From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: [PATCH 5/5] x86: drop failsafe callback invocation from assembly Date: Wed, 17 Feb 2016 19:01:19 +0000 Message-ID: <56C4C37F.7050101@citrix.com> References: <56C4AC2802000078000D3473@prv-mh.provo.novell.com> <56C4B00102000078000D34B1@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.bemta14.messagelabs.com ([193.109.254.103]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1aW7M8-0008Qh-5p for xen-devel@lists.xenproject.org; Wed, 17 Feb 2016 19:01:44 +0000 In-Reply-To: <56C4B00102000078000D34B1@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 17/02/16 16:38, Jan Beulich wrote: > Afaict this was never necessary on a 64-bit hypervisor, and was instead > just blindly cloned over from 32-bit code: We don't fiddle with (and > hence don't reload) any of DS, ES, FS, or GS, and an exception on IRET > itself can equally well be reported to the guest as that very exception > on the target of that IRET. > > Signed-off-by: Jan Beulich As best as I can tell, this looks safe. Reviewed-by: Andrew Cooper This is one area I intend to write an XTF test for, but I havn't had time to yet. I will see if I can dig out the start of the test and complete it. ~Andrew