Re: [Qemu-devel] [PATCH/RFC] Set a (distinguishable) subsystem id for Cirrus VGA

[Anthony Liguori <anthony@codemonkey.ws>]

Jeremy Katz wrote:
> On Fri, 2007-08-10 at 17:28 +0100, Paul Brook wrote:
>   
>> On Thursday 09 August 2007, Jeremy Katz wrote:
>>     
>>> The attached adds a PCI subsystem vendor ID of 0x514D (QM ascii->hex)
>>> for the Cirrus emulation so that you can tell that the system is running
>>> under qemu.  This will make it so that, eg, we can detect that in X and
>>> know that resolutions > 800x600 won't blow up a monitor.
>>>       
>> I'd rather not. If you want autodetection to work then implement vesa DDC 
>> emulation.
>>     
>
> The Cirrus hardware never supported it, so it's basically going to be
> making up all new code for the emulation, the drivers, etc.  For
> basically dead end emulation, this seems a bit overkill.  Especially as
> subsystem vendor/device ids are strongly recommended anyway by the PCI
> spec (though not required)
>
> Longer term, getting emulation of more capable video chipsets is the
> better answer (including DDC or some of the stuff that the VMware SVGA
> adapter supports for passing information back and forth).  
>   

QEMU already supports the VMware SVGA adapter nicely but the issue is 
that AFAIK the Windows driver is not licensed in such a way that it 
could be utilized for QEMU.

I suspect our best long term bet is a new paravirtual graphics driver 
that's also a standard VESA device and the hope that someone writes a 
proper Windows driver for it.

Regards,

Anthony Liguori

> Jeremy
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