Commit 138ac8d8 authored by Jan Kiszka's avatar Jan Kiszka Committed by Marcelo Tosatti
Browse files

KVM: VMX: Fix emulation of DR4 and DR5 



Make sure DR4 and DR5 are aliased to DR6 and DR7, respectively, if
CR4.DE is not set.

Signed-off-by: default avatarJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent f2483415

arch/x86/kvm/vmx.c

+26 −9
Original line number Diff line number Diff line
@@ -3039,6 +3039,15 @@ static int handle_cr(struct kvm_vcpu *vcpu) 
	return 0;

}



static int check_dr_alias(struct kvm_vcpu *vcpu)

{

	if (kvm_read_cr4_bits(vcpu, X86_CR4_DE)) {

		kvm_queue_exception(vcpu, UD_VECTOR);

		return -1;

	}

	return 0;

}



static int handle_dr(struct kvm_vcpu *vcpu)

{

	unsigned long exit_qualification;
@@ -3081,14 +3090,20 @@ static int handle_dr(struct kvm_vcpu *vcpu) 
		case 0 ... 3:

			val = vcpu->arch.db[dr];

			break;

		case 4:

			if (check_dr_alias(vcpu) < 0)

				return 1;

			/* fall through */

		case 6:

			val = vcpu->arch.dr6;

			break;

		case 7:

		case 5:

			if (check_dr_alias(vcpu) < 0)

				return 1;

			/* fall through */

		default: /* 7 */

			val = vcpu->arch.dr7;

			break;

		default:

			val = 0;

		}

		kvm_register_write(vcpu, reg, val);

	} else {
@@ -3099,12 +3114,10 @@ static int handle_dr(struct kvm_vcpu *vcpu) 
			if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP))

				vcpu->arch.eff_db[dr] = val;

			break;

		case 4 ... 5:

			if (kvm_read_cr4_bits(vcpu, X86_CR4_DE)) {

				kvm_queue_exception(vcpu, UD_VECTOR);

		case 4:

			if (check_dr_alias(vcpu) < 0)

				return 1;

			}

			break;

			/* fall through */

		case 6:

			if (val & 0xffffffff00000000ULL) {

				kvm_inject_gp(vcpu, 0);
@@ -3112,7 +3125,11 @@ static int handle_dr(struct kvm_vcpu *vcpu) 
			}

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

			break;

		case 7:

		case 5:

			if (check_dr_alias(vcpu) < 0)

				return 1;

			/* fall through */

		default: /* 7 */

			if (val & 0xffffffff00000000ULL) {

				kvm_inject_gp(vcpu, 0);

				return 1;