From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43)
	id 1LeWTM-00069x-2f
	for qemu-devel@nongnu.org; Tue, 03 Mar 2009 10:23:56 -0500
Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43)
	id 1LeWTK-00069b-JH
	for qemu-devel@nongnu.org; Tue, 03 Mar 2009 10:23:55 -0500
Received: from [199.232.76.173] (port=33236 helo=monty-python.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1LeWTK-00069Y-Fw
	for qemu-devel@nongnu.org; Tue, 03 Mar 2009 10:23:54 -0500
Received: from verein.lst.de ([213.95.11.210]:46544)
	by monty-python.gnu.org with esmtps
	(TLS-1.0:DHE_RSA_3DES_EDE_CBC_SHA1:24) (Exim 4.60)
	(envelope-from <hch@lst.de>) id 1LeWTK-0007e6-0s
	for qemu-devel@nongnu.org; Tue, 03 Mar 2009 10:23:54 -0500
Date: Tue, 3 Mar 2009 16:23:49 +0100
From: Christoph Hellwig <hch@lst.de>
Subject: Re: [Qemu-devel] virtio-blk issues
Message-ID: <20090303152349.GA21900@lst.de>
References: <20090303125411.GA16099@lst.de>
	<200903031422.44151.paul@codesourcery.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <200903031422.44151.paul@codesourcery.com>
Reply-To: qemu-devel@nongnu.org
List-Id: qemu-devel.nongnu.org
List-Unsubscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.gnu.org/pipermail/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Paul Brook <paul@codesourcery.com>
Cc: qemu-devel@nongnu.org, Christoph Hellwig <hch@lst.de>

On Tue, Mar 03, 2009 at 02:22:43PM +0000, Paul Brook wrote:
> On Tuesday 03 March 2009, Christoph Hellwig wrote:
> > I've been trying to move setup from kvm 72 in debian testing to the current
> > qemu CVS.  The setup is using 7 virtio_blk disks and used to work on the
> > old setup, but with current qemu the kernel (current Linus' HEAD from a few
> > days ago) hangs when trying to setup the irq routing for the virtio_pci
> > devices:
> >
> > virtio pci 0000:00:06.0: can't derive routing for PCI INT A
> > virtio pci 0000:00:06.0: PCI INT A: no GSI - using IRQ 9
> 
> IIRC this is partly a bios issue. Real PIIX3 based systems never have more 
> than ~5 PCI slots, so it doesn't have interrupt routing for more devices.
>
> There are two solutions: Fix the bios to handle machines with large numbers of 
> PCI slots, or have create multifunction PCI devices so lots of virtio 
> instances don't use so many virtual PCI slots.
> 

Or we could try to create a pc+PIIX style VM.  Surely having more than
two disks should not be that uncommon..