Merge branch 'kvm-updates/2.6.33' of git://git.kernel.org/pub/scm/virt/kvm/kvm

[safe/jmp/linux-2.6] / arch / x86 / kvm / x86.c

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ce677b2..9d06896 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -43,6 +43,7 @@
 #define CREATE_TRACE_POINTS
 #include "trace.h"
 
+#include <asm/debugreg.h>
 #include <asm/uaccess.h>
 #include <asm/msr.h>
 #include <asm/desc.h>
@@ -3920,14 +3921,15 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
        trace_kvm_entry(vcpu->vcpu_id);
        kvm_x86_ops->run(vcpu);
 
-       if (unlikely(vcpu->arch.switch_db_regs || test_thread_flag(TIF_DEBUG))) {
-               set_debugreg(current->thread.debugreg0, 0);
-               set_debugreg(current->thread.debugreg1, 1);
-               set_debugreg(current->thread.debugreg2, 2);
-               set_debugreg(current->thread.debugreg3, 3);
-               set_debugreg(current->thread.debugreg6, 6);
-               set_debugreg(current->thread.debugreg7, 7);
-       }
+       /*
+        * If the guest has used debug registers, at least dr7
+        * will be disabled while returning to the host.
+        * If we don't have active breakpoints in the host, we don't
+        * care about the messed up debug address registers. But if
+        * we have some of them active, restore the old state.
+        */
+       if (hw_breakpoint_active())
+               hw_breakpoint_restore();
 
        set_bit(KVM_REQ_KICK, &vcpu->requests);
        local_irq_enable();