From: Paul Brook <paul@codesourcery.com>
To: qemu-devel@nongnu.org
Cc: Christoph Hellwig <hch@lst.de>,
Anthony Liguori <anthony@codemonkey.ws>,
kvm@vger.kernel.org, Rusty Russell <rusty@rustcorp.com.au>,
Christian Borntraeger <borntraeger@de.ibm.com>,
Hannes Reinecke <hare@suse.de>
Subject: Re: [Qemu-devel] Re: [PATCH] virtio-blk: add SGI_IO passthru support
Date: Wed, 29 Apr 2009 12:11:19 +0100 [thread overview]
Message-ID: <200904291211.20374.paul@codesourcery.com> (raw)
In-Reply-To: <20090429104854.GA7846@lst.de>
On Wednesday 29 April 2009, Christoph Hellwig wrote:
> On Tue, Apr 28, 2009 at 11:37:01AM -0500, Anthony Liguori wrote:
> > Ah, excellent. I think that's a great thing to do. So do you think
> > virtio-scsi would deprecate virtio-blk?
>
> I don't think so. If you have an image format or a non-scsi blockdevice
> underneath virtio-block avoids the encoding into SCSI CDBs and back and
> should be faster.
Is this actually measurably faster, or just infinitesimally faster in theory?
I can maybe see that virtio-blk is slightly simpler for dumb drivers, though
even then a basic scsi host is pretty straightforward and I find it hard to
believe there's much real benefit.
Paul
WARNING: multiple messages have this Message-ID (diff)
From: Paul Brook <paul@codesourcery.com>
To: qemu-devel@nongnu.org
Cc: kvm@vger.kernel.org, Rusty Russell <rusty@rustcorp.com.au>,
Christian Borntraeger <borntraeger@de.ibm.com>,
Hannes Reinecke <hare@suse.de>, Christoph Hellwig <hch@lst.de>
Subject: Re: [Qemu-devel] Re: [PATCH] virtio-blk: add SGI_IO passthru support
Date: Wed, 29 Apr 2009 12:11:19 +0100 [thread overview]
Message-ID: <200904291211.20374.paul@codesourcery.com> (raw)
In-Reply-To: <20090429104854.GA7846@lst.de>
On Wednesday 29 April 2009, Christoph Hellwig wrote:
> On Tue, Apr 28, 2009 at 11:37:01AM -0500, Anthony Liguori wrote:
> > Ah, excellent. I think that's a great thing to do. So do you think
> > virtio-scsi would deprecate virtio-blk?
>
> I don't think so. If you have an image format or a non-scsi blockdevice
> underneath virtio-block avoids the encoding into SCSI CDBs and back and
> should be faster.
Is this actually measurably faster, or just infinitesimally faster in theory?
I can maybe see that virtio-blk is slightly simpler for dumb drivers, though
even then a basic scsi host is pretty straightforward and I find it hard to
believe there's much real benefit.
Paul
next prev parent reply other threads:[~2009-04-29 11:11 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-27 8:26 [PATCH] virtio-blk: add SGI_IO passthru support Christoph Hellwig
2009-04-27 8:29 ` Christoph Hellwig
2009-04-27 8:29 ` [Qemu-devel] " Christoph Hellwig
2009-04-27 9:15 ` Avi Kivity
2009-04-27 9:15 ` [Qemu-devel] " Avi Kivity
2009-04-28 9:47 ` Christoph Hellwig
2009-04-28 9:47 ` Christoph Hellwig
2009-04-27 14:36 ` Anthony Liguori
2009-04-27 14:36 ` [Qemu-devel] " Anthony Liguori
2009-04-28 9:51 ` Christoph Hellwig
2009-04-28 9:51 ` Christoph Hellwig
2009-04-28 16:37 ` Anthony Liguori
2009-04-28 16:52 ` Christian Borntraeger
2009-04-28 16:52 ` Christian Borntraeger
2009-04-29 10:48 ` Christoph Hellwig
2009-04-29 10:48 ` Christoph Hellwig
2009-04-29 11:11 ` Paul Brook [this message]
2009-04-29 11:11 ` Paul Brook
2009-04-29 11:19 ` Christian Borntraeger
2009-04-29 11:19 ` Christian Borntraeger
2009-04-29 11:29 ` Paul Brook
2009-04-29 11:29 ` Paul Brook
2009-04-29 11:21 ` Christoph Hellwig
2009-04-29 11:21 ` Christoph Hellwig
2009-04-29 11:37 ` Paul Brook
2009-04-29 11:37 ` Paul Brook
2009-04-30 20:13 ` Christoph Hellwig
2009-04-30 20:13 ` Christoph Hellwig
2009-04-30 20:55 ` Nicholas A. Bellinger
2009-04-30 20:55 ` Nicholas A. Bellinger
2009-04-30 21:49 ` Paul Brook
2009-04-30 21:49 ` Paul Brook
2009-04-30 21:56 ` Javier Guerra
2009-04-30 21:56 ` Javier Guerra
2009-05-01 7:24 ` Christoph Hellwig
2009-05-01 7:24 ` Christoph Hellwig
2009-05-01 11:08 ` Jamie Lokier
2009-05-01 11:08 ` Jamie Lokier
2009-05-01 14:28 ` Christoph Hellwig
2009-05-01 14:28 ` Christoph Hellwig
2009-05-05 5:21 ` Rusty Russell
2009-05-05 5:21 ` Rusty Russell
2009-04-28 19:09 ` Christian Borntraeger
2009-04-28 19:09 ` Christian Borntraeger
2009-04-29 10:50 ` Christoph Hellwig
2009-04-29 10:50 ` Christoph Hellwig
2009-04-29 11:07 ` Christian Borntraeger
2009-04-29 11:07 ` Christian Borntraeger
2009-04-28 9:57 ` [PATCH 2/2] virtio-blk: add SG_IO " Christoph Hellwig
2009-04-28 9:57 ` [Qemu-devel] " Christoph Hellwig
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