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/vmx.c b/arch/x86/kvm/vmx.c
index 0989776ee7b0..cee81c9a6653 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1017,6 +1017,11 @@ static int set_guest_debug(struct kvm_vcpu *vcpu, struct kvm_guest_debug *dbg)
         if (!(vcpu->guest_debug & KVM_GUESTDBG_ENABLE))
                 vcpu->guest_debug = 0;
 
+        if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)
+                vmcs_writel(GUEST_DR7, dbg->arch.debugreg[7]);
+        else
+                vmcs_writel(GUEST_DR7, vcpu->arch.dr7);
+
         flags = vmcs_readl(GUEST_RFLAGS);
         if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
                 flags |= X86_EFLAGS_TF | X86_EFLAGS_RF;