KVM: x86: Wire-up hardware breakpoints for guest debugging

Add the remaining bits to make use of debug registers also for guest
debugging, thus enabling the use of hardware breakpoints and
watchpoints.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 815f50e425ac..b3a7a314d55c 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -958,6 +958,11 @@ static int svm_guest_debug(struct kvm_vcpu *vcpu, struct kvm_guest_debug *dbg)
         } else
                 vcpu->guest_debug = 0;
 
+        if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)
+                svm->vmcb->save.dr7 = dbg->arch.debugreg[7];
+        else
+                svm->vmcb->save.dr7 = vcpu->arch.dr7;
+
         if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
                 svm->vmcb->save.rflags |= X86_EFLAGS_TF | X86_EFLAGS_RF;
         else if (old_debug & KVM_GUESTDBG_SINGLESTEP)