Commit a921cf83 authored by Vitaly Kuznetsov's avatar Vitaly Kuznetsov Committed by Paolo Bonzini
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KVM: x86: hyper-v: Honor HV_DEBUGGING privilege bit 



Hyper-V partition must possess 'HV_DEBUGGING' privilege to issue
HVCALL_POST_DEBUG_DATA/HVCALL_RETRIEVE_DEBUG_DATA/
HVCALL_RESET_DEBUG_SESSION hypercalls.

Note, when SynDBG is disabled hv_check_hypercall_access() returns
'true' (like for any other unknown hypercall) so the result will
be HV_STATUS_INVALID_HYPERCALL_CODE and not HV_STATUS_ACCESS_DENIED.

Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210521095204.2161214-25-vkuznets@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent a60b3c59

arch/x86/kvm/hyperv.c

+9 −0
Original line number Diff line number Diff line
@@ -2103,6 +2103,15 @@ static bool hv_check_hypercall_access(struct kvm_vcpu_hv *hv_vcpu, u16 code) 
		return hv_vcpu->cpuid_cache.features_ebx & HV_POST_MESSAGES;

	case HVCALL_SIGNAL_EVENT:

		return hv_vcpu->cpuid_cache.features_ebx & HV_SIGNAL_EVENTS;

	case HVCALL_POST_DEBUG_DATA:

	case HVCALL_RETRIEVE_DEBUG_DATA:

	case HVCALL_RESET_DEBUG_SESSION:

		/*

		 * Return 'true' when SynDBG is disabled so the resulting code

		 * will be HV_STATUS_INVALID_HYPERCALL_CODE.

		 */

		return !kvm_hv_is_syndbg_enabled(hv_vcpu->vcpu) ||

			hv_vcpu->cpuid_cache.features_ebx & HV_DEBUGGING;

	default:

		break;

	}