From: Jan Kiszka <jan.kis...@siemens.com>
Make sure DR4 and DR5 are aliased to DR6 and DR7, respectively, if
CR4.DE is not set.
Signed-off-by: Jan Kiszka <jan.kis...@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosa...@redhat.com>
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 4903b41..834a8eb 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3043,6 +3043,15 @@ 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;
@@ -3085,14 +3094,20 @@ 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 {
@@ -3103,12 +3118,10 @@ 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);
@@ -3116,7 +3129,11 @@ 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;
--
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