From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:49837) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1h190o-000070-Mk for qemu-devel@nongnu.org; Tue, 05 Mar 2019 07:17:35 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1h190n-00032m-U9 for qemu-devel@nongnu.org; Tue, 05 Mar 2019 07:17:34 -0500 Received: from mx1.redhat.com ([209.132.183.28]:54644) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1h190n-0002uk-MM for qemu-devel@nongnu.org; Tue, 05 Mar 2019 07:17:33 -0500 Message-ID: <3571700849fab25a1bc69960ca24284f0760fe02.camel@redhat.com> From: Andrea Bolognani Date: Tue, 05 Mar 2019 13:09:49 +0100 In-Reply-To: <20181205195704.17605-1-ehabkost@redhat.com> References: <20181205195704.17605-1-ehabkost@redhat.com> Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH for-4.0 v4 0/2] virtio: Provide version-specific variants of virtio PCI devices List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eduardo Habkost , qemu-devel@nongnu.org, "Michael S. Tsirkin" Cc: Kevin Wolf , Amit Shah , libvir-list@redhat.com, Markus Armbruster , Jason Wang , Cornelia Huck , Wainer dos Santos Moschetta , Max Reitz , Caio Carrara , Gonglei , Laine Stump , Gerd Hoffmann , Stefan Hajnoczi , Cleber Rosa , Paolo Bonzini , Philippe =?ISO-8859-1?Q?Mathieu-Daud=E9?= , Cole Robinson , Daniel Berrange Sorry to resurrect such an old thread, but I have been wondering... On Wed, 2018-12-05 at 17:57 -0200, Eduardo Habkost wrote: [...] > Changes v1 -> v2: > * Removed *-0.9 devices. Nobody will want to use them, if > transitional devices work with legacy drivers > (Gerd Hoffmann, Michael S. Tsirkin) > * Drop virtio version from name: rename -1.0-transitional to > -transitional (Michael S. Tsirkin) > * Renamed -1.0 to -non-transitional > * Don't add any extra variants to modern-only device types > (they don't need it) ... if doing this was a good idea after all? While I understand that something like virtio-gpu, which supports the 1.0 specification exclusively, only really needs to have a single device associated with it from the functionality point of view, looking at it from a user's perspective it seems to me like providing an explicit non-transitional variant would be appropriate for consistency reasons, so that your guest could look like -device virtio-blk-pci-non-transitional \ -device virtio-net-pci-non-transitional \ -device virtio-gpu-pci-non-transitional \ and you wouldn't have to question why you can use the non-transitional variant for pretty much everything, except for the few cases where you can't - for no apparent reason... It would also signal quite clearly which devices support both transitional and non-transitional variants and which ones don't, without having to infer that the complete lack of (non-)transitional variants means that only the non-transitional variant is available - except you have to use the suffix-less device name to use it. tl;dr providing the non-transitional variant for virtio 1.0-only devices would make using this much more user-friendly. -- Andrea Bolognani / Red Hat / Virtualization