Re: [Qemu-devel] [PATCH v2 0/7] ramfb: simple boot framebuffer, no legacy vga

[Laszlo Ersek]

On 03/23/18 18:07, Gerd Hoffmann wrote:
> On Fri, Mar 23, 2018 at 04:12:21PM +0100, Laszlo Ersek wrote:
>> On 03/23/18 15:51, Gerd Hoffmann wrote:
>>>   Hi,
>>>
>>>> I believe the only point of this device model (and the associated guest
>>>> fw driver) is Windows-on-KVM/aarch64.
>>>
>>> The other one is vgpu boot display.
>>
>> Interesting. I know nearly nothing about vgpu, but I hoped it'd come
>> with its own UEFI GOP driver in the ROM BAR; similarly to assigned
>> physical GPUs.
> 
> Well.  They don't ...
> 
> And even for assigned GPUs it is a PITA.  For example the intel rom
> appears to have the pci slot hardcoded.  You have to place the GPU in
> 00:02.0 (which it has on bare metal), otherwise the rom doesn't work.
> I would be *very* surprised if the rom is able to handle vgpu devices
> correctly.  Beside that it isn't easy to get the rom in the first place,
> at least for intel, as it isn't stored in the rom bar but in the
> firmware flash.

Sure, IGD assignment is a different animal; I thought vgpu would follow
the discrete PCI card assignment case.

Anyway, I just wanted to educate myself on this; thanks!
Laszlo