From: Anthony Liguori <anthony@codemonkey.ws>
To: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] buffer alignment for block backends
Date: Thu, 09 Apr 2009 11:28:37 -0500 [thread overview]
Message-ID: <49DE2235.7050904@codemonkey.ws> (raw)
In-Reply-To: <49DE193B.50703@redhat.com>
Gerd Hoffmann wrote:
>>> The xen block protocol can handle unaligned requests just fine.
>>
>> Not completely arbitrarily aligned requests. They need to be
>> sector-aligned.
>
> Agreed. Sector-alignment you have anyway, thats why I didn't wrote
> that explicitly.
But even sector-alignment is not guaranteed for the buffers in the
bdrv_* API.
You can implement a backend that just implements aio_read/aio_write and
you'll always get sector-aligned offsets, but the actual data buffers
may have any alignment.
Regards,
Anthony Liguori
> cheers,
> Gerd
>
>
>
next prev parent reply other threads:[~2009-04-09 16:28 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-08 13:35 [Qemu-devel] buffer alignment for block backends Stefano Stabellini
2009-04-08 18:53 ` Anthony Liguori
2009-04-09 9:57 ` Stefano Stabellini
2009-04-09 13:11 ` Anthony Liguori
2009-04-09 13:30 ` Stefano Stabellini
2009-04-09 13:54 ` Gerd Hoffmann
2009-04-09 15:21 ` Samuel Thibault
2009-04-09 15:46 ` Stefano Stabellini
2009-04-09 15:50 ` Gerd Hoffmann
2009-04-09 16:11 ` Stefano Stabellini
2009-04-09 16:13 ` Samuel Thibault
2009-04-09 16:28 ` Anthony Liguori [this message]
2009-04-09 15:55 ` Jamie Lokier
2009-04-09 16:15 ` Samuel Thibault
2009-04-09 17:29 ` Lennart Sorensen
2009-04-09 13:33 ` Stefano Stabellini
2009-04-09 15:19 ` Samuel Thibault
2009-04-09 15:38 ` Paul Brook
2009-04-09 15:40 ` Samuel Thibault
2009-04-09 15:56 ` Anthony Liguori
2009-04-09 16:19 ` Samuel Thibault
2009-04-09 10:07 ` Stefano Stabellini
2009-04-09 13:14 ` Anthony Liguori
2009-04-09 13:30 ` Stefano Stabellini
2009-04-09 13:19 ` Christoph Hellwig
2009-04-09 13:30 ` Stefano Stabellini
2009-04-09 15:31 ` Christoph Hellwig
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