KVM: SVM: Add clean-bit for DR6 and DR7

This patch implements the clean-bit for the dr6 and dr7
debug registers in the vmcb.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 0f55b8a..e9224ca 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -193,6 +193,7 @@
 	VMCB_INTR,	 /* int_ctl, int_vector */
 	VMCB_NPT,        /* npt_en, nCR3, gPAT */
 	VMCB_CR,	 /* CR0, CR3, CR4, EFER */
+	VMCB_DR,         /* DR6, DR7 */
 	VMCB_DIRTY_MAX,
 };
 
@@ -1484,6 +1485,8 @@
 	else
 		svm->vmcb->save.dr7 = vcpu->arch.dr7;
 
+	mark_dirty(svm->vmcb, VMCB_DR);
+
 	update_db_intercept(vcpu);
 }
 
@@ -1506,6 +1509,7 @@
 	struct vcpu_svm *svm = to_svm(vcpu);
 
 	svm->vmcb->save.dr7 = value;
+	mark_dirty(svm->vmcb, VMCB_DR);
 }
 
 static int pf_interception(struct vcpu_svm *svm)