Re: [patch V2 27/33] genirq/msi: Provide constants for PCI/IMS support

[Thomas Gleixner]

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