Commit a6c6ed1e authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: x86: Don't attempt VMWare emulation on #GP with non-zero error code 



The VMware backdoor hooks #GP faults on IN{S}, OUT{S}, and RDPMC, none
of which generate a non-zero error code for their #GP.  Re-injecting #GP
instead of attempting emulation on a non-zero error code will allow a
future patch to move #GP injection (for emulation failure) into
kvm_emulate_instruction() without having to plumb in the error code.

Reviewed-and-tested-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: default avatarLiran Alon <liran.alon@oracle.com>
Signed-off-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 120c2c4f

arch/x86/kvm/svm.c

+9 −1
Original line number Diff line number Diff line
@@ -2772,12 +2772,20 @@ static int gp_interception(struct vcpu_svm *svm) 


	WARN_ON_ONCE(!enable_vmware_backdoor);



	/*

	 * VMware backdoor emulation on #GP interception only handles IN{S},

	 * OUT{S}, and RDPMC, none of which generate a non-zero error code.

	 */

	if (error_code) {

		kvm_queue_exception_e(vcpu, GP_VECTOR, error_code);

		return 1;

	}

	er = kvm_emulate_instruction(vcpu,

		EMULTYPE_VMWARE | EMULTYPE_NO_UD_ON_FAIL);

	if (er == EMULATE_USER_EXIT)

		return 0;

	else if (er != EMULATE_DONE)

		kvm_queue_exception_e(vcpu, GP_VECTOR, error_code);

		kvm_queue_exception_e(vcpu, GP_VECTOR, 0);

	return 1;

}

arch/x86/kvm/vmx/vmx.c

+11 −1
Original line number Diff line number Diff line
@@ -4539,12 +4539,22 @@ static int handle_exception_nmi(struct kvm_vcpu *vcpu) 


	if (!vmx->rmode.vm86_active && is_gp_fault(intr_info)) {

		WARN_ON_ONCE(!enable_vmware_backdoor);



		/*

		 * VMware backdoor emulation on #GP interception only handles

		 * IN{S}, OUT{S}, and RDPMC, none of which generate a non-zero

		 * error code on #GP.

		 */

		if (error_code) {

			kvm_queue_exception_e(vcpu, GP_VECTOR, error_code);

			return 1;

		}

		er = kvm_emulate_instruction(vcpu,

			EMULTYPE_VMWARE | EMULTYPE_NO_UD_ON_FAIL);

		if (er == EMULATE_USER_EXIT)

			return 0;

		else if (er != EMULATE_DONE)

			kvm_queue_exception_e(vcpu, GP_VECTOR, error_code);

			kvm_queue_exception_e(vcpu, GP_VECTOR, 0);

		return 1;

	}

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