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[17/30] KVM: x86: hyper-v: Honor HV_FEATURE_DEBUG_MSRS_AVAILABLE privilege bit

Message ID 20210419160127.192712-18-vkuznets@redhat.com (mailing list archive)
State New
Headers show
Series KVM: x86: hyper-v: Fine-grained access check to Hyper-V hypercalls and MSRs | expand

Commit Message

Vitaly Kuznetsov April 19, 2021, 4:01 p.m. UTC
Synthetic debugging MSRs (HV_X64_MSR_SYNDBG_CONTROL,
HV_X64_MSR_SYNDBG_STATUS, HV_X64_MSR_SYNDBG_SEND_BUFFER,
HV_X64_MSR_SYNDBG_RECV_BUFFER, HV_X64_MSR_SYNDBG_PENDING_BUFFER,
HV_X64_MSR_SYNDBG_OPTIONS) are only available to guest when
HV_FEATURE_DEBUG_MSRS_AVAILABLE bit is exposed.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
 arch/x86/kvm/hyperv.c | 4 ++++
 1 file changed, 4 insertions(+)
diff mbox series

Patch

diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index 43ebb53b6b38..f54385ffcdc0 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -1257,6 +1257,10 @@  static bool hv_check_msr_access(struct kvm_vcpu_hv *hv_vcpu, u32 msr)
 	case HV_X64_MSR_CRASH_CTL:
 		return hv_vcpu->cpuid_cache.features_edx &
 			HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE;
+	case HV_X64_MSR_SYNDBG_OPTIONS:
+	case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
+		return hv_vcpu->cpuid_cache.features_edx &
+			HV_FEATURE_DEBUG_MSRS_AVAILABLE;
 	default:
 		break;
 	}