> From: Jason Gunthorpe <jgg@xxxxxxxxxx> > Sent: Thursday, September 22, 2022 8:14 PM > > On Thu, Sep 22, 2022 at 05:11:00AM +0000, Tian, Kevin wrote: > > > > Thinking of the interrupt routing as a host resource is the problem - > > > it is a device resource and just like PASID the ideal design would > > > have each RID have its own stable numberspace scoped within it. The > > > entire RID and all its stable numberspace would be copied over. > > > > > > > Unfortunately it is not the case at least on Intel VT-d. The interrupt > > remapping table is per VT-d instead of per RID. > > Doesn't that just turn it into a SW problem how it manages it? > When IRTEs are shared cross RID's I'm not sure how to make the allocation stable between the src and the dest. They are allocated dynamically and hierarchically in request_irq(). I'm not sure what SW mechanism can cleanly ensure a stable allocation scheme between two machines. Can you elaborate?