From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=42705 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Onpra-0003oj-21 for qemu-devel@nongnu.org; Tue, 24 Aug 2010 05:32:15 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OnprY-0002bh-LJ for qemu-devel@nongnu.org; Tue, 24 Aug 2010 05:32:13 -0400 Received: from mx1.redhat.com ([209.132.183.28]:31936) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OnprY-0002bR-Ez for qemu-devel@nongnu.org; Tue, 24 Aug 2010 05:32:12 -0400 Date: Tue, 24 Aug 2010 10:31:55 +0100 From: "Daniel P. Berrange" Subject: Re: [Qemu-devel] [PATCH 4/5] Add generic drive hotplugging Message-ID: <20100824093155.GB7376@redhat.com> References: <1282600951-30803-1-git-send-email-agraf@suse.de> <1282600951-30803-5-git-send-email-agraf@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1282600951-30803-5-git-send-email-agraf@suse.de> Reply-To: "Daniel P. Berrange" List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf Cc: Markus Armbruster , Luiz Capitulino , qemu-devel List , Aurelien Jarno , Gerd Hoffmann On Tue, Aug 24, 2010 at 12:02:30AM +0200, Alexander Graf wrote: > The monitor command for hotplugging is in i386 specific code. This is just > plain wrong, as S390 just learned how to do hotplugging too and needs to > get drives for that. > > So let's add a generic copy to generic code that handles drive_add in a > way that doesn't have pci dependencies. > > I'm not fully happy with the patch as is. IMHO there should only be a > single target agnostic drive_hot_add function available. How we could > potentially fit IF_SCSI in there I don't know though. I'm not sure that this patch is actually neccessary. Via a undocumented, sick, dirty hack, you can already use the current drive_add command without a PCI address, for both virtio + scsi. In fact not using the PCI address with drive_add is the preferred approach in the new qdev world even on x86 The key is that you should use if=none for all cases. Here are two examples of how libvirt does it currently: VirtIO: drive_add dummy file=/var/lib/libvirt/images/data.img,if=none,id=drive-virtio-disk1,format=raw device_add virtio-blk-pci,bus=pci.0,addr=0x0,drive=drive-virtio-disk1,id=virtio-disk1' SCSI: drive_add dummy file=/var/lib/libvirt/images/data.img,if=none,id=drive-scsi0-0-1,format=raw' device_add scsi-disk,bus=scsi0.0,scsi-id=1,drive=drive-scsi0-0-1,id=scsi0-0-1 The 'dummy' value there can be absolutely anything you want. It is totaly ignored when QEMU sees if=none in 2nd arg. Regards, Daniel -- |: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :| |: http://libvirt.org -o- http://virt-manager.org -o- http://deltacloud.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|