Contributors: 38
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Vitaly Kuznetsov |
345 |
16.76% |
15 |
13.64% |
| Dexuan Cui |
221 |
10.74% |
9 |
8.18% |
| K. Y. Srinivasan |
209 |
10.16% |
10 |
9.09% |
| Lan Tianyu |
201 |
9.77% |
8 |
7.27% |
| Michael Kelley |
170 |
8.26% |
13 |
11.82% |
| Wei Liu |
135 |
6.56% |
3 |
2.73% |
| Thomas Gleixner |
121 |
5.88% |
7 |
6.36% |
| Jinank Jain |
119 |
5.78% |
2 |
1.82% |
| Nuno Das Neves |
112 |
5.44% |
5 |
4.55% |
| Andrea Parri |
81 |
3.94% |
3 |
2.73% |
| H. Peter Anvin |
75 |
3.64% |
3 |
2.73% |
| Yi Sun |
50 |
2.43% |
1 |
0.91% |
| Sean Christopherson |
45 |
2.19% |
1 |
0.91% |
| Vineeth Pillai |
21 |
1.02% |
1 |
0.91% |
| Uros Bizjak |
21 |
1.02% |
1 |
0.91% |
| Jason (Hui) Wang |
21 |
1.02% |
2 |
1.82% |
| Baoquan He |
16 |
0.78% |
1 |
0.91% |
| Ani Sinha |
14 |
0.68% |
2 |
1.82% |
| Olaf Hering |
10 |
0.49% |
2 |
1.82% |
| Xin Li |
9 |
0.44% |
1 |
0.91% |
| Sunil Muthuswamy |
8 |
0.39% |
1 |
0.91% |
| Juergen Gross |
8 |
0.39% |
2 |
1.82% |
| Joseph Salisbury |
6 |
0.29% |
1 |
0.91% |
| Jeremy Fitzhardinge |
6 |
0.29% |
2 |
1.82% |
| Gleb Natapov |
3 |
0.15% |
1 |
0.91% |
| Hank Janssen |
3 |
0.15% |
1 |
0.91% |
| Linus Torvalds (pre-git) |
3 |
0.15% |
1 |
0.91% |
| David Rientjes |
3 |
0.15% |
1 |
0.91% |
| Saurabh Sengar |
3 |
0.15% |
1 |
0.91% |
| Denis V. Lunev |
3 |
0.15% |
1 |
0.91% |
| Alexander van Heukelum |
3 |
0.15% |
1 |
0.91% |
| Hannes Eder |
3 |
0.15% |
1 |
0.91% |
| Chen Yucong |
2 |
0.10% |
1 |
0.91% |
| Dave Hansen |
2 |
0.10% |
1 |
0.91% |
| Daniel Drake |
2 |
0.10% |
1 |
0.91% |
| Ingo Molnar |
2 |
0.10% |
1 |
0.91% |
| Anirudh Rayabharam (Microsoft) |
1 |
0.05% |
1 |
0.91% |
| Paul Gortmaker |
1 |
0.05% |
1 |
0.91% |
| Total |
2058 |
|
110 |
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* HyperV Detection code.
*
* Copyright (C) 2010, Novell, Inc.
* Author : K. Y. Srinivasan <ksrinivasan@novell.com>
*/
#include <linux/types.h>
#include <linux/time.h>
#include <linux/clocksource.h>
#include <linux/init.h>
#include <linux/export.h>
#include <linux/hardirq.h>
#include <linux/efi.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/kexec.h>
#include <linux/i8253.h>
#include <linux/random.h>
#include <asm/processor.h>
#include <asm/hypervisor.h>
#include <asm/hyperv-tlfs.h>
#include <asm/mshyperv.h>
#include <asm/desc.h>
#include <asm/idtentry.h>
#include <asm/irq_regs.h>
#include <asm/i8259.h>
#include <asm/apic.h>
#include <asm/timer.h>
#include <asm/reboot.h>
#include <asm/nmi.h>
#include <clocksource/hyperv_timer.h>
#include <asm/numa.h>
#include <asm/svm.h>
/* Is Linux running as the root partition? */
bool hv_root_partition;
/* Is Linux running on nested Microsoft Hypervisor */
bool hv_nested;
struct ms_hyperv_info ms_hyperv;
/* Used in modules via hv_do_hypercall(): see arch/x86/include/asm/mshyperv.h */
bool hyperv_paravisor_present __ro_after_init;
EXPORT_SYMBOL_GPL(hyperv_paravisor_present);
#if IS_ENABLED(CONFIG_HYPERV)
static inline unsigned int hv_get_nested_msr(unsigned int reg)
{
if (hv_is_sint_msr(reg))
return reg - HV_X64_MSR_SINT0 + HV_X64_MSR_NESTED_SINT0;
switch (reg) {
case HV_X64_MSR_SIMP:
return HV_X64_MSR_NESTED_SIMP;
case HV_X64_MSR_SIEFP:
return HV_X64_MSR_NESTED_SIEFP;
case HV_X64_MSR_SVERSION:
return HV_X64_MSR_NESTED_SVERSION;
case HV_X64_MSR_SCONTROL:
return HV_X64_MSR_NESTED_SCONTROL;
case HV_X64_MSR_EOM:
return HV_X64_MSR_NESTED_EOM;
default:
return reg;
}
}
u64 hv_get_non_nested_msr(unsigned int reg)
{
u64 value;
if (hv_is_synic_msr(reg) && ms_hyperv.paravisor_present)
hv_ivm_msr_read(reg, &value);
else
rdmsrl(reg, value);
return value;
}
EXPORT_SYMBOL_GPL(hv_get_non_nested_msr);
void hv_set_non_nested_msr(unsigned int reg, u64 value)
{
if (hv_is_synic_msr(reg) && ms_hyperv.paravisor_present) {
hv_ivm_msr_write(reg, value);
/* Write proxy bit via wrmsl instruction */
if (hv_is_sint_msr(reg))
wrmsrl(reg, value | 1 << 20);
} else {
wrmsrl(reg, value);
}
}
EXPORT_SYMBOL_GPL(hv_set_non_nested_msr);
u64 hv_get_msr(unsigned int reg)
{
if (hv_nested)
reg = hv_get_nested_msr(reg);
return hv_get_non_nested_msr(reg);
}
EXPORT_SYMBOL_GPL(hv_get_msr);
void hv_set_msr(unsigned int reg, u64 value)
{
if (hv_nested)
reg = hv_get_nested_msr(reg);
hv_set_non_nested_msr(reg, value);
}
EXPORT_SYMBOL_GPL(hv_set_msr);
static void (*vmbus_handler)(void);
static void (*hv_stimer0_handler)(void);
static void (*hv_kexec_handler)(void);
static void (*hv_crash_handler)(struct pt_regs *regs);
DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_callback)
{
struct pt_regs *old_regs = set_irq_regs(regs);
inc_irq_stat(irq_hv_callback_count);
if (vmbus_handler)
vmbus_handler();
if (ms_hyperv.hints & HV_DEPRECATING_AEOI_RECOMMENDED)
apic_eoi();
set_irq_regs(old_regs);
}
void hv_setup_vmbus_handler(void (*handler)(void))
{
vmbus_handler = handler;
}
void hv_remove_vmbus_handler(void)
{
/* We have no way to deallocate the interrupt gate */
vmbus_handler = NULL;
}
/*
* Routines to do per-architecture handling of stimer0
* interrupts when in Direct Mode
*/
DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_stimer0)
{
struct pt_regs *old_regs = set_irq_regs(regs);
inc_irq_stat(hyperv_stimer0_count);
if (hv_stimer0_handler)
hv_stimer0_handler();
add_interrupt_randomness(HYPERV_STIMER0_VECTOR);
apic_eoi();
set_irq_regs(old_regs);
}
/* For x86/x64, override weak placeholders in hyperv_timer.c */
void hv_setup_stimer0_handler(void (*handler)(void))
{
hv_stimer0_handler = handler;
}
void hv_remove_stimer0_handler(void)
{
/* We have no way to deallocate the interrupt gate */
hv_stimer0_handler = NULL;
}
void hv_setup_kexec_handler(void (*handler)(void))
{
hv_kexec_handler = handler;
}
void hv_remove_kexec_handler(void)
{
hv_kexec_handler = NULL;
}
void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs))
{
hv_crash_handler = handler;
}
void hv_remove_crash_handler(void)
{
hv_crash_handler = NULL;
}
#ifdef CONFIG_KEXEC_CORE
static void hv_machine_shutdown(void)
{
if (kexec_in_progress && hv_kexec_handler)
hv_kexec_handler();
/*
* Call hv_cpu_die() on all the CPUs, otherwise later the hypervisor
* corrupts the old VP Assist Pages and can crash the kexec kernel.
*/
if (kexec_in_progress)
cpuhp_remove_state(CPUHP_AP_HYPERV_ONLINE);
/* The function calls stop_other_cpus(). */
native_machine_shutdown();
/* Disable the hypercall page when there is only 1 active CPU. */
if (kexec_in_progress)
hyperv_cleanup();
}
#endif /* CONFIG_KEXEC_CORE */
#ifdef CONFIG_CRASH_DUMP
static void hv_machine_crash_shutdown(struct pt_regs *regs)
{
if (hv_crash_handler)
hv_crash_handler(regs);
/* The function calls crash_smp_send_stop(). */
native_machine_crash_shutdown(regs);
/* Disable the hypercall page when there is only 1 active CPU. */
hyperv_cleanup();
}
#endif /* CONFIG_CRASH_DUMP */
#endif /* CONFIG_HYPERV */
static uint32_t __init ms_hyperv_platform(void)
{
u32 eax;
u32 hyp_signature[3];
if (!boot_cpu_has(X86_FEATURE_HYPERVISOR))
return 0;
cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS,
&eax, &hyp_signature[0], &hyp_signature[1], &hyp_signature[2]);
if (eax < HYPERV_CPUID_MIN || eax > HYPERV_CPUID_MAX ||
memcmp("Microsoft Hv", hyp_signature, 12))
return 0;
/* HYPERCALL and VP_INDEX MSRs are mandatory for all features. */
eax = cpuid_eax(HYPERV_CPUID_FEATURES);
if (!(eax & HV_MSR_HYPERCALL_AVAILABLE)) {
pr_warn("x86/hyperv: HYPERCALL MSR not available.\n");
return 0;
}
if (!(eax & HV_MSR_VP_INDEX_AVAILABLE)) {
pr_warn("x86/hyperv: VP_INDEX MSR not available.\n");
return 0;
}
return HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS;
}
#ifdef CONFIG_X86_LOCAL_APIC
/*
* Prior to WS2016 Debug-VM sends NMIs to all CPUs which makes
* it difficult to process CHANNELMSG_UNLOAD in case of crash. Handle
* unknown NMI on the first CPU which gets it.
*/
static int hv_nmi_unknown(unsigned int val, struct pt_regs *regs)
{
static atomic_t nmi_cpu = ATOMIC_INIT(-1);
unsigned int old_cpu, this_cpu;
if (!unknown_nmi_panic)
return NMI_DONE;
old_cpu = -1;
this_cpu = raw_smp_processor_id();
if (!atomic_try_cmpxchg(&nmi_cpu, &old_cpu, this_cpu))
return NMI_HANDLED;
return NMI_DONE;
}
#endif
static unsigned long hv_get_tsc_khz(void)
{
unsigned long freq;
rdmsrl(HV_X64_MSR_TSC_FREQUENCY, freq);
return freq / 1000;
}
#if defined(CONFIG_SMP) && IS_ENABLED(CONFIG_HYPERV)
static void __init hv_smp_prepare_boot_cpu(void)
{
native_smp_prepare_boot_cpu();
#if defined(CONFIG_X86_64) && defined(CONFIG_PARAVIRT_SPINLOCKS)
hv_init_spinlocks();
#endif
}
static void __init hv_smp_prepare_cpus(unsigned int max_cpus)
{
#ifdef CONFIG_X86_64
int i;
int ret;
#endif
native_smp_prepare_cpus(max_cpus);
/*
* Override wakeup_secondary_cpu_64 callback for SEV-SNP
* enlightened guest.
*/
if (!ms_hyperv.paravisor_present && hv_isolation_type_snp()) {
apic->wakeup_secondary_cpu_64 = hv_snp_boot_ap;
return;
}
#ifdef CONFIG_X86_64
for_each_present_cpu(i) {
if (i == 0)
continue;
ret = hv_call_add_logical_proc(numa_cpu_node(i), i, cpu_physical_id(i));
BUG_ON(ret);
}
for_each_present_cpu(i) {
if (i == 0)
continue;
ret = hv_call_create_vp(numa_cpu_node(i), hv_current_partition_id, i, i);
BUG_ON(ret);
}
#endif
}
#endif
/*
* When a fully enlightened TDX VM runs on Hyper-V, the firmware sets the
* HW_REDUCED flag: refer to acpi_tb_create_local_fadt(). Consequently ttyS0
* interrupts can't work because request_irq() -> ... -> irq_to_desc() returns
* NULL for ttyS0. This happens because mp_config_acpi_legacy_irqs() sees a
* nr_legacy_irqs() of 0, so it doesn't initialize the array 'mp_irqs[]', and
* later setup_IO_APIC_irqs() -> find_irq_entry() fails to find the legacy irqs
* from the array and hence doesn't create the necessary irq description info.
*
* Clone arch/x86/kernel/acpi/boot.c: acpi_generic_reduced_hw_init() here,
* except don't change 'legacy_pic', which keeps its default value
* 'default_legacy_pic'. This way, mp_config_acpi_legacy_irqs() sees a non-zero
* nr_legacy_irqs() and eventually serial console interrupts works properly.
*/
static void __init reduced_hw_init(void)
{
x86_init.timers.timer_init = x86_init_noop;
x86_init.irqs.pre_vector_init = x86_init_noop;
}
int hv_get_hypervisor_version(union hv_hypervisor_version_info *info)
{
unsigned int hv_max_functions;
hv_max_functions = cpuid_eax(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS);
if (hv_max_functions < HYPERV_CPUID_VERSION) {
pr_err("%s: Could not detect Hyper-V version\n", __func__);
return -ENODEV;
}
cpuid(HYPERV_CPUID_VERSION, &info->eax, &info->ebx, &info->ecx, &info->edx);
return 0;
}
static void __init ms_hyperv_init_platform(void)
{
int hv_max_functions_eax;
#ifdef CONFIG_PARAVIRT
pv_info.name = "Hyper-V";
#endif
/*
* Extract the features and hints
*/
ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES);
ms_hyperv.priv_high = cpuid_ebx(HYPERV_CPUID_FEATURES);
ms_hyperv.misc_features = cpuid_edx(HYPERV_CPUID_FEATURES);
ms_hyperv.hints = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO);
hv_max_functions_eax = cpuid_eax(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS);
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);
ms_hyperv.max_vp_index = cpuid_eax(HYPERV_CPUID_IMPLEMENT_LIMITS);
ms_hyperv.max_lp_index = cpuid_ebx(HYPERV_CPUID_IMPLEMENT_LIMITS);
pr_debug("Hyper-V: max %u virtual processors, %u logical processors\n",
ms_hyperv.max_vp_index, ms_hyperv.max_lp_index);
/*
* Check CPU management privilege.
*
* To mirror what Windows does we should extract CPU management
* features and use the ReservedIdentityBit to detect if Linux is the
* root partition. But that requires negotiating CPU management
* interface (a process to be finalized). For now, use the privilege
* flag as the indicator for running as root.
*
* Hyper-V should never specify running as root and as a Confidential
* VM. But to protect against a compromised/malicious Hyper-V trying
* to exploit root behavior to expose Confidential VM memory, ignore
* the root partition setting if also a Confidential VM.
*/
if ((ms_hyperv.priv_high & HV_CPU_MANAGEMENT) &&
!(ms_hyperv.priv_high & HV_ISOLATION)) {
hv_root_partition = true;
pr_info("Hyper-V: running as root partition\n");
}
if (ms_hyperv.hints & HV_X64_HYPERV_NESTED) {
hv_nested = true;
pr_info("Hyper-V: running on a nested hypervisor\n");
}
if (ms_hyperv.features & HV_ACCESS_FREQUENCY_MSRS &&
ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE) {
x86_platform.calibrate_tsc = hv_get_tsc_khz;
x86_platform.calibrate_cpu = hv_get_tsc_khz;
setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ);
}
if (ms_hyperv.priv_high & HV_ISOLATION) {
ms_hyperv.isolation_config_a = cpuid_eax(HYPERV_CPUID_ISOLATION_CONFIG);
ms_hyperv.isolation_config_b = cpuid_ebx(HYPERV_CPUID_ISOLATION_CONFIG);
if (ms_hyperv.shared_gpa_boundary_active)
ms_hyperv.shared_gpa_boundary =
BIT_ULL(ms_hyperv.shared_gpa_boundary_bits);
hyperv_paravisor_present = !!ms_hyperv.paravisor_present;
pr_info("Hyper-V: Isolation Config: Group A 0x%x, Group B 0x%x\n",
ms_hyperv.isolation_config_a, ms_hyperv.isolation_config_b);
if (hv_get_isolation_type() == HV_ISOLATION_TYPE_SNP) {
static_branch_enable(&isolation_type_snp);
} else if (hv_get_isolation_type() == HV_ISOLATION_TYPE_TDX) {
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
};