On Wed, Aug 02, 2023 at 01:09:28AM +0000, Tian, Kevin wrote: > > From: Jason Gunthorpe <jgg@xxxxxxxxxx> > > Sent: Wednesday, August 2, 2023 2:23 AM > > > > On Tue, Aug 01, 2023 at 02:40:44AM +0000, Tian, Kevin wrote: > > > > > > So, I guess we should leave it like this? > > > > > > > > > > Yes. Along with this discussion (including what you explained for sw_msi) > > > let's abandon this new cmd and leave it as today. > > > > You sure? This makes it basically impossible to write a "correct" vmm > > that is aware of what the physical memory map must be early on > > > > emmm... I thought it's what you meant by "leave it like this" and the > fact that existing VMM's memory layout happens to match the reserved > regions. Nobody complains lacking of such a interface for years then > we may postpone supporting it until it's really required. > > btw even if we add this new cmd now, getting the Qemu support to > use the aggregated list when creating the guest memory map is not > a simple task given currently vfio only passively acts on change > notifications in the guest memory layout. It requires a new mechanism > to enforce strict order (probe all vfio devices before creating the memory > layout) and then injects vfio reserved regions into the layout. > > Preferably let's not making it a hard dependency for this series. I see, if qemu won't use it then lets not do it Jason