From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:41568) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QAjaK-0002C6-CR for qemu-devel@nongnu.org; Fri, 15 Apr 2011 10:01:21 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QAjaG-00013y-8h for qemu-devel@nongnu.org; Fri, 15 Apr 2011 10:01:20 -0400 Received: from mail-gx0-f173.google.com ([209.85.161.173]:60142) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QAjaG-00013u-4t for qemu-devel@nongnu.org; Fri, 15 Apr 2011 10:01:16 -0400 Received: by gxk26 with SMTP id 26so1404193gxk.4 for ; Fri, 15 Apr 2011 07:01:15 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1302874976-22248-1-git-send-email-pbonzini@redhat.com> References: <1302874976-22248-1-git-send-email-pbonzini@redhat.com> Date: Fri, 15 Apr 2011 15:01:15 +0100 Message-ID: From: Stefan Hajnoczi Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [RFC PATCH] implement vmware pvscsi device List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: Hannes Reinecke , Zachary Amsden , qemu-devel@nongnu.org, "Nicholas A. Bellinger" , "Michael S. Tsirkin" On Fri, Apr 15, 2011 at 2:42 PM, Paolo Bonzini wrote: > Lightly tested with Linux guests; at least it can successfully partition > and format a disk. =A0scsi-generic also lightly tested. > > Doesn't do migration, doesn't do hotplug (the device would support that, > but it is not 100% documented and the Linux driver in particular cannot > initiate hot-unplug). =A0I did it as quick one-day hack to study the SCSI > subsystem and it is my first real foray into device model land, please > be gentle. :) > > vmw_pvscsi.h is taken from Linux, so it doesn't fully respect coding > standards. =A0I think that's fair. > > Size is curiously close to the recently added sPAPR adapter: > > =A0911 =A02354 25553 hw/vmw_pvscsi.c > =A0988 =A03177 29628 hw/spapr_vscsi.c > > Sounds like that's just the amount of code it takes to implement a SCSI > HBA in QEMU. :) Interesting, thanks for posting this. I've been playing with virtio SCSI and it is still in the early stages. Nicholas A. Bellinger and I have been wiring the in-kernel SCSI target up to KVM using vhost. Feel free to take a peek at the work-in-progress: http://repo.or.cz/w/qemu/stefanha.git/shortlog/refs/heads/virtio-scsi http://git.kernel.org/?p=3Dlinux/kernel/git/nab/lio-core-2.6.git;a=3Dshortl= og;h=3Drefs/heads/tcm_vhost I think SCSI brings many benefits. Guests can deal with it better than these alien vdX virtio-blk devices, which makes migration easier. It becomes possible to attach many disks without burning through free PCI slots. We don't need to update guests to add cache control, discard, and other commands because they are part of SCSI. We can pass through more exotic devices. The list goes on... Stefan