From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=34736 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OcGSo-0002vX-7S for qemu-devel@nongnu.org; Fri, 23 Jul 2010 07:30:51 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OcGSn-0004Rv-5K for qemu-devel@nongnu.org; Fri, 23 Jul 2010 07:30:50 -0400 Received: from verein.lst.de ([213.95.11.210]:60317) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OcGSm-0004RR-TU for qemu-devel@nongnu.org; Fri, 23 Jul 2010 07:30:49 -0400 Date: Fri, 23 Jul 2010 13:30:46 +0200 From: Christoph Hellwig Subject: Re: [Qemu-devel] [PATCH] block: default to 0 minimal / optiomal I/O size Message-ID: <20100723113046.GA8898@lst.de> References: <20100723073504.GA28166@lst.de> <4C4973E4.5030502@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4C4973E4.5030502@redhat.com> List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kevin Wolf Cc: Christoph Hellwig , qemu-devel@nongnu.org On Fri, Jul 23, 2010 at 12:50:12PM +0200, Kevin Wolf wrote: > This isn't reverting to the state before we reported anything, but it > reports values of 0 now. Is this defined for both virtio-blk and SCSI to > mean the same as no report at all? Or should we rather not advertise > VIRTIO_BLK_F_TOPOLOGY (and the SCSI equivalent) in this case? For scsi it's explicitly defined that way, and there is not equivalent to the VIRTIO_BLK_F_TOPOLOGY because it will just use the VPD data if the page is long enough. virtio is a bit underspecified, but the Linux guest driver has the same behaviour as scsi in that respect.