> From: Jason Gunthorpe <jgg@xxxxxxxxxx> > Sent: Wednesday, September 21, 2022 8:48 PM > > On Wed, Sep 21, 2022 at 07:57:00AM +0000, Tian, Kevin wrote: > > > From: Jason Gunthorpe <jgg@xxxxxxxxxx> > > > Sent: Tuesday, September 20, 2022 10:10 PM > > > > > > On Thu, Sep 15, 2022 at 09:24:07AM +0000, Tian, Kevin wrote: > > > > > > > After migration the IRTE index could change hence the addr/data pair > > > > acquired before migration becomes stale and must be fixed. > > > > > > The migration has to keep this stuff stable somehow, it seems > > > infeasible to fix it after the fact. > > > > > > > This is not how live migration typically works, i.e. we don't try to > > freeze the same host resource cross migration. It's pretty fragile > > and the chance of failure is high. > > 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.
