Re: [Qemu-devel] VFIO based vGPU(was Re: [Announcement] 2015-Q3 release of XenGT - a Mediated ...)

[Jike Song]

On 01/26/2016 10:05 PM, Yang Zhang wrote:
> On 2016/1/26 15:41, Jike Song wrote:
>
>> We will need to extend:
>>
>>      - VFIO_DEVICE_GET_REGION_INFO
>>
>>
>> a) adding a flag: DONT_MAP. For example, the MMIO of vgpu
>> should be trapped instead of being mmap-ed.
> 
> I may not in the context, but i am curious how to handle the DONT_MAP in 
> vfio driver? Since there are no real MMIO maps into the region and i 
> suppose the access to the region should be handled by vgpu in i915 
> driver, but currently most of the mmio accesses are handled by Qemu.
>

Hi Yang,

MMIO accesses are supposed to be handled in kernel, without vm-exiting
to QEMU, similar to in-kernel irqchip :)

--
Thanks,
Jike