From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39453) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XypNL-0001wg-9d for qemu-devel@nongnu.org; Wed, 10 Dec 2014 17:05:00 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XypNC-0007Ph-7Q for qemu-devel@nongnu.org; Wed, 10 Dec 2014 17:04:51 -0500 Received: from mail-wi0-x22c.google.com ([2a00:1450:400c:c05::22c]:40369) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XypNB-0007Pd-VT for qemu-devel@nongnu.org; Wed, 10 Dec 2014 17:04:42 -0500 Received: by mail-wi0-f172.google.com with SMTP id n3so12714282wiv.11 for ; Wed, 10 Dec 2014 14:04:41 -0800 (PST) Sender: Paolo Bonzini Message-ID: <5488C375.4090601@redhat.com> Date: Wed, 10 Dec 2014 23:04:37 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: <1418148909-19870-1-git-send-email-dgilbert@redhat.com> <1418148909-19870-3-git-send-email-dgilbert@redhat.com> In-Reply-To: <1418148909-19870-3-git-send-email-dgilbert@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 2/2] atapi migration: Throw recoverable error to avoid recovery List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert (git)" , qemu-devel@nongnu.org Cc: jsnow@redhat.com On 09/12/2014 19:15, Dr. David Alan Gilbert (git) wrote: > (With the previous atapi_dma flag recovery) > If migration happens between the ATAPI command being written and the > bmdma being started, the DMA is dropped. Eventually the guest times > out and recovers, but that can take many seconds. > (This is rare, on a pingpong reading the CD continuously I hit > this about ~1/30-1/50 migrates) > > I don't think we've got enough state to be able to recover safely > at this point, so I throw a 'medium error, no seek complete' > that I'm assuming guests will try and recover from an apparently > dirty CD. What is the part of the state that is not being migrated? Also, what is the ATAPI command that is being run? Paolo