Re: [PATCH v4 06/17] PCI: add SIOV and IMS capability detection

Jason Gunthorpe
2020-10-30T22:45:44Z

On Fri, Oct 30, 2020 at 02:20:03PM -0700, Dave Jiang wrote:
> So the intel-iommu driver checks for the SIOV cap. And the idxd driver
> checks for SIOV and IMS cap. There will be other upcoming drivers that will
> check for such cap too. It is Intel vendor specific right now, but SIOV is
> public and other vendors may implement to the spec. Is there a good place to
> put the common capability check for that?

I'm still really unhappy with these SIOV caps. It was explained this
is just a hack to make up for pci_ims_array_create_msi_irq_domain()
succeeding in VM cases when it doesn't actually work.

Someday this is likely to get fixed, so tying platform behavior to PCI
caps is completely wrong.

This needs to be solved in the platform code,
pci_ims_array_create_msi_irq_domain() should not succeed in these
cases.

Jason