Re: [PATCH] content: Reserve ID 52 for Snapdragon device

[Stefan Hajnoczi <stefanha@redhat.com>]

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On Wed, Aug 26, 2026 at 05:31:54PM +0200, Jan Kiszka wrote:
> On 26.08.26 13:55, Peter Hilber wrote:
> > Reserve a device ID for the Snapdragon device.  A Virtio Snapdragon
> > device exposes functionality across Snapdragon SoC subsystems through a
> > common Virtio-based protocol.
> > 
> 
> Virtio is supposed to provide generic hardware models, not so much a
> channel to expose concrete, physical chip IP over it. This looks very
> weird to me.

Device IDs assignments don't have to result in standardized devices. See
"5 Device Types" in VIRTIO 1.4 where there is a table of currently
reserved Device IDs.

While I'm in favor of defining generic device interfaces with many
possible implementations like virtio-net, virtio-blk, etc, I think a
SoC-specific control device is unlikely to fit into that category and
it's acceptable to allocate the Device ID with the understanding that
there will never be standardization of the device.

Stefan

> 
> Also, isn't Snapdragon a protected brand by Qualcomm? Would it even
> legally be fine use it in the spec?
> 
> > Device ID 51 is already reserved for the Virtio HAB device:
> > 
> > https://lore.kernel.org/virtio-comment/20260702140939.3535968-1-zeloren@qti.qualcomm.com/
> > 
> 
> I think I even voted for this, but likely without checking back what
> this may become. I was expecting (hoping?) for a generic, portable inter
> VM channel using shared memory. I hope HAB can be that as well - besides
> enabling some very Qualcomm-specific and unportable pass-through of
> accelerators or so.
> 
> Does a "Snapdragon device" have any relation to / dependency on HAB, or
> is this just the ID collision why it is mentioned here?
> 
> Jan
> 
> -- 
> Siemens AG, Foundational Technologies
> Linux Expert Center
> 

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