From: kaf24@firebug.cl.cam.ac.uk <kaf24@firebug.cl.cam.ac.uk>
Date: Fri, 9 Jun 2006 13:29:00 +0000 (+0100)
Subject: [XEN] IOPL is ignored for VM86 mode port accesses. Fix Xen
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~15972^2~26
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=d6a9b3738c05e04aec6f361a3706909d18e7e09e;p=xen.git

[XEN] IOPL is ignored for VM86 mode port accesses. Fix Xen
emulation to match native behaviour.
Signed-off-by: Jan Beulich <jbeulich@novel..com>
---

diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index 74de928a37..031ee87e4f 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -748,7 +748,8 @@ static inline int guest_io_okay(
 #define TOGGLE_MODE() ((void)0)
 #endif
 
-    if ( v->arch.iopl >= (guest_kernel_mode(v, regs) ? 1 : 3) )
+    if ( !vm86_mode(regs) &&
+         (v->arch.iopl >= (guest_kernel_mode(v, regs) ? 1 : 3)) )
         return 1;
 
     if ( v->arch.iobmp_limit > (port + bytes) )