From: Christoph Egger <Christoph.Egger@amd.com>
Date: Thu, 13 Oct 2011 11:21:10 +0000 (+0100)
Subject: nestedsvm: fix checks of guest writes to HSAVE_PA MSR
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=e2f608687690c28fba52eb78cede62e516b1d26d;p=xen.git

nestedsvm: fix checks of guest writes to HSAVE_PA MSR

Accessing HSAVE_PA MSR does not require SVM to be enabled nor any
special guest paging mode.
But accessing HSAVE_PA MSR requires the address to be 4k aligned.

Signed-off-by: Christoph Egger <Christoph.Egger@amd.com>
Acked-by: Tim Deegan <tim@xen.org>
Committed-by: Tim Deegan <tim@xen.org>
---

diff --git a/xen/arch/x86/hvm/svm/nestedsvm.c b/xen/arch/x86/hvm/svm/nestedsvm.c
index bbd8866c1d..f7fae0da78 100644
--- a/xen/arch/x86/hvm/svm/nestedsvm.c
+++ b/xen/arch/x86/hvm/svm/nestedsvm.c
@@ -51,7 +51,8 @@ nestedsvm_vcpu_stgi(struct vcpu *v)
 static int
 nestedsvm_vmcb_isvalid(struct vcpu *v, uint64_t vmcxaddr)
 {
-    if ( !hvm_svm_enabled(v) || hvm_guest_x86_mode(v) < 2 )
+    /* Address must be 4k aligned */
+    if ( (vmcxaddr & ~PAGE_MASK) != 0 )
         return 0;
 
     /* Maximum valid physical address.