KVM: SVM: Fix reading of DR6

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. And as SVM now picks the DR6 state
from its VMCB, we also need a set callback in order to write updates of
DR6 back.

Fixes a regression of 020df0794f.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 33fef0738a29..fdf83afbb7d9 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -700,6 +700,8 @@ 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_dr6)(struct kvm_vcpu *vcpu, unsigned long value);
         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);