Re: Plan for /dev/ioasid RFC v2

Leon Romanovsky
2021-06-09T09:01:58Z

On Mon, Jun 07, 2021 at 02:58:18AM +0000, Tian, Kevin wrote:
> Hi, all,

<...>

> (Remaining opens in v1)

<...>

> - Device-centric (Jason) vs. group-centric (David) uAPI. David is not fully
> convinced yet. Based on discussion v2 will continue to have ioasid uAPI
> being device-centric (but it's fine for vfio to be group-centric). A new
> section will be added to elaborate this part;

<...>

> (Adopted suggestions)

<...>

> - (Jason) Addition of device label allows per-device capability/format
> check before IOASIDs are created. This leads to another major uAPI
> change in v2 - specify format info when creating an IOASID (mapping
> protocol, nesting, coherent, etc.). User is expected to check per-device
> format and then set proper format for IOASID upon to-be-attached
> device;

Sorry for my naive question, I still didn't read all v1 thread and maybe
the answer is already written, but will ask anyway.

Doesn't this adopted suggestion to allow device-specific configuration
actually means that uAPI should be device-centric?

User already needs to be aware of device, configure it explicitly, maybe
gracefully clean it later, it looks like not so much left to be group-centric.

Thanks