From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:37779) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1goBEi-00040H-9h for qemu-devel@nongnu.org; Mon, 28 Jan 2019 13:02:21 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1goB2g-0002WM-VI for qemu-devel@nongnu.org; Mon, 28 Jan 2019 12:49:56 -0500 Date: Mon, 28 Jan 2019 18:49:19 +0100 From: Kevin Wolf Message-ID: <20190128174919.GL5756@localhost.localdomain> References: <20190125174653.4604-1-kwolf@redhat.com> <20190125174653.4604-3-kwolf@redhat.com> <20190128085041.GA16630@andariel.pipo.sk> <20190128144147.GA5756@localhost.localdomain> <87tvhszpql.fsf@dusky.pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87tvhszpql.fsf@dusky.pond.sub.org> Subject: Re: [Qemu-devel] [PATCH 2/3] scsi-disk: Add device_id property List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Markus Armbruster Cc: Peter Krempa , qemu-block@nongnu.org, libvir-list@redhat.com, qemu-devel@nongnu.org, pbonzini@redhat.com Am 28.01.2019 um 17:55 hat Markus Armbruster geschrieben: > Kevin Wolf writes: > > > Am 28.01.2019 um 09:50 hat Peter Krempa geschrieben: > [...] > >> 2) Is actually using 'scsi-cd'/'scsi-hd' the better option than > >> 'scsi-disk'? > > > > Yes, scsi-disk is a legacy device. Maybe we should formally deprecate > > it. > > There's an internal use in scsi_bus_legacy_add_drive(), which in turn > powers two legacy features: > > 1. -drive if=scsi > > Creates scsi-disk frontends. > > Only works with onboard HBAs since commit 14545097267, v2.12.0. > > 2. -device usb-storage > > Bad magic: usb-storage pretends to be a block device, but it's really > a SCSI bus that can serve only a single device, which it creates > automatically. > > If we deprecate scsi-disk, we should deprecate these, too. Can't say > whether that's practical right now. Most likely not worth the effort anyway. I don't think it's blocking anything. > >> 3) Since upstream libvirt supports qemu-1.5 and newer and 'scsi-cd' is > >> already supported there, can we assume that all newer versions support > >> it? (Basically the question is whether it can be compiled out by > >> upstream means). > > > > I think so. > > Compiling out scsi-hd or scsi-cd, but not scsi-disk would be silly. All > three devices are in scsi-disk.c. You'd have to hack that up to be > silly. I understood this as a question about libvirt, i.e. whether libvirt can drop/compile out their scsi-disk code and instead assume that scsi-hd/cd are always present. Maybe I misunderstood, though? Kevin