Commit f2483415 authored by Jan Kiszka's avatar Jan Kiszka Committed by Marcelo Tosatti
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KVM: VMX: Fix exceptions of mov to dr 



Injecting GP without an error code is a bad idea (causes unhandled guest
exits). Moreover, we must not skip the instruction if we injected an
exception.

Signed-off-by: default avatarJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent b60d513c

arch/x86/kvm/vmx.c

+8 −5
Original line number Diff line number Diff line
@@ -3045,6 +3045,7 @@ static int handle_dr(struct kvm_vcpu *vcpu) 
	unsigned long val;

	int dr, reg;



	/* Do not handle if the CPL > 0, will trigger GP on re-entry */

	if (!kvm_require_cpl(vcpu, 0))

		return 1;

	dr = vmcs_readl(GUEST_DR7);
@@ -3099,20 +3100,22 @@ static int handle_dr(struct kvm_vcpu *vcpu) 
				vcpu->arch.eff_db[dr] = val;

			break;

		case 4 ... 5:

			if (kvm_read_cr4_bits(vcpu, X86_CR4_DE))

			if (kvm_read_cr4_bits(vcpu, X86_CR4_DE)) {

				kvm_queue_exception(vcpu, UD_VECTOR);

				return 1;

			}

			break;

		case 6:

			if (val & 0xffffffff00000000ULL) {

				kvm_queue_exception(vcpu, GP_VECTOR);

				break;

				kvm_inject_gp(vcpu, 0);

				return 1;

			}

			vcpu->arch.dr6 = (val & DR6_VOLATILE) | DR6_FIXED_1;

			break;

		case 7:

			if (val & 0xffffffff00000000ULL) {

				kvm_queue_exception(vcpu, GP_VECTOR);

				break;

				kvm_inject_gp(vcpu, 0);

				return 1;

			}

			vcpu->arch.dr7 = (val & DR7_VOLATILE) | DR7_FIXED_1;

			if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)) {