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* [PATCH v2] KVM: vmx: Advance rip to after an ICEBP instruction.
@ 2014-04-16  9:02 Huw Davies
  2014-04-16  9:22 ` Jan Kiszka
  2014-04-28 10:18 ` Paolo Bonzini
  0 siblings, 2 replies; 3+ messages in thread
From: Huw Davies @ 2014-04-16  9:02 UTC (permalink / raw)
  To: kvm; +Cc: Gleb Natapov, Paolo Bonzini, Marcelo Tosatti, Jan Kiszka

When entering an exception after an ICEBP, the saved instruction
pointer should point to after the instruction.

This fixes the bug here: https://bugs.launchpad.net/qemu/+bug/1119686

Signed-off-by: Huw Davies <huw@codeweavers.com>

---
v2: Mask off DR6_RESERVED before comparing to zero.

 arch/x86/kvm/vmx.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 1f68c58..930a0df 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -4841,6 +4841,9 @@ static int handle_exception(struct kvm_vcpu *vcpu)
 		      (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP))) {
 			vcpu->arch.dr6 &= ~15;
 			vcpu->arch.dr6 |= dr6;
+			if (!(dr6 & ~DR6_RESERVED)) /* icebp */
+				skip_emulated_instruction(vcpu);
+
 			kvm_queue_exception(vcpu, DB_VECTOR);
 			return 1;
 		}
-- 
1.8.0


^ permalink raw reply related	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2014-04-28 10:19 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2014-04-16  9:02 [PATCH v2] KVM: vmx: Advance rip to after an ICEBP instruction Huw Davies
2014-04-16  9:22 ` Jan Kiszka
2014-04-28 10:18 ` Paolo Bonzini

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