KVM: SEV: Do cache maintenance on the source VM during intra-host migrationgrafted

Manually perform cache maintenance on the source VM during intra-host
migration to ensure no stale data is left in CPU caches after the VM is
destroyed.  Because the source VM is "converted" to a non-SEV VM, KVM's
memory reclaim flows won't trigger cache maintenance, e.g. when all guest
memory is reclaimed in response to detaching from the mmu_notifier.

Note, relying on the destination VM to do cache maintenance isn't an option
as KVM doesn't require identical guest memory configurations, i.e. the
source VM may have access to memory that the destination VM does not.
Enforcing equivalent memory configurations is infeasible, as it would
require a *deep* comparison of memslots, e.g. to verify that not only are
the memslot identical, but what the memslots point at is also identical.

Fixes: b56639318bb2 ("KVM: SEV: Add support for SEV intra host migration")
Cc: stable@vger.kernel.org
Reported-by: Stefan Teodorescu <fane@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260923163721.1584779-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 137 insertions, 0 deletions

diff --git a/drivers/crypto/ccp/psp-dev.h b/drivers/crypto/ccp/psp-dev.h
new file mode 100644
index 000000000..4e370e76b
--- /dev/null
+++ b/drivers/crypto/ccp/psp-dev.h
@@ -0,0 +1,137 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * AMD Platform Security Processor (PSP) interface driver
+ *
+ * Copyright (C) 2017-2019 Advanced Micro Devices, Inc.
+ *
+ * Author: Brijesh Singh <brijesh.singh@amd.com>
+ */
+
+#ifndef __PSP_DEV_H__
+#define __PSP_DEV_H__
+
+#include <linux/device.h>
+#include <linux/list.h>
+#include <linux/bits.h>
+#include <linux/interrupt.h>
+#include <linux/mutex.h>
+#include <linux/psp.h>
+#include <linux/psp-platform-access.h>
+
+#include "sp-dev.h"
+
+#define MAX_PSP_NAME_LEN		16
+
+extern struct psp_device *psp_master;
+
+typedef void (*psp_irq_handler_t)(int, void *, unsigned int);
+
+union psp_cap_register {
+	unsigned int raw;
+	struct {
+		unsigned int sev			:1,
+			     tee			:1,
+			     dbc_thru_ext		:1,
+			     sfs			:1,
+			     rsvd1			:3,
+			     security_reporting		:1,
+			     fused_part			:1,
+			     boot_integrity		:1,
+			     debug_lock_on		:1,
+			     rsvd3			:2,
+			     tsme_status		:1,
+			     rsvd4			:1,
+			     anti_rollback_status	:1,
+			     rpmc_production_enabled	:1,
+			     rpmc_spirom_available	:1,
+			     hsp_tpm_available		:1,
+			     rom_armor_enforced		:1,
+			     rsvd5			:12;
+	};
+};
+
+struct psp_device {
+	struct list_head entry;
+
+	struct psp_vdata *vdata;
+	char name[MAX_PSP_NAME_LEN];
+
+	struct device *dev;
+	struct sp_device *sp;
+
+	void __iomem *io_regs;
+	struct mutex mailbox_mutex;
+
+	psp_irq_handler_t sev_irq_handler;
+	void *sev_irq_data;
+
+	void *sev_data;
+	void *tee_data;
+	void *platform_access_data;
+	void *dbc_data;
+	void *sfs_data;
+
+	union psp_cap_register capability;
+};
+
+void psp_set_sev_irq_handler(struct psp_device *psp, psp_irq_handler_t handler,
+			     void *data);
+void psp_clear_sev_irq_handler(struct psp_device *psp);
+
+struct psp_device *psp_get_master_device(void);
+
+/**
+ * enum psp_cmd - PSP mailbox commands
+ * @PSP_CMD_TEE_RING_INIT:	Initialize TEE ring buffer
+ * @PSP_CMD_TEE_RING_DESTROY:	Destroy TEE ring buffer
+ * @PSP_CMD_TEE_EXTENDED_CMD:	Extended command
+ * @PSP_CMD_MAX:		Maximum command id
+ */
+enum psp_cmd {
+	PSP_CMD_TEE_RING_INIT		= 1,
+	PSP_CMD_TEE_RING_DESTROY	= 2,
+	PSP_CMD_TEE_EXTENDED_CMD	= 14,
+	PSP_CMD_MAX			= 15,
+};
+
+int psp_mailbox_command(struct psp_device *psp, enum psp_cmd cmd, void *cmdbuff,
+			unsigned int timeout_msecs, unsigned int *cmdresp);
+
+/**
+ * struct psp_ext_req_buffer_hdr - Structure of the extended command header
+ * @payload_size: total payload size
+ * @sub_cmd_id: extended command ID
+ * @status: status of command execution (out)
+ */
+struct psp_ext_req_buffer_hdr {
+	u32 payload_size;
+	u32 sub_cmd_id;
+	u32 status;
+} __packed;
+
+struct psp_ext_request {
+	struct psp_ext_req_buffer_hdr header;
+	void *buf;
+} __packed;
+
+/**
+ * enum psp_sub_cmd - PSP mailbox sub commands
+ * @PSP_SUB_CMD_DBC_GET_NONCE:		Get nonce from DBC
+ * @PSP_SUB_CMD_DBC_SET_UID:		Set UID for DBC
+ * @PSP_SUB_CMD_DBC_GET_PARAMETER:	Get parameter from DBC
+ * @PSP_SUB_CMD_DBC_SET_PARAMETER:	Set parameter for DBC
+ * @PSP_SUB_CMD_SFS_GET_FW_VERS:	Get firmware versions for ASP and other MP
+ * @PSP_SUB_CMD_SFS_UPDATE:		Command to load, verify and execute SFS package
+ */
+enum psp_sub_cmd {
+	PSP_SUB_CMD_DBC_GET_NONCE	= PSP_DYNAMIC_BOOST_GET_NONCE,
+	PSP_SUB_CMD_DBC_SET_UID		= PSP_DYNAMIC_BOOST_SET_UID,
+	PSP_SUB_CMD_DBC_GET_PARAMETER	= PSP_DYNAMIC_BOOST_GET_PARAMETER,
+	PSP_SUB_CMD_DBC_SET_PARAMETER	= PSP_DYNAMIC_BOOST_SET_PARAMETER,
+	PSP_SUB_CMD_SFS_GET_FW_VERS	= PSP_SFS_GET_FW_VERSIONS,
+	PSP_SUB_CMD_SFS_UPDATE		= PSP_SFS_UPDATE,
+};
+
+int psp_extended_mailbox_cmd(struct psp_device *psp, unsigned int timeout_msecs,
+			     struct psp_ext_request *req);
+#endif /* __PSP_DEV_H */