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Date: Mon, 22 Sep 2008 09:53:16 -0500
From: Anthony Liguori <anthony@codemonkey.ws>
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Subject: Re: [Qemu-devel] LSI SCSI: raise UDC on infinite loop (resend #1)
References: <20080912123831.GA22472@dmt.cnet>
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To: qemu-devel@nongnu.org
Cc: Marcelo Tosatti <mtosatti@redhat.com>, Paul Brook <paul@codesourcery.com>

Hi Marcelo,

Marcelo Tosatti wrote:
> Raise UDC (Unexpected Disconnect) when a large enough number of
> instructions has been executed by the SCRIPTS processor. This "solution"
> is much simpler than temporarily interrupting execution.
>
> This remedies the situation with Windows which downloads SCRIPTS code
> that busy loops on guest main memory. Their drivers _do_ handle UDC 
> appropriately (at least XP and 2003).
>
> It would be nicer to actually detect infinite loops, but until then,
> this bandaid seems acceptable.
>
> Since the situation seems to be rare enough, raise the number 
> of instructions to 10000 (previously 1000).
>
> Three people other than myself had success with this patch.
>   

Please add a Signed-off-by and I'll apply this patch.  I don't know that 
Paul has gotten a chance to look yet but we talked in IRC a while ago 
and he mentioned that it's probably the best solution we'll be able to 
come up with so that seems to suggest to me that it's safe to apply.

Regards,

Anthony Liguori