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From: Paul Brook <paul@codesourcery.com>
Subject: Re: [Qemu-devel] [PATCH] ATAPI pass through
Date: Wed, 1 Jul 2009 10:36:01 +0100
References: <200906301634.53197.alexandre.bique@citrix.com>
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To: qemu-devel@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>, Alexander Graf <agraf@suse.de>, Bique Alexandre <alexandre.bique@citrix.com>

> I don't really know what became of the SCSI layer since I haven't
> looked at it for quite some time now.
> But last time I checked, we had a cdrom emulation in scsi-disk.c _and_
> in ide.c.

IIRC ATAPI and SCSI are not the same. They provide very similar functionality, 
however the actual commands are different.

While it is possible to connect SATA drives to a SAS HBA, I believe this is 
done by tunneling IDE/ATAPI commands, rather then using native SCSI commands.

The common bits of the cdrom emulation are already broken out into cdrom.c.

USB Mass Storage can (in theory) use both ATAPI and SCSI devices. Currently we 
only implement SCSI.

Paul