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

Raj, Ashok
2020-11-08T23:37:03Z

Hi Jason,

On Sun, Nov 08, 2020 at 07:23:41PM -0400, Jason Gunthorpe wrote:
>
> IDXD is worring about case #4, I think, but I didn't follow in that
> whole discussion about the IMS table layout if they PASID tag the IMS
> MemWr or not?? Ashok can you clarify?
>

The PASID in the interrupt store is for the IDXD to verify the interrupt handle
that came with the ENQCMD. User applications can obtain an interrupt handle and
ask for interrupt to be generated for transactions submitted via ENQCMD.

IDXD will compare the PASID that came with ENQCMD and verify if the PASID matches
the one stored in the Interrupt Table before generating the MemWr.

So MemWr for interrupts remains unchanged for IDXD on the wire. PASID is present in interrupt
store because the value was programmed by user space, and needs OS/hardware to ensure
the entity asking for interrupts has ownership for the interrupt handle.