On Thu, Nov 24 2022 at 09:09, Jason Gunthorpe wrote: > On Thu, Nov 24, 2022 at 10:10:05AM +0100, Thomas Gleixner wrote: >> On Thu, Nov 24 2022 at 03:01, Kevin Tian wrote: >> > SECONDARY or be explicit IMS? Are we envisioning non-IMS usages to >> > occupy this slot in the future? >> >> I'm not really decided on that. Whatever the name or use-case for a >> secondary domain is. Not, that this is not restricted to PCI. > > This is hierarchical right? So if a pci_device spawns an > auxiliary_device, its driver could stick a msi domain on the > MSI_DEFAULT_DOMAIN of the aux device as a child of the PCI device's > domain? A child of the PCI devices parent domain. The per device domains are endpoint domains. They cannot serve as parent domains themself right now. If there is a real reason and use case which requires that, it can be made work with trivial tweaks. Thanks, tglx