From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43736) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZHr80-0000bx-1g for qemu-devel@nongnu.org; Wed, 22 Jul 2015 06:19:57 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZHr7w-0000Br-Ot for qemu-devel@nongnu.org; Wed, 22 Jul 2015 06:19:55 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53123) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZHr7w-0000Bl-Je for qemu-devel@nongnu.org; Wed, 22 Jul 2015 06:19:52 -0400 Date: Wed, 22 Jul 2015 13:19:49 +0300 From: "Michael S. Tsirkin" Message-ID: <20150722131342-mutt-send-email-mst@redhat.com> References: <1437544792-3949-1-git-send-email-jasowang@redhat.com> <1437544792-3949-3-git-send-email-jasowang@redhat.com> <20150722093145.GD12010@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150722093145.GD12010@redhat.com> Subject: Re: [Qemu-devel] [PATCH V3 2/3] virtio-blk: fail get_features when both scsi and 1.0 were set List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Daniel P. Berrange" Cc: cornelia.huck@de.ibm.com, pbonzini@redhat.com, Jason Wang , qemu-devel@nongnu.org On Wed, Jul 22, 2015 at 10:31:45AM +0100, Daniel P. Berrange wrote: > On Wed, Jul 22, 2015 at 01:59:51PM +0800, Jason Wang wrote: > > SCSI passthrough was no longer supported in virtio 1.0, so this patch > > fail the get_features() when both 1.0 and scsi is set. And also only > > advertise VIRTIO_BLK_F_SCSI for legacy virtio-blk device. > > Why is SCSI passthrough support not available in virtio 1.0 ? This > will cause a regression for any users of that as & when QEMU changes > to use virtio 1.0 by default. Can we not fix this regression instead. > > Regards, > Daniel If we wanted to, we might be able to fix this but not for 2.4: we'd have to extend the spec and guest drivers, in some way TBD. Paolo would be best placed to answer whether this feature is desirable in the future, I think the argument made when the spec was written was that the feature is not widely used, and virtio scsi is available as a replacement for people who need it. > -- > |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| > |: http://libvirt.org -o- http://virt-manager.org :| > |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| > |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|