From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: [PATCH] x86: constrain MFN range Dom0 may access Date: Wed, 20 Jan 2016 18:23:03 +0000 Message-ID: <569FD087.5070309@citrix.com> References: <569FB7F902000078000C93DA@prv-mh.provo.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta4.messagelabs.com ([85.158.143.247]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1aLxPQ-0007nv-I3 for xen-devel@lists.xenproject.org; Wed, 20 Jan 2016 18:23:08 +0000 In-Reply-To: <569FB7F902000078000C93DA@prv-mh.provo.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Jan Beulich , xen-devel Cc: Keir Fraser List-Id: xen-devel@lists.xenproject.org On 20/01/16 15:38, Jan Beulich wrote: > ... to that covered by the physical address width supported by the > processor. This implicitly avoids Dom0 (accidentally or due to some > kind of abuse) passing out of range addresses to a guest, which in > turn eliminates this only possibility for PV guests to create PTEs > with one or more reserved bits set. > > Note that this is not a security issue due to XSA-77. > > Signed-off-by: Jan Beulich Reviewed-by: Andrew Cooper