From mboxrd@z Thu Jan  1 00:00:00 1970
From: Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [RFC] Virtual disk configuration, PV vs. emulated,
 backward compatibility etc
Date: Wed, 28 Jul 2010 14:31:59 +0200
Message-ID: <4C50233F.3060209@redhat.com>
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To: Ian Campbell <Ian.Campbell@citrix.com>
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On 07/27/2010 05:58 PM, Ian Campbell wrote:
> The sd* syntax is not covered. It's unclear if this is used in the wild
> or what the existing semantics of emul= are for SCSI devices. If someone
> cares to investigate the existing behaviour then it can be added.

I don't know what semantics xl uses for SCSI devices, but I know that 
we've seen bugs about SCSI emulation so it is sometimes used, and this 
is the semantics that it should use given your IDE example:

         sda => d0p0,pv=true,emul=scsi0.0,_vdevice=8:0
         sdb => d0p0,pv=true,emul=scsi0.1,_vdevice=8:16

where the first number is the bus and the second is the unit as passed 
to -drive.  The second number goes from 0 to 7 (that's what QEMU does at 
least).

Paolo