In contrast to VMX, SVM dose not automatically transfer DR6 into the
VCPU's arch.dr6. So if we face a DR6 read, we must consult a new vendor
hook to obtain the current value.
Fixes a regression of 020df0794f.
Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
---
Should go to stable as well.
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/svm.c | 9 +++++++++
arch/x86/kvm/vmx.c | 6 ++++++
arch/x86/kvm/x86.c | 2 +-
4 files changed, 17 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index ae5d783..f115f46 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -699,6 +699,7 @@ struct kvm_x86_ops {
void (*set_idt)(struct kvm_vcpu *vcpu, struct desc_ptr *dt);
void (*get_gdt)(struct kvm_vcpu *vcpu, struct desc_ptr *dt);
void (*set_gdt)(struct kvm_vcpu *vcpu, struct desc_ptr *dt);
+ u64 (*get_dr6)(struct kvm_vcpu *vcpu);
void (*set_dr7)(struct kvm_vcpu *vcpu, unsigned long value);
void (*cache_reg)(struct kvm_vcpu *vcpu, enum kvm_reg reg);
unsigned long (*get_rflags)(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index c7168a5..48fa63e 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1671,6 +1671,14 @@ static void new_asid(struct vcpu_svm *svm, struct svm_cpu_data *sd)
mark_dirty(svm->vmcb, VMCB_ASID);
}
+static u64 svm_get_dr6(struct kvm_vcpu *vcpu)
+{
+ if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)
+ return vcpu->arch.dr6;
+ else
+ return to_svm(vcpu)->vmcb->save.dr6;
+}
+
static void svm_set_dr7(struct kvm_vcpu *vcpu, unsigned long value)
{
struct vcpu_svm *svm = to_svm(vcpu);
@@ -4286,6 +4294,7 @@ static struct kvm_x86_ops svm_x86_ops = {
.set_idt = svm_set_idt,
.get_gdt = svm_get_gdt,
.set_gdt = svm_set_gdt,
+ .get_dr6 = svm_get_dr6,
.set_dr7 = svm_set_dr7,
.cache_reg = svm_cache_reg,
.get_rflags = svm_get_rflags,
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index ee3bf54..c5c7e62 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5153,6 +5153,11 @@ static int handle_dr(struct kvm_vcpu *vcpu)
return 1;
}
+static u64 vmx_get_dr6(struct kvm_vcpu *vcpu)
+{
+ return vcpu->arch.dr6;
+}
+
static void vmx_set_dr7(struct kvm_vcpu *vcpu, unsigned long val)
{
vmcs_writel(GUEST_DR7, val);
@@ -8573,6 +8578,7 @@ static struct kvm_x86_ops vmx_x86_ops = {
.set_idt = vmx_set_idt,
.get_gdt = vmx_get_gdt,
.set_gdt = vmx_set_gdt,
+ .get_dr6 = vmx_get_dr6,
.set_dr7 = vmx_set_dr7,
.cache_reg = vmx_cache_reg,
.get_rflags = vmx_get_rflags,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 1dc0359..8fe227c 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -788,7 +788,7 @@ static int _kvm_get_dr(struct kvm_vcpu *vcpu, int dr, unsigned long *val)
return 1;
/* fall through */
case 6:
- *val = vcpu->arch.dr6;
+ *val = kvm_x86_ops->get_dr6(vcpu);
break;
case 5:
if (kvm_read_cr4_bits(vcpu, X86_CR4_DE))
--
1.8.1.1.298.ge7eed54
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