From 4352b8aee98005853aa63f57d6377282de17a33f Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 23 Aug 2026 13:28:57 -0700 Subject: Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ... --- arch/arm64/hyperv/Makefile | 2 + arch/arm64/hyperv/hv_core.c | 197 +++++++++++++++++++++++++++++++++++++++++++ arch/arm64/hyperv/mshyperv.c | 136 +++++++++++++++++++++++++++++ 3 files changed, 335 insertions(+) create mode 100644 arch/arm64/hyperv/Makefile create mode 100644 arch/arm64/hyperv/hv_core.c create mode 100644 arch/arm64/hyperv/mshyperv.c (limited to 'arch/arm64/hyperv') diff --git a/arch/arm64/hyperv/Makefile b/arch/arm64/hyperv/Makefile new file mode 100644 index 000000000..87c31c001 --- /dev/null +++ b/arch/arm64/hyperv/Makefile @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0 +obj-y := hv_core.o mshyperv.o diff --git a/arch/arm64/hyperv/hv_core.c b/arch/arm64/hyperv/hv_core.c new file mode 100644 index 000000000..e33a9e3c3 --- /dev/null +++ b/arch/arm64/hyperv/hv_core.c @@ -0,0 +1,197 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Low level utility routines for interacting with Hyper-V. + * + * Copyright (C) 2021, Microsoft, Inc. + * + * Author : Michael Kelley + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * hv_do_hypercall- Invoke the specified hypercall + */ +u64 hv_do_hypercall(u64 control, void *input, void *output) +{ + struct arm_smccc_res res; + u64 input_address; + u64 output_address; + + input_address = input ? virt_to_phys(input) : 0; + output_address = output ? virt_to_phys(output) : 0; + + arm_smccc_1_1_hvc(HV_FUNC_ID, control, + input_address, output_address, &res); + return res.a0; +} +EXPORT_SYMBOL_GPL(hv_do_hypercall); + +/* + * hv_do_fast_hypercall8 -- Invoke the specified hypercall + * with arguments in registers instead of physical memory. + * Avoids the overhead of virt_to_phys for simple hypercalls. + */ + +u64 hv_do_fast_hypercall8(u16 code, u64 input) +{ + struct arm_smccc_res res; + u64 control; + + control = (u64)code | HV_HYPERCALL_FAST_BIT; + + arm_smccc_1_1_hvc(HV_FUNC_ID, control, input, &res); + return res.a0; +} +EXPORT_SYMBOL_GPL(hv_do_fast_hypercall8); + +/* + * hv_do_fast_hypercall16 -- Invoke the specified hypercall + * with arguments in registers instead of physical memory. + * Avoids the overhead of virt_to_phys for simple hypercalls. + */ +u64 hv_do_fast_hypercall16(u16 code, u64 input1, u64 input2) +{ + struct arm_smccc_res res; + u64 control; + + control = (u64)code | HV_HYPERCALL_FAST_BIT; + + arm_smccc_1_1_hvc(HV_FUNC_ID, control, input1, input2, &res); + return res.a0; +} +EXPORT_SYMBOL_GPL(hv_do_fast_hypercall16); + +/* + * Set a single VP register to a 64-bit value. + */ +void hv_set_vpreg(u32 msr, u64 value) +{ + struct arm_smccc_res res; + + arm_smccc_1_1_hvc(HV_FUNC_ID, + HVCALL_SET_VP_REGISTERS | HV_HYPERCALL_FAST_BIT | + HV_HYPERCALL_REP_COMP_1, + HV_PARTITION_ID_SELF, + HV_VP_INDEX_SELF, + msr, + 0, + value, + 0, + &res); + + /* + * Something is fundamentally broken in the hypervisor if + * setting a VP register fails. There's really no way to + * continue as a guest VM, so panic. + */ + BUG_ON(!hv_result_success(res.a0)); +} +EXPORT_SYMBOL_GPL(hv_set_vpreg); + +/* + * Get the value of a single VP register. One version + * returns just 64 bits and another returns the full 128 bits. + * The two versions are separate to avoid complicating the + * calling sequence for the more frequently used 64 bit version. + */ + +void hv_get_vpreg_128(u32 msr, struct hv_get_vp_registers_output *result) +{ + struct arm_smccc_1_2_regs args; + struct arm_smccc_1_2_regs res; + + args.a0 = HV_FUNC_ID; + args.a1 = HVCALL_GET_VP_REGISTERS | HV_HYPERCALL_FAST_BIT | + HV_HYPERCALL_REP_COMP_1; + args.a2 = HV_PARTITION_ID_SELF; + args.a3 = HV_VP_INDEX_SELF; + args.a4 = msr; + + /* + * Use the SMCCC 1.2 interface because the results are in registers + * beyond X0-X3. + */ + arm_smccc_1_2_hvc(&args, &res); + + /* + * Something is fundamentally broken in the hypervisor if + * getting a VP register fails. There's really no way to + * continue as a guest VM, so panic. + */ + BUG_ON(!hv_result_success(res.a0)); + + result->as64.low = res.a6; + result->as64.high = res.a7; +} +EXPORT_SYMBOL_GPL(hv_get_vpreg_128); + +u64 hv_get_vpreg(u32 msr) +{ + struct hv_get_vp_registers_output output; + + hv_get_vpreg_128(msr, &output); + + return output.as64.low; +} +EXPORT_SYMBOL_GPL(hv_get_vpreg); + +/* + * hyperv_report_panic - report a panic to Hyper-V. This function uses + * the older version of the Hyper-V interface that admittedly doesn't + * pass enough information to be useful beyond just recording the + * occurrence of a panic. The parallel hv_kmsg_dump() uses the + * new interface that allows reporting 4 Kbytes of data, which is much + * more useful. Hyper-V on ARM64 always supports the newer interface, but + * we retain support for the older version because the sysadmin is allowed + * to disable the newer version via sysctl in case of information security + * concerns about the more verbose version. + */ +void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die) +{ + static bool panic_reported; + u64 guest_id; + + /* Don't report a panic to Hyper-V if we're not going to panic */ + if (in_die && !panic_on_oops) + return; + + /* + * We prefer to report panic on 'die' chain as we have proper + * registers to report, but if we miss it (e.g. on BUG()) we need + * to report it on 'panic'. + * + * Calling code in the 'die' and 'panic' paths ensures that only + * one CPU is running this code, so no atomicity is needed. + */ + if (panic_reported) + return; + panic_reported = true; + + guest_id = hv_get_vpreg(HV_REGISTER_GUEST_OS_ID); + + /* + * Hyper-V provides the ability to store only 5 values. + * Pick the passed in error value, the guest_id, the PC, + * and the SP. + */ + hv_set_vpreg(HV_REGISTER_GUEST_CRASH_P0, err); + hv_set_vpreg(HV_REGISTER_GUEST_CRASH_P1, guest_id); + hv_set_vpreg(HV_REGISTER_GUEST_CRASH_P2, regs->pc); + hv_set_vpreg(HV_REGISTER_GUEST_CRASH_P3, regs->sp); + hv_set_vpreg(HV_REGISTER_GUEST_CRASH_P4, 0); + + /* + * Let Hyper-V know there is crash data available + */ + hv_set_vpreg(HV_REGISTER_GUEST_CRASH_CTL, HV_CRASH_CTL_CRASH_NOTIFY); +} +EXPORT_SYMBOL_GPL(hyperv_report_panic); diff --git a/arch/arm64/hyperv/mshyperv.c b/arch/arm64/hyperv/mshyperv.c new file mode 100644 index 000000000..4fdc26ade --- /dev/null +++ b/arch/arm64/hyperv/mshyperv.c @@ -0,0 +1,136 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Core routines for interacting with Microsoft's Hyper-V hypervisor, + * including hypervisor initialization. + * + * Copyright (C) 2021, Microsoft, Inc. + * + * Author : Michael Kelley + */ + +#include +#include +#include +#include +#include +#include +#include + +static bool hyperv_initialized; + +int hv_get_hypervisor_version(union hv_hypervisor_version_info *info) +{ + hv_get_vpreg_128(HV_REGISTER_HYPERVISOR_VERSION, + (struct hv_get_vp_registers_output *)info); + + return 0; +} +EXPORT_SYMBOL_GPL(hv_get_hypervisor_version); + +#ifdef CONFIG_ACPI + +static bool __init hyperv_detect_via_acpi(void) +{ + if (acpi_disabled) + return false; + /* + * Hypervisor ID is only available in ACPI v6+, and the + * structure layout was extended in v6 to accommodate that + * new field. + * + * At the very minimum, this check makes sure not to read + * past the FADT structure. + * + * It is also needed to catch running in some unknown + * non-Hyper-V environment that has ACPI 5.x or less. + * In such a case, it can't be Hyper-V. + */ + if (acpi_gbl_FADT.header.revision < 6) + return false; + return strncmp((char *)&acpi_gbl_FADT.hypervisor_id, "MsHyperV", 8) == 0; +} + +#else + +static bool __init hyperv_detect_via_acpi(void) +{ + return false; +} + +#endif + +static bool __init hyperv_detect_via_smccc(void) +{ + uuid_t hyperv_uuid = UUID_INIT( + 0x58ba324d, 0x6447, 0x24cd, + 0x75, 0x6c, 0xef, 0x8e, + 0x24, 0x70, 0x59, 0x16); + + return arm_smccc_hypervisor_has_uuid(&hyperv_uuid); +} + +static int __init hyperv_init(void) +{ + struct hv_get_vp_registers_output result; + u64 guest_id; + int ret; + + /* + * Allow for a kernel built with CONFIG_HYPERV to be running in + * a non-Hyper-V environment. + * + * In such cases, do nothing and return success. + */ + if (!hyperv_detect_via_acpi() && !hyperv_detect_via_smccc()) + return 0; + + /* Setup the guest ID */ + guest_id = hv_generate_guest_id(LINUX_VERSION_CODE); + hv_set_vpreg(HV_REGISTER_GUEST_OS_ID, guest_id); + + /* Get the features and hints from Hyper-V */ + hv_get_vpreg_128(HV_REGISTER_PRIVILEGES_AND_FEATURES_INFO, &result); + ms_hyperv.features = result.as32.a; + ms_hyperv.priv_high = result.as32.b; + ms_hyperv.misc_features = result.as32.c; + + hv_get_vpreg_128(HV_REGISTER_FEATURES_INFO, &result); + ms_hyperv.hints = result.as32.a; + + pr_info("Hyper-V: privilege flags low 0x%x, high 0x%x, hints 0x%x, misc 0x%x\n", + ms_hyperv.features, ms_hyperv.priv_high, ms_hyperv.hints, + ms_hyperv.misc_features); + + hv_identify_partition_type(); + + ret = hv_common_init(); + if (ret) + return ret; + + ret = cpuhp_setup_state(CPUHP_AP_HYPERV_ONLINE, "arm64/hyperv_init:online", + hv_common_cpu_init, hv_common_cpu_die); + if (ret < 0) { + hv_common_free(); + return ret; + } + + if (ms_hyperv.priv_high & HV_ACCESS_PARTITION_ID) + hv_get_partition_id(); + ms_hyperv.vtl = get_vtl(); + if (ms_hyperv.vtl > 0) /* non default VTL */ + pr_info("Linux runs in Hyper-V Virtual Trust Level %d\n", ms_hyperv.vtl); + + ms_hyperv_late_init(); + + hyperv_initialized = true; + return 0; +} + +early_initcall(hyperv_init); + +bool hv_is_hyperv_initialized(void) +{ + return hyperv_initialized; +} +EXPORT_SYMBOL_GPL(hv_is_hyperv_initialized); -- cgit v1.3.1