From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: Xenner design and kvm msr handling Date: Tue, 21 Apr 2009 19:15:45 +0300 Message-ID: <49EDF131.9060705@redhat.com> References: <1239155601.6384.3.camel@yhuang-dev.sh.intel.com> <49DE195D.1020303@redhat.com> <1239332455.6384.108.camel@yhuang-dev.sh.intel.com> <49E08762.1010206@redhat.com> <1239590499.6384.4016.camel@yhuang-dev.sh.intel.com> <49E337D7.5050502@redhat.com> <49EA515C.9000507@codemonkey.ws> <49EAE1F6.9050205@redhat.com> <49EC29D1.8040407@redhat.com> <49EC3198.9070902@redhat.com> <49EC3987.2040001@redhat.com> <49EC3AD6.3090905@redhat.com> <49EC5B2A.9080403@redhat.com> <49EC5C3A.6020108@redhat.com> <49EC68A7.8080403@redhat.com> <49EC6DEE.4070703@redhat.com> <49EC7797.7060004@redhat.com> <49EC7C5F.2000006@redhat.com> <49ED8E6D.80005@redhat.com> <49ED9C70.5010906@redhat.com> <49EDB0E0.5060101@redhat.com> <49EDBBBF.90509@redhat.com> <49EDC050.1040700@redhat.com> <49EDCB1D.1010301@redhat.com> < 49EDEDAD.20900@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Anthony Liguori , Huang Ying , "kvm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Andi Kleen To: Gerd Hoffmann Return-path: Received: from mx2.redhat.com ([66.187.237.31]:33977 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754011AbZDUQPx (ORCPT ); Tue, 21 Apr 2009 12:15:53 -0400 In-Reply-To: <49EDEDAD.20900@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Gerd Hoffmann wrote: > On 04/21/09 15:33, Avi Kivity wrote: >> Gerd Hoffmann wrote: >>> Not sure, have to dig into the xen code to figure. >>> >>> Could be xen doesn't remember the page in the first place. They might >>> let the illegal instruction fault handler patch the opcode. At least I >>> vaguely remember some discussions about that. > > Xen does a simple msr-triggered memcpy() as well, without keeping > track of the page. On a quick glimpse I can't find a opcode patching > place either. Hmm. > Maybe migration is cooperative, that is the host tells the guest it is migrated, so it can re-register the hypercall area? -- error compiling committee.c: too many arguments to function