From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:35718) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QHy2q-0006zz-CX for qemu-devel@nongnu.org; Thu, 05 May 2011 08:52:41 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QHy2p-0007jh-A5 for qemu-devel@nongnu.org; Thu, 05 May 2011 08:52:40 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56567) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QHy2p-0007jd-1e for qemu-devel@nongnu.org; Thu, 05 May 2011 08:52:39 -0400 Message-ID: <4DC29D8B.7030604@redhat.com> Date: Thu, 05 May 2011 14:52:27 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <4DC1D30F.4070408@redhat.com> <20110505125058.GA24197@lst.de> In-Reply-To: <20110505125058.GA24197@lst.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] virtio-scsi spec, first public draft List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Christoph Hellwig Cc: qemu-devel , Stefan Hajnoczi , Hannes Reinecke On 05/05/2011 02:50 PM, Christoph Hellwig wrote: > Please don't repeat the barrier mistake done in the Xen and virtio-blk/lguest > protocols. It really doesn't make sense to put this kind of strict odering > in. If we really want ordering let's do it using SCSI ordered tags at least > to use a standard implementation. > > And SCSI already supports the FUA bit to force a write to be writethrough, > even if the QEMU SCSI code doesn't implement. You're right, I reviewed the history of barriers and you can consider this gone. Paolo