From mboxrd@z Thu Jan 1 00:00:00 1970 From: Asias He Subject: Re: [PATCH V3 3/3] virtio-blk: Add bio-based IO path for virtio-blk Date: Thu, 02 Aug 2012 14:28:16 +0800 Message-ID: <501A1E00.2010605@redhat.com> References: <971756309.4742543.1343457753475.JavaMail.root@redhat.com> <501610E0.8000504@redhat.com> <5016383A.5090008@redhat.com> <20120730134424.GC6041@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20120730134424.GC6041@lst.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: Christoph Hellwig Cc: kvm@vger.kernel.org, "Michael S. Tsirkin" , linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, Paolo Bonzini List-Id: virtualization@lists.linuxfoundation.org On 07/30/2012 09:44 PM, Christoph Hellwig wrote: > On Mon, Jul 30, 2012 at 09:31:06AM +0200, Paolo Bonzini wrote: >> You only need to add REQ_FLUSH support. The virtio-blk protocol does >> not support REQ_FUA, because there's no easy way to do it in userspace. > > A bio-based driver needs to handle both REQ_FLUSH and REQ_FUA as it does > not get the sequencing of REQ_FUA into REQ_FLUSH that request based drivers > can request. To what the REQ_FUA request gets translated is a different story. I just sent out V5 to support both REQ_FLUSH AND REQ_FUA. Thanks, Christoph! -- Asias