diff options
Diffstat (limited to 'arch/x86/kernel/cpu/mshyperv.c')
| -rw-r--r-- | arch/x86/kernel/cpu/mshyperv.c | 132 |
1 files changed, 93 insertions, 39 deletions
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index e0fd57a8ba84..3e2533954675 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -16,11 +16,10 @@ #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 <hyperv/hvhdk.h> #include <asm/mshyperv.h> #include <asm/desc.h> #include <asm/idtentry.h> @@ -34,8 +33,6 @@ #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; @@ -110,6 +107,7 @@ void hv_set_msr(unsigned int reg, u64 value) } EXPORT_SYMBOL_GPL(hv_set_msr); +static void (*mshv_handler)(void); static void (*vmbus_handler)(void); static void (*hv_stimer0_handler)(void); static void (*hv_kexec_handler)(void); @@ -120,6 +118,9 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_callback) struct pt_regs *old_regs = set_irq_regs(regs); inc_irq_stat(irq_hv_callback_count); + if (mshv_handler) + mshv_handler(); + if (vmbus_handler) vmbus_handler(); @@ -129,6 +130,11 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_callback) set_irq_regs(old_regs); } +void hv_setup_mshv_handler(void (*handler)(void)) +{ + mshv_handler = handler; +} + void hv_setup_vmbus_handler(void (*handler)(void)) { vmbus_handler = handler; @@ -199,8 +205,8 @@ static void hv_machine_shutdown(void) * 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 && hyperv_init_cpuhp > 0) - cpuhp_remove_state(hyperv_init_cpuhp); + if (kexec_in_progress) + cpuhp_remove_state(CPUHP_AP_HYPERV_ONLINE); /* The function calls stop_other_cpus(). */ native_machine_shutdown(); @@ -224,6 +230,63 @@ static void hv_machine_crash_shutdown(struct pt_regs *regs) hyperv_cleanup(); } #endif /* CONFIG_CRASH_DUMP */ + +static u64 hv_ref_counter_at_suspend; +static void (*old_save_sched_clock_state)(void); +static void (*old_restore_sched_clock_state)(void); + +/* + * Hyper-V clock counter resets during hibernation. Save and restore clock + * offset during suspend/resume, while also considering the time passed + * before suspend. This is to make sure that sched_clock using hv tsc page + * based clocksource, proceeds from where it left off during suspend and + * it shows correct time for the timestamps of kernel messages after resume. + */ +static void save_hv_clock_tsc_state(void) +{ + hv_ref_counter_at_suspend = hv_read_reference_counter(); +} + +static void restore_hv_clock_tsc_state(void) +{ + /* + * Adjust the offsets used by hv tsc clocksource to + * account for the time spent before hibernation. + * adjusted value = reference counter (time) at suspend + * - reference counter (time) now. + */ + hv_adj_sched_clock_offset(hv_ref_counter_at_suspend - hv_read_reference_counter()); +} + +/* + * Functions to override save_sched_clock_state and restore_sched_clock_state + * functions of x86_platform. The Hyper-V clock counter is reset during + * suspend-resume and the offset used to measure time needs to be + * corrected, post resume. + */ +static void hv_save_sched_clock_state(void) +{ + old_save_sched_clock_state(); + save_hv_clock_tsc_state(); +} + +static void hv_restore_sched_clock_state(void) +{ + restore_hv_clock_tsc_state(); + old_restore_sched_clock_state(); +} + +static void __init x86_setup_ops_for_tsc_pg_clock(void) +{ + if (!(ms_hyperv.features & HV_MSR_REFERENCE_TSC_AVAILABLE)) + return; + + old_save_sched_clock_state = x86_platform.save_sched_clock_state; + x86_platform.save_sched_clock_state = hv_save_sched_clock_state; + + old_restore_sched_clock_state = x86_platform.restore_sched_clock_state; + x86_platform.restore_sched_clock_state = hv_restore_sched_clock_state; +} #endif /* CONFIG_HYPERV */ static uint32_t __init ms_hyperv_platform(void) @@ -366,6 +429,7 @@ int hv_get_hypervisor_version(union hv_hypervisor_version_info *info) return 0; } +EXPORT_SYMBOL_GPL(hv_get_hypervisor_version); static void __init ms_hyperv_init_platform(void) { @@ -380,13 +444,15 @@ static void __init ms_hyperv_init_platform(void) */ ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES); ms_hyperv.priv_high = cpuid_ebx(HYPERV_CPUID_FEATURES); + ms_hyperv.ext_features = cpuid_ecx(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, + pr_info("Hyper-V: privilege flags low %#x, high %#x, ext %#x, hints %#x, misc %#x\n", + ms_hyperv.features, ms_hyperv.priv_high, + ms_hyperv.ext_features, ms_hyperv.hints, ms_hyperv.misc_features); ms_hyperv.max_vp_index = cpuid_eax(HYPERV_CPUID_IMPLEMENT_LIMITS); @@ -395,25 +461,7 @@ static void __init ms_hyperv_init_platform(void) 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"); - } + hv_identify_partition_type(); if (ms_hyperv.hints & HV_X64_HYPERV_NESTED) { hv_nested = true; @@ -424,6 +472,7 @@ static void __init ms_hyperv_init_platform(void) 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) { @@ -449,9 +498,23 @@ static void __init ms_hyperv_init_platform(void) ms_hyperv.hints &= ~HV_X64_APIC_ACCESS_RECOMMENDED; if (!ms_hyperv.paravisor_present) { - /* To be supported: more work is required. */ + /* + * 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; @@ -522,16 +585,6 @@ static void __init ms_hyperv_init_platform(void) 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) @@ -557,7 +610,7 @@ static void __init ms_hyperv_init_platform(void) # ifdef CONFIG_SMP smp_ops.smp_prepare_boot_cpu = hv_smp_prepare_boot_cpu; - if (hv_root_partition || + if (hv_root_partition() || (!ms_hyperv.paravisor_present && hv_isolation_type_snp())) smp_ops.smp_prepare_cpus = hv_smp_prepare_cpus; # endif @@ -575,6 +628,7 @@ static void __init ms_hyperv_init_platform(void) /* Register Hyper-V specific clocksource */ hv_init_clocksource(); + x86_setup_ops_for_tsc_pg_clock(); hv_vtl_init_platform(); #endif /* |