Re: [PATCH] hvmloader: probe memory below 4G before allocation for OVMF

[Jan Beulich <jbeulich@xxxxxxxx>]

On 03.04.2020 17:17, Igor Druzhinin wrote:
> On 03/04/2020 16:05, Jan Beulich wrote:
>> On 03.04.2020 16:47, Igor Druzhinin wrote:
>>> There multiple technical complications that caused this mess.
>>> One of them is that there is no unfortunately a better place for the
>>> framebuffer to be located initially. Second, SR-IOV device
>>> is real and adding a virtual BAR to it is also complicated (due to
>>> compatibility reasons) and NVIDIA decided to avoid that.
>>
>> In which case I wonder - aren't you ending up with the MMIO case
>> that I had mentioned, and that you said is difficult to deal with?
> 
> No, it's VRAM area (normal RAM pages) - not MMIO.

Well, VRAM is still MMIO from the CPU's perspective, just without
any side effects. But if it was another device that was passed
through, couldn't its MMIO similarly end up in that area?

Jan