linux-kernel - [PATCH 2/8] KVM: SVM: Make sure rip is synced to vmcb before nested vmexit

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Date:	Thu, 22 Apr 2010 12:33:08 +0200
From:	Joerg Roedel <joerg.roedel@....com>
To:	Avi Kivity <avi@...hat.com>, Marcelo Tosatti <mtosatti@...hat.com>
CC:	kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
	Joerg Roedel <joerg.roedel@....com>
Subject: [PATCH 2/8] KVM: SVM: Make sure rip is synced to vmcb before nested vmexit

This patch fixes a bug where a nested guest always went over
the same instruction because the rip was not advanced on a
nested vmexit.

Signed-off-by: Joerg Roedel <joerg.roedel@....com>
---
 arch/x86/kvm/svm.c |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index ec20584..c480d7f 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2960,6 +2960,10 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu)
 	u16 gs_selector;
 	u16 ldt_selector;
 
+	svm->vmcb->save.rax = vcpu->arch.regs[VCPU_REGS_RAX];
+	svm->vmcb->save.rsp = vcpu->arch.regs[VCPU_REGS_RSP];
+	svm->vmcb->save.rip = vcpu->arch.regs[VCPU_REGS_RIP];
+
 	/*
 	 * A vmexit emulation is required before the vcpu can be executed
 	 * again.
@@ -2967,10 +2971,6 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu)
 	if (unlikely(svm->nested.exit_required))
 		return;
 
-	svm->vmcb->save.rax = vcpu->arch.regs[VCPU_REGS_RAX];
-	svm->vmcb->save.rsp = vcpu->arch.regs[VCPU_REGS_RSP];
-	svm->vmcb->save.rip = vcpu->arch.regs[VCPU_REGS_RIP];
-
 	pre_svm_run(svm);
 
 	sync_lapic_to_cr8(vcpu);
-- 
1.7.0.4


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