On Thu, Dec 9, 2021 at 1:41 PM Tian, Kevin <kevin.tian@xxxxxxxxx> wrote: > > > From: Jason Gunthorpe <jgg@xxxxxxxxxx> > > Sent: Thursday, December 2, 2021 9:55 PM > > > > Further, there is no reason why IMS should be reserved exclusively for > > VFIO! > > This is correct. Just as what you agreed with Thomas, the only difference > between IMS and MSI is on where the messages are stored. Physically > it is unreasonable for the HW to check whether an interrupt is used for > a specific software usage (e.g. virtualization) since it doesn't have such > knowledge. At most an entry is associated to PASID, but again the PASID > can be used anywhere. Note that vDPA had the plan to use IMS for the parent that can have a huge amount of instances. Thanks > > The wording in current IDXD spec is not clear on this part. We'll talk to > the spec owner to have it fixed. > > Thanks > Kevin >