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Date: Wed, 1 Jul 2009 10:43:25 +0200
From: Christoph Hellwig <hch@lst.de>
Subject: Re: [Qemu-devel] [PATCH] ATAPI pass through
Message-ID: <20090701084325.GA2959@lst.de>
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To: Bique Alexandre <alexandre.bique@citrix.com>
Cc: Christoph Hellwig <hch@lst.de>, "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>

On Tue, Jun 30, 2009 at 06:55:42PM +0100, Bique Alexandre wrote:
> I can switch to aio_ioctl, and use CDROM_SEND_PACKET ioctl.

CDROM_SEND_PACKET has a rather horrible API and should be avoided.
Just use SG_IO like the the scsi passthrough code.  In fact there might
be some quite a few ways to unify that code if you're motivated.

> Is it possible to send multiple requests at the same time with aio_ioctl ? 

SG_IO sends one requests per ioctl, but you can have multiple requests
outstanding on a single file descriptor.

> When CONFIG_AIO is not available ?

aio_ioctl needs CONFIG_AIO - but on Linux hosts where you have
bsd/sg/etc it always is available.