PR/49150 CVS commit: src/sys/arch/x86/x86

["John Nemeth" <jnemeth%netbsd.org@localhost>]

The following reply was made to PR port-amd64/49150; it has been noted by GNATS.

From: "John Nemeth" <jnemeth%netbsd.org@localhost>
To: gnats-bugs%gnats.NetBSD.org@localhost
Cc: 
Subject: PR/49150 CVS commit: src/sys/arch/x86/x86
Date: Tue, 14 Oct 2014 03:16:56 +0000

 Module Name:	src
 Committed By:	jnemeth
 Date:		Tue Oct 14 03:16:56 UTC 2014
 
 Modified Files:
 	src/sys/arch/x86/x86: identcpu.c
 
 Log Message:
 Force x86_xsave_features to 0 when running under XEN for AMD
 processors.  This prevents the use of xsave and xrstor thus fixing
 the problem in PR/49150.  The basic problem is that the way AMD
 implements those instructions means that information can leak
 between domains so XEN treats them as privileged.
 
 XXX If anybody else comes up with a better / more "proper" fix, go
 for it.  However, this solves the problem I was having.  And, given
 that XEN being broken is pretty much a show-stopper for a release,
 something needed to be done.
 
 
 To generate a diff of this commit:
 cvs rdiff -u -r1.45 -r1.46 src/sys/arch/x86/x86/identcpu.c
 
 Please note that diffs are not public domain; they are subject to the
 copyright notices on the relevant files.