mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2026-04-08 12:02:33 +02:00
commit9636be85cc("x86/hyperv: Fix hyperv_pcpu_input_arg handling when CPUs go online/offline") introduces a new cpuhp state for hyperv initialization. cpuhp_setup_state() returns the state number if state is CPUHP_AP_ONLINE_DYN or CPUHP_BP_PREPARE_DYN and 0 for all other states. For the hyperv case, since a new cpuhp state was introduced it would return 0. However, in hv_machine_shutdown(), the cpuhp_remove_state() call is conditioned upon "hyperv_init_cpuhp > 0". This will never be true and so hv_cpu_die() won't be called on all CPUs. This means the VP assist page won't be reset. When the kexec kernel tries to setup the VP assist page again, the hypervisor corrupts the memory region of the old VP assist page causing a panic in case the kexec kernel is using that memory elsewhere. This was originally fixed in commitdfe94d4086("x86/hyperv: Fix kexec panic/hang issues"). Get rid of hyperv_init_cpuhp entirely since we are no longer using a dynamic cpuhp state and use CPUHP_AP_HYPERV_ONLINE directly with cpuhp_remove_state(). Cc: stable@vger.kernel.org Fixes:9636be85cc("x86/hyperv: Fix hyperv_pcpu_input_arg handling when CPUs go online/offline") Signed-off-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/20240828112158.3538342-1-anirudh@anirudhrb.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20240828112158.3538342-1-anirudh@anirudhrb.com>
668 lines
19 KiB
C
668 lines
19 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* HyperV Detection code.
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*
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* Copyright (C) 2010, Novell, Inc.
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* Author : K. Y. Srinivasan <ksrinivasan@novell.com>
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*/
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#include <linux/types.h>
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#include <linux/time.h>
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#include <linux/clocksource.h>
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#include <linux/init.h>
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#include <linux/export.h>
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#include <linux/hardirq.h>
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#include <linux/efi.h>
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#include <linux/interrupt.h>
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#include <linux/irq.h>
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#include <linux/kexec.h>
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#include <linux/i8253.h>
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#include <linux/random.h>
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#include <asm/processor.h>
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#include <asm/hypervisor.h>
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#include <asm/hyperv-tlfs.h>
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#include <asm/mshyperv.h>
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#include <asm/desc.h>
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#include <asm/idtentry.h>
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#include <asm/irq_regs.h>
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#include <asm/i8259.h>
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#include <asm/apic.h>
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#include <asm/timer.h>
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#include <asm/reboot.h>
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#include <asm/nmi.h>
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#include <clocksource/hyperv_timer.h>
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#include <asm/numa.h>
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#include <asm/svm.h>
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/* Is Linux running as the root partition? */
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bool hv_root_partition;
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/* Is Linux running on nested Microsoft Hypervisor */
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bool hv_nested;
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struct ms_hyperv_info ms_hyperv;
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/* Used in modules via hv_do_hypercall(): see arch/x86/include/asm/mshyperv.h */
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bool hyperv_paravisor_present __ro_after_init;
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EXPORT_SYMBOL_GPL(hyperv_paravisor_present);
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#if IS_ENABLED(CONFIG_HYPERV)
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static inline unsigned int hv_get_nested_msr(unsigned int reg)
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{
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if (hv_is_sint_msr(reg))
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return reg - HV_X64_MSR_SINT0 + HV_X64_MSR_NESTED_SINT0;
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switch (reg) {
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case HV_X64_MSR_SIMP:
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return HV_X64_MSR_NESTED_SIMP;
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case HV_X64_MSR_SIEFP:
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return HV_X64_MSR_NESTED_SIEFP;
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case HV_X64_MSR_SVERSION:
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return HV_X64_MSR_NESTED_SVERSION;
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case HV_X64_MSR_SCONTROL:
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return HV_X64_MSR_NESTED_SCONTROL;
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case HV_X64_MSR_EOM:
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return HV_X64_MSR_NESTED_EOM;
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default:
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return reg;
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}
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}
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u64 hv_get_non_nested_msr(unsigned int reg)
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{
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u64 value;
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if (hv_is_synic_msr(reg) && ms_hyperv.paravisor_present)
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hv_ivm_msr_read(reg, &value);
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else
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rdmsrl(reg, value);
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return value;
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}
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EXPORT_SYMBOL_GPL(hv_get_non_nested_msr);
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void hv_set_non_nested_msr(unsigned int reg, u64 value)
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{
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if (hv_is_synic_msr(reg) && ms_hyperv.paravisor_present) {
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hv_ivm_msr_write(reg, value);
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/* Write proxy bit via wrmsl instruction */
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if (hv_is_sint_msr(reg))
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wrmsrl(reg, value | 1 << 20);
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} else {
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wrmsrl(reg, value);
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}
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}
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EXPORT_SYMBOL_GPL(hv_set_non_nested_msr);
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u64 hv_get_msr(unsigned int reg)
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{
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if (hv_nested)
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reg = hv_get_nested_msr(reg);
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return hv_get_non_nested_msr(reg);
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}
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EXPORT_SYMBOL_GPL(hv_get_msr);
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void hv_set_msr(unsigned int reg, u64 value)
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{
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if (hv_nested)
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reg = hv_get_nested_msr(reg);
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hv_set_non_nested_msr(reg, value);
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}
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EXPORT_SYMBOL_GPL(hv_set_msr);
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static void (*vmbus_handler)(void);
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static void (*hv_stimer0_handler)(void);
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static void (*hv_kexec_handler)(void);
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static void (*hv_crash_handler)(struct pt_regs *regs);
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DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_callback)
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{
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struct pt_regs *old_regs = set_irq_regs(regs);
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inc_irq_stat(irq_hv_callback_count);
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if (vmbus_handler)
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vmbus_handler();
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if (ms_hyperv.hints & HV_DEPRECATING_AEOI_RECOMMENDED)
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apic_eoi();
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set_irq_regs(old_regs);
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}
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void hv_setup_vmbus_handler(void (*handler)(void))
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{
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vmbus_handler = handler;
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}
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void hv_remove_vmbus_handler(void)
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{
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/* We have no way to deallocate the interrupt gate */
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vmbus_handler = NULL;
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}
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/*
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* Routines to do per-architecture handling of stimer0
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* interrupts when in Direct Mode
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*/
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DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_stimer0)
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{
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struct pt_regs *old_regs = set_irq_regs(regs);
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inc_irq_stat(hyperv_stimer0_count);
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if (hv_stimer0_handler)
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hv_stimer0_handler();
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add_interrupt_randomness(HYPERV_STIMER0_VECTOR);
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apic_eoi();
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set_irq_regs(old_regs);
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}
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/* For x86/x64, override weak placeholders in hyperv_timer.c */
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void hv_setup_stimer0_handler(void (*handler)(void))
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{
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hv_stimer0_handler = handler;
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}
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void hv_remove_stimer0_handler(void)
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{
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/* We have no way to deallocate the interrupt gate */
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hv_stimer0_handler = NULL;
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}
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void hv_setup_kexec_handler(void (*handler)(void))
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{
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hv_kexec_handler = handler;
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}
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void hv_remove_kexec_handler(void)
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{
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hv_kexec_handler = NULL;
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}
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void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs))
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{
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hv_crash_handler = handler;
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}
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void hv_remove_crash_handler(void)
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{
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hv_crash_handler = NULL;
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}
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#ifdef CONFIG_KEXEC_CORE
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static void hv_machine_shutdown(void)
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{
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if (kexec_in_progress && hv_kexec_handler)
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hv_kexec_handler();
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/*
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* Call hv_cpu_die() on all the CPUs, otherwise later the hypervisor
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* corrupts the old VP Assist Pages and can crash the kexec kernel.
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*/
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if (kexec_in_progress)
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cpuhp_remove_state(CPUHP_AP_HYPERV_ONLINE);
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/* The function calls stop_other_cpus(). */
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native_machine_shutdown();
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/* Disable the hypercall page when there is only 1 active CPU. */
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if (kexec_in_progress)
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hyperv_cleanup();
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}
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#endif /* CONFIG_KEXEC_CORE */
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#ifdef CONFIG_CRASH_DUMP
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static void hv_machine_crash_shutdown(struct pt_regs *regs)
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{
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if (hv_crash_handler)
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hv_crash_handler(regs);
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/* The function calls crash_smp_send_stop(). */
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native_machine_crash_shutdown(regs);
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/* Disable the hypercall page when there is only 1 active CPU. */
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hyperv_cleanup();
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}
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#endif /* CONFIG_CRASH_DUMP */
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#endif /* CONFIG_HYPERV */
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static uint32_t __init ms_hyperv_platform(void)
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{
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u32 eax;
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u32 hyp_signature[3];
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if (!boot_cpu_has(X86_FEATURE_HYPERVISOR))
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return 0;
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cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS,
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&eax, &hyp_signature[0], &hyp_signature[1], &hyp_signature[2]);
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if (eax < HYPERV_CPUID_MIN || eax > HYPERV_CPUID_MAX ||
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memcmp("Microsoft Hv", hyp_signature, 12))
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return 0;
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/* HYPERCALL and VP_INDEX MSRs are mandatory for all features. */
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eax = cpuid_eax(HYPERV_CPUID_FEATURES);
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if (!(eax & HV_MSR_HYPERCALL_AVAILABLE)) {
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pr_warn("x86/hyperv: HYPERCALL MSR not available.\n");
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return 0;
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}
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if (!(eax & HV_MSR_VP_INDEX_AVAILABLE)) {
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pr_warn("x86/hyperv: VP_INDEX MSR not available.\n");
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return 0;
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}
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return HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS;
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}
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#ifdef CONFIG_X86_LOCAL_APIC
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/*
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* Prior to WS2016 Debug-VM sends NMIs to all CPUs which makes
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* it difficult to process CHANNELMSG_UNLOAD in case of crash. Handle
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* unknown NMI on the first CPU which gets it.
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*/
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static int hv_nmi_unknown(unsigned int val, struct pt_regs *regs)
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{
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static atomic_t nmi_cpu = ATOMIC_INIT(-1);
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unsigned int old_cpu, this_cpu;
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if (!unknown_nmi_panic)
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return NMI_DONE;
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old_cpu = -1;
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this_cpu = raw_smp_processor_id();
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if (!atomic_try_cmpxchg(&nmi_cpu, &old_cpu, this_cpu))
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return NMI_HANDLED;
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return NMI_DONE;
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}
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#endif
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static unsigned long hv_get_tsc_khz(void)
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{
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unsigned long freq;
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rdmsrl(HV_X64_MSR_TSC_FREQUENCY, freq);
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return freq / 1000;
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}
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#if defined(CONFIG_SMP) && IS_ENABLED(CONFIG_HYPERV)
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static void __init hv_smp_prepare_boot_cpu(void)
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{
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native_smp_prepare_boot_cpu();
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#if defined(CONFIG_X86_64) && defined(CONFIG_PARAVIRT_SPINLOCKS)
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hv_init_spinlocks();
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#endif
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}
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static void __init hv_smp_prepare_cpus(unsigned int max_cpus)
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{
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#ifdef CONFIG_X86_64
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int i;
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int ret;
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#endif
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native_smp_prepare_cpus(max_cpus);
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/*
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* Override wakeup_secondary_cpu_64 callback for SEV-SNP
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* enlightened guest.
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*/
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if (!ms_hyperv.paravisor_present && hv_isolation_type_snp()) {
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apic->wakeup_secondary_cpu_64 = hv_snp_boot_ap;
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return;
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}
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#ifdef CONFIG_X86_64
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for_each_present_cpu(i) {
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if (i == 0)
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continue;
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ret = hv_call_add_logical_proc(numa_cpu_node(i), i, cpu_physical_id(i));
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BUG_ON(ret);
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}
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for_each_present_cpu(i) {
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if (i == 0)
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continue;
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ret = hv_call_create_vp(numa_cpu_node(i), hv_current_partition_id, i, i);
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BUG_ON(ret);
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}
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#endif
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}
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#endif
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/*
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* When a fully enlightened TDX VM runs on Hyper-V, the firmware sets the
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* HW_REDUCED flag: refer to acpi_tb_create_local_fadt(). Consequently ttyS0
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* interrupts can't work because request_irq() -> ... -> irq_to_desc() returns
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* NULL for ttyS0. This happens because mp_config_acpi_legacy_irqs() sees a
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* nr_legacy_irqs() of 0, so it doesn't initialize the array 'mp_irqs[]', and
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* later setup_IO_APIC_irqs() -> find_irq_entry() fails to find the legacy irqs
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* from the array and hence doesn't create the necessary irq description info.
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*
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* Clone arch/x86/kernel/acpi/boot.c: acpi_generic_reduced_hw_init() here,
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* except don't change 'legacy_pic', which keeps its default value
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* 'default_legacy_pic'. This way, mp_config_acpi_legacy_irqs() sees a non-zero
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* nr_legacy_irqs() and eventually serial console interrupts works properly.
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*/
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static void __init reduced_hw_init(void)
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{
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x86_init.timers.timer_init = x86_init_noop;
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x86_init.irqs.pre_vector_init = x86_init_noop;
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}
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int hv_get_hypervisor_version(union hv_hypervisor_version_info *info)
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{
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unsigned int hv_max_functions;
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hv_max_functions = cpuid_eax(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS);
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if (hv_max_functions < HYPERV_CPUID_VERSION) {
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pr_err("%s: Could not detect Hyper-V version\n", __func__);
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return -ENODEV;
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}
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cpuid(HYPERV_CPUID_VERSION, &info->eax, &info->ebx, &info->ecx, &info->edx);
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return 0;
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}
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static void __init ms_hyperv_init_platform(void)
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{
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int hv_max_functions_eax;
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#ifdef CONFIG_PARAVIRT
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pv_info.name = "Hyper-V";
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#endif
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/*
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* Extract the features and hints
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*/
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ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES);
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ms_hyperv.priv_high = cpuid_ebx(HYPERV_CPUID_FEATURES);
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ms_hyperv.misc_features = cpuid_edx(HYPERV_CPUID_FEATURES);
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ms_hyperv.hints = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO);
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hv_max_functions_eax = cpuid_eax(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS);
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pr_info("Hyper-V: privilege flags low 0x%x, high 0x%x, hints 0x%x, misc 0x%x\n",
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ms_hyperv.features, ms_hyperv.priv_high, ms_hyperv.hints,
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ms_hyperv.misc_features);
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ms_hyperv.max_vp_index = cpuid_eax(HYPERV_CPUID_IMPLEMENT_LIMITS);
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ms_hyperv.max_lp_index = cpuid_ebx(HYPERV_CPUID_IMPLEMENT_LIMITS);
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pr_debug("Hyper-V: max %u virtual processors, %u logical processors\n",
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ms_hyperv.max_vp_index, ms_hyperv.max_lp_index);
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/*
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* Check CPU management privilege.
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*
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* To mirror what Windows does we should extract CPU management
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* features and use the ReservedIdentityBit to detect if Linux is the
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* root partition. But that requires negotiating CPU management
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* interface (a process to be finalized). For now, use the privilege
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* flag as the indicator for running as root.
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*
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* Hyper-V should never specify running as root and as a Confidential
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* VM. But to protect against a compromised/malicious Hyper-V trying
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* to exploit root behavior to expose Confidential VM memory, ignore
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* the root partition setting if also a Confidential VM.
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*/
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if ((ms_hyperv.priv_high & HV_CPU_MANAGEMENT) &&
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!(ms_hyperv.priv_high & HV_ISOLATION)) {
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hv_root_partition = true;
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pr_info("Hyper-V: running as root partition\n");
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}
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if (ms_hyperv.hints & HV_X64_HYPERV_NESTED) {
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hv_nested = true;
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pr_info("Hyper-V: running on a nested hypervisor\n");
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}
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if (ms_hyperv.features & HV_ACCESS_FREQUENCY_MSRS &&
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ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE) {
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x86_platform.calibrate_tsc = hv_get_tsc_khz;
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x86_platform.calibrate_cpu = hv_get_tsc_khz;
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setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ);
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}
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if (ms_hyperv.priv_high & HV_ISOLATION) {
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ms_hyperv.isolation_config_a = cpuid_eax(HYPERV_CPUID_ISOLATION_CONFIG);
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ms_hyperv.isolation_config_b = cpuid_ebx(HYPERV_CPUID_ISOLATION_CONFIG);
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if (ms_hyperv.shared_gpa_boundary_active)
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ms_hyperv.shared_gpa_boundary =
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BIT_ULL(ms_hyperv.shared_gpa_boundary_bits);
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hyperv_paravisor_present = !!ms_hyperv.paravisor_present;
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pr_info("Hyper-V: Isolation Config: Group A 0x%x, Group B 0x%x\n",
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ms_hyperv.isolation_config_a, ms_hyperv.isolation_config_b);
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if (hv_get_isolation_type() == HV_ISOLATION_TYPE_SNP) {
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static_branch_enable(&isolation_type_snp);
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} else if (hv_get_isolation_type() == HV_ISOLATION_TYPE_TDX) {
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static_branch_enable(&isolation_type_tdx);
|
|
|
|
/* A TDX VM must use x2APIC and doesn't use lazy EOI. */
|
|
ms_hyperv.hints &= ~HV_X64_APIC_ACCESS_RECOMMENDED;
|
|
|
|
if (!ms_hyperv.paravisor_present) {
|
|
/*
|
|
* Mark the Hyper-V TSC page feature as disabled
|
|
* in a TDX VM without paravisor so that the
|
|
* Invariant TSC, which is a better clocksource
|
|
* anyway, is used instead.
|
|
*/
|
|
ms_hyperv.features &= ~HV_MSR_REFERENCE_TSC_AVAILABLE;
|
|
|
|
/*
|
|
* The Invariant TSC is expected to be available
|
|
* in a TDX VM without paravisor, but if not,
|
|
* print a warning message. The slower Hyper-V MSR-based
|
|
* Ref Counter should end up being the clocksource.
|
|
*/
|
|
if (!(ms_hyperv.features & HV_ACCESS_TSC_INVARIANT))
|
|
pr_warn("Hyper-V: Invariant TSC is unavailable\n");
|
|
|
|
/* HV_MSR_CRASH_CTL is unsupported. */
|
|
ms_hyperv.misc_features &= ~HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE;
|
|
|
|
/* Don't trust Hyper-V's TLB-flushing hypercalls. */
|
|
ms_hyperv.hints &= ~HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED;
|
|
|
|
x86_init.acpi.reduced_hw_early_init = reduced_hw_init;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (hv_max_functions_eax >= HYPERV_CPUID_NESTED_FEATURES) {
|
|
ms_hyperv.nested_features =
|
|
cpuid_eax(HYPERV_CPUID_NESTED_FEATURES);
|
|
pr_info("Hyper-V: Nested features: 0x%x\n",
|
|
ms_hyperv.nested_features);
|
|
}
|
|
|
|
#ifdef CONFIG_X86_LOCAL_APIC
|
|
if (ms_hyperv.features & HV_ACCESS_FREQUENCY_MSRS &&
|
|
ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE) {
|
|
/*
|
|
* Get the APIC frequency.
|
|
*/
|
|
u64 hv_lapic_frequency;
|
|
|
|
rdmsrl(HV_X64_MSR_APIC_FREQUENCY, hv_lapic_frequency);
|
|
hv_lapic_frequency = div_u64(hv_lapic_frequency, HZ);
|
|
lapic_timer_period = hv_lapic_frequency;
|
|
pr_info("Hyper-V: LAPIC Timer Frequency: %#x\n",
|
|
lapic_timer_period);
|
|
}
|
|
|
|
register_nmi_handler(NMI_UNKNOWN, hv_nmi_unknown, NMI_FLAG_FIRST,
|
|
"hv_nmi_unknown");
|
|
#endif
|
|
|
|
#ifdef CONFIG_X86_IO_APIC
|
|
no_timer_check = 1;
|
|
#endif
|
|
|
|
#if IS_ENABLED(CONFIG_HYPERV)
|
|
#if defined(CONFIG_KEXEC_CORE)
|
|
machine_ops.shutdown = hv_machine_shutdown;
|
|
#endif
|
|
#if defined(CONFIG_CRASH_DUMP)
|
|
machine_ops.crash_shutdown = hv_machine_crash_shutdown;
|
|
#endif
|
|
#endif
|
|
if (ms_hyperv.features & HV_ACCESS_TSC_INVARIANT) {
|
|
/*
|
|
* Writing to synthetic MSR 0x40000118 updates/changes the
|
|
* guest visible CPUIDs. Setting bit 0 of this MSR enables
|
|
* guests to report invariant TSC feature through CPUID
|
|
* instruction, CPUID 0x800000007/EDX, bit 8. See code in
|
|
* early_init_intel() where this bit is examined. The
|
|
* setting of this MSR bit should happen before init_intel()
|
|
* is called.
|
|
*/
|
|
wrmsrl(HV_X64_MSR_TSC_INVARIANT_CONTROL, HV_EXPOSE_INVARIANT_TSC);
|
|
setup_force_cpu_cap(X86_FEATURE_TSC_RELIABLE);
|
|
}
|
|
|
|
/*
|
|
* Generation 2 instances don't support reading the NMI status from
|
|
* 0x61 port.
|
|
*/
|
|
if (efi_enabled(EFI_BOOT))
|
|
x86_platform.get_nmi_reason = hv_get_nmi_reason;
|
|
|
|
/*
|
|
* Hyper-V VMs have a PIT emulation quirk such that zeroing the
|
|
* counter register during PIT shutdown restarts the PIT. So it
|
|
* continues to interrupt @18.2 HZ. Setting i8253_clear_counter
|
|
* to false tells pit_shutdown() not to zero the counter so that
|
|
* the PIT really is shutdown. Generation 2 VMs don't have a PIT,
|
|
* and setting this value has no effect.
|
|
*/
|
|
i8253_clear_counter_on_shutdown = false;
|
|
|
|
#if IS_ENABLED(CONFIG_HYPERV)
|
|
if ((hv_get_isolation_type() == HV_ISOLATION_TYPE_VBS) ||
|
|
ms_hyperv.paravisor_present)
|
|
hv_vtom_init();
|
|
/*
|
|
* Setup the hook to get control post apic initialization.
|
|
*/
|
|
x86_platform.apic_post_init = hyperv_init;
|
|
hyperv_setup_mmu_ops();
|
|
|
|
/* Install system interrupt handler for hypervisor callback */
|
|
sysvec_install(HYPERVISOR_CALLBACK_VECTOR, sysvec_hyperv_callback);
|
|
|
|
/* Install system interrupt handler for reenlightenment notifications */
|
|
if (ms_hyperv.features & HV_ACCESS_REENLIGHTENMENT) {
|
|
sysvec_install(HYPERV_REENLIGHTENMENT_VECTOR, sysvec_hyperv_reenlightenment);
|
|
}
|
|
|
|
/* Install system interrupt handler for stimer0 */
|
|
if (ms_hyperv.misc_features & HV_STIMER_DIRECT_MODE_AVAILABLE) {
|
|
sysvec_install(HYPERV_STIMER0_VECTOR, sysvec_hyperv_stimer0);
|
|
}
|
|
|
|
# ifdef CONFIG_SMP
|
|
smp_ops.smp_prepare_boot_cpu = hv_smp_prepare_boot_cpu;
|
|
if (hv_root_partition ||
|
|
(!ms_hyperv.paravisor_present && hv_isolation_type_snp()))
|
|
smp_ops.smp_prepare_cpus = hv_smp_prepare_cpus;
|
|
# endif
|
|
|
|
/*
|
|
* Hyper-V doesn't provide irq remapping for IO-APIC. To enable x2apic,
|
|
* set x2apic destination mode to physical mode when x2apic is available
|
|
* and Hyper-V IOMMU driver makes sure cpus assigned with IO-APIC irqs
|
|
* have 8-bit APIC id.
|
|
*/
|
|
# ifdef CONFIG_X86_X2APIC
|
|
if (x2apic_supported())
|
|
x2apic_phys = 1;
|
|
# endif
|
|
|
|
/* Register Hyper-V specific clocksource */
|
|
hv_init_clocksource();
|
|
hv_vtl_init_platform();
|
|
#endif
|
|
/*
|
|
* TSC should be marked as unstable only after Hyper-V
|
|
* clocksource has been initialized. This ensures that the
|
|
* stability of the sched_clock is not altered.
|
|
*/
|
|
if (!(ms_hyperv.features & HV_ACCESS_TSC_INVARIANT))
|
|
mark_tsc_unstable("running on Hyper-V");
|
|
|
|
hardlockup_detector_disable();
|
|
}
|
|
|
|
static bool __init ms_hyperv_x2apic_available(void)
|
|
{
|
|
return x2apic_supported();
|
|
}
|
|
|
|
/*
|
|
* If ms_hyperv_msi_ext_dest_id() returns true, hyperv_prepare_irq_remapping()
|
|
* returns -ENODEV and the Hyper-V IOMMU driver is not used; instead, the
|
|
* generic support of the 15-bit APIC ID is used: see __irq_msi_compose_msg().
|
|
*
|
|
* Note: for a VM on Hyper-V, the I/O-APIC is the only device which
|
|
* (logically) generates MSIs directly to the system APIC irq domain.
|
|
* There is no HPET, and PCI MSI/MSI-X interrupts are remapped by the
|
|
* pci-hyperv host bridge.
|
|
*
|
|
* Note: for a Hyper-V root partition, this will always return false.
|
|
* The hypervisor doesn't expose these HYPERV_CPUID_VIRT_STACK_* cpuids by
|
|
* default, they are implemented as intercepts by the Windows Hyper-V stack.
|
|
* Even a nested root partition (L2 root) will not get them because the
|
|
* nested (L1) hypervisor filters them out.
|
|
*/
|
|
static bool __init ms_hyperv_msi_ext_dest_id(void)
|
|
{
|
|
u32 eax;
|
|
|
|
eax = cpuid_eax(HYPERV_CPUID_VIRT_STACK_INTERFACE);
|
|
if (eax != HYPERV_VS_INTERFACE_EAX_SIGNATURE)
|
|
return false;
|
|
|
|
eax = cpuid_eax(HYPERV_CPUID_VIRT_STACK_PROPERTIES);
|
|
return eax & HYPERV_VS_PROPERTIES_EAX_EXTENDED_IOAPIC_RTE;
|
|
}
|
|
|
|
#ifdef CONFIG_AMD_MEM_ENCRYPT
|
|
static void hv_sev_es_hcall_prepare(struct ghcb *ghcb, struct pt_regs *regs)
|
|
{
|
|
/* RAX and CPL are already in the GHCB */
|
|
ghcb_set_rcx(ghcb, regs->cx);
|
|
ghcb_set_rdx(ghcb, regs->dx);
|
|
ghcb_set_r8(ghcb, regs->r8);
|
|
}
|
|
|
|
static bool hv_sev_es_hcall_finish(struct ghcb *ghcb, struct pt_regs *regs)
|
|
{
|
|
/* No checking of the return state needed */
|
|
return true;
|
|
}
|
|
#endif
|
|
|
|
const __initconst struct hypervisor_x86 x86_hyper_ms_hyperv = {
|
|
.name = "Microsoft Hyper-V",
|
|
.detect = ms_hyperv_platform,
|
|
.type = X86_HYPER_MS_HYPERV,
|
|
.init.x2apic_available = ms_hyperv_x2apic_available,
|
|
.init.msi_ext_dest_id = ms_hyperv_msi_ext_dest_id,
|
|
.init.init_platform = ms_hyperv_init_platform,
|
|
.init.guest_late_init = ms_hyperv_late_init,
|
|
#ifdef CONFIG_AMD_MEM_ENCRYPT
|
|
.runtime.sev_es_hcall_prepare = hv_sev_es_hcall_prepare,
|
|
.runtime.sev_es_hcall_finish = hv_sev_es_hcall_finish,
|
|
#endif
|
|
};
|