Re: [PATCH] firmware: smccc: support both conduits for getting hyp UUID

[Roman Kisel <romank@linux.microsoft.com>]

> (sorry for the delay, found the patch in the spam 🙁)

"b4" shows the the mail server used for the patch submission
doesn't pass the DKIM check, so finding the patch in the spam seems
expected :) Thanks for your help!

>
> On Wed, May 21, 2025 at 09:40:48AM +0000, Anirudh Rayabharam wrote:
>> From: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
>>
>> When Linux is running as the root partition under Microsoft Hypervisor
>> (MSHV) a.k.a Hyper-V, smc is used as the conduit for smc calls.
>>
>> Extend arm_smccc_hypervisor_has_uuid() to support this usecase. Use
>> arm_smccc_1_1_invoke to retrieve and use the appropriate conduit instead
>> of supporting only hvc.
>>
>> Boot tested on MSHV guest, MSHV root & KVM guest.
>>
>
> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
>
> Are they any dependent patches or series using this ? Do you plan to
> route it via KVM tree if there are any dependency. Or else I can push
> it through (arm-)soc tree. Let me know.

Anirudh had been OOF for some time and would be for another
week iiuc so I thought I'd reply.

The patch this depends on is 13423063c7cb
("arm64: kvm, smccc: Introduce and use API for getting hypervisor UUID"),
and this patch has already been pulled into the Linus'es tree.

As for routing, (arm-)soc should be good it appears as the change
is contained within the firmware drivers path. Although I'd trust more to your,
Arnd's or Wei's opinion than mine!

>
> --
> Regards,
> Sudeep