From: Jan Kiszka <jan.kiszka@siemens.com>
Date: Wed, 18 Dec 2013 18:16:24 +0000 (+0100)
Subject: KVM: VMX: Do not skip the instruction if handle_dr injects a fault
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=4c4d563b49830a66537c3f51070dad74d7a81d3a;p=openwrt%2Fstaging%2Fblogic.git

KVM: VMX: Do not skip the instruction if handle_dr injects a fault

If kvm_get_dr or kvm_set_dr reports that it raised a fault, we must not
advance the instruction pointer. Otherwise the exception will hit the
wrong instruction.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 31eb5776d854..9cc54842ae14 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5137,10 +5137,14 @@ static int handle_dr(struct kvm_vcpu *vcpu)
 	reg = DEBUG_REG_ACCESS_REG(exit_qualification);
 	if (exit_qualification & TYPE_MOV_FROM_DR) {
 		unsigned long val;
-		if (!kvm_get_dr(vcpu, dr, &val))
-			kvm_register_write(vcpu, reg, val);
+
+		if (kvm_get_dr(vcpu, dr, &val))
+			return 1;
+		kvm_register_write(vcpu, reg, val);
 	} else
-		kvm_set_dr(vcpu, dr, vcpu->arch.regs[reg]);
+		if (kvm_set_dr(vcpu, dr, vcpu->arch.regs[reg]))
+			return 1;
+
 	skip_emulated_instruction(vcpu);
 	return 1;
 }