Re: Any plans to implement more ARM SMMUv3 features?

[Mostafa Saleh <smostafa@google.com>]

Hi Alex,

On Tue, Oct 31, 2023 at 12:02:03PM +0000, Alex Bennée wrote:
> 
> Hi All,
> 
> Since 8.1 we enabled the FEAT_RME CPU feature to allow for Arm CCA
> guests to be run under QEMU's Arm emulation. While this is enough for
> pure software guests eventually we would want to support modelling
> systems with "real" hardware. One part of that is updating the SMMU
> emulation to make it RME aware.
> 
> The recently published F.a spec is available on the Arm site:
> 
>   https://developer.arm.com/documentation/ihi0070/latest/
> 
> As we have a keen interest on tracking (and implementing!) Arm features
> we have coded up the various sub-features as stories under an EPIC for
> each level of SMMU feature on our public JIRA:
> 
>   https://linaro.atlassian.net/browse/QEMU-533 (SMMUv3.0)
>   https://linaro.atlassian.net/browse/QEMU-553 (SMMUv3.1)
>   https://linaro.atlassian.net/browse/QEMU-558 (SMMUv3.2)
>   https://linaro.atlassian.net/browse/QEMU-566 (SMMUv3.3)
>   
> I think the state of the cards currently represents what has been
> implemented and what is left to do. As you can see it adds up to a fair
> bit of stuff. As a lot of people have been hacking on the SMMU code over
> the last few years I thought it would be useful to reach out and see who
> else is interested in further enhancing the SMMU emulation support?
> 
> If anyone has any patches/branches cooking or is intending to implement
> any particular bits please do let me know and I can update the cards to
> reflect the current state of work. As ever we will do our best to help
> review and smooth the up-streaming process for all Arm related feature
> enhancements.

I worked on adding stage-2 SMMUv3 support in qemu and was planning on
working on nesting (stage-1 + stage-2). However, I haven't done any
work on this yet and I will be busy till early next year.

If this work would start before that I can put some time to help with
the review, otherwise I can start working on this early next year.

Thanks,
Mostafa