Re: [RFC PATCH 0/5] hw/arm/virt: Add support for user-creatable nested SMMUv3

[Eric Auger]

Hi Nicolin,


On 2/5/25 1:08 AM, Nicolin Chen wrote:
> On Tue, Feb 04, 2025 at 06:49:15PM +0100, Eric Auger wrote:
>>> In summary, we will have the following series:
>>> 1) HWPT uAPI patches in backends/iommufd.c (Zhenzhong or Shameer)
>>>    
>>> https://lore.kernel.org/qemu-devel/SJ0PR11MB6744943702EB5798EC9B3B9992E02@SJ0PR11MB6744.namprd11.prod.outlook.com/
>>> 2) vIOMMU uAPI patches in backends/iommufd.c (I will rebase/send)
>> for 1 and 2, are you taking about the "Add VIOMMU infrastructure support
>> " series in Shameer's branch: private-smmuv3-nested-dev-rfc-v1.
>> Sorry I may instead refer to NVidia or Intel's branch but I am not sure
>> about the last ones.
> That "vIOMMU infrastructure" is for 2, yes.
>
> For 1, it's inside the Intel's series:
> "cover-letter: intel_iommu: Enable stage-1 translation for passthrough device"
>
> So, we need to extract them out and make it separately..

OK
>
>>> 3) vSMMUv3 patches for HW-acc/nesting (Hoping Don/you could take over)
>> We can start sending it upstream assuming we have a decent test environment.
>>
>> However in
>> https://lore.kernel.org/all/329445b2f68a47269292aefb34584375@huawei.com/
>>
>> Shameer suggested he may include it in his SMMU multi instance series.
>> What do you both prefer?
> Sure, I think it's good to include those patches, though I believe
> we need to build a new shared branch as Shameer's branch might not
> reflect the latest kernel uAPI header.
>
> Here is a new branch on top of latest master tree (v9.2.50):
> https://github.com/nicolinc/qemu/commits/wip/for_shameer_02042025
>
> I took HWPT patches from Zhenzhong's series and rebased all related
> changes from my tree. I did some sanity and it should work with RMR.
>
> Shameer, would you please try this branch and then integrate your
> series on top of the following series?
>    cover-letter: Add HW accelerated nesting support for arm SMMUv3
>    cover-letter: Add vIOMMU-based nesting infrastructure support
>    cover-letter: Add HWPT-based nesting infrastructure support
> Basically, just replace my old multi-instance series with yours, to
> create a shared branch for all of us.
>
> Eric, perhaps you can start to look at the these series. Even the
> first two iommufd series are a bit of rough integrations :)
OK I am starting this week

Eric
>
> Thanks
> Nicolin
>