry = data->hdr.cur_entry;
+ end_entry = data->hdr.end_entry;
+
+ while (data->hdr.cur_entry <= data->hdr.end_entry) {
+ ghcb_set_sw_scratch(ghcb, (u64)__pa(data));
+
+ /* This will advance the shared buffer data points to. */
+ ret = sev_es_ghcb_hv_call(ghcb, &ctxt, SVM_VMGEXIT_PSC, 0, 0);
+
+ /*
+ * Page State Change VMGEXIT can pass error code through
+ * exit_info_2.
+ */
+ if (WARN(ret || ghcb->save.sw_exit_info_2,
+ "SNP: PSC failed ret=%d exit_info_2=%llx\n",
+ ret, ghcb->save.sw_exit_info_2)) {
+ ret = 1;
+ goto out;
+ }
+
+ /* Verify that reserved bit is not set */
+ if (WARN(data->hdr.reserved, "Reserved bit is set in the PSC header\n")) {
+ ret = 1;
+ goto out;
+ }
+
+ /*
+ * Sanity check that entry processing is not going backwards.
+ * This will happen only if hypervisor is tricking us.
+ */
+ if (WARN(data->hdr.end_entry > end_entry || cur_entry > data->hdr.cur_entry,
+"SNP: PSC processing going backward, end_entry %d (got %d) cur_entry %d (got %d)\n",
+ end_entry, data->hdr.end_entry, cur_entry, data->hdr.cur_entry)) {
+ ret = 1;
+ goto out;
+ }
+ }
+
+out:
+ return ret;
+}
+
+static unsigned long __set_pages_state(struct snp_psc_desc *data, unsigned long vaddr,
+ unsigned long vaddr_end, int op)
+{
+ struct ghcb_state state;
+ bool use_large_entry;
+ struct psc_hdr *hdr;
+ struct psc_entry *e;
+ unsigned long flags;
+ unsigned long pfn;
+ struct ghcb *ghcb;
+ int i;
+
+ hdr = &data->hdr;
+ e = data->entries;
+
+ memset(data, 0, sizeof(*data));
+ i = 0;
+
+ while (vaddr < vaddr_end && i < ARRAY_SIZE(data->entries)) {
+ hdr->end_entry = i;
+
+ if (is_vmalloc_addr((void *)vaddr)) {
+ pfn = vmalloc_to_pfn((void *)vaddr);
+ use_large_entry = false;
+ } else {
+ pfn = __pa(vaddr) >> PAGE_SHIFT;
+ use_large_entry = true;
+ }
+
+ e->gfn = pfn;
+ e->operation = op;
+
+ if (use_large_entry && IS_ALIGNED(vaddr, PMD_SIZE) &&
+ (vaddr_end - vaddr) >= PMD_SIZE) {
+ e->pagesize = RMP_PG_SIZE_2M;
+ vaddr += PMD_SIZE;
+ } else {
+ e->pagesize = RMP_PG_SIZE_4K;
+ vaddr += PAGE_SIZE;
+ }
+
+ e++;
+ i++;
+ }
+
+ /* Page validation must be rescinded before changing to shared */
+ if (op == SNP_PAGE_STATE_SHARED)
+ pvalidate_pages(data);
+
+ local_irq_save(flags);
+
+ ghcb = __sev_get_ghcb(&state);
+
+ /* Invoke the hypervisor to perform the page state changes */
+ if (!ghcb || vmgexit_psc(ghcb, data))
+ sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PSC);
+
+ __sev_put_ghcb(&state);
+
+ local_irq_restore(flags);
+
+ /* Page validation must be performed after changing to private */
+ if (op == SNP_PAGE_STATE_PRIVATE)
+ pvalidate_pages(data);
+
+ return vaddr;
+}
+
+static void set_pages_state(unsigned long vaddr, unsigned long npages, int op)
+{
+ struct snp_psc_desc desc;
+ unsigned long vaddr_end;
+
+ /* Use the MSR protocol when a GHCB is not available. */
+ if (!boot_ghcb) {
+ struct psc_desc d = { op, svsm_get_caa(), svsm_get_caa_pa() };
+
+ return early_set_pages_state(vaddr, __pa(vaddr), npages, &d);
+ }
+
+ vaddr = vaddr & PAGE_MASK;
+ vaddr_end = vaddr + (npages << PAGE_SHIFT);
+
+ while (vaddr < vaddr_end)
+ vaddr = __set_pages_state(&desc, vaddr, vaddr_end, op);
+}
+
+void snp_set_memory_shared(unsigned long vaddr, unsigned long npages)
+{
+ if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
+ return;
+
+ set_pages_state(vaddr, npages, SNP_PAGE_STATE_SHARED);
+}
+
+void snp_set_memory_private(unsigned long vaddr, unsigned long npages)
+{
+ if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
+ return;
+
+ set_pages_state(vaddr, npages, SNP_PAGE_STATE_PRIVATE);
+}
+
+void snp_accept_memory(phys_addr_t start, phys_addr_t end)
+{
+ unsigned long vaddr, npages;
+
+ if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
+ return;
+
+ vaddr = (unsigned long)__va(start);
+ npages = (end - start) >> PAGE_SHIFT;
+
+ set_pages_state(vaddr, npages, SNP_PAGE_STATE_PRIVATE);
+}
+
+static int vmgexit_ap_control(u64 event, struct sev_es_save_area *vmsa, u32 apic_id)
+{
+ bool create = event != SVM_VMGEXIT_AP_DESTROY;
+ struct ghcb_state state;
+ unsigned long flags;
+ struct ghcb *ghcb;
+ int ret = 0;
+
+ local_irq_save(flags);
+
+ ghcb = __sev_get_ghcb(&state);
+
+ vc_ghcb_invalidate(ghcb);
+
+ if (create)
+ ghcb_set_rax(ghcb, vmsa->sev_features);
+
+ ghcb_set_sw_exit_code(ghcb, SVM_VMGEXIT_AP_CREATION);
+ ghcb_set_sw_exit_info_1(ghcb,
+ ((u64)apic_id << 32) |
+ ((u64)snp_vmpl << 16) |
+ event);
+ ghcb_set_sw_exit_info_2(ghcb, __pa(vmsa));
+
+ sev_es_wr_ghcb_msr(__pa(ghcb));
+ VMGEXIT();
+
+ if (!ghcb_sw_exit_info_1_is_valid(ghcb) ||
+ lower_32_bits(ghcb->save.sw_exit_info_1)) {
+ pr_err("SNP AP %s error\n", (create ? "CREATE" : "DESTROY"));
+ ret = -EINVAL;
+ }
+
+ __sev_put_ghcb(&state);
+
+ local_irq_restore(flags);
+
+ return ret;
+}
+
+static int snp_set_vmsa(void *va, void *caa, int apic_id, bool make_vmsa)
+{
+ int ret;
+
+ if (snp_vmpl) {
+ struct svsm_call call = {};
+ unsigned long flags;
+
+ local_irq_save(flags);
+
+ call.caa = this_cpu_read(svsm_caa);
+ call.rcx = __pa(va);
+
+ if (make_vmsa) {
+ /* Protocol 0, Call ID 2 */
+ call.rax = SVSM_CORE_CALL(SVSM_CORE_CREATE_VCPU);
+ call.rdx = __pa(caa);
+ call.r8 = apic_id;
+ } else {
+ /* Protocol 0, Call ID 3 */
+ call.rax = SVSM_CORE_CALL(SVSM_CORE_DELETE_VCPU);
+ }
+
+ ret = svsm_perform_call_protocol(&call);
+
+ local_irq_restore(flags);
+ } else {
+ /*
+ * If the kernel runs at VMPL0, it can change the VMSA
+ * bit for a page using the RMPADJUST instruction.
+ * However, for the instruction to succeed it must
+ * target the permissions of a lesser privileged (higher
+ * numbered) VMPL level, so use VMPL1.
+ */
+ u64 attrs = 1;
+
+ if (make_vmsa)
+ attrs |= RMPADJUST_VMSA_PAGE_BIT;
+
+ ret = rmpadjust((unsigned long)va, RMP_PG_SIZE_4K, attrs);
+ }
+
+ return ret;
+}
+
+static void snp_cleanup_vmsa(struct sev_es_save_area *vmsa, int apic_id)
+{
+ int err;
+
+ err = snp_set_vmsa(vmsa, NULL, apic_id, false);
+ if (err)
+ pr_err("clear VMSA page failed (%u), leaking page\n", err);
+ else
+ free_page((unsigned long)vmsa);
+}
+
+static void set_pte_enc(pte_t *kpte, int level, void *va)
+{
+ struct pte_enc_desc d = {
+ .kpte = kpte,
+ .pte_level = level,
+ .va = va,
+ .encrypt = true
+ };
+
+ prepare_pte_enc(&d);
+ set_pte_enc_mask(kpte, d.pfn, d.new_pgprot);
+}
+
+static void unshare_all_memory(void)
+{
+ unsigned long addr, end, size, ghcb;
+ struct sev_es_runtime_data *data;
+ unsigned int npages, level;
+ bool skipped_addr;
+ pte_t *pte;
+ int cpu;
+
+ /* Unshare the direct mapping. */
+ addr = PAGE_OFFSET;
+ end = PAGE_OFFSET + get_max_mapped();
+
+ while (addr < end) {
+ pte = lookup_address(addr, &level);
+ size = page_level_size(level);
+ npages = size / PAGE_SIZE;
+ skipped_addr = false;
+
+ if (!pte || !pte_decrypted(*pte) || pte_none(*pte)) {
+ addr += size;
+ continue;
+ }
+
+ /*
+ * Ensure that all the per-CPU GHCBs are made private at the
+ * end of the unsharing loop so that the switch to the slower
+ * MSR protocol happens last.
+ */
+ for_each_possible_cpu(cpu) {
+ data = per_cpu(runtime_data, cpu);
+ ghcb = (unsigned long)&data->ghcb_page;
+
+ /* Handle the case of a huge page containing the GHCB page */
+ if (addr <= ghcb && ghcb < addr + size) {
+ skipped_addr = true;
+ break;
+ }
+ }
+
+ if (!skipped_addr) {
+ set_pte_enc(pte, level, (void *)addr);
+ snp_set_memory_private(addr, npages);
+ }
+ addr += size;
+ }
+
+ /* Unshare all bss decrypted memory. */
+ addr = (unsigned long)__start_bss_decrypted;
+ end = (unsigned long)__start_bss_decrypted_unused;
+ npages = (end - addr) >> PAGE_SHIFT;
+
+ for (; addr < end; addr += PAGE_SIZE) {
+ pte = lookup_address(addr, &level);
+ if (!pte || !pte_decrypted(*pte) || pte_none(*pte))
+ continue;
+
+ set_pte_enc(pte, level, (void *)addr);
+ }
+ addr = (unsigned long)__start_bss_decrypted;
+ snp_set_memory_private(addr, npages);
+
+ __flush_tlb_all();
+}
+
+/* Stop new private<->shared conversions */
+void snp_kexec_begin(void)
+{
+ if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
+ return;
+
+ if (!IS_ENABLED(CONFIG_KEXEC_CORE))
+ return;
+
+ /*
+ * Crash kernel ends up here with interrupts disabled: can't wait for
+ * conversions to finish.
+ *
+ * If race happened, just report and proceed.
+ */
+ if (!set_memory_enc_stop_conversion())
+ pr_warn("Failed to stop shared<->private conversions\n");
+}
+
+/*
+ * Shutdown all APs except the one handling kexec/kdump and clearing
+ * the VMSA tag on AP's VMSA pages as they are not being used as
+ * VMSA page anymore.
+ */
+static void shutdown_all_aps(void)
+{
+ struct sev_es_save_area *vmsa;
+ int apic_id, this_cpu, cpu;
+
+ this_cpu = get_cpu();
+
+ /*
+ * APs are already in HLT loop when enc_kexec_finish() callback
+ * is invoked.
+ */
+ for_each_present_cpu(cpu) {
+ vmsa = per_cpu(sev_vmsa, cpu);
+
+ /*
+ * The BSP or offlined APs do not have guest allocated VMSA
+ * and there is no need to clear the VMSA tag for this page.
+ */
+ if (!vmsa)
+ continue;
+
+ /*
+ * Cannot clear the VMSA tag for the currently running vCPU.
+ */
+ if (this_cpu == cpu) {
+ unsigned long pa;
+ struct page *p;
+
+ pa = __pa(vmsa);
+ /*
+ * Mark the VMSA page of the running vCPU as offline
+ * so that is excluded and not touched by makedumpfile
+ * while generating vmcore during kdump.
+ */
+ p = pfn_to_online_page(pa >> PAGE_SHIFT);
+ if (p)
+ __SetPageOffline(p);
+ continue;
+ }
+
+ apic_id = cpuid_to_apicid[cpu];
+
+ /*
+ * Issue AP destroy to ensure AP gets kicked out of guest mode
+ * to allow using RMPADJUST to remove the VMSA tag on it's
+ * VMSA page.
+ */
+ vmgexit_ap_control(SVM_VMGEXIT_AP_DESTROY, vmsa, apic_id);
+ snp_cleanup_vmsa(vmsa, apic_id);
+ }
+
+ put_cpu();
+}
+
+void snp_kexec_finish(void)
+{
+ struct sev_es_runtime_data *data;
+ unsigned long size, addr;
+ unsigned int level, cpu;
+ struct ghcb *ghcb;
+ pte_t *pte;
+
+ if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
+ return;
+
+ if (!IS_ENABLED(CONFIG_KEXEC_CORE))
+ return;
+
+ shutdown_all_aps();
+
+ unshare_all_memory();
+
+ /*
+ * Switch to using the MSR protocol to change per-CPU GHCBs to
+ * private. All the per-CPU GHCBs have been switched back to private,
+ * so can't do any more GHCB calls to the hypervisor beyond this point
+ * until the kexec'ed kernel starts running.
+ */
+ boot_ghcb = NULL;
+ sev_cfg.ghcbs_initialized = false;
+
+ for_each_possible_cpu(cpu) {
+ data = per_cpu(runtime_data, cpu);
+ ghcb = &data->ghcb_page;
+ pte = lookup_address((unsigned long)ghcb, &level);
+ size = page_level_size(level);
+ /* Handle the case of a huge page containing the GHCB page */
+ addr = (unsigned long)ghcb & page_level_mask(level);
+ set_pte_enc(pte, level, (void *)addr);
+ snp_set_memory_private(addr, (size / PAGE_SIZE));
+ }
+}
+
+#define __ATTR_BASE (SVM_SELECTOR_P_MASK | SVM_SELECTOR_S_MASK)
+#define INIT_CS_ATTRIBS (__ATTR_BASE | SVM_SELECTOR_READ_MASK | SVM_SELECTOR_CODE_MASK)
+#define INIT_DS_ATTRIBS (__ATTR_BASE | SVM_SELECTOR_WRITE_MASK)
+
+#define INIT_LDTR_ATTRIBS (SVM_SELECTOR_P_MASK | 2)
+#define INIT_TR_ATTRIBS (SVM_SELECTOR_P_MASK | 3)
+
+static void *snp_alloc_vmsa_page(int cpu)
+{
+ struct page *p;
+
+ /*
+ * Allocate VMSA page to work around the SNP erratum where the CPU will
+ * incorrectly signal an RMP violation #PF if a large page (2MB or 1GB)
+ * collides with the RMP entry of VMSA page. The recommended workaround
+ * is to not use a large page.
+ *
+ * Allocate an 8k page which is also 8k-aligned.
+ */
+ p = alloc_pages_node(cpu_to_node(cpu), GFP_KERNEL_ACCOUNT | __GFP_ZERO, 1);
+ if (!p)
+ return NULL;
+
+ split_page(p, 1);
+
+ /* Free the first 4k. This page may be 2M/1G aligned and cannot be used. */
+ __free_page(p);
+
+ return page_address(p + 1);
+}
+
+static int wakeup_cpu_via_vmgexit(u32 apic_id, unsigned long start_ip, unsigned int cpu)
+{
+ struct sev_es_save_area *cur_vmsa, *vmsa;
+ struct svsm_ca *caa;
+ u8 sipi_vector;
+ int ret;
+ u64 cr4;
+
+ /*
+ * The hypervisor SNP feature support check has happened earlier, just check
+ * the AP_CREATION one here.
+ */
+ if (!(sev_hv_features & GHCB_HV_FT_SNP_AP_CREATION))
+ return -EOPNOTSUPP;
+
+ /*
+ * Verify the desired start IP against the known trampoline start IP
+ * to catch any future new trampolines that may be introduced that
+ * would require a new protected guest entry point.
+ */
+ if (WARN_ONCE(start_ip != real_mode_header->trampoline_start,
+ "Unsupported SNP start_ip: %lx\n", start_ip))
+ return -EINVAL;
+
+ /* Override start_ip with known protected guest start IP */
+ start_ip = real_mode_header->sev_es_trampoline_start;
+ cur_vmsa = per_cpu(sev_vmsa, cpu);
+
+ /*
+ * A new VMSA is created each time because there is no guarantee that
+ * the current VMSA is the kernels or that the vCPU is not running. If
+ * an attempt was done to use the current VMSA with a running vCPU, a
+ * #VMEXIT of that vCPU would wipe out all of the settings being done
+ * here.
+ */
+ vmsa = (struct sev_es_save_area *)snp_alloc_vmsa_page(cpu);
+ if (!vmsa)
+ return -ENOMEM;
+
+ /* If an SVSM is present, the SVSM per-CPU CAA will be !NULL */
+ caa = per_cpu(svsm_caa, cpu);
+
+ /* CR4 should maintain the MCE value */
+ cr4 = native_read_cr4() & X86_CR4_MCE;
+
+ /* Set the CS value based on the start_ip converted to a SIPI vector */
+ sipi_vector = (start_ip >> 12);
+ vmsa->cs.base = sipi_vector << 12;
+ vmsa->cs.limit = AP_INIT_CS_LIMIT;
+ vmsa->cs.attrib = INIT_CS_ATTRIBS;
+ vmsa->cs.selector = sipi_vector << 8;
+
+ /* Set the RIP value based on start_ip */
+ vmsa->rip = start_ip & 0xfff;
+
+ /* Set AP INIT defaults as documented in the APM */
+ vmsa->ds.limit = AP_INIT_DS_LIMIT;
+ vmsa->ds.attrib = INIT_DS_ATTRIBS;
+ vmsa->es = vmsa->ds;
+ vmsa->fs = vmsa->ds;
+ vmsa->gs = vmsa->ds;
+ vmsa->ss = vmsa->ds;
+
+ vmsa->gdtr.limit = AP_INIT_GDTR_LIMIT;
+ vmsa->ldtr.limit = AP_INIT_LDTR_LIMIT;
+ vmsa->ldtr.attrib = INIT_LDTR_ATTRIBS;
+ vmsa->idtr.limit = AP_INIT_IDTR_LIMIT;
+ vmsa->tr.limit = AP_INIT_TR_LIMIT;
+ vmsa->tr.attrib = INIT_TR_ATTRIBS;
+
+ vmsa->cr4 = cr4;
+ vmsa->cr0 = AP_INIT_CR0_DEFAULT;
+ vmsa->dr7 = DR7_RESET_VALUE;
+ vmsa->dr6 = AP_INIT_DR6_DEFAULT;
+ vmsa->rflags = AP_INIT_RFLAGS_DEFAULT;
+ vmsa->g_pat = AP_INIT_GPAT_DEFAULT;
+ vmsa->xcr0 = AP_INIT_XCR0_DEFAULT;
+ vmsa->mxcsr = AP_INIT_MXCSR_DEFAULT;
+ vmsa->x87_ftw = AP_INIT_X87_FTW_DEFAULT;
+ vmsa->x87_fcw = AP_INIT_X87_FCW_DEFAULT;
+
+ if (cc_platform_has(CC_ATTR_SNP_SECURE_AVIC))
+ vmsa->vintr_ctrl |= V_GIF_MASK | V_NMI_ENABLE_MASK;
+
+ /* SVME must be set. */
+ vmsa->efer = EFER_SVME;
+
+ /*
+ * Set the SNP-specific fields for this VMSA:
+ * VMPL level
+ * SEV_FEATURES (matches the SEV STATUS MSR right shifted 2 bits)
+ */
+ vmsa->vmpl = snp_vmpl;
+ vmsa->sev_features = sev_status >> 2;
+
+ /* Populate AP's TSC scale/offset to get accurate TSC values. */
+ if (cc_platform_has(CC_ATTR_GUEST_SNP_SECURE_TSC)) {
+ vmsa->tsc_scale = snp_tsc_scale;
+ vmsa->tsc_offset = snp_tsc_offset;
+ }
+
+ /* Switch the page over to a VMSA page now that it is initialized */
+ ret = snp_set_vmsa(vmsa, caa, apic_id, true);
+ if (ret) {
+ pr_err("set VMSA page failed (%u)\n", ret);
+ free_page((unsigned long)vmsa);
+
+ return -EINVAL;
+ }
+
+ /* Issue VMGEXIT AP Creation NAE event */
+ ret = vmgexit_ap_control(SVM_VMGEXIT_AP_CREATE, vmsa, apic_id);
+ if (ret) {
+ snp_cleanup_vmsa(vmsa, apic_id);
+ vmsa = NULL;
+ }
+
+ /* Free up any previous VMSA page */
+ if (cur_vmsa)
+ snp_cleanup_vmsa(cur_vmsa, apic_id);
+
+ /* Record the current VMSA page */
+ per_cpu(sev_vmsa, cpu) = vmsa;
+
+ return ret;
+}
+
+void __init snp_set_wakeup_secondary_cpu(void)
+{
+ if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
+ return;
+
+ /*
+ * Always set this override if SNP is enabled. This makes it the
+ * required method to start APs under SNP. If the hypervisor does
+ * not support AP creation, then no APs will be started.
+ */
+ apic_update_callback(wakeup_secondary_cpu, wakeup_cpu_via_vmgexit);
+}
+
+int __init sev_es_setup_ap_jump_table(struct real_mode_header *rmh)
+{
+ u16 startup_cs, startup_ip;
+ phys_addr_t jump_table_pa;
+ u64 jump_table_addr;
+ u16 __iomem *jump_table;
+
+ jump_table_addr = get_jump_table_addr();
+
+ /* On UP guests there is no jump table so this is not a failure */
+ if (!jump_table_addr)
+ return 0;
+
+ /* Check if AP Jump Table is page-aligned */
+ if (jump_table_addr & ~PAGE_MASK)
+ return -EINVAL;
+
+ jump_table_pa = jump_table_addr & PAGE_MASK;
+
+ startup_cs = (u16)(rmh->trampoline_start >> 4);
+ startup_ip = (u16)(rmh->sev_es_trampoline_start -
+ rmh->trampoline_start);
+
+ jump_table = ioremap_encrypted(jump_table_pa, PAGE_SIZE);
+ if (!jump_table)
+ return -EIO;
+
+ writew(startup_ip, &jump_table[0]);
+ writew(startup_cs, &jump_table[1]);
+
+ iounmap(jump_table);
+
+ return 0;
+}
+
+/*
+ * This is needed by the OVMF UEFI firmware which will use whatever it finds in
+ * the GHCB MSR as its GHCB to talk to the hypervisor. So make sure the per-cpu
+ * runtime GHCBs used by the kernel are also mapped in the EFI page-table.
+ *
+ * When running under SVSM the CA page is needed too, so map it as well.
+ */
+int __init sev_es_efi_map_ghcbs_cas(pgd_t *pgd)
+{
+ unsigned long address, pflags, pflags_enc;
+ struct sev_es_runtime_data *data;
+ int cpu;
+ u64 pfn;
+
+ if (!cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
+ return 0;
+
+ pflags = _PAGE_NX | _PAGE_RW;
+ pflags_enc = cc_mkenc(pflags);
+
+ for_each_possible_cpu(cpu) {
+ data = per_cpu(runtime_data, cpu);
+
+ address = __pa(&data->ghcb_page);
+ pfn = address >> PAGE_SHIFT;
+
+ if (kernel_map_pages_in_pgd(pgd, pfn, address, 1, pflags))
+ return 1;
+
+ if (snp_vmpl) {
+ address = per_cpu(svsm_caa_pa, cpu);
+ if (!address)
+ return 1;
+
+ pfn = address >> PAGE_SHIFT;
+ if (kernel_map_pages_in_pgd(pgd, pfn, address, 1, pflags_enc))
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+u64 savic_ghcb_msr_read(u32 reg)
+{
+ u64 msr = APIC_BASE_MSR + (reg >> 4);
+ struct pt_regs regs = { .cx = msr };
+ struct es_em_ctxt ctxt = { .regs = &regs };
+ struct ghcb_state state;
+ enum es_result res;
+ struct ghcb *ghcb;
+
+ guard(irqsave)();
+
+ ghcb = __sev_get_ghcb(&state);
+ vc_ghcb_invalidate(ghcb);
+
+ res = __vc_handle_msr(ghcb, &ctxt, false);
+ if (res != ES_OK) {
+ pr_err("Secure AVIC MSR (0x%llx) read returned error (%d)\n", msr, res);
+ /* MSR read failures are treated as fatal errors */
+ sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_SAVIC_FAIL);
+ }
+
+ __sev_put_ghcb(&state);
+
+ return regs.ax | regs.dx << 32;
+}
+
+void savic_ghcb_msr_write(u32 reg, u64 value)
+{
+ u64 msr = APIC_BASE_MSR + (reg >> 4);
+ struct pt_regs regs = {
+ .cx = msr,
+ .ax = lower_32_bits(value),
+ .dx = upper_32_bits(value)
+ };
+ struct es_em_ctxt ctxt = { .regs = &regs };
+ struct ghcb_state state;
+ enum es_result res;
+ struct ghcb *ghcb;
+
+ guard(irqsave)();
+
+ ghcb = __sev_get_ghcb(&state);
+ vc_ghcb_invalidate(ghcb);
+
+ res = __vc_handle_msr(ghcb, &ctxt, true);
+ if (res != ES_OK) {
+ pr_err("Secure AVIC MSR (0x%llx) write returned error (%d)\n", msr, res);
+ /* MSR writes should never fail. Any failure is fatal error for SNP guest */
+ sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_SAVIC_FAIL);
+ }
+
+ __sev_put_ghcb(&state);
+}
+
+enum es_result savic_register_gpa(u64 gpa)
+{
+ struct ghcb_state state;
+ struct es_em_ctxt ctxt;
+ enum es_result res;
+ struct ghcb *ghcb;
+
+ guard(irqsave)();
+
+ ghcb = __sev_get_ghcb(&state);
+ vc_ghcb_invalidate(ghcb);
+
+ ghcb_set_rax(ghcb, SVM_VMGEXIT_SAVIC_SELF_GPA);
+ ghcb_set_rbx(ghcb, gpa);
+ res = sev_es_ghcb_hv_call(ghcb, &ctxt, SVM_VMGEXIT_SAVIC,
+ SVM_VMGEXIT_SAVIC_REGISTER_GPA, 0);
+
+ __sev_put_ghcb(&state);
+
+ return res;
+}
+
+enum es_result savic_unregister_gpa(u64 *gpa)
+{
+ struct ghcb_state state;
+ struct es_em_ctxt ctxt;
+ enum es_result res;
+ struct ghcb *ghcb;
+
+ guard(irqsave)();
+
+ ghcb = __sev_get_ghcb(&state);
+ vc_ghcb_invalidate(ghcb);
+
+ ghcb_set_rax(ghcb, SVM_VMGEXIT_SAVIC_SELF_GPA);
+ res = sev_es_ghcb_hv_call(ghcb, &ctxt, SVM_VMGEXIT_SAVIC,
+ SVM_VMGEXIT_SAVIC_UNREGISTER_GPA, 0);
+ if (gpa && res == ES_OK)
+ *gpa = ghcb->save.rbx;
+
+ __sev_put_ghcb(&state);
+
+ return res;
+}
+
+static void snp_register_per_cpu_ghcb(void)
+{
+ struct sev_es_runtime_data *data;
+ struct ghcb *ghcb;
+
+ data = this_cpu_read(runtime_data);
+ ghcb = &data->ghcb_page;
+
+ snp_register_ghcb_early(__pa(ghcb));
+}
+
+void setup_ghcb(void)
+{
+ if (!cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
+ return;
+
+ /*
+ * Check whether the runtime #VC exception handler is active. It uses
+ * the per-CPU GHCB page which is set up by sev_es_init_vc_handling().
+ *
+ * If SNP is active, register the per-CPU GHCB page so that the runtime
+ * exception handler can use it.
+ */
+ if (initial_vc_handler == (unsigned long)kernel_exc_vmm_communication) {
+ if (cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
+ snp_register_per_cpu_ghcb();
+
+ sev_cfg.ghcbs_initialized = true;
+
+ return;
+ }
+
+ /*
+ * Make sure the hypervisor talks a supported protocol.
+ * This gets called only in the BSP boot phase.
+ */
+ if (!sev_es_negotiate_protocol())
+ sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ);
+
+ /*
+ * Clear the boot_ghcb. The first exception comes in before the bss
+ * section is cleared.
+ */
+ memset(&boot_ghcb_page, 0, PAGE_SIZE);
+
+ /* Alright - Make the boot-ghcb public */
+ boot_ghcb = &boot_ghcb_page;
+
+ /* SNP guest requires that GHCB GPA must be registered. */
+ if (cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
+ snp_register_ghcb_early(__pa(&boot_ghcb_page));
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+static void sev_es_ap_hlt_loop(void)
+{
+ struct ghcb_state state;
+ struct ghcb *ghcb;
+
+ ghcb = __sev_get_ghcb(&state);
+
+ while (true) {
+ vc_ghcb_invalidate(ghcb);
+ ghcb_set_sw_exit_code(ghcb, SVM_VMGEXIT_AP_HLT_LOOP);
+ ghcb_set_sw_exit_info_1(ghcb, 0);
+ ghcb_set_sw_exit_info_2(ghcb, 0);
+
+ sev_es_wr_ghcb_msr(__pa(ghcb));
+ VMGEXIT();
+
+ /* Wakeup signal? */
+ if (ghcb_sw_exit_info_2_is_valid(ghcb) &&
+ ghcb->save.sw_exit_info_2)
+ break;
+ }
+
+ __sev_put_ghcb(&state);
+}
+
+/*
+ * Play_dead handler when running under SEV-ES. This is needed because
+ * the hypervisor can't deliver an SIPI request to restart the AP.
+ * Instead the kernel has to issue a VMGEXIT to halt the VCPU until the
+ * hypervisor wakes it up again.
+ */
+static void sev_es_play_dead(void)
+{
+ play_dead_common();
+
+ /* IRQs now disabled */
+
+ sev_es_ap_hlt_loop();
+
+ /*
+ * If we get here, the VCPU was woken up again. Jump to CPU
+ * startup code to get it back online.
+ */
+ soft_restart_cpu();
+}
+#else /* CONFIG_HOTPLUG_CPU */
+#define sev_es_play_dead native_play_dead
+#endif /* CONFIG_HOTPLUG_CPU */
+
+#ifdef CONFIG_SMP
+static void __init sev_es_setup_play_dead(void)
+{
+ smp_ops.play_dead = sev_es_play_dead;
+}
+#else
+static inline void sev_es_setup_play_dead(void) { }
+#endif
+
+static void __init alloc_runtime_data(int cpu)
+{
+ struct sev_es_runtime_data *data;
+
+ data = memblock_alloc_node(sizeof(*data), PAGE_SIZE, cpu_to_node(cpu));
+ if (!data)
+ panic("Can't allocate SEV-ES runtime data");
+
+ per_cpu(runtime_data, cpu) = data;
+
+ if (snp_vmpl) {
+ struct svsm_ca *caa;
+
+ /* Allocate the SVSM CA page if an SVSM is present */
+ caa = cpu ? memblock_alloc_or_panic(sizeof(*caa), PAGE_SIZE)
+ : &boot_svsm_ca_page;
+
+ per_cpu(svsm_caa, cpu) = caa;
+ per_cpu(svsm_caa_pa, cpu) = __pa(caa);
+ }
+}
+
+static void __init init_ghcb(int cpu)
+{
+ struct sev_es_runtime_data *data;
+ int err;
+
+ data = per_cpu(runtime_data, cpu);
+
+ err = early_set_memory_decrypted((unsigned long)&data->ghcb_page,
+ sizeof(data->ghcb_page));
+ if (err)
+ panic("Can't map GHCBs unencrypted");
+
+ memset(&data->ghcb_page, 0, sizeof(data->ghcb_page));
+
+ data->ghcb_active = false;
+ data->backup_ghcb_active = false;
+}
+
+void __init sev_es_init_vc_handling(void)
+{
+ int cpu;
+
+ BUILD_BUG_ON(offsetof(struct sev_es_runtime_data, ghcb_page) % PAGE_SIZE);
+
+ if (!cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
+ return;
+
+ if (!sev_es_check_cpu_features())
+ panic("SEV-ES CPU Features missing");
+
+ /*
+ * SNP is supported in v2 of the GHCB spec which mandates support for HV
+ * features.
+ */
+ if (cc_platform_has(CC_ATTR_GUEST_SEV_SNP)) {
+ sev_hv_features = get_hv_features();
+
+ if (!(sev_hv_features & GHCB_HV_FT_SNP))
+ sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED);
+ }
+
+ /* Initialize per-cpu GHCB pages */
+ for_each_possible_cpu(cpu) {
+ alloc_runtime_data(cpu);
+ init_ghcb(cpu);
+ }
+
+ if (snp_vmpl)
+ sev_cfg.use_cas = true;
+
+ sev_es_setup_play_dead();
+
+ /* Secondary CPUs use the runtime #VC handler */
+ initial_vc_handler = (unsigned long)kernel_exc_vmm_communication;
+}
+
+/*
+ * SEV-SNP guests should only execute dmi_setup() if EFI_CONFIG_TABLES are
+ * enabled, as the alternative (fallback) logic for DMI probing in the legacy
+ * ROM region can cause a crash since this region is not pre-validated.
+ */
+void __init snp_dmi_setup(void)
+{
+ if (efi_enabled(EFI_CONFIG_TABLES))
+ dmi_setup();
+}
+
+static void dump_cpuid_table(void)
+{
+ const struct snp_cpuid_table *cpuid_table = snp_cpuid_get_table();
+ int i = 0;
+
+ pr_info("count=%d reserved=0x%x reserved2=0x%llx\n",
+ cpuid_table->count, cpuid_table->__reserved1, cpuid_table->__reserved2);
+
+ for (i = 0; i < SNP_CPUID_COUNT_MAX; i++) {
+ const struct snp_cpuid_fn *fn = &cpuid_table->fn[i];
+
+ pr_info("index=%3d fn=0x%08x subfn=0x%08x: eax=0x%08x ebx=0x%08x ecx=0x%08x edx=0x%08x xcr0_in=0x%016llx xss_in=0x%016llx reserved=0x%016llx\n",
+ i, fn->eax_in, fn->ecx_in, fn->eax, fn->ebx, fn->ecx,
+ fn->edx, fn->xcr0_in, fn->xss_in, fn->__reserved);
+ }
+}
+
+/*
+ * It is useful from an auditing/testing perspective to provide an easy way
+ * for the guest owner to know that the CPUID table has been initialized as
+ * expected, but that initialization happens too early in boot to print any
+ * sort of indicator, and there's not really any other good place to do it,
+ * so do it here.
+ *
+ * If running as an SNP guest, report the current VM privilege level (VMPL).
+ */
+static int __init report_snp_info(void)
+{
+ const struct snp_cpuid_table *cpuid_table = snp_cpuid_get_table();
+
+ if (cpuid_table->count) {
+ pr_info("Using SNP CPUID table, %d entries present.\n",
+ cpuid_table->count);
+
+ if (sev_cfg.debug)
+ dump_cpuid_table();
+ }
+
+ if (cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
+ pr_info("SNP running at VMPL%u.\n", snp_vmpl);
+
+ return 0;
+}
+arch_initcall(report_snp_info);
+
+static int snp_issue_guest_request(struct snp_guest_req *req)
+{
+ struct snp_req_data *input = &req->input;
+ struct ghcb_state state;
+ struct es_em_ctxt ctxt;
+ unsigned long flags;
+ struct ghcb *ghcb;
+ int ret;
+
+ req->exitinfo2 = SEV_RET_NO_FW_CALL;
+
+ /*
+ * __sev_get_ghcb() needs to run with IRQs disabled because it is using
+ * a per-CPU GHCB.
+ */
+ local_irq_save(flags);
+
+ ghcb = __sev_get_ghcb(&state);
+ if (!ghcb) {
+ ret = -EIO;
+ goto e_restore_irq;
+ }
+
+ vc_ghcb_invalidate(ghcb);
+
+ if (req->exit_code == SVM_VMGEXIT_EXT_GUEST_REQUEST) {
+ ghcb_set_rax(ghcb, input->data_gpa);
+ ghcb_set_rbx(ghcb, input->data_npages);
+ }
+
+ ret = sev_es_ghcb_hv_call(ghcb, &ctxt, req->exit_code, input->req_gpa, input->resp_gpa);
+ if (ret)
+ goto e_put;
+
+ req->exitinfo2 = ghcb->save.sw_exit_info_2;
+ switch (req->exitinfo2) {
+ case 0:
+ break;
+
+ case SNP_GUEST_VMM_ERR(SNP_GUEST_VMM_ERR_BUSY):
+ ret = -EAGAIN;
+ break;
+
+ case SNP_GUEST_VMM_ERR(SNP_GUEST_VMM_ERR_INVALID_LEN):
+ /* Number of expected pages are returned in RBX */
+ if (req->exit_code == SVM_VMGEXIT_EXT_GUEST_REQUEST) {
+ input->data_npages = ghcb_get_rbx(ghcb);
+ ret = -ENOSPC;
+ break;
+ }
+ fallthrough;
+ default:
+ ret = -EIO;
+ break;
+ }
+
+e_put:
+ __sev_put_ghcb(&state);
+e_restore_irq:
+ local_irq_restore(flags);
+
+ return ret;
+}
+
+static struct platform_device sev_guest_device = {
+ .name = "sev-guest",
+ .id = -1,
+};
+
+static struct platform_device tpm_svsm_device = {
+ .name = "tpm-svsm",
+ .id = -1,
+};
+
+static int __init snp_init_platform_device(void)
+{
+ if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
+ return -ENODEV;
+
+ if (platform_device_register(&sev_guest_device))
+ return -ENODEV;
+
+ if (snp_svsm_vtpm_probe() &&
+ platform_device_register(&tpm_svsm_device))
+ return -ENODEV;
+
+ pr_info("SNP guest platform devices initialized.\n");
+ return 0;
+}
+device_initcall(snp_init_platform_device);
+
+void sev_show_status(void)
+{
+ int i;
+
+ pr_info("Status: ");
+ for (i = 0; i < MSR_AMD64_SNP_RESV_BIT; i++) {
+ if (sev_status & BIT_ULL(i)) {
+ if (!sev_status_feat_names[i])
+ continue;
+
+ pr_cont("%s ", sev_status_feat_names[i]);
+ }
+ }
+ pr_cont("\n");
+}
+
+#ifdef CONFIG_SYSFS
+static ssize_t vmpl_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return sysfs_emit(buf, "%d\n", snp_vmpl);
+}
+
+static struct kobj_attribute vmpl_attr = __ATTR_RO(vmpl);
+
+static struct attribute *vmpl_attrs[] = {
+ &vmpl_attr.attr,
+ NULL
+};
+
+static struct attribute_group sev_attr_group = {
+ .attrs = vmpl_attrs,
+};
+
+static int __init sev_sysfs_init(void)
+{
+ struct kobject *sev_kobj;
+ struct device *dev_root;
+ int ret;
+
+ if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
+ return -ENODEV;
+
+ dev_root = bus_get_dev_root(&cpu_subsys);
+ if (!dev_root)
+ return -ENODEV;
+
+ sev_kobj = kobject_create_and_add("sev", &dev_root->kobj);
+ put_device(dev_root);
+
+ if (!sev_kobj)
+ return -ENOMEM;
+
+ ret = sysfs_create_group(sev_kobj, &sev_attr_group);
+ if (ret)
+ kobject_put(sev_kobj);
+
+ return ret;
+}
+arch_initcall(sev_sysfs_init);
+#endif // CONFIG_SYSFS
+
+static void free_shared_pages(void *buf, size_t sz)
+{
+ unsigned int npages = PAGE_ALIGN(sz) >> PAGE_SHIFT;
+ int ret;
+
+ if (!buf)
+ return;
+
+ ret = set_memory_encrypted((unsigned long)buf, npages);
+ if (ret) {
+ WARN_ONCE(ret, "failed to restore encryption mask (leak it)\n");
+ return;
+ }
+
+ __free_pages(virt_to_page(buf), get_order(sz));
+}
+
+static void *alloc_shared_pages(size_t sz)
+{
+ unsigned int npages = PAGE_ALIGN(sz) >> PAGE_SHIFT;
+ struct page *page;
+ int ret;
+
+ page = alloc_pages(GFP_KERNEL_ACCOUNT, get_order(sz));
+ if (!page)
+ return NULL;
+
+ ret = set_memory_decrypted((unsigned long)page_address(page), npages);
+ if (ret) {
+ pr_err("failed to mark page shared, ret=%d\n", ret);
+ __free_pages(page, get_order(sz));
+ return NULL;
+ }
+
+ return page_address(page);
+}
+
+static u8 *get_vmpck(int id, struct snp_secrets_page *secrets, u32 **seqno)
+{
+ u8 *key = NULL;
+
+ switch (id) {
+ case 0:
+ *seqno = &secrets->os_area.msg_seqno_0;
+ key = secrets->vmpck0;
+ break;
+ case 1:
+ *seqno = &secrets->os_area.msg_seqno_1;
+ key = secrets->vmpck1;
+ break;
+ case 2:
+ *seqno = &secrets->os_area.msg_seqno_2;
+ key = secrets->vmpck2;
+ break;
+ case 3:
+ *seqno = &secrets->os_area.msg_seqno_3;
+ key = secrets->vmpck3;
+ break;
+ default:
+ break;
+ }
+
+ return key;
+}
+
+static struct aes_gcm_key *snp_init_crypto(const u8 *key, size_t keylen)
+{
+ struct aes_gcm_key *gcm_key;
+
+ gcm_key = kzalloc_obj(*gcm_key);
+ if (!gcm_key)
+ return NULL;
+
+ if (aes_gcm_preparekey(gcm_key, key, keylen, AUTHTAG_LEN)) {
+ pr_err("AES-GCM key preparation failed\n");
+ kfree_sensitive(gcm_key);
+ return NULL;
+ }
+
+ return gcm_key;
+}
+
+int snp_msg_init(struct snp_msg_desc *mdesc, int vmpck_id)
+{
+ /* Adjust the default VMPCK key based on the executing VMPL level */
+ if (vmpck_id == -1)
+ vmpck_id = snp_vmpl;
+
+ mdesc->vmpck = get_vmpck(vmpck_id, mdesc->secrets, &mdesc->os_area_msg_seqno);
+ if (!mdesc->vmpck) {
+ pr_err("Invalid VMPCK%d communication key\n", vmpck_id);
+ return -EINVAL;
+ }
+
+ /* Verify that VMPCK is not zero. */
+ if (!memchr_inv(mdesc->vmpck, 0, VMPCK_KEY_LEN)) {
+ pr_err("Empty VMPCK%d communication key\n", vmpck_id);
+ return -EINVAL;
+ }
+
+ mdesc->vmpck_id = vmpck_id;
+
+ mdesc->gcm_key = snp_init_crypto(mdesc->vmpck, VMPCK_KEY_LEN);
+ if (!mdesc->gcm_key)
+ return -ENOMEM;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(snp_msg_init);
+
+struct snp_msg_desc *snp_msg_alloc(void)
+{
+ struct snp_msg_desc *mdesc;
+ void __iomem *mem;
+
+ BUILD_BUG_ON(sizeof(struct snp_guest_msg) > PAGE_SIZE);
+
+ mdesc = kzalloc_obj(struct snp_msg_desc);
+ if (!mdesc)
+ return ERR_PTR(-ENOMEM);
+
+ mem = ioremap_encrypted(sev_secrets_pa, PAGE_SIZE);
+ if (!mem)
+ goto e_free_mdesc;
+
+ mdesc->secrets = (__force struct snp_secrets_page *)mem;
+
+ /* Allocate the shared page used for the request and response message. */
+ mdesc->request = alloc_shared_pages(sizeof(struct snp_guest_msg));
+ if (!mdesc->request)
+ goto e_unmap;
+
+ mdesc->response = alloc_shared_pages(sizeof(struct snp_guest_msg));
+ if (!mdesc->response)
+ goto e_free_request;
+
+ return mdesc;
+
+e_free_request:
+ free_shared_pages(mdesc->request, sizeof(struct snp_guest_msg));
+e_unmap:
+ iounmap(mem);
+e_free_mdesc:
+ kfree(mdesc);
+
+ return ERR_PTR(-ENOMEM);
+}
+EXPORT_SYMBOL_GPL(snp_msg_alloc);
+
+void snp_msg_free(struct snp_msg_desc *mdesc)
+{
+ if (!mdesc)
+ return;
+
+ kfree_sensitive(mdesc->gcm_key);
+ free_shared_pages(mdesc->response, sizeof(struct snp_guest_msg));
+ free_shared_pages(mdesc->request, sizeof(struct snp_guest_msg));
+ iounmap((__force void __iomem *)mdesc->secrets);
+
+ kfree_sensitive(mdesc);
+}
+EXPORT_SYMBOL_GPL(snp_msg_free);
+
+/* Mutex to serialize the shared buffer access and command handling. */
+static DEFINE_MUTEX(snp_cmd_mutex);
+
+/*
+ * If an error is received from the host or AMD Secure Processor (ASP) there
+ * are two options. Either retry the exact same encrypted request or discontinue
+ * using the VMPCK.
+ *
+ * This is because in the current encryption scheme GHCB v2 uses AES-GCM to
+ * encrypt the requests. The IV for this scheme is the sequence number. GCM
+ * cannot tolerate IV reuse.
+ *
+ * The ASP FW v1.51 only increments the sequence numbers on a successful
+ * guest<->ASP back and forth and only accepts messages at its exact sequence
+ * number.
+ *
+ * So if the sequence number were to be reused the encryption scheme is
+ * vulnerable. If the sequence number were incremented for a fresh IV the ASP
+ * will reject the request.
+ */
+static void snp_disable_vmpck(struct snp_msg_desc *mdesc)
+{
+ pr_alert("Disabling VMPCK%d communication key to prevent IV reuse.\n",
+ mdesc->vmpck_id);
+ memzero_explicit(mdesc->vmpck, VMPCK_KEY_LEN);
+ mdesc->vmpck = NULL;
+}
+
+static inline u64 __snp_get_msg_seqno(struct snp_msg_desc *mdesc)
+{
+ u64 count;
+
+ lockdep_assert_held(&snp_cmd_mutex);
+
+ /* Read the current message sequence counter from secrets pages */
+ count = *mdesc->os_area_msg_seqno;
+
+ return count + 1;
+}
+
+/* Return a non-zero on success */
+static u64 snp_get_msg_seqno(struct snp_msg_desc *mdesc)
+{
+ u64 count = __snp_get_msg_seqno(mdesc);
+
+ /*
+ * The message sequence counter for the SNP guest request is a 64-bit
+ * value but the version 2 of GHCB specification defines a 32-bit storage
+ * for it. If the counter exceeds the 32-bit value then return zero.
+ * The caller should check the return value, but if the caller happens to
+ * not check the value and use it, then the firmware treats zero as an
+ * invalid number and will fail the message request.
+ */
+ if (count >= UINT_MAX) {
+ pr_err("request message sequence counter overflow\n");
+ return 0;
+ }
+
+ return count;
+}
+
+static void snp_inc_msg_seqno(struct snp_msg_desc *mdesc)
+{
+ /*
+ * The counter is also incremented by the PSP, so increment it by 2
+ * and save in secrets page.
+ */
+ *mdesc->os_area_msg_seqno += 2;
+}
+
+static int verify_and_dec_payload(struct snp_msg_desc *mdesc, struct snp_guest_req *req)
+{
+ struct snp_guest_msg *resp_msg = &mdesc->secret_response;
+ struct snp_guest_msg *req_msg = &mdesc->secret_request;
+ struct snp_guest_msg_hdr *req_msg_hdr = &req_msg->hdr;
+ struct snp_guest_msg_hdr *resp_msg_hdr = &resp_msg->hdr;
+ struct aes_gcm_key *gcm_key = mdesc->gcm_key;
+ u8 iv[GCM_AES_IV_SIZE] = {};
+
+ pr_debug("response [seqno %lld type %d version %d sz %d]\n",
+ resp_msg_hdr->msg_seqno, resp_msg_hdr->msg_type, resp_msg_hdr->msg_version,
+ resp_msg_hdr->msg_sz);
+
+ /* Copy response from shared memory to encrypted memory. */
+ memcpy(resp_msg, mdesc->response, sizeof(*resp_msg));
+
+ /* Verify that the sequence counter is incremented by 1 */
+ if (unlikely(resp_msg_hdr->msg_seqno != (req_msg_hdr->msg_seqno + 1)))
+ return -EBADMSG;
+
+ /* Verify response message type and version number. */
+ if (resp_msg_hdr->msg_type != (req_msg_hdr->msg_type + 1) ||
+ resp_msg_hdr->msg_version != req_msg_hdr->msg_version)
+ return -EBADMSG;
+
+ /*
+ * If the message size is greater than our buffer length then return
+ * an error.
+ */
+ if (unlikely(resp_msg_hdr->msg_sz + AUTHTAG_LEN > req->resp_sz))
+ return -EBADMSG;
+
+ /* Decrypt the payload */
+ memcpy(iv, &resp_msg_hdr->msg_seqno, min(sizeof(iv), sizeof(resp_msg_hdr->msg_seqno)));
+ return aes_gcm_decrypt(req->resp_buf, resp_msg->payload,
+ resp_msg_hdr->msg_sz, resp_msg_hdr->authtag,
+ &resp_msg_hdr->algo, AAD_LEN, iv, gcm_key);
+}
+
+static int enc_payload(struct snp_msg_desc *mdesc, u64 seqno, struct snp_guest_req *req)
+{
+ struct snp_guest_msg *msg = &mdesc->secret_request;
+ struct snp_guest_msg_hdr *hdr = &msg->hdr;
+ struct aes_gcm_key *gcm_key = mdesc->gcm_key;
+ u8 iv[GCM_AES_IV_SIZE] = {};
+
+ memset(msg, 0, sizeof(*msg));
+
+ hdr->algo = SNP_AEAD_AES_256_GCM;
+ hdr->hdr_version = MSG_HDR_VER;
+ hdr->hdr_sz = sizeof(*hdr);
+ hdr->msg_type = req->msg_type;
+ hdr->msg_version = req->msg_version;
+ hdr->msg_seqno = seqno;
+ hdr->msg_vmpck = req->vmpck_id;
+ hdr->msg_sz = req->req_sz;
+
+ /* Verify the sequence number is non-zero */
+ if (!hdr->msg_seqno)
+ return -ENOSR;
+
+ pr_debug("request [seqno %lld type %d version %d sz %d]\n",
+ hdr->msg_seqno, hdr->msg_type, hdr->msg_version, hdr->msg_sz);
+
+ if (WARN_ON(req->req_sz + AUTHTAG_LEN > sizeof(msg->payload)))
+ return -EBADMSG;
+
+ memcpy(iv, &hdr->msg_seqno, min(sizeof(iv), sizeof(hdr->msg_seqno)));
+ aes_gcm_encrypt(msg->payload, req->req_buf, req->req_sz, hdr->authtag,
+ &hdr->algo, AAD_LEN, iv, gcm_key);
+
+ return 0;
+}
+
+static int __handle_guest_request(struct snp_msg_desc *mdesc, struct snp_guest_req *req)
+{
+ unsigned long req_start = jiffies;
+ unsigned int override_npages = 0;
+ u64 override_err = 0;
+ int rc;
+
+retry_request:
+ /*
+ * Call firmware to process the request. In this function the encrypted
+ * message enters shared memory with the host. So after this call the
+ * sequence number must be incremented or the VMPCK must be deleted to
+ * prevent reuse of the IV.
+ */
+ rc = snp_issue_guest_request(req);
+ switch (rc) {
+ case -ENOSPC:
+ /*
+ * If the extended guest request fails due to having too
+ * small of a certificate data buffer, retry the same
+ * guest request without the extended data request in
+ * order to increment the sequence number and thus avoid
+ * IV reuse.
+ */
+ override_npages = req->input.data_npages;
+ req->exit_code = SVM_VMGEXIT_GUEST_REQUEST;
+
+ /*
+ * Override the error to inform callers the given extended
+ * request buffer size was too small and give the caller the
+ * required buffer size.
+ */
+ override_err = SNP_GUEST_VMM_ERR(SNP_GUEST_VMM_ERR_INVALID_LEN);
+
+ /*
+ * If this call to the firmware succeeds, the sequence number can
+ * be incremented allowing for continued use of the VMPCK. If
+ * there is an error reflected in the return value, this value
+ * is checked further down and the result will be the deletion
+ * of the VMPCK and the error code being propagated back to the
+ * user as an ioctl() return code.
+ */
+ goto retry_request;
+
+ /*
+ * The host may return SNP_GUEST_VMM_ERR_BUSY if the request has been
+ * throttled. Retry in the driver to avoid returning and reusing the
+ * message sequence number on a different message.
+ */
+ case -EAGAIN:
+ if (jiffies - req_start > SNP_REQ_MAX_RETRY_DURATION) {
+ rc = -ETIMEDOUT;
+ break;
+ }
+ schedule_timeout_killable(SNP_REQ_RETRY_DELAY);
+ goto retry_request;
+ }
+
+ /*
+ * Increment the message sequence number. There is no harm in doing
+ * this now because decryption uses the value stored in the response
+ * structure and any failure will wipe the VMPCK, preventing further
+ * use anyway.
+ */
+ snp_inc_msg_seqno(mdesc);
+
+ if (override_err) {
+ req->exitinfo2 = override_err;
+
+ /*
+ * If an extended guest request was issued and the supplied certificate
+ * buffer was not large enough, a standard guest request was issued to
+ * prevent IV reuse. If the standard request was successful, return -EIO
+ * back to the caller as would have originally been returned.
+ */
+ if (!rc && override_err == SNP_GUEST_VMM_ERR(SNP_GUEST_VMM_ERR_INVALID_LEN))
+ rc = -EIO;
+ }
+
+ if (override_npages)
+ req->input.data_npages = override_npages;
+
+ return rc;
+}
+
+int snp_send_guest_request(struct snp_msg_desc *mdesc, struct snp_guest_req *req)
+{
+ u64 seqno;
+ int rc;
+
+ guard(mutex)(&snp_cmd_mutex);
+
+ /* Check if the VMPCK is not empty */
+ if (!mdesc->vmpck || !memchr_inv(mdesc->vmpck, 0, VMPCK_KEY_LEN)) {
+ pr_err_ratelimited("VMPCK is disabled\n");
+ return -ENOTTY;
+ }
+
+ /* Get message sequence and verify that its a non-zero */
+ seqno = snp_get_msg_seqno(mdesc);
+ if (!seqno)
+ return -EIO;
+
+ /* Clear shared memory's response for the host to populate. */
+ memset(mdesc->response, 0, sizeof(struct snp_guest_msg));
+
+ /* Encrypt the userspace provided payload in mdesc->secret_request. */
+ rc = enc_payload(mdesc, seqno, req);
+ if (rc)
+ return rc;
+
+ /*
+ * Write the fully encrypted request to the shared unencrypted
+ * request page.
+ */
+ memcpy(mdesc->request, &mdesc->secret_request, sizeof(mdesc->secret_request));
+
+ /* Initialize the input address for guest request */
+ req->input.req_gpa = __pa(mdesc->request);
+ req->input.resp_gpa = __pa(mdesc->response);
+ req->input.data_gpa = req->certs_data ? __pa(req->certs_data) : 0;
+
+ rc = __handle_guest_request(mdesc, req);
+ if (rc) {
+ if (rc == -EIO &&
+ req->exitinfo2 == SNP_GUEST_VMM_ERR(SNP_GUEST_VMM_ERR_INVALID_LEN))
+ return rc;
+
+ pr_alert("Detected error from ASP request. rc: %d, exitinfo2: 0x%llx\n",
+ rc, req->exitinfo2);
+
+ snp_disable_vmpck(mdesc);
+ return rc;
+ }
+
+ rc = verify_and_dec_payload(mdesc, req);
+ if (rc) {
+ pr_alert("Detected unexpected decode failure from ASP. rc: %d\n", rc);
+ snp_disable_vmpck(mdesc);
+ return rc;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(snp_send_guest_request);
+
+static int __init snp_get_tsc_info(void)
+{
+ struct snp_tsc_info_resp *tsc_resp;
+ struct snp_tsc_info_req *tsc_req;
+ struct snp_msg_desc *mdesc;
+ struct snp_guest_req req = {};
+ int rc = -ENOMEM;
+
+ tsc_req = kzalloc_obj(*tsc_req);
+ if (!tsc_req)
+ return rc;
+
+ /*
+ * The intermediate response buffer is used while decrypting the
+ * response payload. Make sure that it has enough space to cover
+ * the authtag.
+ */
+ tsc_resp = kzalloc(sizeof(*tsc_resp) + AUTHTAG_LEN, GFP_KERNEL);
+ if (!tsc_resp)
+ goto e_free_tsc_req;
+
+ mdesc = snp_msg_alloc();
+ if (IS_ERR_OR_NULL(mdesc))
+ goto e_free_tsc_resp;
+
+ rc = snp_msg_init(mdesc, snp_vmpl);
+ if (rc)
+ goto e_free_mdesc;
+
+ req.msg_version = MSG_HDR_VER;
+ req.msg_type = SNP_MSG_TSC_INFO_REQ;
+ req.vmpck_id = snp_vmpl;
+ req.req_buf = tsc_req;
+ req.req_sz = sizeof(*tsc_req);
+ req.resp_buf = (void *)tsc_resp;
+ req.resp_sz = sizeof(*tsc_resp) + AUTHTAG_LEN;
+ req.exit_code = SVM_VMGEXIT_GUEST_REQUEST;
+
+ rc = snp_send_guest_request(mdesc, &req);
+ if (rc)
+ goto e_request;
+
+ pr_debug("%s: response status 0x%x scale 0x%llx offset 0x%llx factor 0x%x\n",
+ __func__, tsc_resp->status, tsc_resp->tsc_scale, tsc_resp->tsc_offset,
+ tsc_resp->tsc_factor);
+
+ if (!tsc_resp->status) {
+ snp_tsc_scale = tsc_resp->tsc_scale;
+ snp_tsc_offset = tsc_resp->tsc_offset;
+ } else {
+ pr_err("Failed to get TSC info, response status 0x%x\n", tsc_resp->status);
+ rc = -EIO;
+ }
+
+e_request:
+ /* The response buffer contains sensitive data, explicitly clear it. */
+ memzero_explicit(tsc_resp, sizeof(*tsc_resp) + AUTHTAG_LEN);
+e_free_mdesc:
+ snp_msg_free(mdesc);
+e_free_tsc_resp:
+ kfree(tsc_resp);
+e_free_tsc_req:
+ kfree(tsc_req);
+
+ return rc;
+}
+
+void __init snp_secure_tsc_prepare(void)
+{
+ if (!cc_platform_has(CC_ATTR_GUEST_SNP_SECURE_TSC))
+ return;
+
+ if (snp_get_tsc_info()) {
+ pr_alert("Unable to retrieve Secure TSC info from ASP\n");
+ sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_SECURE_TSC);
+ }
+
+ pr_debug("SecureTSC enabled");
+}
+
+static unsigned long securetsc_get_tsc_khz(void)
+{
+ return snp_tsc_freq_khz;
+}
+
+void __init snp_secure_tsc_init(void)
+{
+ struct snp_secrets_page *secrets;
+ unsigned long tsc_freq_mhz;
+ void *mem;
+
+ if (!cc_platform_has(CC_ATTR_GUEST_SNP_SECURE_TSC))
+ return;
+
+ mem = early_memremap_encrypted(sev_secrets_pa, PAGE_SIZE);
+ if (!mem) {
+ pr_err("Unable to get TSC_FACTOR: failed to map the SNP secrets page.\n");
+ sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_SECURE_TSC);
+ }
+
+ secrets = (__force struct snp_secrets_page *)mem;
+
+ setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ);
+ rdmsrq(MSR_AMD64_GUEST_TSC_FREQ, tsc_freq_mhz);
+
+ /* Extract the GUEST TSC MHZ from BIT[17:0], rest is reserved space */
+ tsc_freq_mhz &= GENMASK_ULL(17, 0);
+
+ snp_tsc_freq_khz = SNP_SCALE_TSC_FREQ(tsc_freq_mhz * 1000, secrets->tsc_factor);
+
+ x86_platform.calibrate_cpu = securetsc_get_tsc_khz;
+ x86_platform.calibrate_tsc = securetsc_get_tsc_khz;
+
+ early_memunmap(mem, PAGE_SIZE);
+}
diff --git a/arch/x86/coco/sev/internal.h b/arch/x86/coco/sev/internal.h
new file mode 100644
index 000000000..b9632c0fc
--- /dev/null
+++ b/arch/x86/coco/sev/internal.h
@@ -0,0 +1,122 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __X86_COCO_SEV_INTERNAL_H__
+#define __X86_COCO_SEV_INTERNAL_H__
+
+#define DR7_RESET_VALUE 0x400
+
+extern u64 sev_hv_features;
+extern u64 sev_secrets_pa;
+
+/* #VC handler runtime per-CPU data */
+struct sev_es_runtime_data {
+ struct ghcb ghcb_page;
+
+ /*
+ * Reserve one page per CPU as backup storage for the unencrypted GHCB.
+ * It is needed when an NMI happens while the #VC handler uses the real
+ * GHCB, and the NMI handler itself is causing another #VC exception. In
+ * that case the GHCB content of the first handler needs to be backed up
+ * and restored.
+ */
+ struct ghcb backup_ghcb;
+
+ /*
+ * Mark the per-cpu GHCBs as in-use to detect nested #VC exceptions.
+ * There is no need for it to be atomic, because nothing is written to
+ * the GHCB between the read and the write of ghcb_active. So it is safe
+ * to use it when a nested #VC exception happens before the write.
+ *
+ * This is necessary for example in the #VC->NMI->#VC case when the NMI
+ * happens while the first #VC handler uses the GHCB. When the NMI code
+ * raises a second #VC handler it might overwrite the contents of the
+ * GHCB written by the first handler. To avoid this the content of the
+ * GHCB is saved and restored when the GHCB is detected to be in use
+ * already.
+ */
+ bool ghcb_active;
+ bool backup_ghcb_active;
+
+ /*
+ * Cached DR7 value - write it on DR7 writes and return it on reads.
+ * That value will never make it to the real hardware DR7 as debugging
+ * is currently unsupported in SEV-ES guests.
+ */
+ unsigned long dr7;
+};
+
+struct ghcb_state {
+ struct ghcb *ghcb;
+};
+
+extern struct svsm_ca boot_svsm_ca_page;
+
+struct ghcb *__sev_get_ghcb(struct ghcb_state *state);
+void __sev_put_ghcb(struct ghcb_state *state);
+
+DECLARE_PER_CPU(struct sev_es_runtime_data*, runtime_data);
+DECLARE_PER_CPU(struct sev_es_save_area *, sev_vmsa);
+
+void early_set_pages_state(unsigned long vaddr, unsigned long paddr,
+ unsigned long npages, const struct psc_desc *desc);
+
+DECLARE_PER_CPU(struct svsm_ca *, svsm_caa);
+DECLARE_PER_CPU(u64, svsm_caa_pa);
+
+extern u64 boot_svsm_caa_pa;
+
+enum es_result verify_exception_info(struct ghcb *ghcb, struct es_em_ctxt *ctxt);
+void vc_forward_exception(struct es_em_ctxt *ctxt);
+void svsm_pval_pages(struct snp_psc_desc *desc);
+int svsm_perform_call_protocol(struct svsm_call *call);
+bool snp_svsm_vtpm_probe(void);
+
+noinstr void kernel_exc_vmm_communication(struct pt_regs *regs, unsigned long error_code);
+noinstr void user_exc_vmm_communication(struct pt_regs *regs, unsigned long error_code);
+
+static inline u64 sev_es_rd_ghcb_msr(void)
+{
+ return native_rdmsrq(MSR_AMD64_SEV_ES_GHCB);
+}
+
+static __always_inline void sev_es_wr_ghcb_msr(u64 val)
+{
+ u32 low, high;
+
+ low = (u32)(val);
+ high = (u32)(val >> 32);
+
+ native_wrmsr(MSR_AMD64_SEV_ES_GHCB, low, high);
+}
+
+enum es_result __vc_handle_msr(struct ghcb *ghcb, struct es_em_ctxt *ctxt, bool write);
+
+u64 get_hv_features(void);
+
+const struct snp_cpuid_table *snp_cpuid_get_table(void);
+
+static inline struct svsm_ca *svsm_get_caa(void)
+{
+ if (sev_cfg.use_cas)
+ return this_cpu_read(svsm_caa);
+ else
+ return rip_rel_ptr(&boot_svsm_ca_page);
+}
+
+static inline u64 svsm_get_caa_pa(void)
+{
+ if (sev_cfg.use_cas)
+ return this_cpu_read(svsm_caa_pa);
+ else
+ return boot_svsm_caa_pa;
+}
+
+static inline void __pval_terminate(u64 pfn, bool action, unsigned int page_size,
+ int ret, u64 svsm_ret)
+{
+ WARN(1, "PVALIDATE failure: pfn: 0x%llx, action: %u, size: %u, ret: %d, svsm_ret: 0x%llx\n",
+ pfn, action, page_size, ret, svsm_ret);
+
+ sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PVALIDATE);
+}
+
+#endif /* __X86_COCO_SEV_INTERNAL_H__ */
diff --git a/arch/x86/coco/sev/noinstr.c b/arch/x86/coco/sev/noinstr.c
new file mode 100644
index 000000000..e1e03f12f
--- /dev/null
+++ b/arch/x86/coco/sev/noinstr.c
@@ -0,0 +1,191 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AMD Memory Encryption Support
+ *
+ * Copyright (C) 2019 SUSE
+ *
+ * Author: Joerg Roedel <jroedel@suse.de>
+ */
+
+#define pr_fmt(fmt) "SEV: " fmt
+
+#include <linux/bug.h>
+#include <linux/kernel.h>
+
+#include <asm/cpu_entry_area.h>
+#include <asm/msr.h>
+#include <asm/ptrace.h>
+#include <asm/sev.h>
+
+#include "internal.h"
+
+static __always_inline bool on_vc_stack(struct pt_regs *regs)
+{
+ unsigned long sp = regs->sp;
+
+ /* User-mode RSP is not trusted */
+ if (user_mode(regs))
+ return false;
+
+ /* SYSCALL gap still has user-mode RSP */
+ if (ip_within_syscall_gap(regs))
+ return false;
+
+ return ((sp >= __this_cpu_ist_bottom_va(VC)) && (sp < __this_cpu_ist_top_va(VC)));
+}
+
+/*
+ * This function handles the case when an NMI is raised in the #VC
+ * exception handler entry code, before the #VC handler has switched off
+ * its IST stack. In this case, the IST entry for #VC must be adjusted,
+ * so that any nested #VC exception will not overwrite the stack
+ * contents of the interrupted #VC handler.
+ *
+ * The IST entry is adjusted unconditionally so that it can be also be
+ * unconditionally adjusted back in __sev_es_ist_exit(). Otherwise a
+ * nested sev_es_ist_exit() call may adjust back the IST entry too
+ * early.
+ *
+ * The __sev_es_ist_enter() and __sev_es_ist_exit() functions always run
+ * on the NMI IST stack, as they are only called from NMI handling code
+ * right now.
+ */
+void noinstr __sev_es_ist_enter(struct pt_regs *regs)
+{
+ unsigned long old_ist, new_ist;
+
+ /* Read old IST entry */
+ new_ist = old_ist = __this_cpu_read(cpu_tss_rw.x86_tss.ist[IST_INDEX_VC]);
+
+ /*
+ * If NMI happened while on the #VC IST stack, set the new IST
+ * value below regs->sp, so that the interrupted stack frame is
+ * not overwritten by subsequent #VC exceptions.
+ */
+ if (on_vc_stack(regs))
+ new_ist = regs->sp;
+
+ /*
+ * Reserve additional 8 bytes and store old IST value so this
+ * adjustment can be unrolled in __sev_es_ist_exit().
+ */
+ new_ist -= sizeof(old_ist);
+ *(unsigned long *)new_ist = old_ist;
+
+ /* Set new IST entry */
+ this_cpu_write(cpu_tss_rw.x86_tss.ist[IST_INDEX_VC], new_ist);
+}
+
+void noinstr __sev_es_ist_exit(void)
+{
+ unsigned long ist;
+
+ /* Read IST entry */
+ ist = __this_cpu_read(cpu_tss_rw.x86_tss.ist[IST_INDEX_VC]);
+
+ if (WARN_ON(ist == __this_cpu_ist_top_va(VC)))
+ return;
+
+ /* Read back old IST entry and write it to the TSS */
+ this_cpu_write(cpu_tss_rw.x86_tss.ist[IST_INDEX_VC], *(unsigned long *)ist);
+}
+
+void noinstr __sev_es_nmi_complete(void)
+{
+ struct ghcb_state state;
+ struct ghcb *ghcb;
+
+ ghcb = __sev_get_ghcb(&state);
+
+ vc_ghcb_invalidate(ghcb);
+ ghcb_set_sw_exit_code(ghcb, SVM_VMGEXIT_NMI_COMPLETE);
+ ghcb_set_sw_exit_info_1(ghcb, 0);
+ ghcb_set_sw_exit_info_2(ghcb, 0);
+
+ sev_es_wr_ghcb_msr(__pa_nodebug(ghcb));
+ VMGEXIT();
+
+ __sev_put_ghcb(&state);
+}
+
+/*
+ * Nothing shall interrupt this code path while holding the per-CPU
+ * GHCB. The backup GHCB is only for NMIs interrupting this path.
+ *
+ * Callers must disable local interrupts around it.
+ */
+noinstr struct ghcb *__sev_get_ghcb(struct ghcb_state *state)
+{
+ struct sev_es_runtime_data *data;
+ struct ghcb *ghcb;
+
+ WARN_ON(!irqs_disabled());
+
+ if (!sev_cfg.ghcbs_initialized) {
+ state->ghcb = NULL;
+ return boot_ghcb;
+ }
+
+ data = this_cpu_read(runtime_data);
+ ghcb = &data->ghcb_page;
+
+ if (unlikely(data->ghcb_active)) {
+ /* GHCB is already in use - save its contents */
+
+ if (unlikely(data->backup_ghcb_active)) {
+ /*
+ * Backup-GHCB is also already in use. There is no way
+ * to continue here so just kill the machine. To make
+ * panic() work, mark GHCBs inactive so that messages
+ * can be printed out.
+ */
+ data->ghcb_active = false;
+ data->backup_ghcb_active = false;
+
+ instrumentation_begin();
+ panic("Unable to handle #VC exception! GHCB and Backup GHCB are already in use");
+ instrumentation_end();
+ }
+
+ /* Mark backup_ghcb active before writing to it */
+ data->backup_ghcb_active = true;
+
+ state->ghcb = &data->backup_ghcb;
+
+ /* Backup GHCB content */
+ *state->ghcb = *ghcb;
+ } else {
+ state->ghcb = NULL;
+ data->ghcb_active = true;
+ }
+
+ return ghcb;
+}
+
+noinstr void __sev_put_ghcb(struct ghcb_state *state)
+{
+ struct sev_es_runtime_data *data;
+ struct ghcb *ghcb;
+
+ WARN_ON(!irqs_disabled());
+
+ if (!sev_cfg.ghcbs_initialized)
+ return;
+
+ data = this_cpu_read(runtime_data);
+ ghcb = &data->ghcb_page;
+
+ if (state->ghcb) {
+ /* Restore GHCB from Backup */
+ *ghcb = *state->ghcb;
+ data->backup_ghcb_active = false;
+ state->ghcb = NULL;
+ } else {
+ /*
+ * Invalidate the GHCB so a VMGEXIT instruction issued
+ * from userspace won't appear to be valid.
+ */
+ vc_ghcb_invalidate(ghcb);
+ data->ghcb_active = false;
+ }
+}
diff --git a/arch/x86/coco/sev/svsm.c b/arch/x86/coco/sev/svsm.c
new file mode 100644
index 000000000..916d62cd1
--- /dev/null
+++ b/arch/x86/coco/sev/svsm.c
@@ -0,0 +1,356 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * SVSM support code
+ */
+
+#include <linux/types.h>
+
+#include <asm/sev.h>
+
+#include "internal.h"
+
+/* For early boot SVSM communication */
+struct svsm_ca boot_svsm_ca_page __aligned(PAGE_SIZE);
+SYM_PIC_ALIAS(boot_svsm_ca_page);
+
+/*
+ * SVSM related information:
+ * During boot, the page tables are set up as identity mapped and later
+ * changed to use kernel virtual addresses. Maintain separate virtual and
+ * physical addresses for the CAA to allow SVSM functions to be used during
+ * early boot, both with identity mapped virtual addresses and proper kernel
+ * virtual addresses.
+ */
+u64 boot_svsm_caa_pa __ro_after_init;
+SYM_PIC_ALIAS(boot_svsm_caa_pa);
+
+DEFINE_PER_CPU(struct svsm_ca *, svsm_caa);
+DEFINE_PER_CPU(u64, svsm_caa_pa);
+
+static int svsm_perform_ghcb_protocol(struct ghcb *ghcb, struct svsm_call *call)
+{
+ struct es_em_ctxt ctxt;
+ u8 pending = 0;
+
+ vc_ghcb_invalidate(ghcb);
+
+ /*
+ * Fill in protocol and format specifiers. This can be called very early
+ * in the boot, so use rip-relative references as needed.
+ */
+ ghcb->protocol_version = ghcb_version;
+ ghcb->ghcb_usage = GHCB_DEFAULT_USAGE;
+
+ ghcb_set_sw_exit_code(ghcb, SVM_VMGEXIT_SNP_RUN_VMPL);
+ ghcb_set_sw_exit_info_1(ghcb, 0);
+ ghcb_set_sw_exit_info_2(ghcb, 0);
+
+ sev_es_wr_ghcb_msr(__pa(ghcb));
+
+ svsm_issue_call(call, &pending);
+
+ if (pending)
+ return -EINVAL;
+
+ switch (verify_exception_info(ghcb, &ctxt)) {
+ case ES_OK:
+ break;
+ case ES_EXCEPTION:
+ vc_forward_exception(&ctxt);
+ fallthrough;
+ default:
+ return -EINVAL;
+ }
+
+ return svsm_process_result_codes(call);
+}
+
+int svsm_perform_call_protocol(struct svsm_call *call)
+{
+ struct ghcb_state state;
+ unsigned long flags;
+ struct ghcb *ghcb;
+ int ret;
+
+ flags = native_local_irq_save();
+
+ ghcb = __sev_get_ghcb(&state);
+
+ do {
+ ret = ghcb ? svsm_perform_ghcb_protocol(ghcb, call)
+ : __pi_svsm_perform_msr_protocol(call);
+ } while (ret == -EAGAIN);
+
+ __sev_put_ghcb(&state);
+
+ native_local_irq_restore(flags);
+
+ return ret;
+}
+
+static u64 svsm_build_ca_from_pfn_range(u64 pfn, u64 pfn_end, bool action,
+ struct svsm_pvalidate_call *pc)
+{
+ struct svsm_pvalidate_entry *pe;
+
+ /* Nothing in the CA yet */
+ pc->num_entries = 0;
+ pc->cur_index = 0;
+
+ pe = &pc->entry[0];
+
+ while (pfn < pfn_end) {
+ pe->page_size = RMP_PG_SIZE_4K;
+ pe->action = action;
+ pe->ignore_cf = 0;
+ pe->rsvd = 0;
+ pe->pfn = pfn;
+
+ pe++;
+ pfn++;
+
+ pc->num_entries++;
+ if (pc->num_entries == SVSM_PVALIDATE_MAX_COUNT)
+ break;
+ }
+
+ return pfn;
+}
+
+static int svsm_build_ca_from_psc_desc(struct snp_psc_desc *desc, unsigned int desc_entry,
+ struct svsm_pvalidate_call *pc)
+{
+ struct svsm_pvalidate_entry *pe;
+ struct psc_entry *e;
+
+ /* Nothing in the CA yet */
+ pc->num_entries = 0;
+ pc->cur_index = 0;
+
+ pe = &pc->entry[0];
+ e = &desc->entries[desc_entry];
+
+ while (desc_entry <= desc->hdr.end_entry) {
+ pe->page_size = e->pagesize ? RMP_PG_SIZE_2M : RMP_PG_SIZE_4K;
+ pe->action = e->operation == SNP_PAGE_STATE_PRIVATE;
+ pe->ignore_cf = 0;
+ pe->rsvd = 0;
+ pe->pfn = e->gfn;
+
+ pe++;
+ e++;
+
+ desc_entry++;
+ pc->num_entries++;
+ if (pc->num_entries == SVSM_PVALIDATE_MAX_COUNT)
+ break;
+ }
+
+ return desc_entry;
+}
+
+static void svsm_pval_terminate(struct svsm_pvalidate_call *pc, int ret, u64 svsm_ret)
+{
+ unsigned int page_size;
+ bool action;
+ u64 pfn;
+
+ pfn = pc->entry[pc->cur_index].pfn;
+ action = pc->entry[pc->cur_index].action;
+ page_size = pc->entry[pc->cur_index].page_size;
+
+ __pval_terminate(pfn, action, page_size, ret, svsm_ret);
+}
+
+void svsm_pval_pages(struct snp_psc_desc *desc)
+{
+ struct svsm_pvalidate_entry pv_4k[VMGEXIT_PSC_MAX_ENTRY];
+ unsigned int i, pv_4k_count = 0;
+ struct svsm_pvalidate_call *pc;
+ struct svsm_call call = {};
+ unsigned long flags;
+ bool action;
+ u64 pc_pa;
+ int ret;
+
+ /*
+ * This can be called very early in the boot, use native functions in
+ * order to avoid paravirt issues.
+ */
+ flags = native_local_irq_save();
+
+ /*
+ * The SVSM calling area (CA) can support processing 510 entries at a
+ * time. Loop through the Page State Change descriptor until the CA is
+ * full or the last entry in the descriptor is reached, at which time
+ * the SVSM is invoked. This repeats until all entries in the descriptor
+ * are processed.
+ */
+ call.caa = svsm_get_caa();
+
+ pc = (struct svsm_pvalidate_call *)call.caa->svsm_buffer;
+ pc_pa = svsm_get_caa_pa() + offsetof(struct svsm_ca, svsm_buffer);
+
+ /* Protocol 0, Call ID 1 */
+ call.rax = SVSM_CORE_CALL(SVSM_CORE_PVALIDATE);
+ call.rcx = pc_pa;
+
+ for (i = 0; i <= desc->hdr.end_entry;) {
+ i = svsm_build_ca_from_psc_desc(desc, i, pc);
+
+ do {
+ ret = svsm_perform_call_protocol(&call);
+ if (!ret)
+ continue;
+
+ /*
+ * Check if the entry failed because of an RMP mismatch (a
+ * PVALIDATE at 2M was requested, but the page is mapped in
+ * the RMP as 4K).
+ */
+
+ if (call.rax_out == SVSM_PVALIDATE_FAIL_SIZEMISMATCH &&
+ pc->entry[pc->cur_index].page_size == RMP_PG_SIZE_2M) {
+ /* Save this entry for post-processing at 4K */
+ pv_4k[pv_4k_count++] = pc->entry[pc->cur_index];
+
+ /* Skip to the next one unless at the end of the list */
+ pc->cur_index++;
+ if (pc->cur_index < pc->num_entries)
+ ret = -EAGAIN;
+ else
+ ret = 0;
+ }
+ } while (ret == -EAGAIN);
+
+ if (ret)
+ svsm_pval_terminate(pc, ret, call.rax_out);
+ }
+
+ /* Process any entries that failed to be validated at 2M and validate them at 4K */
+ for (i = 0; i < pv_4k_count; i++) {
+ u64 pfn, pfn_end;
+
+ action = pv_4k[i].action;
+ pfn = pv_4k[i].pfn;
+ pfn_end = pfn + 512;
+
+ while (pfn < pfn_end) {
+ pfn = svsm_build_ca_from_pfn_range(pfn, pfn_end, action, pc);
+
+ ret = svsm_perform_call_protocol(&call);
+ if (ret)
+ svsm_pval_terminate(pc, ret, call.rax_out);
+ }
+ }
+
+ native_local_irq_restore(flags);
+}
+
+static void update_attest_input(struct svsm_call *call, struct svsm_attest_call *input)
+{
+ /* If (new) lengths have been returned, propagate them up */
+ if (call->rcx_out != call->rcx)
+ input->manifest_buf.len = call->rcx_out;
+
+ if (call->rdx_out != call->rdx)
+ input->certificates_buf.len = call->rdx_out;
+
+ if (call->r8_out != call->r8)
+ input->report_buf.len = call->r8_out;
+}
+
+int snp_issue_svsm_attest_req(u64 call_id, struct svsm_call *call,
+ struct svsm_attest_call *input)
+{
+ struct svsm_attest_call *ac;
+ unsigned long flags;
+ u64 attest_call_pa;
+ int ret;
+
+ if (!snp_vmpl)
+ return -EINVAL;
+
+ local_irq_save(flags);
+
+ call->caa = svsm_get_caa();
+
+ ac = (struct svsm_attest_call *)call->caa->svsm_buffer;
+ attest_call_pa = svsm_get_caa_pa() + offsetof(struct svsm_ca, svsm_buffer);
+
+ *ac = *input;
+
+ /*
+ * Set input registers for the request and set RDX and R8 to known
+ * values in order to detect length values being returned in them.
+ */
+ call->rax = call_id;
+ call->rcx = attest_call_pa;
+ call->rdx = -1;
+ call->r8 = -1;
+ ret = svsm_perform_call_protocol(call);
+ update_attest_input(call, input);
+
+ local_irq_restore(flags);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(snp_issue_svsm_attest_req);
+
+/**
+ * snp_svsm_vtpm_send_command() - Execute a vTPM operation on SVSM
+ * @buffer: A buffer used to both send the command and receive the response.
+ *
+ * Execute a SVSM_VTPM_CMD call as defined by
+ * "Secure VM Service Module for SEV-SNP Guests" Publication # 58019 Revision: 1.00
+ *
+ * All command request/response buffers have a common structure as specified by
+ * the following table:
+ * Byte Size     In/Out    Description
+ * Offset    (Bytes)
+ * 0x000     4          In        Platform command
+ *                         Out       Platform command response size
+ *
+ * Each command can build upon this common request/response structure to create
+ * a structure specific to the command. See include/linux/tpm_svsm.h for more
+ * details.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+int snp_svsm_vtpm_send_command(u8 *buffer)
+{
+ struct svsm_call call = {};
+
+ call.caa = svsm_get_caa();
+ call.rax = SVSM_VTPM_CALL(SVSM_VTPM_CMD);
+ call.rcx = __pa(buffer);
+
+ return svsm_perform_call_protocol(&call);
+}
+EXPORT_SYMBOL_GPL(snp_svsm_vtpm_send_command);
+
+/**
+ * snp_svsm_vtpm_probe() - Probe if SVSM provides a vTPM device
+ *
+ * Check that there is SVSM and that it supports at least TPM_SEND_COMMAND
+ * which is the only request used so far.
+ *
+ * Return: true if the platform provides a vTPM SVSM device, false otherwise.
+ */
+bool snp_svsm_vtpm_probe(void)
+{
+ struct svsm_call call = {};
+
+ /* The vTPM device is available only if a SVSM is present */
+ if (!snp_vmpl)
+ return false;
+
+ call.caa = svsm_get_caa();
+ call.rax = SVSM_VTPM_CALL(SVSM_VTPM_QUERY);
+
+ if (svsm_perform_call_protocol(&call))
+ return false;
+
+ /* Check platform commands contains TPM_SEND_COMMAND - platform command 8 */
+ return call.rcx_out & BIT_ULL(8);
+}
diff --git a/arch/x86/coco/sev/vc-handle.c b/arch/x86/coco/sev/vc-handle.c
new file mode 100644
index 000000000..96b62b49b
--- /dev/null
+++ b/arch/x86/coco/sev/vc-handle.c
@@ -0,0 +1,1089 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AMD Memory Encryption Support
+ *
+ * Copyright (C) 2019 SUSE
+ *
+ * Author: Joerg Roedel <jroedel@suse.de>
+ */
+
+#define pr_fmt(fmt) "SEV: " fmt
+
+#include <linux/sched/debug.h> /* For show_regs() */
+#include <linux/cc_platform.h>
+#include <linux/printk.h>
+#include <linux/mm_types.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/io.h>
+#include <linux/psp-sev.h>
+#include <linux/efi.h>
+#include <uapi/linux/sev-guest.h>
+
+#include <asm/init.h>
+#include <asm/stacktrace.h>
+#include <asm/sev.h>
+#include <asm/insn-eval.h>
+#include <asm/fpu/xcr.h>
+#include <asm/processor.h>
+#include <asm/setup.h>
+#include <asm/traps.h>
+#include <asm/svm.h>
+#include <asm/smp.h>
+#include <asm/cpu.h>
+#include <asm/apic.h>
+#include <asm/cpuid/api.h>
+
+#include "internal.h"
+
+static enum es_result vc_slow_virt_to_phys(struct ghcb *ghcb, struct es_em_ctxt *ctxt,
+ unsigned long vaddr, phys_addr_t *paddr)
+{
+ unsigned long va = (unsigned long)vaddr;
+ unsigned int level;
+ phys_addr_t pa;
+ pgd_t *pgd;
+ pte_t *pte;
+
+ pgd = __va(read_cr3_pa());
+ pgd = &pgd[pgd_index(va)];
+ pte = lookup_address_in_pgd(pgd, va, &level);
+ if (!pte) {
+ ctxt->fi.vector = X86_TRAP_PF;
+ ctxt->fi.cr2 = vaddr;
+ ctxt->fi.error_code = 0;
+
+ if (user_mode(ctxt->regs))
+ ctxt->fi.error_code |= X86_PF_USER;
+
+ return ES_EXCEPTION;
+ }
+
+ if (WARN_ON_ONCE(pte_val(*pte) & _PAGE_ENC))
+ /* Emulated MMIO to/from encrypted memory not supported */
+ return ES_UNSUPPORTED;
+
+ pa = (phys_addr_t)pte_pfn(*pte) << PAGE_SHIFT;
+ pa |= va & ~page_level_mask(level);
+
+ *paddr = pa;
+
+ return ES_OK;
+}
+
+static enum es_result vc_ioio_check(struct es_em_ctxt *ctxt, u16 port, size_t size)
+{
+ BUG_ON(size > 4);
+
+ if (user_mode(ctxt->regs)) {
+ struct thread_struct *t = &current->thread;
+ struct io_bitmap *iobm = t->io_bitmap;
+ size_t idx;
+
+ if (!iobm)
+ goto fault;
+
+ for (idx = port; idx < port + size; ++idx) {
+ if (test_bit(idx, iobm->bitmap))
+ goto fault;
+ }
+ }
+
+ return ES_OK;
+
+fault:
+ ctxt->fi.vector = X86_TRAP_GP;
+ ctxt->fi.error_code = 0;
+
+ return ES_EXCEPTION;
+}
+
+void vc_forward_exception(struct es_em_ctxt *ctxt)
+{
+ long error_code = ctxt->fi.error_code;
+ int trapnr = ctxt->fi.vector;
+
+ ctxt->regs->orig_ax = ctxt->fi.error_code;
+
+ switch (trapnr) {
+ case X86_TRAP_GP:
+ exc_general_protection(ctxt->regs, error_code);
+ break;
+ case X86_TRAP_UD:
+ exc_invalid_op(ctxt->regs);
+ break;
+ case X86_TRAP_PF:
+ write_cr2(ctxt->fi.cr2);
+ exc_page_fault(ctxt->regs, error_code);
+ break;
+ case X86_TRAP_AC:
+ exc_alignment_check(ctxt->regs, error_code);
+ break;
+ default:
+ pr_emerg("Unsupported exception in #VC instruction emulation - can't continue\n");
+ BUG();
+ }
+}
+
+static int vc_fetch_insn_kernel(struct es_em_ctxt *ctxt,
+ unsigned char *buffer)
+{
+ return copy_from_kernel_nofault(buffer, (unsigned char *)ctxt->regs->ip, MAX_INSN_SIZE);
+}
+
+static enum es_result __vc_decode_user_insn(struct es_em_ctxt *ctxt)
+{
+ char buffer[MAX_INSN_SIZE];
+ int insn_bytes;
+
+ insn_bytes = insn_fetch_from_user_inatomic(ctxt->regs, buffer);
+ if (insn_bytes == 0) {
+ /* Nothing could be copied */
+ ctxt->fi.vector = X86_TRAP_PF;
+ ctxt->fi.error_code = X86_PF_INSTR | X86_PF_USER;
+ ctxt->fi.cr2 = ctxt->regs->ip;
+ return ES_EXCEPTION;
+ } else if (insn_bytes == -EINVAL) {
+ /* Effective RIP could not be calculated */
+ ctxt->fi.vector = X86_TRAP_GP;
+ ctxt->fi.error_code = 0;
+ ctxt->fi.cr2 = 0;
+ return ES_EXCEPTION;
+ }
+
+ if (!insn_decode_from_regs(&ctxt->insn, ctxt->regs, buffer, insn_bytes))
+ return ES_DECODE_FAILED;
+
+ if (ctxt->insn.immediate.got)
+ return ES_OK;
+ else
+ return ES_DECODE_FAILED;
+}
+
+static enum es_result __vc_decode_kern_insn(struct es_em_ctxt *ctxt)
+{
+ char buffer[MAX_INSN_SIZE];
+ int res, ret;
+
+ res = vc_fetch_insn_kernel(ctxt, buffer);
+ if (res) {
+ ctxt->fi.vector = X86_TRAP_PF;
+ ctxt->fi.error_code = X86_PF_INSTR;
+ ctxt->fi.cr2 = ctxt->regs->ip;
+ return ES_EXCEPTION;
+ }
+
+ ret = insn_decode(&ctxt->insn, buffer, MAX_INSN_SIZE, INSN_MODE_64);
+ if (ret < 0)
+ return ES_DECODE_FAILED;
+ else
+ return ES_OK;
+}
+
+/*
+ * User instruction decoding is also required for the EFI runtime. Even though
+ * the EFI runtime is running in kernel mode, it uses special EFI virtual
+ * address mappings that require the use of efi_mm to properly address and
+ * decode.
+ */
+static enum es_result vc_decode_insn(struct es_em_ctxt *ctxt)
+{
+ if (user_mode(ctxt->regs) || mm_is_efi(current->active_mm))
+ return __vc_decode_user_insn(ctxt);
+ else
+ return __vc_decode_kern_insn(ctxt);
+}
+
+static enum es_result vc_write_mem(struct es_em_ctxt *ctxt,
+ char *dst, char *buf, size_t size)
+{
+ unsigned long error_code = X86_PF_PROT | X86_PF_WRITE;
+
+ /*
+ * This function uses __put_user() independent of whether kernel or user
+ * memory is accessed. This works fine because __put_user() does no
+ * sanity checks of the pointer being accessed. All that it does is
+ * to report when the access failed.
+ *
+ * Also, this function runs in atomic context, so __put_user() is not
+ * allowed to sleep. The page-fault handler detects that it is running
+ * in atomic context and will not try to take mmap_sem and handle the
+ * fault, so additional pagefault_enable()/disable() calls are not
+ * needed.
+ *
+ * The access can't be done via copy_to_user() here because
+ * vc_write_mem() must not use string instructions to access unsafe
+ * memory. The reason is that MOVS is emulated by the #VC handler by
+ * splitting the move up into a read and a write and taking a nested #VC
+ * exception on whatever of them is the MMIO access. Using string
+ * instructions here would cause infinite nesting.
+ */
+ switch (size) {
+ case 1: {
+ u8 d1;
+ u8 __user *target = (u8 __user *)dst;
+
+ memcpy(&d1, buf, 1);
+ if (__put_user(d1, target))
+ goto fault;
+ break;
+ }
+ case 2: {
+ u16 d2;
+ u16 __user *target = (u16 __user *)dst;
+
+ memcpy(&d2, buf, 2);
+ if (__put_user(d2, target))
+ goto fault;
+ break;
+ }
+ case 4: {
+ u32 d4;
+ u32 __user *target = (u32 __user *)dst;
+
+ memcpy(&d4, buf, 4);
+ if (__put_user(d4, target))
+ goto fault;
+ break;
+ }
+ case 8: {
+ u64 d8;
+ u64 __user *target = (u64 __user *)dst;
+
+ memcpy(&d8, buf, 8);
+ if (__put_user(d8, target))
+ goto fault;
+ break;
+ }
+ default:
+ WARN_ONCE(1, "%s: Invalid size: %zu\n", __func__, size);
+ return ES_UNSUPPORTED;
+ }
+
+ return ES_OK;
+
+fault:
+ if (user_mode(ctxt->regs))
+ error_code |= X86_PF_USER;
+
+ ctxt->fi.vector = X86_TRAP_PF;
+ ctxt->fi.error_code = error_code;
+ ctxt->fi.cr2 = (unsigned long)dst;
+
+ return ES_EXCEPTION;
+}
+
+static enum es_result vc_read_mem(struct es_em_ctxt *ctxt,
+ char *src, char *buf, size_t size)
+{
+ unsigned long error_code = X86_PF_PROT;
+
+ /*
+ * This function uses __get_user() independent of whether kernel or user
+ * memory is accessed. This works fine because __get_user() does no
+ * sanity checks of the pointer being accessed. All that it does is
+ * to report when the access failed.
+ *
+ * Also, this function runs in atomic context, so __get_user() is not
+ * allowed to sleep. The page-fault handler detects that it is running
+ * in atomic context and will not try to take mmap_sem and handle the
+ * fault, so additional pagefault_enable()/disable() calls are not
+ * needed.
+ *
+ * The access can't be done via copy_from_user() here because
+ * vc_read_mem() must not use string instructions to access unsafe
+ * memory. The reason is that MOVS is emulated by the #VC handler by
+ * splitting the move up into a read and a write and taking a nested #VC
+ * exception on whatever of them is the MMIO access. Using string
+ * instructions here would cause infinite nesting.
+ */
+ switch (size) {
+ case 1: {
+ u8 d1;
+ u8 __user *s = (u8 __user *)src;
+
+ if (__get_user(d1, s))
+ goto fault;
+ memcpy(buf, &d1, 1);
+ break;
+ }
+ case 2: {
+ u16 d2;
+ u16 __user *s = (u16 __user *)src;
+
+ if (__get_user(d2, s))
+ goto fault;
+ memcpy(buf, &d2, 2);
+ break;
+ }
+ case 4: {
+ u32 d4;
+ u32 __user *s = (u32 __user *)src;
+
+ if (__get_user(d4, s))
+ goto fault;
+ memcpy(buf, &d4, 4);
+ break;
+ }
+ case 8: {
+ u64 d8;
+ u64 __user *s = (u64 __user *)src;
+ if (__get_user(d8, s))
+ goto fault;
+ memcpy(buf, &d8, 8);
+ break;
+ }
+ default:
+ WARN_ONCE(1, "%s: Invalid size: %zu\n", __func__, size);
+ return ES_UNSUPPORTED;
+ }
+
+ return ES_OK;
+
+fault:
+ if (user_mode(ctxt->regs))
+ error_code |= X86_PF_USER;
+
+ ctxt->fi.vector = X86_TRAP_PF;
+ ctxt->fi.error_code = error_code;
+ ctxt->fi.cr2 = (unsigned long)src;
+
+ return ES_EXCEPTION;
+}
+
+#define sev_printk(fmt, ...) printk(fmt, ##__VA_ARGS__)
+#define error(v)
+
+#include "vc-shared.c"
+
+/* Writes to the SVSM CAA MSR are ignored */
+static enum es_result __vc_handle_msr_caa(struct pt_regs *regs, bool write)
+{
+ if (write)
+ return ES_OK;
+
+ regs->ax = lower_32_bits(this_cpu_read(svsm_caa_pa));
+ regs->dx = upper_32_bits(this_cpu_read(svsm_caa_pa));
+
+ return ES_OK;
+}
+
+/*
+ * TSC related accesses should not exit to the hypervisor when a guest is
+ * executing with Secure TSC enabled, so special handling is required for
+ * accesses of MSR_IA32_TSC and MSR_AMD64_GUEST_TSC_FREQ.
+ */
+static enum es_result __vc_handle_secure_tsc_msrs(struct es_em_ctxt *ctxt, bool write)
+{
+ struct pt_regs *regs = ctxt->regs;
+ u64 tsc;
+
+ /*
+ * Writing to MSR_IA32_TSC can cause subsequent reads of the TSC to
+ * return undefined values, and GUEST_TSC_FREQ is read-only. Generate
+ * a #GP on all writes.
+ */
+ if (write) {
+ ctxt->fi.vector = X86_TRAP_GP;
+ ctxt->fi.error_code = 0;
+ return ES_EXCEPTION;
+ }
+
+ /*
+ * GUEST_TSC_FREQ read should not be intercepted when Secure TSC is
+ * enabled. Terminate the guest if a read is attempted.
+ */
+ if (regs->cx == MSR_AMD64_GUEST_TSC_FREQ)
+ return ES_VMM_ERROR;
+
+ /* Reads of MSR_IA32_TSC should return the current TSC value. */
+ tsc = rdtsc_ordered();
+ regs->ax = lower_32_bits(tsc);
+ regs->dx = upper_32_bits(tsc);
+
+ return ES_OK;
+}
+
+enum es_result __vc_handle_msr(struct ghcb *ghcb, struct es_em_ctxt *ctxt, bool write)
+{
+ struct pt_regs *regs = ctxt->regs;
+ enum es_result ret;
+
+ switch (regs->cx) {
+ case MSR_SVSM_CAA:
+ return __vc_handle_msr_caa(regs, write);
+ case MSR_IA32_TSC:
+ case MSR_AMD64_GUEST_TSC_FREQ:
+ if (sev_status & MSR_AMD64_SNP_SECURE_TSC)
+ return __vc_handle_secure_tsc_msrs(ctxt, write);
+ break;
+ case MSR_AMD64_SAVIC_CONTROL:
+ /*
+ * AMD64_SAVIC_CONTROL should not be intercepted when
+ * Secure AVIC is enabled. Terminate the Secure AVIC guest
+ * if the interception is enabled.
+ */
+ if (cc_platform_has(CC_ATTR_SNP_SECURE_AVIC))
+ return ES_VMM_ERROR;
+ break;
+ default:
+ break;
+ }
+
+ ghcb_set_rcx(ghcb, regs->cx);
+ if (write) {
+ ghcb_set_rax(ghcb, regs->ax);
+ ghcb_set_rdx(ghcb, regs->dx);
+ }
+
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_MSR, write, 0);
+
+ if ((ret == ES_OK) && !write) {
+ regs->ax = ghcb->save.rax;
+ regs->dx = ghcb->save.rdx;
+ }
+
+ return ret;
+}
+
+static enum es_result vc_handle_msr(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
+{
+ return __vc_handle_msr(ghcb, ctxt, ctxt->insn.opcode.bytes[1] == 0x30);
+}
+
+static void __init vc_early_forward_exception(struct es_em_ctxt *ctxt)
+{
+ int trapnr = ctxt->fi.vector;
+
+ if (trapnr == X86_TRAP_PF)
+ native_write_cr2(ctxt->fi.cr2);
+
+ ctxt->regs->orig_ax = ctxt->fi.error_code;
+ do_early_exception(ctxt->regs, trapnr);
+}
+
+static long *vc_insn_get_rm(struct es_em_ctxt *ctxt)
+{
+ long *reg_array;
+ int offset;
+
+ reg_array = (long *)ctxt->regs;
+ offset = insn_get_modrm_rm_off(&ctxt->insn, ctxt->regs);
+
+ if (offset < 0)
+ return NULL;
+
+ offset /= sizeof(long);
+
+ return reg_array + offset;
+}
+static enum es_result vc_do_mmio(struct ghcb *ghcb, struct es_em_ctxt *ctxt,
+ unsigned int bytes, bool read)
+{
+ u64 exit_code, exit_info_1, exit_info_2;
+ unsigned long ghcb_pa = __pa(ghcb);
+ enum es_result res;
+ phys_addr_t paddr;
+ void __user *ref;
+
+ ref = insn_get_addr_ref(&ctxt->insn, ctxt->regs);
+ if (ref == (void __user *)-1L)
+ return ES_UNSUPPORTED;
+
+ exit_code = read ? SVM_VMGEXIT_MMIO_READ : SVM_VMGEXIT_MMIO_WRITE;
+
+ res = vc_slow_virt_to_phys(ghcb, ctxt, (unsigned long)ref, &paddr);
+ if (res != ES_OK) {
+ if (res == ES_EXCEPTION && !read)
+ ctxt->fi.error_code |= X86_PF_WRITE;
+
+ return res;
+ }
+
+ exit_info_1 = paddr;
+ /* Can never be greater than 8 */
+ exit_info_2 = bytes;
+
+ ghcb_set_sw_scratch(ghcb, ghcb_pa + offsetof(struct ghcb, shared_buffer));
+
+ return sev_es_ghcb_hv_call(ghcb, ctxt, exit_code, exit_info_1, exit_info_2);
+}
+
+/*
+ * The MOVS instruction has two memory operands, which raises the
+ * problem that it is not known whether the access to the source or the
+ * destination caused the #VC exception (and hence whether an MMIO read
+ * or write operation needs to be emulated).
+ *
+ * Instead of playing games with walking page-tables and trying to guess
+ * whether the source or destination is an MMIO range, split the move
+ * into two operations, a read and a write with only one memory operand.
+ * This will cause a nested #VC exception on the MMIO address which can
+ * then be handled.
+ *
+ * This implementation has the benefit that it also supports MOVS where
+ * source _and_ destination are MMIO regions.
+ *
+ * It will slow MOVS on MMIO down a lot, but in SEV-ES guests it is a
+ * rare operation. If it turns out to be a performance problem the split
+ * operations can be moved to memcpy_fromio() and memcpy_toio().
+ */
+static enum es_result vc_handle_mmio_movs(struct es_em_ctxt *ctxt,
+ unsigned int bytes)
+{
+ unsigned long ds_base, es_base;
+ unsigned char *src, *dst;
+ unsigned char buffer[8];
+ enum es_result ret;
+ bool rep;
+ int off;
+
+ ds_base = insn_get_seg_base(ctxt->regs, INAT_SEG_REG_DS);
+ es_base = insn_get_seg_base(ctxt->regs, INAT_SEG_REG_ES);
+
+ if (ds_base == -1L || es_base == -1L) {
+ ctxt->fi.vector = X86_TRAP_GP;
+ ctxt->fi.error_code = 0;
+ return ES_EXCEPTION;
+ }
+
+ src = ds_base + (unsigned char *)ctxt->regs->si;
+ dst = es_base + (unsigned char *)ctxt->regs->di;
+
+ ret = vc_read_mem(ctxt, src, buffer, bytes);
+ if (ret != ES_OK)
+ return ret;
+
+ ret = vc_write_mem(ctxt, dst, buffer, bytes);
+ if (ret != ES_OK)
+ return ret;
+
+ if (ctxt->regs->flags & X86_EFLAGS_DF)
+ off = -bytes;
+ else
+ off = bytes;
+
+ ctxt->regs->si += off;
+ ctxt->regs->di += off;
+
+ rep = insn_has_rep_prefix(&ctxt->insn);
+ if (rep)
+ ctxt->regs->cx -= 1;
+
+ if (!rep || ctxt->regs->cx == 0)
+ return ES_OK;
+ else
+ return ES_RETRY;
+}
+
+static enum es_result vc_handle_mmio(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
+{
+ struct insn *insn = &ctxt->insn;
+ enum insn_mmio_type mmio;
+ unsigned int bytes = 0;
+ enum es_result ret;
+ u8 sign_byte;
+ long *reg_data;
+
+ mmio = insn_decode_mmio(insn, &bytes);
+ if (mmio == INSN_MMIO_DECODE_FAILED)
+ return ES_DECODE_FAILED;
+
+ if (mmio != INSN_MMIO_WRITE_IMM && mmio != INSN_MMIO_MOVS) {
+ reg_data = insn_get_modrm_reg_ptr(insn, ctxt->regs);
+ if (!reg_data)
+ return ES_DECODE_FAILED;
+ }
+
+ if (user_mode(ctxt->regs))
+ return ES_UNSUPPORTED;
+
+ switch (mmio) {
+ case INSN_MMIO_WRITE:
+ memcpy(ghcb->shared_buffer, reg_data, bytes);
+ ret = vc_do_mmio(ghcb, ctxt, bytes, false);
+ break;
+ case INSN_MMIO_WRITE_IMM:
+ memcpy(ghcb->shared_buffer, insn->immediate1.bytes, bytes);
+ ret = vc_do_mmio(ghcb, ctxt, bytes, false);
+ break;
+ case INSN_MMIO_READ:
+ ret = vc_do_mmio(ghcb, ctxt, bytes, true);
+ if (ret)
+ break;
+
+ /* Zero-extend for 32-bit operation */
+ if (bytes == 4)
+ *reg_data = 0;
+
+ memcpy(reg_data, ghcb->shared_buffer, bytes);
+ break;
+ case INSN_MMIO_READ_ZERO_EXTEND:
+ ret = vc_do_mmio(ghcb, ctxt, bytes, true);
+ if (ret)
+ break;
+
+ /* Zero extend based on operand size */
+ memset(reg_data, 0, insn->opnd_bytes);
+ memcpy(reg_data, ghcb->shared_buffer, bytes);
+ break;
+ case INSN_MMIO_READ_SIGN_EXTEND:
+ ret = vc_do_mmio(ghcb, ctxt, bytes, true);
+ if (ret)
+ break;
+
+ if (bytes == 1) {
+ u8 *val = (u8 *)ghcb->shared_buffer;
+
+ sign_byte = (*val & 0x80) ? 0xff : 0x00;
+ } else {
+ u16 *val = (u16 *)ghcb->shared_buffer;
+
+ sign_byte = (*val & 0x8000) ? 0xff : 0x00;
+ }
+
+ /* Sign extend based on operand size */
+ memset(reg_data, sign_byte, insn->opnd_bytes);
+ memcpy(reg_data, ghcb->shared_buffer, bytes);
+ break;
+ case INSN_MMIO_MOVS:
+ ret = vc_handle_mmio_movs(ctxt, bytes);
+ break;
+ default:
+ ret = ES_UNSUPPORTED;
+ break;
+ }
+
+ return ret;
+}
+
+static enum es_result vc_handle_dr7_write(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt)
+{
+ struct sev_es_runtime_data *data = this_cpu_read(runtime_data);
+ long val, *reg = vc_insn_get_rm(ctxt);
+ enum es_result ret;
+
+ if (sev_status & MSR_AMD64_SNP_DEBUG_SWAP)
+ return ES_VMM_ERROR;
+
+ if (!reg)
+ return ES_DECODE_FAILED;
+
+ val = *reg;
+
+ /* Upper 32 bits must be written as zeroes */
+ if (val >> 32) {
+ ctxt->fi.vector = X86_TRAP_GP;
+ ctxt->fi.error_code = 0;
+ return ES_EXCEPTION;
+ }
+
+ /* Clear out other reserved bits and set bit 10 */
+ val = (val & 0xffff23ffL) | BIT(10);
+
+ /* Early non-zero writes to DR7 are not supported */
+ if (!data && (val & ~DR7_RESET_VALUE))
+ return ES_UNSUPPORTED;
+
+ /* Using a value of 0 for ExitInfo1 means RAX holds the value */
+ ghcb_set_rax(ghcb, val);
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_WRITE_DR7, 0, 0);
+ if (ret != ES_OK)
+ return ret;
+
+ if (data)
+ data->dr7 = val;
+
+ return ES_OK;
+}
+
+static enum es_result vc_handle_dr7_read(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt)
+{
+ struct sev_es_runtime_data *data = this_cpu_read(runtime_data);
+ long *reg = vc_insn_get_rm(ctxt);
+
+ if (sev_status & MSR_AMD64_SNP_DEBUG_SWAP)
+ return ES_VMM_ERROR;
+
+ if (!reg)
+ return ES_DECODE_FAILED;
+
+ if (data)
+ *reg = data->dr7;
+ else
+ *reg = DR7_RESET_VALUE;
+
+ return ES_OK;
+}
+
+static enum es_result vc_handle_wbinvd(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt)
+{
+ return sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_WBINVD, 0, 0);
+}
+
+static enum es_result vc_handle_rdpmc(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
+{
+ enum es_result ret;
+
+ ghcb_set_rcx(ghcb, ctxt->regs->cx);
+
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_RDPMC, 0, 0);
+ if (ret != ES_OK)
+ return ret;
+
+ if (!(ghcb_rax_is_valid(ghcb) && ghcb_rdx_is_valid(ghcb)))
+ return ES_VMM_ERROR;
+
+ ctxt->regs->ax = ghcb->save.rax;
+ ctxt->regs->dx = ghcb->save.rdx;
+
+ return ES_OK;
+}
+
+static enum es_result vc_handle_monitor(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt)
+{
+ /*
+ * Treat it as a NOP and do not leak a physical address to the
+ * hypervisor.
+ */
+ return ES_OK;
+}
+
+static enum es_result vc_handle_mwait(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt)
+{
+ /* Treat the same as MONITOR/MONITORX */
+ return ES_OK;
+}
+
+static enum es_result vc_handle_vmmcall(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt)
+{
+ enum es_result ret;
+
+ ghcb_set_rax(ghcb, ctxt->regs->ax);
+ ghcb_set_cpl(ghcb, user_mode(ctxt->regs) ? 3 : 0);
+
+ if (x86_platform.hyper.sev_es_hcall_prepare)
+ x86_platform.hyper.sev_es_hcall_prepare(ghcb, ctxt->regs);
+
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_VMMCALL, 0, 0);
+ if (ret != ES_OK)
+ return ret;
+
+ if (!ghcb_rax_is_valid(ghcb))
+ return ES_VMM_ERROR;
+
+ ctxt->regs->ax = ghcb->save.rax;
+
+ /*
+ * Call sev_es_hcall_finish() after regs->ax is already set.
+ * This allows the hypervisor handler to overwrite it again if
+ * necessary.
+ */
+ if (x86_platform.hyper.sev_es_hcall_finish &&
+ !x86_platform.hyper.sev_es_hcall_finish(ghcb, ctxt->regs))
+ return ES_VMM_ERROR;
+
+ return ES_OK;
+}
+
+static enum es_result vc_handle_trap_ac(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt)
+{
+ /*
+ * Calling ecx_alignment_check() directly does not work, because it
+ * enables IRQs and the GHCB is active. Forward the exception and call
+ * it later from vc_forward_exception().
+ */
+ ctxt->fi.vector = X86_TRAP_AC;
+ ctxt->fi.error_code = 0;
+ return ES_EXCEPTION;
+}
+
+static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt,
+ struct ghcb *ghcb,
+ unsigned long exit_code)
+{
+ enum es_result result = vc_check_opcode_bytes(ctxt, exit_code);
+
+ if (result != ES_OK)
+ return result;
+
+ switch (exit_code) {
+ case SVM_EXIT_READ_DR7:
+ result = vc_handle_dr7_read(ghcb, ctxt);
+ break;
+ case SVM_EXIT_WRITE_DR7:
+ result = vc_handle_dr7_write(ghcb, ctxt);
+ break;
+ case SVM_EXIT_EXCP_BASE + X86_TRAP_AC:
+ result = vc_handle_trap_ac(ghcb, ctxt);
+ break;
+ case SVM_EXIT_RDTSC:
+ case SVM_EXIT_RDTSCP:
+ result = vc_handle_rdtsc(ghcb, ctxt, exit_code);
+ break;
+ case SVM_EXIT_RDPMC:
+ result = vc_handle_rdpmc(ghcb, ctxt);
+ break;
+ case SVM_EXIT_INVD:
+ pr_err_ratelimited("#VC exception for INVD??? Seriously???\n");
+ result = ES_UNSUPPORTED;
+ break;
+ case SVM_EXIT_CPUID:
+ result = vc_handle_cpuid(ghcb, ctxt);
+ break;
+ case SVM_EXIT_IOIO:
+ result = vc_handle_ioio(ghcb, ctxt);
+ break;
+ case SVM_EXIT_MSR:
+ result = vc_handle_msr(ghcb, ctxt);
+ break;
+ case SVM_EXIT_VMMCALL:
+ result = vc_handle_vmmcall(ghcb, ctxt);
+ break;
+ case SVM_EXIT_WBINVD:
+ result = vc_handle_wbinvd(ghcb, ctxt);
+ break;
+ case SVM_EXIT_MONITOR:
+ result = vc_handle_monitor(ghcb, ctxt);
+ break;
+ case SVM_EXIT_MWAIT:
+ result = vc_handle_mwait(ghcb, ctxt);
+ break;
+ case SVM_EXIT_NPF:
+ result = vc_handle_mmio(ghcb, ctxt);
+ break;
+ default:
+ /*
+ * Unexpected #VC exception
+ */
+ result = ES_UNSUPPORTED;
+ }
+
+ return result;
+}
+
+static __always_inline bool is_vc2_stack(unsigned long sp)
+{
+ return (sp >= __this_cpu_ist_bottom_va(VC2) && sp < __this_cpu_ist_top_va(VC2));
+}
+
+static __always_inline bool vc_from_invalid_context(struct pt_regs *regs)
+{
+ unsigned long sp, prev_sp;
+
+ sp = (unsigned long)regs;
+ prev_sp = regs->sp;
+
+ /*
+ * If the code was already executing on the VC2 stack when the #VC
+ * happened, let it proceed to the normal handling routine. This way the
+ * code executing on the VC2 stack can cause #VC exceptions to get handled.
+ */
+ return is_vc2_stack(sp) && !is_vc2_stack(prev_sp);
+}
+
+static bool vc_raw_handle_exception(struct pt_regs *regs, unsigned long error_code)
+{
+ struct ghcb_state state;
+ struct es_em_ctxt ctxt;
+ enum es_result result;
+ struct ghcb *ghcb;
+ bool ret = true;
+
+ ghcb = __sev_get_ghcb(&state);
+
+ vc_ghcb_invalidate(ghcb);
+ result = vc_init_em_ctxt(&ctxt, regs, error_code);
+
+ if (result == ES_OK)
+ result = vc_handle_exitcode(&ctxt, ghcb, error_code);
+
+ __sev_put_ghcb(&state);
+
+ /* Done - now check the result */
+ switch (result) {
+ case ES_OK:
+ vc_finish_insn(&ctxt);
+ break;
+ case ES_UNSUPPORTED:
+ pr_err_ratelimited("Unsupported exit-code 0x%02lx in #VC exception (IP: 0x%lx)\n",
+ error_code, regs->ip);
+ ret = false;
+ break;
+ case ES_VMM_ERROR:
+ pr_err_ratelimited("Failure in communication with VMM (exit-code 0x%02lx IP: 0x%lx)\n",
+ error_code, regs->ip);
+ ret = false;
+ break;
+ case ES_DECODE_FAILED:
+ pr_err_ratelimited("Failed to decode instruction (exit-code 0x%02lx IP: 0x%lx)\n",
+ error_code, regs->ip);
+ ret = false;
+ break;
+ case ES_EXCEPTION:
+ vc_forward_exception(&ctxt);
+ break;
+ case ES_RETRY:
+ /* Nothing to do */
+ break;
+ default:
+ pr_emerg("Unknown result in %s():%d\n", __func__, result);
+ /*
+ * Emulating the instruction which caused the #VC exception
+ * failed - can't continue so print debug information
+ */
+ BUG();
+ }
+
+ return ret;
+}
+
+static __always_inline bool vc_is_db(unsigned long error_code)
+{
+ return error_code == SVM_EXIT_EXCP_BASE + X86_TRAP_DB;
+}
+
+/*
+ * Runtime #VC exception handler when raised from kernel mode. Runs in NMI mode
+ * and will panic when an error happens.
+ */
+noinstr void kernel_exc_vmm_communication(struct pt_regs *regs, unsigned long error_code)
+{
+ irqentry_state_t irq_state;
+
+ /*
+ * With the current implementation it is always possible to switch to a
+ * safe stack because #VC exceptions only happen at known places, like
+ * intercepted instructions or accesses to MMIO areas/IO ports. They can
+ * also happen with code instrumentation when the hypervisor intercepts
+ * #DB, but the critical paths are forbidden to be instrumented, so #DB
+ * exceptions currently also only happen in safe places.
+ *
+ * But keep this here in case the noinstr annotations are violated due
+ * to bug elsewhere.
+ */
+ if (unlikely(vc_from_invalid_context(regs))) {
+ instrumentation_begin();
+ panic("Can't handle #VC exception from unsupported context\n");
+ instrumentation_end();
+ }
+
+ /*
+ * Handle #DB before calling into !noinstr code to avoid recursive #DB.
+ */
+ if (vc_is_db(error_code)) {
+ exc_debug(regs);
+ return;
+ }
+
+ irq_state = irqentry_nmi_enter(regs);
+
+ instrumentation_begin();
+
+ if (!vc_raw_handle_exception(regs, error_code)) {
+ /* Show some debug info */
+ show_regs(regs);
+
+ /* Ask hypervisor to sev_es_terminate */
+ sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ);
+
+ /* If that fails and we get here - just panic */
+ panic("Returned from Terminate-Request to Hypervisor\n");
+ }
+
+ instrumentation_end();
+ irqentry_nmi_exit(regs, irq_state);
+}
+
+/*
+ * Runtime #VC exception handler when raised from user mode. Runs in IRQ mode
+ * and will kill the current task with SIGBUS when an error happens.
+ */
+noinstr void user_exc_vmm_communication(struct pt_regs *regs, unsigned long error_code)
+{
+ /*
+ * Handle #DB before calling into !noinstr code to avoid recursive #DB.
+ */
+ if (vc_is_db(error_code)) {
+ noist_exc_debug(regs);
+ return;
+ }
+
+ irqentry_enter_from_user_mode(regs);
+ instrumentation_begin();
+
+ if (!vc_raw_handle_exception(regs, error_code)) {
+ /*
+ * Do not kill the machine if user-space triggered the
+ * exception. Send SIGBUS instead and let user-space deal with
+ * it.
+ */
+ force_sig_fault(SIGBUS, BUS_OBJERR, (void __user *)0);
+ }
+
+ instrumentation_end();
+ irqentry_exit_to_user_mode(regs);
+}
+
+DEFINE_IDTENTRY_RAW_ERRORCODE(exc_vmm_communication)
+{
+ if (user_mode(regs))
+ return user_exc_vmm_communication(regs, error_code);
+ else
+ return kernel_exc_vmm_communication(regs, error_code);
+}
+
+bool __init handle_vc_boot_ghcb(struct pt_regs *regs)
+{
+ unsigned long exit_code = regs->orig_ax;
+ struct es_em_ctxt ctxt;
+ enum es_result result;
+
+ vc_ghcb_invalidate(boot_ghcb);
+
+ result = vc_init_em_ctxt(&ctxt, regs, exit_code);
+ if (result == ES_OK)
+ result = vc_handle_exitcode(&ctxt, boot_ghcb, exit_code);
+
+ /* Done - now check the result */
+ switch (result) {
+ case ES_OK:
+ vc_finish_insn(&ctxt);
+ break;
+ case ES_UNSUPPORTED:
+ early_printk("PANIC: Unsupported exit-code 0x%02lx in early #VC exception (IP: 0x%lx)\n",
+ exit_code, regs->ip);
+ goto fail;
+ case ES_VMM_ERROR:
+ early_printk("PANIC: Failure in communication with VMM (exit-code 0x%02lx IP: 0x%lx)\n",
+ exit_code, regs->ip);
+ goto fail;
+ case ES_DECODE_FAILED:
+ early_printk("PANIC: Failed to decode instruction (exit-code 0x%02lx IP: 0x%lx)\n",
+ exit_code, regs->ip);
+ goto fail;
+ case ES_EXCEPTION:
+ vc_early_forward_exception(&ctxt);
+ break;
+ case ES_RETRY:
+ /* Nothing to do */
+ break;
+ default:
+ BUG();
+ }
+
+ return true;
+
+fail:
+ show_regs(regs);
+
+ sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ);
+}
+
diff --git a/arch/x86/coco/sev/vc-shared.c b/arch/x86/coco/sev/vc-shared.c
new file mode 100644
index 000000000..58b2f985d
--- /dev/null
+++ b/arch/x86/coco/sev/vc-shared.c
@@ -0,0 +1,656 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#ifndef __BOOT_COMPRESSED
+#define has_cpuflag(f) cpu_feature_enabled(f)
+#endif
+
+static enum es_result vc_check_opcode_bytes(struct es_em_ctxt *ctxt,
+ unsigned long exit_code)
+{
+ unsigned int opcode = (unsigned int)ctxt->insn.opcode.value;
+ u8 modrm = ctxt->insn.modrm.value;
+
+ switch (exit_code) {
+
+ case SVM_EXIT_IOIO:
+ case SVM_EXIT_NPF:
+ /* handled separately */
+ return ES_OK;
+
+ case SVM_EXIT_CPUID:
+ if (opcode == 0xa20f)
+ return ES_OK;
+ break;
+
+ case SVM_EXIT_INVD:
+ if (opcode == 0x080f)
+ return ES_OK;
+ break;
+
+ case SVM_EXIT_MONITOR:
+ /* MONITOR and MONITORX instructions generate the same error code */
+ if (opcode == 0x010f && (modrm == 0xc8 || modrm == 0xfa))
+ return ES_OK;
+ break;
+
+ case SVM_EXIT_MWAIT:
+ /* MWAIT and MWAITX instructions generate the same error code */
+ if (opcode == 0x010f && (modrm == 0xc9 || modrm == 0xfb))
+ return ES_OK;
+ break;
+
+ case SVM_EXIT_MSR:
+ /* RDMSR */
+ if (opcode == 0x320f ||
+ /* WRMSR */
+ opcode == 0x300f)
+ return ES_OK;
+ break;
+
+ case SVM_EXIT_RDPMC:
+ if (opcode == 0x330f)
+ return ES_OK;
+ break;
+
+ case SVM_EXIT_RDTSC:
+ if (opcode == 0x310f)
+ return ES_OK;
+ break;
+
+ case SVM_EXIT_RDTSCP:
+ if (opcode == 0x010f && modrm == 0xf9)
+ return ES_OK;
+ break;
+
+ case SVM_EXIT_READ_DR7:
+ if (opcode == 0x210f &&
+ X86_MODRM_REG(ctxt->insn.modrm.value) == 7)
+ return ES_OK;
+ break;
+
+ case SVM_EXIT_VMMCALL:
+ if (opcode == 0x010f && modrm == 0xd9)
+ return ES_OK;
+
+ break;
+
+ case SVM_EXIT_WRITE_DR7:
+ if (opcode == 0x230f &&
+ X86_MODRM_REG(ctxt->insn.modrm.value) == 7)
+ return ES_OK;
+ break;
+
+ case SVM_EXIT_WBINVD:
+ if (opcode == 0x90f)
+ return ES_OK;
+ break;
+
+ default:
+ break;
+ }
+
+ sev_printk(KERN_ERR "Wrong/unhandled opcode bytes: 0x%x, exit_code: 0x%lx, rIP: 0x%lx\n",
+ opcode, exit_code, ctxt->regs->ip);
+
+ return ES_UNSUPPORTED;
+}
+
+static bool vc_decoding_needed(unsigned long exit_code)
+{
+ /* Exceptions don't require to decode the instruction */
+ return !(exit_code >= SVM_EXIT_EXCP_BASE &&
+ exit_code <= SVM_EXIT_LAST_EXCP);
+}
+
+static enum es_result vc_init_em_ctxt(struct es_em_ctxt *ctxt,
+ struct pt_regs *regs,
+ unsigned long exit_code)
+{
+ enum es_result ret = ES_OK;
+
+ memset(ctxt, 0, sizeof(*ctxt));
+ ctxt->regs = regs;
+
+ if (vc_decoding_needed(exit_code))
+ ret = vc_decode_insn(ctxt);
+
+ return ret;
+}
+
+static void vc_finish_insn(struct es_em_ctxt *ctxt)
+{
+ ctxt->regs->ip += ctxt->insn.length;
+}
+
+static enum es_result vc_insn_string_check(struct es_em_ctxt *ctxt,
+ unsigned long address,
+ bool write)
+{
+ if (user_mode(ctxt->regs) && fault_in_kernel_space(address)) {
+ ctxt->fi.vector = X86_TRAP_PF;
+ ctxt->fi.error_code = X86_PF_USER;
+ ctxt->fi.cr2 = address;
+ if (write)
+ ctxt->fi.error_code |= X86_PF_WRITE;
+
+ return ES_EXCEPTION;
+ }
+
+ return ES_OK;
+}
+
+static enum es_result vc_insn_string_read(struct es_em_ctxt *ctxt,
+ void *src, char *buf,
+ unsigned int data_size,
+ unsigned int count,
+ bool backwards)
+{
+ int i, b = backwards ? -1 : 1;
+ unsigned long address = (unsigned long)src;
+ enum es_result ret;
+
+ ret = vc_insn_string_check(ctxt, address, false);
+ if (ret != ES_OK)
+ return ret;
+
+ for (i = 0; i < count; i++) {
+ void *s = src + (i * data_size * b);
+ char *d = buf + (i * data_size);
+
+ ret = vc_read_mem(ctxt, s, d, data_size);
+ if (ret != ES_OK)
+ break;
+ }
+
+ return ret;
+}
+
+static enum es_result vc_insn_string_write(struct es_em_ctxt *ctxt,
+ void *dst, char *buf,
+ unsigned int data_size,
+ unsigned int count,
+ bool backwards)
+{
+ int i, s = backwards ? -1 : 1;
+ unsigned long address = (unsigned long)dst;
+ enum es_result ret;
+
+ ret = vc_insn_string_check(ctxt, address, true);
+ if (ret != ES_OK)
+ return ret;
+
+ for (i = 0; i < count; i++) {
+ void *d = dst + (i * data_size * s);
+ char *b = buf + (i * data_size);
+
+ ret = vc_write_mem(ctxt, d, b, data_size);
+ if (ret != ES_OK)
+ break;
+ }
+
+ return ret;
+}
+
+#define IOIO_TYPE_STR BIT(2)
+#define IOIO_TYPE_IN 1
+#define IOIO_TYPE_INS (IOIO_TYPE_IN | IOIO_TYPE_STR)
+#define IOIO_TYPE_OUT 0
+#define IOIO_TYPE_OUTS (IOIO_TYPE_OUT | IOIO_TYPE_STR)
+
+#define IOIO_REP BIT(3)
+
+#define IOIO_ADDR_64 BIT(9)
+#define IOIO_ADDR_32 BIT(8)
+#define IOIO_ADDR_16 BIT(7)
+
+#define IOIO_DATA_32 BIT(6)
+#define IOIO_DATA_16 BIT(5)
+#define IOIO_DATA_8 BIT(4)
+
+#define IOIO_SEG_ES (0 << 10)
+#define IOIO_SEG_DS (3 << 10)
+
+static enum es_result vc_ioio_exitinfo(struct es_em_ctxt *ctxt, u64 *exitinfo)
+{
+ struct insn *insn = &ctxt->insn;
+ size_t size;
+ u64 port;
+
+ *exitinfo = 0;
+
+ switch (insn->opcode.bytes[0]) {
+ /* INS opcodes */
+ case 0x6c:
+ case 0x6d:
+ *exitinfo |= IOIO_TYPE_INS;
+ *exitinfo |= IOIO_SEG_ES;
+ port = ctxt->regs->dx & 0xffff;
+ break;
+
+ /* OUTS opcodes */
+ case 0x6e:
+ case 0x6f:
+ *exitinfo |= IOIO_TYPE_OUTS;
+ *exitinfo |= IOIO_SEG_DS;
+ port = ctxt->regs->dx & 0xffff;
+ break;
+
+ /* IN immediate opcodes */
+ case 0xe4:
+ case 0xe5:
+ *exitinfo |= IOIO_TYPE_IN;
+ port = (u8)insn->immediate.value & 0xffff;
+ break;
+
+ /* OUT immediate opcodes */
+ case 0xe6:
+ case 0xe7:
+ *exitinfo |= IOIO_TYPE_OUT;
+ port = (u8)insn->immediate.value & 0xffff;
+ break;
+
+ /* IN register opcodes */
+ case 0xec:
+ case 0xed:
+ *exitinfo |= IOIO_TYPE_IN;
+ port = ctxt->regs->dx & 0xffff;
+ break;
+
+ /* OUT register opcodes */
+ case 0xee:
+ case 0xef:
+ *exitinfo |= IOIO_TYPE_OUT;
+ port = ctxt->regs->dx & 0xffff;
+ break;
+
+ default:
+ return ES_DECODE_FAILED;
+ }
+
+ *exitinfo |= port << 16;
+
+ switch (insn->opcode.bytes[0]) {
+ case 0x6c:
+ case 0x6e:
+ case 0xe4:
+ case 0xe6:
+ case 0xec:
+ case 0xee:
+ /* Single byte opcodes */
+ *exitinfo |= IOIO_DATA_8;
+ size = 1;
+ break;
+ default:
+ /* Length determined by instruction parsing */
+ *exitinfo |= (insn->opnd_bytes == 2) ? IOIO_DATA_16
+ : IOIO_DATA_32;
+ size = (insn->opnd_bytes == 2) ? 2 : 4;
+ }
+
+ switch (insn->addr_bytes) {
+ case 2:
+ *exitinfo |= IOIO_ADDR_16;
+ break;
+ case 4:
+ *exitinfo |= IOIO_ADDR_32;
+ break;
+ case 8:
+ *exitinfo |= IOIO_ADDR_64;
+ break;
+ }
+
+ if (insn_has_rep_prefix(insn))
+ *exitinfo |= IOIO_REP;
+
+ return vc_ioio_check(ctxt, (u16)port, size);
+}
+
+static enum es_result vc_handle_ioio(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
+{
+ struct pt_regs *regs = ctxt->regs;
+ u64 exit_info_1, exit_info_2;
+ enum es_result ret;
+
+ ret = vc_ioio_exitinfo(ctxt, &exit_info_1);
+ if (ret != ES_OK)
+ return ret;
+
+ if (exit_info_1 & IOIO_TYPE_STR) {
+
+ /* (REP) INS/OUTS */
+
+ bool df = ((regs->flags & X86_EFLAGS_DF) == X86_EFLAGS_DF);
+ unsigned int io_bytes, exit_bytes;
+ unsigned int ghcb_count, op_count;
+ unsigned long es_base;
+ u64 sw_scratch;
+
+ /*
+ * For the string variants with rep prefix the amount of in/out
+ * operations per #VC exception is limited so that the kernel
+ * has a chance to take interrupts and re-schedule while the
+ * instruction is emulated.
+ */
+ io_bytes = (exit_info_1 >> 4) & 0x7;
+ ghcb_count = sizeof(ghcb->shared_buffer) / io_bytes;
+
+ op_count = (exit_info_1 & IOIO_REP) ? regs->cx : 1;
+ exit_info_2 = min(op_count, ghcb_count);
+ exit_bytes = exit_info_2 * io_bytes;
+
+ es_base = insn_get_seg_base(ctxt->regs, INAT_SEG_REG_ES);
+
+ /* Read bytes of OUTS into the shared buffer */
+ if (!(exit_info_1 & IOIO_TYPE_IN)) {
+ ret = vc_insn_string_read(ctxt,
+ (void *)(es_base + regs->si),
+ ghcb->shared_buffer, io_bytes,
+ exit_info_2, df);
+ if (ret)
+ return ret;
+ }
+
+ /*
+ * Issue an VMGEXIT to the HV to consume the bytes from the
+ * shared buffer or to have it write them into the shared buffer
+ * depending on the instruction: OUTS or INS.
+ */
+ sw_scratch = __pa(ghcb) + offsetof(struct ghcb, shared_buffer);
+ ghcb_set_sw_scratch(ghcb, sw_scratch);
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_IOIO,
+ exit_info_1, exit_info_2);
+ if (ret != ES_OK)
+ return ret;
+
+ /* Read bytes from shared buffer into the guest's destination. */
+ if (exit_info_1 & IOIO_TYPE_IN) {
+ ret = vc_insn_string_write(ctxt,
+ (void *)(es_base + regs->di),
+ ghcb->shared_buffer, io_bytes,
+ exit_info_2, df);
+ if (ret)
+ return ret;
+
+ if (df)
+ regs->di -= exit_bytes;
+ else
+ regs->di += exit_bytes;
+ } else {
+ if (df)
+ regs->si -= exit_bytes;
+ else
+ regs->si += exit_bytes;
+ }
+
+ if (exit_info_1 & IOIO_REP)
+ regs->cx -= exit_info_2;
+
+ ret = regs->cx ? ES_RETRY : ES_OK;
+
+ } else {
+
+ /* IN/OUT into/from rAX */
+
+ int bits = (exit_info_1 & 0x70) >> 1;
+ u64 rax = 0;
+
+ if (!(exit_info_1 & IOIO_TYPE_IN))
+ rax = lower_bits(regs->ax, bits);
+
+ ghcb_set_rax(ghcb, rax);
+
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_IOIO, exit_info_1, 0);
+ if (ret != ES_OK)
+ return ret;
+
+ if (exit_info_1 & IOIO_TYPE_IN) {
+ if (!ghcb_rax_is_valid(ghcb))
+ return ES_VMM_ERROR;
+ regs->ax = lower_bits(ghcb->save.rax, bits);
+ }
+ }
+
+ return ret;
+}
+
+enum es_result verify_exception_info(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
+{
+ u32 ret;
+
+ ret = ghcb->save.sw_exit_info_1 & GENMASK_ULL(31, 0);
+ if (!ret)
+ return ES_OK;
+
+ if (ret == 1) {
+ u64 info = ghcb->save.sw_exit_info_2;
+ unsigned long v = info & SVM_EVTINJ_VEC_MASK;
+
+ /* Check if exception information from hypervisor is sane. */
+ if ((info & SVM_EVTINJ_VALID) &&
+ ((v == X86_TRAP_GP) || (v == X86_TRAP_UD)) &&
+ ((info & SVM_EVTINJ_TYPE_MASK) == SVM_EVTINJ_TYPE_EXEPT)) {
+ ctxt->fi.vector = v;
+
+ if (info & SVM_EVTINJ_VALID_ERR)
+ ctxt->fi.error_code = info >> 32;
+
+ return ES_EXCEPTION;
+ }
+ }
+
+ return ES_VMM_ERROR;
+}
+
+enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt,
+ u64 exit_code, u64 exit_info_1,
+ u64 exit_info_2)
+{
+ /* Fill in protocol and format specifiers */
+ ghcb->protocol_version = ghcb_version;
+ ghcb->ghcb_usage = GHCB_DEFAULT_USAGE;
+
+ ghcb_set_sw_exit_code(ghcb, exit_code);
+ ghcb_set_sw_exit_info_1(ghcb, exit_info_1);
+ ghcb_set_sw_exit_info_2(ghcb, exit_info_2);
+
+ sev_es_wr_ghcb_msr(__pa(ghcb));
+ VMGEXIT();
+
+ return verify_exception_info(ghcb, ctxt);
+}
+
+static int __sev_cpuid_hv_ghcb(struct ghcb *ghcb, struct es_em_ctxt *ctxt, struct cpuid_leaf *leaf)
+{
+ u32 cr4 = native_read_cr4();
+ int ret;
+
+ ghcb_set_rax(ghcb, leaf->fn);
+ ghcb_set_rcx(ghcb, leaf->subfn);
+
+ if (cr4 & X86_CR4_OSXSAVE)
+ /* Safe to read xcr0 */
+ ghcb_set_xcr0(ghcb, xgetbv(XCR_XFEATURE_ENABLED_MASK));
+ else
+ /* xgetbv will cause #UD - use reset value for xcr0 */
+ ghcb_set_xcr0(ghcb, 1);
+
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_CPUID, 0, 0);
+ if (ret != ES_OK)
+ return ret;
+
+ if (!(ghcb_rax_is_valid(ghcb) &&
+ ghcb_rbx_is_valid(ghcb) &&
+ ghcb_rcx_is_valid(ghcb) &&
+ ghcb_rdx_is_valid(ghcb)))
+ return ES_VMM_ERROR;
+
+ leaf->eax = ghcb->save.rax;
+ leaf->ebx = ghcb->save.rbx;
+ leaf->ecx = ghcb->save.rcx;
+ leaf->edx = ghcb->save.rdx;
+
+ return ES_OK;
+}
+
+struct cpuid_ctx {
+ struct ghcb *ghcb;
+ struct es_em_ctxt *ctxt;
+};
+
+static void snp_cpuid_hv_ghcb(void *p, struct cpuid_leaf *leaf)
+{
+ struct cpuid_ctx *ctx = p;
+
+ if (__sev_cpuid_hv_ghcb(ctx->ghcb, ctx->ctxt, leaf))
+ sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_CPUID_HV);
+}
+
+static int vc_handle_cpuid_snp(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
+{
+ struct cpuid_ctx ctx = { ghcb, ctxt };
+ struct pt_regs *regs = ctxt->regs;
+ struct cpuid_leaf leaf;
+ int ret;
+
+ leaf.fn = regs->ax;
+ leaf.subfn = regs->cx;
+ ret = snp_cpuid(snp_cpuid_hv_ghcb, &ctx, &leaf);
+ if (!ret) {
+ regs->ax = leaf.eax;
+ regs->bx = leaf.ebx;
+ regs->cx = leaf.ecx;
+ regs->dx = leaf.edx;
+ }
+
+ return ret;
+}
+
+static enum es_result vc_handle_cpuid(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt)
+{
+ struct pt_regs *regs = ctxt->regs;
+ u32 cr4 = native_read_cr4();
+ enum es_result ret;
+ int snp_cpuid_ret;
+
+ snp_cpuid_ret = vc_handle_cpuid_snp(ghcb, ctxt);
+ if (!snp_cpuid_ret)
+ return ES_OK;
+ if (snp_cpuid_ret != -EOPNOTSUPP)
+ return ES_VMM_ERROR;
+
+ ghcb_set_rax(ghcb, regs->ax);
+ ghcb_set_rcx(ghcb, regs->cx);
+
+ if (cr4 & X86_CR4_OSXSAVE)
+ /* Safe to read xcr0 */
+ ghcb_set_xcr0(ghcb, xgetbv(XCR_XFEATURE_ENABLED_MASK));
+ else
+ /* xgetbv will cause #GP - use reset value for xcr0 */
+ ghcb_set_xcr0(ghcb, 1);
+
+ if (has_cpuflag(X86_FEATURE_SHSTK) && regs->ax == 0xd && regs->cx == 1) {
+ struct msr m;
+
+ raw_rdmsr(MSR_IA32_XSS, &m);
+ ghcb_set_xss(ghcb, m.q);
+ }
+
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_CPUID, 0, 0);
+ if (ret != ES_OK)
+ return ret;
+
+ if (!(ghcb_rax_is_valid(ghcb) &&
+ ghcb_rbx_is_valid(ghcb) &&
+ ghcb_rcx_is_valid(ghcb) &&
+ ghcb_rdx_is_valid(ghcb)))
+ return ES_VMM_ERROR;
+
+ regs->ax = ghcb->save.rax;
+ regs->bx = ghcb->save.rbx;
+ regs->cx = ghcb->save.rcx;
+ regs->dx = ghcb->save.rdx;
+
+ return ES_OK;
+}
+
+static enum es_result vc_handle_rdtsc(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt,
+ unsigned long exit_code)
+{
+ bool rdtscp = (exit_code == SVM_EXIT_RDTSCP);
+ enum es_result ret;
+
+ /*
+ * The hypervisor should not be intercepting RDTSC/RDTSCP when Secure
+ * TSC is enabled. A #VC exception will be generated if the RDTSC/RDTSCP
+ * instructions are being intercepted. If this should occur and Secure
+ * TSC is enabled, guest execution should be terminated as the guest
+ * cannot rely on the TSC value provided by the hypervisor.
+ */
+ if (sev_status & MSR_AMD64_SNP_SECURE_TSC)
+ return ES_VMM_ERROR;
+
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, exit_code, 0, 0);
+ if (ret != ES_OK)
+ return ret;
+
+ if (!(ghcb_rax_is_valid(ghcb) && ghcb_rdx_is_valid(ghcb) &&
+ (!rdtscp || ghcb_rcx_is_valid(ghcb))))
+ return ES_VMM_ERROR;
+
+ ctxt->regs->ax = ghcb->save.rax;
+ ctxt->regs->dx = ghcb->save.rdx;
+ if (rdtscp)
+ ctxt->regs->cx = ghcb->save.rcx;
+
+ return ES_OK;
+}
+
+void snp_register_ghcb_early(unsigned long paddr)
+{
+ unsigned long pfn = paddr >> PAGE_SHIFT;
+ u64 val;
+
+ sev_es_wr_ghcb_msr(GHCB_MSR_REG_GPA_REQ_VAL(pfn));
+ VMGEXIT();
+
+ val = sev_es_rd_ghcb_msr();
+
+ /* If the response GPA is not ours then abort the guest */
+ if ((GHCB_RESP_CODE(val) != GHCB_MSR_REG_GPA_RESP) ||
+ (GHCB_MSR_REG_GPA_RESP_VAL(val) != pfn))
+ sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_REGISTER);
+}
+
+bool __init sev_es_check_cpu_features(void)
+{
+ if (!has_cpuflag(X86_FEATURE_RDRAND)) {
+ error("RDRAND instruction not supported - no trusted source of randomness available\n");
+ return false;
+ }
+
+ return true;
+}
+
+bool sev_es_negotiate_protocol(void)
+{
+ u64 val;
+
+ /* Do the GHCB protocol version negotiation */
+ sev_es_wr_ghcb_msr(GHCB_MSR_SEV_INFO_REQ);
+ VMGEXIT();
+ val = sev_es_rd_ghcb_msr();
+
+ if (GHCB_MSR_INFO(val) != GHCB_MSR_SEV_INFO_RESP)
+ return false;
+
+ if (GHCB_MSR_PROTO_MAX(val) < GHCB_PROTOCOL_MIN ||
+ GHCB_MSR_PROTO_MIN(val) > GHCB_PROTOCOL_MAX)
+ return false;
+
+ ghcb_version = min_t(size_t, GHCB_MSR_PROTO_MAX(val), GHCB_PROTOCOL_MAX);
+
+ return true;
+}
diff --git a/arch/x86/coco/tdx/Makefile b/arch/x86/coco/tdx/Makefile
new file mode 100644
index 000000000..b3c47d370
--- /dev/null
+++ b/arch/x86/coco/tdx/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-y += debug.o tdcall.o tdx.o tdx-shared.o
diff --git a/arch/x86/coco/tdx/debug.c b/arch/x86/coco/tdx/debug.c
new file mode 100644
index 000000000..8e477db4c
--- /dev/null
+++ b/arch/x86/coco/tdx/debug.c
@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#undef pr_fmt
+#define pr_fmt(fmt) "tdx: " fmt
+
+#include <linux/array_size.h>
+#include <linux/printk.h>
+#include <asm/tdx.h>
+
+#define DEF_TDX_TD_ATTR_NAME(_name) [TDX_TD_ATTR_##_name##_BIT] = __stringify(_name)
+
+static __initdata const char *tdx_attributes[] = {
+ DEF_TDX_TD_ATTR_NAME(DEBUG),
+ DEF_TDX_TD_ATTR_NAME(HGS_PLUS_PROF),
+ DEF_TDX_TD_ATTR_NAME(PERF_PROF),
+ DEF_TDX_TD_ATTR_NAME(PMT_PROF),
+ DEF_TDX_TD_ATTR_NAME(ICSSD),
+ DEF_TDX_TD_ATTR_NAME(LASS),
+ DEF_TDX_TD_ATTR_NAME(SEPT_VE_DISABLE),
+ DEF_TDX_TD_ATTR_NAME(MIGRATABLE),
+ DEF_TDX_TD_ATTR_NAME(PKS),
+ DEF_TDX_TD_ATTR_NAME(KL),
+ DEF_TDX_TD_ATTR_NAME(TPA),
+ DEF_TDX_TD_ATTR_NAME(PERFMON),
+};
+
+#define DEF_TD_CTLS_NAME(_name) [TD_CTLS_##_name##_BIT] = __stringify(_name)
+
+static __initdata const char *tdcs_td_ctls[] = {
+ DEF_TD_CTLS_NAME(PENDING_VE_DISABLE),
+ DEF_TD_CTLS_NAME(ENUM_TOPOLOGY),
+ DEF_TD_CTLS_NAME(VIRT_CPUID2),
+ DEF_TD_CTLS_NAME(REDUCE_VE),
+ DEF_TD_CTLS_NAME(LOCK),
+};
+
+void __init tdx_dump_attributes(u64 td_attr)
+{
+ pr_info("Attributes:");
+
+ for (int i = 0; i < ARRAY_SIZE(tdx_attributes); i++) {
+ if (!tdx_attributes[i])
+ continue;
+ if (td_attr & BIT(i))
+ pr_cont(" %s", tdx_attributes[i]);
+ td_attr &= ~BIT(i);
+ }
+
+ if (td_attr)
+ pr_cont(" unknown:%#llx", td_attr);
+ pr_cont("\n");
+
+}
+
+void __init tdx_dump_td_ctls(u64 td_ctls)
+{
+ pr_info("TD_CTLS:");
+
+ for (int i = 0; i < ARRAY_SIZE(tdcs_td_ctls); i++) {
+ if (!tdcs_td_ctls[i])
+ continue;
+ if (td_ctls & BIT(i))
+ pr_cont(" %s", tdcs_td_ctls[i]);
+ td_ctls &= ~BIT(i);
+ }
+ if (td_ctls)
+ pr_cont(" unknown:%#llx", td_ctls);
+ pr_cont("\n");
+}
diff --git a/arch/x86/coco/tdx/tdcall.S b/arch/x86/coco/tdx/tdcall.S
new file mode 100644
index 000000000..52d9786da
--- /dev/null
+++ b/arch/x86/coco/tdx/tdcall.S
@@ -0,0 +1,63 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <asm/asm-offsets.h>
+#include <asm/asm.h>
+
+#include <linux/linkage.h>
+#include <linux/errno.h>
+
+#include "../../virt/vmx/tdx/tdxcall.S"
+
+.section .noinstr.text, "ax"
+
+/*
+ * __tdcall() - Used by TDX guests to request services from the TDX
+ * module (does not include VMM services) using TDCALL instruction.
+ *
+ * __tdcall() function ABI:
+ *
+ * @fn (RDI) - TDCALL Leaf ID, moved to RAX
+ * @args (RSI) - struct tdx_module_args for input
+ *
+ * Only RCX/RDX/R8-R11 are used as input registers.
+ *
+ * Return status of TDCALL via RAX.
+ */
+SYM_FUNC_START(__tdcall)
+ TDX_MODULE_CALL host=0
+SYM_FUNC_END(__tdcall)
+
+/*
+ * __tdcall_ret() - Used by TDX guests to request services from the TDX
+ * module (does not include VMM services) using TDCALL instruction, with
+ * saving output registers to the 'struct tdx_module_args' used as input.
+ *
+ * __tdcall_ret() function ABI:
+ *
+ * @fn (RDI) - TDCALL Leaf ID, moved to RAX
+ * @args (RSI) - struct tdx_module_args for input and output
+ *
+ * Only RCX/RDX/R8-R11 are used as input/output registers.
+ *
+ * Return status of TDCALL via RAX.
+ */
+SYM_FUNC_START(__tdcall_ret)
+ TDX_MODULE_CALL host=0 ret=1
+SYM_FUNC_END(__tdcall_ret)
+
+/*
+ * __tdcall_saved_ret() - Used by TDX guests to request services from the
+ * TDX module (including VMM services) using TDCALL instruction, with
+ * saving output registers to the 'struct tdx_module_args' used as input.
+ *
+ * __tdcall_saved_ret() function ABI:
+ *
+ * @fn (RDI) - TDCALL leaf ID, moved to RAX
+ * @args (RSI) - struct tdx_module_args for input/output
+ *
+ * All registers in @args are used as input/output registers.
+ *
+ * On successful completion, return the hypercall error code.
+ */
+SYM_FUNC_START(__tdcall_saved_ret)
+ TDX_MODULE_CALL host=0 ret=1 saved=1
+SYM_FUNC_END(__tdcall_saved_ret)
diff --git a/arch/x86/coco/tdx/tdx-shared.c b/arch/x86/coco/tdx/tdx-shared.c
new file mode 100644
index 000000000..1655aa56a
--- /dev/null
+++ b/arch/x86/coco/tdx/tdx-shared.c
@@ -0,0 +1,91 @@
+#include <asm/tdx.h>
+#include <asm/pgtable.h>
+
+static unsigned long try_accept_one(phys_addr_t start, unsigned long len,
+ enum pg_level pg_level)
+{
+ unsigned long accept_size = page_level_size(pg_level);
+ struct tdx_module_args args = {};
+ u8 page_size;
+
+ if (!IS_ALIGNED(start, accept_size))
+ return 0;
+
+ if (len < accept_size)
+ return 0;
+
+ /*
+ * Pass the page physical address to the TDX module to accept the
+ * pending, private page.
+ *
+ * Bits 2:0 of RCX encode page size: 0 - 4K, 1 - 2M, 2 - 1G.
+ */
+ switch (pg_level) {
+ case PG_LEVEL_4K:
+ page_size = TDX_PS_4K;
+ break;
+ case PG_LEVEL_2M:
+ page_size = TDX_PS_2M;
+ break;
+ case PG_LEVEL_1G:
+ page_size = TDX_PS_1G;
+ break;
+ default:
+ return 0;
+ }
+
+ args.rcx = start | page_size;
+ if (__tdcall(TDG_MEM_PAGE_ACCEPT, &args))
+ return 0;
+
+ return accept_size;
+}
+
+bool tdx_accept_memory(phys_addr_t start, phys_addr_t end)
+{
+ /*
+ * For shared->private conversion, accept the page using
+ * TDG_MEM_PAGE_ACCEPT TDX module call.
+ */
+ while (start < end) {
+ unsigned long len = end - start;
+ unsigned long accept_size;
+
+ /*
+ * Try larger accepts first. It gives chance to VMM to keep
+ * 1G/2M Secure EPT entries where possible and speeds up
+ * process by cutting number of hypercalls (if successful).
+ */
+
+ accept_size = try_accept_one(start, len, PG_LEVEL_1G);
+ if (!accept_size)
+ accept_size = try_accept_one(start, len, PG_LEVEL_2M);
+ if (!accept_size)
+ accept_size = try_accept_one(start, len, PG_LEVEL_4K);
+ if (!accept_size)
+ return false;
+ start += accept_size;
+ }
+
+ return true;
+}
+
+noinstr u64 __tdx_hypercall(struct tdx_module_args *args)
+{
+ /*
+ * For TDVMCALL explicitly set RCX to the bitmap of shared registers.
+ * The caller isn't expected to set @args->rcx anyway.
+ */
+ args->rcx = TDVMCALL_EXPOSE_REGS_MASK;
+
+ /*
+ * Failure of __tdcall_saved_ret() indicates a failure of the TDVMCALL
+ * mechanism itself and that something has gone horribly wrong with
+ * the TDX module. __tdx_hypercall_failed() never returns.
+ */
+ if (__tdcall_saved_ret(TDG_VP_VMCALL, args))
+ __tdx_hypercall_failed();
+
+ /* TDVMCALL leaf return code is in R10 */
+ return args->r10;
+}
diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c
new file mode 100644
index 000000000..f904a636d
--- /dev/null
+++ b/arch/x86/coco/tdx/tdx.c
@@ -0,0 +1,1195 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2021-2022 Intel Corporation */
+
+#undef pr_fmt
+#define pr_fmt(fmt) "tdx: " fmt
+
+#include <linux/cpufeature.h>
+#include <linux/export.h>
+#include <linux/io.h>
+#include <linux/kexec.h>
+#include <asm/coco.h>
+#include <asm/tdx.h>
+#include <asm/vmx.h>
+#include <asm/ia32.h>
+#include <asm/insn.h>
+#include <asm/insn-eval.h>
+#include <asm/cpuid/api.h>
+#include <asm/paravirt_types.h>
+#include <asm/pgtable.h>
+#include <asm/set_memory.h>
+#include <asm/traps.h>
+
+/* MMIO direction */
+#define EPT_READ 0
+#define EPT_WRITE 1
+
+/* Port I/O direction */
+#define PORT_READ 0
+#define PORT_WRITE 1
+
+/* See Exit Qualification for I/O Instructions in VMX documentation */
+#define VE_IS_IO_IN(e) ((e) & BIT(3))
+#define VE_GET_IO_SIZE(e) (((e) & GENMASK(2, 0)) + 1)
+#define VE_GET_PORT_NUM(e) ((e) >> 16)
+#define VE_IS_IO_STRING(e) ((e) & BIT(4))
+
+/* TDX Module call error codes */
+#define TDCALL_RETURN_CODE(a) ((a) >> 32)
+#define TDCALL_INVALID_OPERAND 0xc0000100
+#define TDCALL_OPERAND_BUSY 0x80000200
+
+#define TDREPORT_SUBTYPE_0 0
+
+static atomic_long_t nr_shared;
+
+/* Called from __tdx_hypercall() for unrecoverable failure */
+noinstr void __noreturn __tdx_hypercall_failed(void)
+{
+ instrumentation_begin();
+ panic("TDVMCALL failed. TDX module bug?");
+}
+
+#ifdef CONFIG_KVM_GUEST
+long tdx_kvm_hypercall(unsigned int nr, unsigned long p1, unsigned long p2,
+ unsigned long p3, unsigned long p4)
+{
+ struct tdx_module_args args = {
+ .r10 = nr,
+ .r11 = p1,
+ .r12 = p2,
+ .r13 = p3,
+ .r14 = p4,
+ };
+
+ return __tdx_hypercall(&args);
+}
+EXPORT_SYMBOL_GPL(tdx_kvm_hypercall);
+#endif
+
+/*
+ * Used for TDX guests to make calls directly to the TD module. This
+ * should only be used for calls that have no legitimate reason to fail
+ * or where the kernel can not survive the call failing.
+ */
+static inline void tdcall(u64 fn, struct tdx_module_args *args)
+{
+ if (__tdcall_ret(fn, args))
+ panic("TDCALL %lld failed (Buggy TDX module!)\n", fn);
+}
+
+/* Read TD-scoped metadata */
+static inline u64 tdg_vm_rd(u64 field, u64 *value)
+{
+ struct tdx_module_args args = {
+ .rdx = field,
+ };
+ u64 ret;
+
+ ret = __tdcall_ret(TDG_VM_RD, &args);
+ *value = args.r8;
+
+ return ret;
+}
+
+/* Write TD-scoped metadata */
+static inline u64 tdg_vm_wr(u64 field, u64 value, u64 mask)
+{
+ struct tdx_module_args args = {
+ .rdx = field,
+ .r8 = value,
+ .r9 = mask,
+ };
+
+ return __tdcall(TDG_VM_WR, &args);
+}
+
+/**
+ * tdx_mcall_get_report0() - Wrapper to get TDREPORT0 (a.k.a. TDREPORT
+ * subtype 0) using TDG.MR.REPORT TDCALL.
+ * @reportdata: Address of the input buffer which contains user-defined
+ * REPORTDATA to be included into TDREPORT.
+ * @tdreport: Address of the output buffer to store TDREPORT.
+ *
+ * Refer to section titled "TDG.MR.REPORT leaf" in the TDX Module v1.0
+ * specification for more information on TDG.MR.REPORT TDCALL.
+ *
+ * It is used in the TDX guest driver module to get the TDREPORT0.
+ *
+ * Return 0 on success, -ENXIO for invalid operands, -EBUSY for busy operation,
+ * or -EIO on other TDCALL failures.
+ */
+int tdx_mcall_get_report0(u8 *reportdata, u8 *tdreport)
+{
+ struct tdx_module_args args = {
+ .rcx = virt_to_phys(tdreport),
+ .rdx = virt_to_phys(reportdata),
+ .r8 = TDREPORT_SUBTYPE_0,
+ };
+ u64 ret;
+
+ ret = __tdcall(TDG_MR_REPORT, &args);
+ if (ret) {
+ if (TDCALL_RETURN_CODE(ret) == TDCALL_INVALID_OPERAND)
+ return -ENXIO;
+ else if (TDCALL_RETURN_CODE(ret) == TDCALL_OPERAND_BUSY)
+ return -EBUSY;
+ return -EIO;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(tdx_mcall_get_report0);
+
+/**
+ * tdx_mcall_extend_rtmr() - Wrapper to extend RTMR registers using
+ * TDG.MR.RTMR.EXTEND TDCALL.
+ * @index: Index of RTMR register to be extended.
+ * @data: Address of the input buffer with RTMR register extend data.
+ *
+ * Refer to section titled "TDG.MR.RTMR.EXTEND leaf" in the TDX Module v1.0
+ * specification for more information on TDG.MR.RTMR.EXTEND TDCALL.
+ *
+ * It is used in the TDX guest driver module to allow user to extend the RTMR
+ * registers.
+ *
+ * Return 0 on success, -ENXIO for invalid operands, -EBUSY for busy operation,
+ * or -EIO on other TDCALL failures.
+ */
+int tdx_mcall_extend_rtmr(u8 index, u8 *data)
+{
+ struct tdx_module_args args = {
+ .rcx = virt_to_phys(data),
+ .rdx = index,
+ };
+ u64 ret;
+
+ ret = __tdcall(TDG_MR_RTMR_EXTEND, &args);
+ if (ret) {
+ if (TDCALL_RETURN_CODE(ret) == TDCALL_INVALID_OPERAND)
+ return -ENXIO;
+ if (TDCALL_RETURN_CODE(ret) == TDCALL_OPERAND_BUSY)
+ return -EBUSY;
+ return -EIO;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(tdx_mcall_extend_rtmr);
+
+/**
+ * tdx_hcall_get_quote() - Wrapper to request TD Quote using GetQuote
+ * hypercall.
+ * @buf: Address of the directly mapped shared kernel buffer which
+ * contains TDREPORT. The same buffer will be used by VMM to
+ * store the generated TD Quote output.
+ * @size: size of the tdquote buffer (4KB-aligned).
+ *
+ * Refer to section titled "TDG.VP.VMCALL<GetQuote>" in the TDX GHCI
+ * v1.0 specification for more information on GetQuote hypercall.
+ * It is used in the TDX guest driver module to get the TD Quote.
+ *
+ * Return 0 on success or error code on failure.
+ */
+u64 tdx_hcall_get_quote(u8 *buf, size_t size)
+{
+ /* Since buf is a shared memory, set the shared (decrypted) bits */
+ return _tdx_hypercall(TDVMCALL_GET_QUOTE, cc_mkdec(virt_to_phys(buf)), size, 0, 0);
+}
+EXPORT_SYMBOL_GPL(tdx_hcall_get_quote);
+
+static void __noreturn tdx_panic(const char *msg)
+{
+ struct tdx_module_args args = {
+ .r10 = TDX_HYPERCALL_STANDARD,
+ .r11 = TDVMCALL_REPORT_FATAL_ERROR,
+ .r12 = 0, /* Error code: 0 is Panic */
+ };
+ union {
+ /* Define register order according to the GHCI */
+ struct { u64 r14, r15, rbx, rdi, rsi, r8, r9, rdx; };
+
+ char bytes[64] __nonstring;
+ } message;
+
+ /* VMM assumes '\0' in byte 65, if the message took all 64 bytes */
+ strtomem_pad(message.bytes, msg, '\0');
+
+ args.r8 = message.r8;
+ args.r9 = message.r9;
+ args.r14 = message.r14;
+ args.r15 = message.r15;
+ args.rdi = message.rdi;
+ args.rsi = message.rsi;
+ args.rbx = message.rbx;
+ args.rdx = message.rdx;
+
+ /*
+ * This hypercall should never return and it is not safe
+ * to keep the guest running. Call it forever if it
+ * happens to return.
+ */
+ while (1)
+ __tdx_hypercall(&args);
+}
+
+/*
+ * The kernel cannot handle #VEs when accessing normal kernel memory. Ensure
+ * that no #VE will be delivered for accesses to TD-private memory.
+ *
+ * TDX 1.0 does not allow the guest to disable SEPT #VE on its own. The VMM
+ * controls if the guest will receive such #VE with TD attribute
+ * TDX_TD_ATTR_SEPT_VE_DISABLE.
+ *
+ * Newer TDX modules allow the guest to control if it wants to receive SEPT
+ * violation #VEs.
+ *
+ * Check if the feature is available and disable SEPT #VE if possible.
+ *
+ * If the TD is allowed to disable/enable SEPT #VEs, the TDX_TD_ATTR_SEPT_VE_DISABLE
+ * attribute is no longer reliable. It reflects the initial state of the
+ * control for the TD, but it will not be updated if someone (e.g. bootloader)
+ * changes it before the kernel starts. Kernel must check TDCS_TD_CTLS bit to
+ * determine if SEPT #VEs are enabled or disabled.
+ */
+static void disable_sept_ve(u64 td_attr)
+{
+ const char *msg = "TD misconfiguration: SEPT #VE has to be disabled";
+ bool debug = td_attr & TDX_TD_ATTR_DEBUG;
+ u64 config, controls;
+
+ /* Is this TD allowed to disable SEPT #VE */
+ tdg_vm_rd(TDCS_CONFIG_FLAGS, &config);
+ if (!(config & TDCS_CONFIG_FLEXIBLE_PENDING_VE)) {
+ /* No SEPT #VE controls for the guest: check the attribute */
+ if (td_attr & TDX_TD_ATTR_SEPT_VE_DISABLE)
+ return;
+
+ /* Relax SEPT_VE_DISABLE check for debug TD for backtraces */
+ if (debug)
+ pr_warn("%s\n", msg);
+ else
+ tdx_panic(msg);
+ return;
+ }
+
+ /* Check if SEPT #VE has been disabled before us */
+ tdg_vm_rd(TDCS_TD_CTLS, &controls);
+ if (controls & TD_CTLS_PENDING_VE_DISABLE)
+ return;
+
+ /* Keep #VEs enabled for splats in debugging environments */
+ if (debug)
+ return;
+
+ /* Disable SEPT #VEs */
+ tdg_vm_wr(TDCS_TD_CTLS, TD_CTLS_PENDING_VE_DISABLE,
+ TD_CTLS_PENDING_VE_DISABLE);
+}
+
+/*
+ * TDX 1.0 generates a #VE when accessing topology-related CPUID leafs (0xB and
+ * 0x1F) and the X2APIC_APICID MSR. The kernel returns all zeros on CPUID #VEs.
+ * In practice, this means that the kernel can only boot with a plain topology.
+ * Any complications will cause problems.
+ *
+ * The ENUM_TOPOLOGY feature allows the VMM to provide topology information.
+ * Enabling the feature eliminates topology-related #VEs: the TDX module
+ * virtualizes accesses to the CPUID leafs and the MSR.
+ *
+ * Enable ENUM_TOPOLOGY if it is available.
+ */
+static void enable_cpu_topology_enumeration(void)
+{
+ u64 configured;
+
+ /* Has the VMM provided a valid topology configuration? */
+ tdg_vm_rd(TDCS_TOPOLOGY_ENUM_CONFIGURED, &configured);
+ if (!configured) {
+ pr_err("VMM did not configure X2APIC_IDs properly\n");
+ return;
+ }
+
+ tdg_vm_wr(TDCS_TD_CTLS, TD_CTLS_ENUM_TOPOLOGY, TD_CTLS_ENUM_TOPOLOGY);
+}
+
+static void reduce_unnecessary_ve(void)
+{
+ u64 err = tdg_vm_wr(TDCS_TD_CTLS, TD_CTLS_REDUCE_VE, TD_CTLS_REDUCE_VE);
+
+ if (err == TDX_SUCCESS)
+ return;
+
+ /*
+ * Enabling REDUCE_VE includes ENUM_TOPOLOGY. Only try to
+ * enable ENUM_TOPOLOGY if REDUCE_VE was not successful.
+ */
+ enable_cpu_topology_enumeration();
+}
+
+static void tdx_setup(u64 *cc_mask)
+{
+ struct tdx_module_args args = {};
+ unsigned int gpa_width;
+ u64 td_attr;
+
+ /*
+ * TDINFO TDX module call is used to get the TD execution environment
+ * information like GPA width, number of available vcpus, debug mode
+ * information, etc. More details about the ABI can be found in TDX
+ * Guest-Host-Communication Interface (GHCI), section 2.4.2 TDCALL
+ * [TDG.VP.INFO].
+ */
+ tdcall(TDG_VP_INFO, &args);
+
+ /*
+ * The highest bit of a guest physical address is the "sharing" bit.
+ * Set it for shared pages and clear it for private pages.
+ *
+ * The GPA width that comes out of this call is critical. TDX guests
+ * can not meaningfully run without it.
+ */
+ gpa_width = args.rcx & GENMASK(5, 0);
+ *cc_mask = BIT_ULL(gpa_width - 1);
+
+ td_attr = args.rdx;
+
+ /* Kernel does not use NOTIFY_ENABLES and does not need random #VEs */
+ tdg_vm_wr(TDCS_NOTIFY_ENABLES, 0, -1ULL);
+
+ disable_sept_ve(td_attr);
+
+ reduce_unnecessary_ve();
+}
+
+/*
+ * The TDX module spec states that #VE may be injected for a limited set of
+ * reasons:
+ *
+ * - Emulation of the architectural #VE injection on EPT violation;
+ *
+ * - As a result of guest TD execution of a disallowed instruction,
+ * a disallowed MSR access, or CPUID virtualization;
+ *
+ * - A notification to the guest TD about anomalous behavior;
+ *
+ * The last one is opt-in and is not used by the kernel.
+ *
+ * The Intel Software Developer's Manual describes cases when instruction
+ * length field can be used in section "Information for VM Exits Due to
+ * Instruction Execution".
+ *
+ * For TDX, it ultimately means GET_VEINFO provides reliable instruction length
+ * information if #VE occurred due to instruction execution, but not for EPT
+ * violations.
+ */
+static int ve_instr_len(struct ve_info *ve)
+{
+ switch (ve->exit_reason) {
+ case EXIT_REASON_HLT:
+ case EXIT_REASON_MSR_READ:
+ case EXIT_REASON_MSR_WRITE:
+ case EXIT_REASON_CPUID:
+ case EXIT_REASON_IO_INSTRUCTION:
+ /* It is safe to use ve->instr_len for #VE due instructions */
+ return ve->instr_len;
+ case EXIT_REASON_EPT_VIOLATION:
+ /*
+ * For EPT violations, ve->insn_len is not defined. For those,
+ * the kernel must decode instructions manually and should not
+ * be using this function.
+ */
+ WARN_ONCE(1, "ve->instr_len is not defined for EPT violations");
+ return 0;
+ default:
+ WARN_ONCE(1, "Unexpected #VE-type: %lld\n", ve->exit_reason);
+ return ve->instr_len;
+ }
+}
+
+static u64 __cpuidle __halt(const bool irq_disabled)
+{
+ struct tdx_module_args args = {
+ .r10 = TDX_HYPERCALL_STANDARD,
+ .r11 = hcall_func(EXIT_REASON_HLT),
+ .r12 = irq_disabled,
+ };
+
+ /*
+ * Emulate HLT operation via hypercall. More info about ABI
+ * can be found in TDX Guest-Host-Communication Interface
+ * (GHCI), section 3.8 TDG.VP.VMCALL<Instruction.HLT>.
+ *
+ * The VMM uses the "IRQ disabled" param to understand IRQ
+ * enabled status (RFLAGS.IF) of the TD guest and to determine
+ * whether or not it should schedule the halted vCPU if an
+ * IRQ becomes pending. E.g. if IRQs are disabled, the VMM
+ * can keep the vCPU in virtual HLT, even if an IRQ is
+ * pending, without hanging/breaking the guest.
+ */
+ return __tdx_hypercall(&args);
+}
+
+static int handle_halt(struct ve_info *ve)
+{
+ const bool irq_disabled = irqs_disabled();
+
+ /*
+ * HLT with IRQs enabled is unsafe, as an IRQ that is intended to be a
+ * wake event may be consumed before requesting HLT emulation, leaving
+ * the vCPU blocking indefinitely.
+ */
+ if (WARN_ONCE(!irq_disabled, "HLT emulation with IRQs enabled"))
+ return -EIO;
+
+ if (__halt(irq_disabled))
+ return -EIO;
+
+ return ve_instr_len(ve);
+}
+
+void __cpuidle tdx_halt(void)
+{
+ const bool irq_disabled = false;
+
+ /*
+ * Use WARN_ONCE() to report the failure.
+ */
+ if (__halt(irq_disabled))
+ WARN_ONCE(1, "HLT instruction emulation failed\n");
+}
+
+static void __cpuidle tdx_safe_halt(void)
+{
+ tdx_halt();
+ /*
+ * "__cpuidle" section doesn't support instrumentation, so stick
+ * with raw_* variant that avoids tracing hooks.
+ */
+ raw_local_irq_enable();
+}
+
+static int read_msr(struct pt_regs *regs, struct ve_info *ve)
+{
+ struct tdx_module_args args = {
+ .r10 = TDX_HYPERCALL_STANDARD,
+ .r11 = hcall_func(EXIT_REASON_MSR_READ),
+ .r12 = regs->cx,
+ };
+
+ /*
+ * Emulate the MSR read via hypercall. More info about ABI
+ * can be found in TDX Guest-Host-Communication Interface
+ * (GHCI), section titled "TDG.VP.VMCALL<Instruction.RDMSR>".
+ */
+ if (__tdx_hypercall(&args))
+ return -EIO;
+
+ regs->ax = lower_32_bits(args.r11);
+ regs->dx = upper_32_bits(args.r11);
+ return ve_instr_len(ve);
+}
+
+static int write_msr(struct pt_regs *regs, struct ve_info *ve)
+{
+ struct tdx_module_args args = {
+ .r10 = TDX_HYPERCALL_STANDARD,
+ .r11 = hcall_func(EXIT_REASON_MSR_WRITE),
+ .r12 = regs->cx,
+ .r13 = (u64)regs->dx << 32 | regs->ax,
+ };
+
+ /*
+ * Emulate the MSR write via hypercall. More info about ABI
+ * can be found in TDX Guest-Host-Communication Interface
+ * (GHCI) section titled "TDG.VP.VMCALL<Instruction.WRMSR>".
+ */
+ if (__tdx_hypercall(&args))
+ return -EIO;
+
+ return ve_instr_len(ve);
+}
+
+static int handle_cpuid(struct pt_regs *regs, struct ve_info *ve)
+{
+ struct tdx_module_args args = {
+ .r10 = TDX_HYPERCALL_STANDARD,
+ .r11 = hcall_func(EXIT_REASON_CPUID),
+ .r12 = regs->ax,
+ .r13 = regs->cx,
+ };
+
+ /*
+ * Only allow VMM to control range reserved for hypervisor
+ * communication.
+ *
+ * Return all-zeros for any CPUID outside the range. It matches CPU
+ * behaviour for non-supported leaf.
+ */
+ if (regs->ax < 0x40000000 || regs->ax > 0x4FFFFFFF) {
+ regs->ax = regs->bx = regs->cx = regs->dx = 0;
+ return ve_instr_len(ve);
+ }
+
+ /*
+ * Emulate the CPUID instruction via a hypercall. More info about
+ * ABI can be found in TDX Guest-Host-Communication Interface
+ * (GHCI), section titled "VP.VMCALL<Instruction.CPUID>".
+ */
+ if (__tdx_hypercall(&args))
+ return -EIO;
+
+ /*
+ * As per TDX GHCI CPUID ABI, r12-r15 registers contain contents of
+ * EAX, EBX, ECX, EDX registers after the CPUID instruction execution.
+ * So copy the register contents back to pt_regs.
+ */
+ regs->ax = args.r12;
+ regs->bx = args.r13;
+ regs->cx = args.r14;
+ regs->dx = args.r15;
+
+ return ve_instr_len(ve);
+}
+
+static bool mmio_read(int size, unsigned long addr, unsigned long *val)
+{
+ struct tdx_module_args args = {
+ .r10 = TDX_HYPERCALL_STANDARD,
+ .r11 = hcall_func(EXIT_REASON_EPT_VIOLATION),
+ .r12 = size,
+ .r13 = EPT_READ,
+ .r14 = addr,
+ };
+
+ if (__tdx_hypercall(&args))
+ return false;
+
+ *val = args.r11;
+ return true;
+}
+
+static bool mmio_write(int size, unsigned long addr, unsigned long val)
+{
+ return !_tdx_hypercall(hcall_func(EXIT_REASON_EPT_VIOLATION), size,
+ EPT_WRITE, addr, val);
+}
+
+static int handle_mmio(struct pt_regs *regs, struct ve_info *ve)
+{
+ unsigned long *reg, val, vaddr;
+ char buffer[MAX_INSN_SIZE];
+ enum insn_mmio_type mmio;
+ struct insn insn = {};
+ int size, extend_size;
+ u8 extend_val = 0;
+
+ /* Only in-kernel MMIO is supported */
+ if (WARN_ON_ONCE(user_mode(regs)))
+ return -EFAULT;
+
+ if (copy_from_kernel_nofault(buffer, (void *)regs->ip, MAX_INSN_SIZE))
+ return -EFAULT;
+
+ if (insn_decode(&insn, buffer, MAX_INSN_SIZE, INSN_MODE_64))
+ return -EINVAL;
+
+ mmio = insn_decode_mmio(&insn, &size);
+ if (WARN_ON_ONCE(mmio == INSN_MMIO_DECODE_FAILED))
+ return -EINVAL;
+
+ if (mmio != INSN_MMIO_WRITE_IMM && mmio != INSN_MMIO_MOVS) {
+ reg = insn_get_modrm_reg_ptr(&insn, regs);
+ if (!reg)
+ return -EINVAL;
+ }
+
+ if (!fault_in_kernel_space(ve->gla)) {
+ WARN_ONCE(1, "Access to userspace address is not supported");
+ return -EINVAL;
+ }
+
+ /*
+ * Reject EPT violation #VEs that split pages.
+ *
+ * MMIO accesses are supposed to be naturally aligned and therefore
+ * never cross page boundaries. Seeing split page accesses indicates
+ * a bug or a load_unaligned_zeropad() that stepped into an MMIO page.
+ *
+ * load_unaligned_zeropad() will recover using exception fixups.
+ */
+ vaddr = (unsigned long)insn_get_addr_ref(&insn, regs);
+ if (vaddr / PAGE_SIZE != (vaddr + size - 1) / PAGE_SIZE)
+ return -EFAULT;
+
+ /* Handle writes first */
+ switch (mmio) {
+ case INSN_MMIO_WRITE:
+ memcpy(&val, reg, size);
+ if (!mmio_write(size, ve->gpa, val))
+ return -EIO;
+ return insn.length;
+ case INSN_MMIO_WRITE_IMM:
+ val = insn.immediate.value;
+ if (!mmio_write(size, ve->gpa, val))
+ return -EIO;
+ return insn.length;
+ case INSN_MMIO_READ:
+ case INSN_MMIO_READ_ZERO_EXTEND:
+ case INSN_MMIO_READ_SIGN_EXTEND:
+ /* Reads are handled below */
+ break;
+ case INSN_MMIO_MOVS:
+ case INSN_MMIO_DECODE_FAILED:
+ /*
+ * MMIO was accessed with an instruction that could not be
+ * decoded or handled properly. It was likely not using io.h
+ * helpers or accessed MMIO accidentally.
+ */
+ return -EINVAL;
+ default:
+ WARN_ONCE(1, "Unknown insn_decode_mmio() decode value?");
+ return -EINVAL;
+ }
+
+ /* Handle reads */
+ if (!mmio_read(size, ve->gpa, &val))
+ return -EIO;
+
+ switch (mmio) {
+ case INSN_MMIO_READ:
+ /* Zero-extend for 32-bit operation */
+ extend_size = size == 4 ? sizeof(*reg) : 0;
+ break;
+ case INSN_MMIO_READ_ZERO_EXTEND:
+ /* Zero extend based on operand size */
+ extend_size = insn.opnd_bytes;
+ break;
+ case INSN_MMIO_READ_SIGN_EXTEND:
+ /* Sign extend based on operand size */
+ extend_size = insn.opnd_bytes;
+ if (size == 1 && val & BIT(7))
+ extend_val = 0xFF;
+ else if (size > 1 && val & BIT(15))
+ extend_val = 0xFF;
+ break;
+ default:
+ /* All other cases has to be covered with the first switch() */
+ WARN_ON_ONCE(1);
+ return -EINVAL;
+ }
+
+ if (extend_size)
+ memset(reg, extend_val, extend_size);
+ memcpy(reg, &val, size);
+ return insn.length;
+}
+
+static bool handle_in(struct pt_regs *regs, int size, int port)
+{
+ struct tdx_module_args args = {
+ .r10 = TDX_HYPERCALL_STANDARD,
+ .r11 = hcall_func(EXIT_REASON_IO_INSTRUCTION),
+ .r12 = size,
+ .r13 = PORT_READ,
+ .r14 = port,
+ };
+ bool success;
+ u64 val;
+
+ /*
+ * Emulate the I/O read via hypercall. More info about ABI can be found
+ * in TDX Guest-Host-Communication Interface (GHCI) section titled
+ * "TDG.VP.VMCALL<Instruction.IO>".
+ */
+ success = !__tdx_hypercall(&args);
+ val = success ? args.r11 : 0;
+
+ insn_assign_reg(&regs->ax, val, size);
+
+ return success;
+}
+
+static bool handle_out(struct pt_regs *regs, int size, int port)
+{
+ u64 mask = GENMASK(BITS_PER_BYTE * size - 1, 0);
+
+ /*
+ * Emulate the I/O write via hypercall. More info about ABI can be found
+ * in TDX Guest-Host-Communication Interface (GHCI) section titled
+ * "TDG.VP.VMCALL<Instruction.IO>".
+ */
+ return !_tdx_hypercall(hcall_func(EXIT_REASON_IO_INSTRUCTION), size,
+ PORT_WRITE, port, regs->ax & mask);
+}
+
+/*
+ * Emulate I/O using hypercall.
+ *
+ * Assumes the IO instruction was using ax, which is enforced
+ * by the standard io.h macros.
+ *
+ * Return True on success or False on failure.
+ */
+static int handle_io(struct pt_regs *regs, struct ve_info *ve)
+{
+ u32 exit_qual = ve->exit_qual;
+ int size, port;
+ bool in, ret;
+
+ if (VE_IS_IO_STRING(exit_qual))
+ return -EIO;
+
+ in = VE_IS_IO_IN(exit_qual);
+ size = VE_GET_IO_SIZE(exit_qual);
+ port = VE_GET_PORT_NUM(exit_qual);
+
+
+ if (in)
+ ret = handle_in(regs, size, port);
+ else
+ ret = handle_out(regs, size, port);
+ if (!ret)
+ return -EIO;
+
+ return ve_instr_len(ve);
+}
+
+/*
+ * Early #VE exception handler. Only handles a subset of port I/O.
+ * Intended only for earlyprintk. If failed, return false.
+ */
+__init bool tdx_early_handle_ve(struct pt_regs *regs)
+{
+ struct ve_info ve;
+ int insn_len;
+
+ tdx_get_ve_info(&ve);
+
+ if (ve.exit_reason != EXIT_REASON_IO_INSTRUCTION)
+ return false;
+
+ insn_len = handle_io(regs, &ve);
+ if (insn_len < 0)
+ return false;
+
+ regs->ip += insn_len;
+ return true;
+}
+
+void tdx_get_ve_info(struct ve_info *ve)
+{
+ struct tdx_module_args args = {};
+
+ /*
+ * Called during #VE handling to retrieve the #VE info from the
+ * TDX module.
+ *
+ * This has to be called early in #VE handling. A "nested" #VE which
+ * occurs before this will raise a #DF and is not recoverable.
+ *
+ * The call retrieves the #VE info from the TDX module, which also
+ * clears the "#VE valid" flag. This must be done before anything else
+ * because any #VE that occurs while the valid flag is set will lead to
+ * #DF.
+ *
+ * Note, the TDX module treats virtual NMIs as inhibited if the #VE
+ * valid flag is set. It means that NMI=>#VE will not result in a #DF.
+ */
+ tdcall(TDG_VP_VEINFO_GET, &args);
+
+ /* Transfer the output parameters */
+ ve->exit_reason = args.rcx;
+ ve->exit_qual = args.rdx;
+ ve->gla = args.r8;
+ ve->gpa = args.r9;
+ ve->instr_len = lower_32_bits(args.r10);
+ ve->instr_info = upper_32_bits(args.r10);
+}
+
+/*
+ * Handle the user initiated #VE.
+ *
+ * On success, returns the number of bytes RIP should be incremented (>=0)
+ * or -errno on error.
+ */
+static int virt_exception_user(struct pt_regs *regs, struct ve_info *ve)
+{
+ switch (ve->exit_reason) {
+ case EXIT_REASON_CPUID:
+ return handle_cpuid(regs, ve);
+ default:
+ pr_warn("Unexpected #VE: %lld\n", ve->exit_reason);
+ return -EIO;
+ }
+}
+
+static inline bool is_private_gpa(u64 gpa)
+{
+ return gpa == cc_mkenc(gpa);
+}
+
+/*
+ * Handle the kernel #VE.
+ *
+ * On success, returns the number of bytes RIP should be incremented (>=0)
+ * or -errno on error.
+ */
+static int virt_exception_kernel(struct pt_regs *regs, struct ve_info *ve)
+{
+ switch (ve->exit_reason) {
+ case EXIT_REASON_HLT:
+ return handle_halt(ve);
+ case EXIT_REASON_MSR_READ:
+ return read_msr(regs, ve);
+ case EXIT_REASON_MSR_WRITE:
+ return write_msr(regs, ve);
+ case EXIT_REASON_CPUID:
+ return handle_cpuid(regs, ve);
+ case EXIT_REASON_EPT_VIOLATION:
+ if (is_private_gpa(ve->gpa))
+ panic("Unexpected EPT-violation on private memory.");
+ return handle_mmio(regs, ve);
+ case EXIT_REASON_IO_INSTRUCTION:
+ return handle_io(regs, ve);
+ default:
+ pr_warn("Unexpected #VE: %lld\n", ve->exit_reason);
+ return -EIO;
+ }
+}
+
+bool tdx_handle_virt_exception(struct pt_regs *regs, struct ve_info *ve)
+{
+ int insn_len;
+
+ if (user_mode(regs))
+ insn_len = virt_exception_user(regs, ve);
+ else
+ insn_len = virt_exception_kernel(regs, ve);
+ if (insn_len < 0)
+ return false;
+
+ /* After successful #VE handling, move the IP */
+ regs->ip += insn_len;
+
+ return true;
+}
+
+static bool tdx_tlb_flush_required(bool private)
+{
+ /*
+ * TDX guest is responsible for flushing TLB on private->shared
+ * transition. VMM is responsible for flushing on shared->private.
+ *
+ * The VMM _can't_ flush private addresses as it can't generate PAs
+ * with the guest's HKID. Shared memory isn't subject to integrity
+ * checking, i.e. the VMM doesn't need to flush for its own protection.
+ *
+ * There's no need to flush when converting from shared to private,
+ * as flushing is the VMM's responsibility in this case, e.g. it must
+ * flush to avoid integrity failures in the face of a buggy or
+ * malicious guest.
+ */
+ return !private;
+}
+
+static bool tdx_cache_flush_required(void)
+{
+ /*
+ * AMD SME/SEV can avoid cache flushing if HW enforces cache coherence.
+ * TDX doesn't have such capability.
+ *
+ * Flush cache unconditionally.
+ */
+ return true;
+}
+
+/*
+ * Notify the VMM about page mapping conversion. More info about ABI
+ * can be found in TDX Guest-Host-Communication Interface (GHCI),
+ * section "TDG.VP.VMCALL<MapGPA>".
+ */
+static bool tdx_map_gpa(phys_addr_t start, phys_addr_t end, bool enc)
+{
+ /* Retrying the hypercall a second time should succeed; use 3 just in case */
+ const int max_retries_per_page = 3;
+ int retry_count = 0;
+
+ if (!enc) {
+ /* Set the shared (decrypted) bits: */
+ start |= cc_mkdec(0);
+ end |= cc_mkdec(0);
+ }
+
+ while (retry_count < max_retries_per_page) {
+ struct tdx_module_args args = {
+ .r10 = TDX_HYPERCALL_STANDARD,
+ .r11 = TDVMCALL_MAP_GPA,
+ .r12 = start,
+ .r13 = end - start };
+
+ u64 map_fail_paddr;
+ u64 ret = __tdx_hypercall(&args);
+
+ if (ret != TDVMCALL_STATUS_RETRY)
+ return !ret;
+ /*
+ * The guest must retry the operation for the pages in the
+ * region starting at the GPA specified in R11. R11 comes
+ * from the untrusted VMM. Sanity check it.
+ */
+ map_fail_paddr = args.r11;
+ if (map_fail_paddr < start || map_fail_paddr >= end)
+ return false;
+
+ /* "Consume" a retry without forward progress */
+ if (map_fail_paddr == start) {
+ retry_count++;
+ continue;
+ }
+
+ start = map_fail_paddr;
+ retry_count = 0;
+ }
+
+ return false;
+}
+
+/*
+ * Inform the VMM of the guest's intent for this physical page: shared with
+ * the VMM or private to the guest. The VMM is expected to change its mapping
+ * of the page in response.
+ */
+static bool tdx_enc_status_changed(unsigned long vaddr, int numpages, bool enc)
+{
+ phys_addr_t start = __pa(vaddr);
+ phys_addr_t end = __pa(vaddr + numpages * PAGE_SIZE);
+
+ if (!tdx_map_gpa(start, end, enc))
+ return false;
+
+ /* shared->private conversion requires memory to be accepted before use */
+ if (enc)
+ return tdx_accept_memory(start, end);
+
+ return true;
+}
+
+static int tdx_enc_status_change_prepare(unsigned long vaddr, int numpages,
+ bool enc)
+{
+ /*
+ * Only handle shared->private conversion here.
+ * See the comment in tdx_early_init().
+ */
+ if (enc && !tdx_enc_status_changed(vaddr, numpages, enc))
+ return -EIO;
+
+ return 0;
+}
+
+static int tdx_enc_status_change_finish(unsigned long vaddr, int numpages,
+ bool enc)
+{
+ /*
+ * Only handle private->shared conversion here.
+ * See the comment in tdx_early_init().
+ */
+ if (!enc && !tdx_enc_status_changed(vaddr, numpages, enc))
+ return -EIO;
+
+ if (enc)
+ atomic_long_sub(numpages, &nr_shared);
+ else
+ atomic_long_add(numpages, &nr_shared);
+
+ return 0;
+}
+
+/* Stop new private<->shared conversions */
+static void tdx_kexec_begin(void)
+{
+ if (!IS_ENABLED(CONFIG_KEXEC_CORE))
+ return;
+
+ /*
+ * Crash kernel reaches here with interrupts disabled: can't wait for
+ * conversions to finish.
+ *
+ * If race happened, just report and proceed.
+ */
+ if (!set_memory_enc_stop_conversion())
+ pr_warn("Failed to stop shared<->private conversions\n");
+}
+
+/* Walk direct mapping and convert all shared memory back to private */
+static void tdx_kexec_finish(void)
+{
+ unsigned long addr, end;
+ long found = 0, shared;
+
+ if (!IS_ENABLED(CONFIG_KEXEC_CORE))
+ return;
+
+ lockdep_assert_irqs_disabled();
+
+ addr = PAGE_OFFSET;
+ end = PAGE_OFFSET + get_max_mapped();
+
+ while (addr < end) {
+ unsigned long size;
+ unsigned int level;
+ pte_t *pte;
+
+ pte = lookup_address(addr, &level);
+ size = page_level_size(level);
+
+ if (pte && pte_decrypted(*pte)) {
+ int pages = size / PAGE_SIZE;
+
+ /*
+ * Touching memory with shared bit set triggers implicit
+ * conversion to shared.
+ *
+ * Make sure nobody touches the shared range from
+ * now on.
+ */
+ set_pte(pte, __pte(0));
+
+ /*
+ * Memory encryption state persists across kexec.
+ * If tdx_enc_status_changed() fails in the first
+ * kernel, it leaves memory in an unknown state.
+ *
+ * If that memory remains shared, accessing it in the
+ * *next* kernel through a private mapping will result
+ * in an unrecoverable guest shutdown.
+ *
+ * The kdump kernel boot is not impacted as it uses
+ * a pre-reserved memory range that is always private.
+ * However, gathering crash information could lead to
+ * a crash if it accesses unconverted memory through
+ * a private mapping which is possible when accessing
+ * that memory through /proc/vmcore, for example.
+ *
+ * In all cases, print error info in order to leave
+ * enough bread crumbs for debugging.
+ */
+ if (!tdx_enc_status_changed(addr, pages, true)) {
+ pr_err("Failed to unshare range %#lx-%#lx\n",
+ addr, addr + size);
+ }
+
+ found += pages;
+ }
+
+ addr += size;
+ }
+
+ __flush_tlb_all();
+
+ shared = atomic_long_read(&nr_shared);
+ if (shared != found) {
+ pr_err("shared page accounting is off\n");
+ pr_err("nr_shared = %ld, nr_found = %ld\n", shared, found);
+ }
+}
+
+static __init void tdx_announce(void)
+{
+ struct tdx_module_args args = {};
+ u64 controls;
+
+ pr_info("Guest detected\n");
+
+ tdcall(TDG_VP_INFO, &args);
+ tdx_dump_attributes(args.rdx);
+
+ tdg_vm_rd(TDCS_TD_CTLS, &controls);
+ tdx_dump_td_ctls(controls);
+}
+
+void __init tdx_early_init(void)
+{
+ u64 cc_mask;
+ u32 eax, sig[3];
+
+ cpuid_count(TDX_CPUID_LEAF_ID, 0, &eax, &sig[0], &sig[2], &sig[1]);
+
+ if (memcmp(TDX_IDENT, sig, sizeof(sig)))
+ return;
+
+ setup_force_cpu_cap(X86_FEATURE_TDX_GUEST);
+
+ /* TSC is the only reliable clock in TDX guest */
+ setup_force_cpu_cap(X86_FEATURE_TSC_RELIABLE);
+
+ cc_vendor = CC_VENDOR_INTEL;
+
+ /* Configure the TD */
+ tdx_setup(&cc_mask);
+
+ cc_set_mask(cc_mask);
+
+ /*
+ * All bits above GPA width are reserved and kernel treats shared bit
+ * as flag, not as part of physical address.
+ *
+ * Adjust physical mask to only cover valid GPA bits.
+ */
+ physical_mask &= cc_mask - 1;
+
+ /*
+ * The kernel mapping should match the TDX metadata for the page.
+ * load_unaligned_zeropad() can touch memory *adjacent* to that which is
+ * owned by the caller and can catch even _momentary_ mismatches. Bad
+ * things happen on mismatch:
+ *
+ * - Private mapping => Shared Page == Guest shutdown
+ * - Shared mapping => Private Page == Recoverable #VE
+ *
+ * guest.enc_status_change_prepare() converts the page from
+ * shared=>private before the mapping becomes private.
+ *
+ * guest.enc_status_change_finish() converts the page from
+ * private=>shared after the mapping becomes private.
+ *
+ * In both cases there is a temporary shared mapping to a private page,
+ * which can result in a #VE. But, there is never a private mapping to
+ * a shared page.
+ */
+ x86_platform.guest.enc_status_change_prepare = tdx_enc_status_change_prepare;
+ x86_platform.guest.enc_status_change_finish = tdx_enc_status_change_finish;
+
+ x86_platform.guest.enc_cache_flush_required = tdx_cache_flush_required;
+ x86_platform.guest.enc_tlb_flush_required = tdx_tlb_flush_required;
+
+ x86_platform.guest.enc_kexec_begin = tdx_kexec_begin;
+ x86_platform.guest.enc_kexec_finish = tdx_kexec_finish;
+
+ /*
+ * Avoid "sti;hlt" execution in TDX guests as HLT induces a #VE that
+ * will enable interrupts before HLT TDCALL invocation if executed
+ * in STI-shadow, possibly resulting in missed wakeup events.
+ *
+ * Modify all possible HLT execution paths to use TDX specific routines
+ * that directly execute TDCALL and toggle the interrupt state as
+ * needed after TDCALL completion. This also reduces HLT related #VEs
+ * in addition to having a reliable halt logic execution.
+ */
+ pv_ops.irq.safe_halt = tdx_safe_halt;
+ pv_ops.irq.halt = tdx_halt;
+
+ /*
+ * TDX intercepts the RDMSR to read the X2APIC ID in the parallel
+ * bringup low level code. That raises #VE which cannot be handled
+ * there.
+ *
+ * Intel-TDX has a secure RDMSR hypercall, but that needs to be
+ * implemented separately in the low level startup ASM code.
+ * Until that is in place, disable parallel bringup for TDX.
+ */
+ x86_cpuinit.parallel_bringup = false;
+
+ tdx_announce();
+}