> 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. 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