From: Avi Kivity <avi@redhat.com>
Date: Sun, 15 Nov 2009 09:42:05 +0000 (+0200)
Subject: KVM: VMX: Fix MSR_KERNEL_GS_BASE leak while switching to long mode
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=2aa60e1dbfb8d952404af17fa8cb12c231dcfb41;p=users%2Fdwmw2%2Flinux.git

KVM: VMX: Fix MSR_KERNEL_GS_BASE leak while switching to long mode

Switching is controlled by is_long_mode(), so we must unload guest MSRs while
switching to or from long mode.

Signed-off-by: Avi Kivity <avi@redhat.com>
---

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index b923f2a287bde..3291ea5b0ab8d 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1538,6 +1538,11 @@ static void vmx_set_efer(struct kvm_vcpu *vcpu, u64 efer)
 
 	if (!msr)
 		return;
+	/*
+	 * Force kernel_gs_base reloading before EFER changes, as control
+	 * of this msr depends on is_long_mode().
+	 */
+	vmx_load_host_state(to_vmx(vcpu));
 	vcpu->arch.shadow_efer = efer;
 	if (!msr)
 		return;