On Tue, 22 Oct 2024 at 22:53, Jason Gunthorpe <j...@nvidia.com> wrote:
>
> On Tue, Oct 22, 2024 at 10:30:10PM +0800, Zhangfei Gao wrote:
> > On Fri, 18 Oct 2024 at 21:53, Jason Gunthorpe <j...@nvidia.com> wrote:
> > >
> > > On Wed, Oct 16, 2024 at 12:25:03PM -0300, Jason Gunthorpe wrote:
> > > > > > smmu-v3 needs some more fixing to move that
> > > > > > arm_smmu_master_enable_sva() logic into domain attachment.
> > > > >
> > > > > Will think about this, Thanks Jason
> > > >
> > > > Can you test it if a patch is made?
> > >
> > > Here it is:
> > >
> > > https://github.com/jgunthorpe/linux/commits/smmuv3_nesting/
> > >
> > > fa1528253d2210 iommu: Remove IOMMU_DEV_FEAT_SVA
> > > 5675560a272cf5 iommu/vt-d: Check if SVA is supported when attaching the
> > > SVA domain
> > > 94bc2b9525b508 iommu/arm-smmu-v3: Put iopf enablement in the domain
> > > attach path
> > >
> > > Let me know..
> >
> > With these patches, do we still need ops->user_pasid_table?
>
> It makes no change - you need user_pasid_table to make
> IOMMU_DOMAIN_NESTED work.
>
> If you aren't using IOMMU_DOMAIN_NESTED you shouldn't need it.
OK, I misunderstood.
Then with user_pasid_table=1
both with these patches and without patches, user page fault is OK.
>
> > if (fault->prm.flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID) {
> > attach_handle = iommu_attach_handle_get(dev->iommu_group,
> > fault->prm.pasid, 0);
> >
> > // is attach_handle expected effect value here?
> > if (IS_ERR(attach_handle)) {
> > const struct iommu_ops *ops = dev_iommu_ops(dev);
> >
> > if (!ops->user_pasid_table)
> > return NULL;
> > /*
> > * The iommu driver for this device supports user-
> > * managed PASID table. Therefore page faults for
> > * any PASID should go through the NESTING domain
> > * attached to the device RID.
> > */
> > attach_handle = iommu_attach_handle_get(
> > dev->iommu_group, IOMMU_NO_PASID,
> > IOMMU_DOMAIN_NESTED);
> >
> > Now I still need set ops->user_pasid_table, since attach_handle can not
> > return from the first iommu_attach_handle_get with fault->prm.pasid = 1,
> > but the second iommu_attach_handle_get with IOMMU_NO_PASID,
> > suppose it is not expected?
>
> The second handle_get will always fail unless you are using
> IOMMU_DOMAIN_NESTED in userspace with iommufd.
>
> What testing are you doing exactly?
I am testing vsva based on Nico's iommufd_viommu_p2-v3 branch,
which requires IOMMU_DOMAIN_NESTED in user space with iommufd.
About the three patches
1. Tested host sva, OK
2. Simply tested vsva on guests, OK, will do more tests.
Thanks
