Re: [PATCH v4 00/12] Initial support for SMMUv3 nested translation

Jason Gunthorpe
2024-11-15T17:55:26Z

On Thu, Nov 14, 2024 at 08:51:47AM +0800, Baolu Lu wrote:
> On 11/14/24 00:43, Jason Gunthorpe wrote:
> > On Wed, Nov 13, 2024 at 10:55:41AM +0800, Baolu Lu wrote:
> > > On 11/13/24 09:23, Jason Gunthorpe wrote:
> > > > > https://github.com/Linaro/linux-kernel-uadk/tree/6.12-wip
> > > > > https://github.com/Linaro/qemu/tree/6.12-wip
> > > > >
> > > > > Still need this hack
> > > > > https://github.com/Linaro/linux-kernel-uadk/commit/
> > > > > eaa194d954112cad4da7852e29343e546baf8683
> > > > >
> > > > > One is adding iommu_dev_enable/disable_feature IOMMU_DEV_FEAT_SVA,
> > > > > which you have patchset before.
> > > > Yes, I have a more complete version of that here someplace. Need some
> > > > help on vt-d but hope to get that done next cycle.
> > >
> > > Can you please elaborate this a bit more? Are you talking about below
> > > change
> >
> > I need your help to remove IOMMU_DEV_FEAT_IOPF from the intel
> > driver. I have a patch series that eliminates it from all the other
> > drivers, and I wrote a patch to remove FEAT_SVA from intel..
>
> Yes, sure. Let's make this happen in the next cycle.
>
> FEAT_IOPF could be removed. IOPF manipulation can be handled in the
> domain attachment path. A per-device refcount can be implemented. This
> count increments with each iopf-capable domain attachment and decrements
> with each detachment. PCI PRI is enabled for the first iopf-capable
> domain and disabled when the last one is removed. Probably we can also
> solve the PF/VF sharing PRI issue.

Here is what I have so far, if you send me a patch for vt-d to move
FEAT_IOPF into attach as you describe above (see what I did to arm for
example), then I can send it next cycle

https://github.com/jgunthorpe/linux/commits/iommu_no_feat/

Thanks,
Jason