KVM sets CPUID.80000007H:EDX[8] to 1, but not set HWCR[TscFreqSel]. This will cause guest kernel printing below log on AMD platform even though the hardware TSC exactly counts with P0 frequency. "[Firmware Bug]: TSC doesn't count with P0 frequency!" Fix it by setting HWCR[TscFreqSel] to host's value to indicate whether the TSC increments at the P0 frequency. Signed-off-by: Shannon Zhao <shannon.zhao@xxxxxxxxxxxxxxxxx> --- arch/x86/kvm/svm/svm.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 7e45d03..fb4bb51 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1139,6 +1139,11 @@ static void __svm_vcpu_reset(struct kvm_vcpu *vcpu) svm_init_osvw(vcpu); vcpu->arch.microcode_version = 0x01000065; svm->tsc_ratio_msr = kvm_default_tsc_scaling_ratio; + /* + * TSC frequency select is HWCR[24], set it to host's value to indicate + * whether the TSC increments at the P0 frequency. + */ + vcpu->arch.msr_hwcr = native_read_msr(MSR_K7_HWCR) & BIT_ULL(24); if (sev_es_guest(vcpu->kvm)) sev_es_vcpu_reset(svm); -- 1.8.3.1
