diff options
| -rw-r--r-- | arch/x86/kvm/x86.c | 27 |
1 files changed, 9 insertions, 18 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 92cb4aa7efd7..1762bde488a2 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -512,6 +512,15 @@ static __always_inline int kvm_do_msr_access(struct kvm_vcpu *vcpu, u32 msr, if (ret != KVM_MSR_RET_UNSUPPORTED) return ret; + /* + * Userspace is allowed to read MSRs, and write '0' to MSRs, that KVM + * reports as to-be-saved, even if an MSR isn't fully supported. + * Simply check that @data is '0', which covers both the write '0' case + * and all reads (in which case @data is zeroed on failure; see above). + */ + if (host_initiated && !*data && kvm_is_msr_to_save(msr)) + return 0; + if (!ignore_msrs) { kvm_debug_ratelimited("unhandled %s: 0x%x data 0x%llx\n", op, msr, *data); @@ -4137,14 +4146,6 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) if (kvm_pmu_is_valid_msr(vcpu, msr)) return kvm_pmu_set_msr(vcpu, msr_info); - /* - * Userspace is allowed to write '0' to MSRs that KVM reports - * as to-be-saved, even if an MSRs isn't fully supported. - */ - if (msr_info->host_initiated && !data && - kvm_is_msr_to_save(msr)) - break; - return KVM_MSR_RET_UNSUPPORTED; } return 0; @@ -4496,16 +4497,6 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) if (kvm_pmu_is_valid_msr(vcpu, msr_info->index)) return kvm_pmu_get_msr(vcpu, msr_info); - /* - * Userspace is allowed to read MSRs that KVM reports as - * to-be-saved, even if an MSR isn't fully supported. - */ - if (msr_info->host_initiated && - kvm_is_msr_to_save(msr_info->index)) { - msr_info->data = 0; - break; - } - return KVM_MSR_RET_UNSUPPORTED; } return 0; |