diff options
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/cpu/mshyperv.c | 11 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/scattered.c | 1 |
2 files changed, 11 insertions, 1 deletions
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index c78f860419d6..25773af116bc 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -565,6 +565,11 @@ static void __init ms_hyperv_init_platform(void) machine_ops.crash_shutdown = hv_machine_crash_shutdown; #endif #endif + /* + * HV_ACCESS_TSC_INVARIANT is always zero for the root partition. Root + * partition doesn't need to write to synthetic MSR to enable invariant + * TSC feature. It sees what the hardware provides. + */ if (ms_hyperv.features & HV_ACCESS_TSC_INVARIANT) { /* * Writing to synthetic MSR 0x40000118 updates/changes the @@ -636,8 +641,12 @@ static void __init ms_hyperv_init_platform(void) * 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. + * + * HV_ACCESS_TSC_INVARIANT is always zero for the root partition. No + * need to check for it. */ - if (!(ms_hyperv.features & HV_ACCESS_TSC_INVARIANT)) + if (!hv_root_partition() && + !(ms_hyperv.features & HV_ACCESS_TSC_INVARIANT)) mark_tsc_unstable("running on Hyper-V"); hardlockup_detector_disable(); diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c index 4cee6213d667..caa4dc885c21 100644 --- a/arch/x86/kernel/cpu/scattered.c +++ b/arch/x86/kernel/cpu/scattered.c @@ -27,6 +27,7 @@ static const struct cpuid_bit cpuid_bits[] = { { X86_FEATURE_APERFMPERF, CPUID_ECX, 0, 0x00000006, 0 }, { X86_FEATURE_EPB, CPUID_ECX, 3, 0x00000006, 0 }, { X86_FEATURE_INTEL_PPIN, CPUID_EBX, 0, 0x00000007, 1 }, + { X86_FEATURE_MSR_IMM, CPUID_ECX, 5, 0x00000007, 1 }, { X86_FEATURE_APX, CPUID_EDX, 21, 0x00000007, 1 }, { X86_FEATURE_RRSBA_CTRL, CPUID_EDX, 2, 0x00000007, 2 }, { X86_FEATURE_BHI_CTRL, CPUID_EDX, 4, 0x00000007, 2 }, |