KVM: vmx, pmu: accept 0 for host-initiated write to MSR_IA32_DS_AREA

Whenever an MSR is part of KVM_GET_MSR_INDEX_LIST, as is the case
for MSR_IA32_DS_AREA, it has to be always settable with KVM_SET_MSR.
Accept a zero value for these MSRs to obey the contract.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index 2fc90080dcce0d706b2b6b610252a3591b6dc931..5bc7cfc753fc149f4da063acdd5cdbc233782f22 100644 (file)
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -443,6 +443,8 @@ static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
                }
                break;
        case MSR_IA32_DS_AREA:
+               if (msr_info->host_initiated && data && !guest_cpuid_has(vcpu, X86_FEATURE_DS))
+                       return 1;
                if (is_noncanonical_address(data, vcpu))
                        return 1;
                pmu->ds_area = data;