From 138ac8d88f91e2a6a278aa5cee9120c714c4ce2d Mon Sep 17 00:00:00 2001
From: Jan Kiszka <jan.kiszka@siemens.com>
Date: Wed, 20 Jan 2010 18:20:20 +0100
Subject: [PATCH] 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: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
---
arch/x86/kvm/vmx.c | 35 ++++++++++++++++++++++++++---------
1 file changed, 26 insertions(+), 9 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 9727773f24b7..c7b99e1f8aae 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -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;
--
2.34.1