Re: [Qemu-devel] [Xen-devel] [v5][PATCH 0/5] xen: add Intel IGD passthrough support

["Chen, Tiejun" <tiejun.chen@intel.com>]

On 2014/7/1 3:31, Ross Philipson wrote:
> On 06/30/2014 03:22 PM, Stefano Stabellini wrote:
>> On Mon, 30 Jun 2014, Michael S. Tsirkin wrote:
>>> On Mon, Jun 30, 2014 at 03:24:58PM +0800, Chen, Tiejun wrote:
>>>> On 2014/6/30 14:48, Michael S. Tsirkin wrote:
>>>>> On Mon, Jun 30, 2014 at 10:51:49AM +0800, Chen, Tiejun wrote:
>>>>>> On 2014/6/26 18:03, Paolo Bonzini wrote:
>>>>>>> Il 26/06/2014 11:18, Chen, Tiejun ha scritto:
>>>>>>>>
>>>>>>>>>
>>>>>>>>> - offsets 0x0000..0x0fff map to configuration space of the host
>>>>>>>>> MCH
>>>>>>>>>
>>>>>>>>
>>>>>>>> Are you saying the config space in the video device?
>>>>>>>
>>>>>>> No, I am saying in a new BAR, or at some magic offset of an existing
>>>>>>> MMIO BAR.
>>>>>>>
>>>>>>
>>>>>> As I mentioned previously, the IGD guy told me we have no any
>>>>>> unused a
>>>>>> offset or BAR in the config space.
>>>>>>
>>>>>> And guy who are responsible for the native driver seems not be
>>>>>> accept to
>>>>>> extend some magic offset of an existing MMIO BAR.
>>>>>>
>>>>>> In addition I think in a short time its not possible to migrate
>>>>>> i440fx to
>>>>>> q35 as a PCIe machine of xen.
>>>>>
>>>>> That seems like a weak motivation.  I don't see a need to get
>>>>> something
>>>>> merged upstream in a short time: this seems sure to miss 2.1,
>>>>> so you have the time to make it architecturally sound.
>>>>> "Making existing guests work" would be a better motivation.
>>>>
>>>> Yes.
>>>
>>> So focus on this then. Existing guests will probably work
>>> fine on a newer chipset - likely better than on i440fx.
>>> xen management tools need to do some work to support this?
>>
>> Unfortunately existing Windows guests don't take well chipset changes.
>> Windows might request a new activation.
>
> That is a very good point. A while back I did a bunch of work to try to
> keep Windows activated between running an instance of Windows on bare
> metal and as a VM. There were numerous bits of hardware and firmware
> that went into the calculation as to whether Windows thought it was the
> same platform for activation purposes. Changing the chipset sounds like
> a likely candidate for inspection. Somewhere out there on the webs is a
> partial list of the things that are inspected - lost the URL.
>

So do this mean currently we still can't go q35?

Thanks
Tiejun