RE: [patch V2 28/33] PCI/MSI: Provide IMS (Interrupt Message Store) support

From: Tian, Kevin
Date: Wed Nov 23 2022 - 22:11:14 EST


> From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Sent: Monday, November 21, 2022 10:38 PM
>
> The IMS domains have a few constraints:
>
> - The index space is managed by the core code.
>
> Device memory based IMS provides a storage array with a fixed size
> which obviously requires an index. But there is no association between
> index and functionality so the core can randomly allocate an index in
> the array.
>
> Queue memory based IMS does not have the concept of an index as the
> storage is somewhere in memory. In that case the index is purely
> software based to keep track of the allocations.

'Queue' could be a HW queue or SW queue. Is it clearer to just use
'system memory based IMS" here?

and for a GPU it is probably just a gfx context to store IMS content, w/o
a queue concept.