Re: Programming PASID in IMS entries

[Jason Gunthorpe]

On Wed, Jul 07, 2021 at 03:12:16PM -0700, Raj, Ashok wrote:
> Hi Thomas
> 
> On Wed, Jul 07, 2021 at 10:50:52AM +0200, Thomas Gleixner wrote:
> > Megha,
> > 
> > On Wed, Jul 07 2021 at 09:49, Megha Dey wrote:
> > > Per your suggestions during the last meeting, we wanted to confirm the 
> > > sequence to program the PASID into the IMS entries:
> > >
> > > 1. Add a PASID member to struct msi_desc (Add as part of a union. Other 
> > > source-id's such as Jason's vm-id can be added to it)
> > 
> > Yes. Though we also discussed storing the default PASID in struct device
> > to begin with which is then copied to the msi_desc entries during
> > allocation.
> 
> Using default PASID in struct device will work for sub-devices until the
> guest needs to enable ENQCMD support. Since the guest kernel can ask for an
> interrupt by specifying something in the descriptor submitted via ENQCMD.
> Using the PASID in struct device won't be sufficient.

Could you could store a pasid table in the struct device and index it
by vector?

Jason