diff options
| -rw-r--r-- | arch/x86/kvm/x86.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 1c972382e5d4..f47db2588a41 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1449,6 +1449,16 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data) pr_unimpl(vcpu, "unimplemented perfctr wrmsr: " "0x%x data 0x%llx\n", msr, data); break; + case MSR_K7_CLK_CTL: + /* + * Ignore all writes to this no longer documented MSR. + * Writes are only relevant for old K7 processors, + * all pre-dating SVM, but a recommended workaround from + * AMD for these chips. It is possible to speicify the + * affected processor models on the command line, hence + * the need to ignore the workaround. + */ + break; case HV_X64_MSR_GUEST_OS_ID ... HV_X64_MSR_SINT15: if (kvm_hv_msr_partition_wide(msr)) { int r; @@ -1674,6 +1684,18 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata) case MSR_IA32_MCG_STATUS: case MSR_IA32_MC0_CTL ... MSR_IA32_MC0_CTL + 4 * KVM_MAX_MCE_BANKS - 1: return get_msr_mce(vcpu, msr, pdata); + case MSR_K7_CLK_CTL: + /* + * Provide expected ramp-up count for K7. All other + * are set to zero, indicating minimum divisors for + * every field. + * + * This prevents guest kernels on AMD host with CPU + * type 6, model 8 and higher from exploding due to + * the rdmsr failing. + */ + data = 0x20000000; + break; case HV_X64_MSR_GUEST_OS_ID ... HV_X64_MSR_SINT15: if (kvm_hv_msr_partition_wide(msr)) { int r; |