From d6f9aadf2177f4ec32cefd30343cdfcca4bfc8fa Mon Sep 17 00:00:00 2001
From: Jan Beulich <jbeulich@suse.com>
Date: Thu, 13 Nov 2014 09:58:11 +0100
Subject: [PATCH] VMX: values written to MSR_IA32_SYSENTER_E[IS]P should be
 canonical

A recent KVM change by Nadav Amit <namit@cs.technion.ac.il> helped spot
that we have the same issue as they did.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Tim Deegan <tim@xen.org>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Kevin Tian <kevin.tian@intel.com>
master commit: 93cc5c6f1641e90eb120826d42f103b7726efb8e
master date: 2014-10-31 11:31:11 +0100
---
 xen/arch/x86/hvm/vmx/vmx.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index 7a2f052b74..9c5ec60ca9 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -2146,9 +2146,13 @@ static int vmx_msr_write_intercept(unsigned int msr, uint64_t msr_content)
         __vmwrite(GUEST_SYSENTER_CS, msr_content);
         break;
     case MSR_IA32_SYSENTER_ESP:
+        if ( !is_canonical_address(msr_content) )
+            goto gp_fault;
         __vmwrite(GUEST_SYSENTER_ESP, msr_content);
         break;
     case MSR_IA32_SYSENTER_EIP:
+        if ( !is_canonical_address(msr_content) )
+            goto gp_fault;
         __vmwrite(GUEST_SYSENTER_EIP, msr_content);
         break;
     case MSR_IA32_DEBUGCTLMSR: {