On 31.07.2024 11:37, Roger Pau Monné wrote:
> On Wed, Jul 31, 2024 at 11:02:01AM +0200, Jan Beulich wrote:
>> On 31.07.2024 10:51, Roger Pau Monné wrote:
>>> I agree with (a), but I don't think enabling PVH dom0 usage of the
>>> hypercalls should be gated on this. As said a PV dom0 is already
>>> capable of issuing PHYSDEVOP_{,un}map_pirq operations against a PVH
>>> domU.
>>
>> Okay, I can accept that as an intermediate position. We ought to deny
>> such requests at some point though for PVH domains, the latest in the
>> course of making vPCI work there.
>
> Hm, once physdev_map_pirq() works as intended against PVH domains, I
> don't see why we would prevent the usage of PHYSDEVOP_{,un}map_pirq
> against such domains.
Well. If it can be made work as intended, then I certainly agree. However,
without even the concept of pIRQ in PVH I'm having a hard time seeing how
it can be made work. Iirc you were advocating for us to not introduce pIRQ
into PVH.
Maybe you're thinking of re-using the sub-ops, requiring PVH domains to
pass in GSIs? I think I suggested something along these lines also to
Jiqian, yet with the now intended exposure to !has_pirq() domains I'm
not sure this could be made work reliably.
Which reminds me of another question I had: What meaning does the pirq
field have right now, if Dom0 would issue the request against a PVH DomU?
What meaning will it have for a !has_pirq() HVM domain?
Jan
