Some guests OSes (including Windows 10) write to MSR 0xc001102c on some cases (possibly while trying to apply a CPU errata). Make KVM ignore reads and writes to that MSR, so the guest won't crash.
The MSR is documented as "Execution Unit Configuration (EX_CFG)", at AMD's "BIOS and Kernel Developer's Guide (BKDG) for AMD Family 15h Models 00h-0Fh Processors". Signed-off-by: Eduardo Habkost <[email protected]> --- arch/x86/include/asm/msr-index.h | 1 + arch/x86/kvm/x86.c | 2 ++ 2 files changed, 3 insertions(+) diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h index c8f73efb4ece..9e39cc8bd989 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -390,6 +390,7 @@ #define MSR_F15H_NB_PERF_CTR 0xc0010241 #define MSR_F15H_PTSC 0xc0010280 #define MSR_F15H_IC_CFG 0xc0011021 +#define MSR_F15H_EX_CFG 0xc001102c /* Fam 10h MSRs */ #define MSR_FAM10H_MMIO_CONF_BASE 0xc0010058 diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 9cbce3ec84ec..69f822165fe2 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2429,6 +2429,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) case MSR_AMD64_PATCH_LOADER: case MSR_AMD64_BU_CFG2: case MSR_AMD64_DC_CFG: + case MSR_F15H_EX_CFG: break; case MSR_IA32_UCODE_REV: @@ -2724,6 +2725,7 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) case MSR_AMD64_BU_CFG2: case MSR_IA32_PERF_CTL: case MSR_AMD64_DC_CFG: + case MSR_F15H_EX_CFG: msr_info->data = 0; break; case MSR_F15H_PERF_CTL0 ... MSR_F15H_PERF_CTR5: -- 2.18.0.rc1.1.g3f1ff2140
