Re: [PATCH v5 05/13] iommufd: Allow hwpt_id to carry viommu_id for IOMMU_HWPT_INVALIDATE

[Nicolin Chen]

On Tue, Oct 29, 2024 at 04:09:41PM -0300, Jason Gunthorpe wrote:
> On Fri, Oct 25, 2024 at 04:50:34PM -0700, Nicolin Chen wrote:
> > @@ -497,17 +497,35 @@ int iommufd_hwpt_invalidate(struct iommufd_ucmd *ucmd)
> > goto out;
> > }
> >  
> > -   hwpt = iommufd_get_hwpt_nested(ucmd, cmd->hwpt_id);
> > -   if (IS_ERR(hwpt)) {
> > -   rc = PTR_ERR(hwpt);
> > +   pt_obj = iommufd_get_object(ucmd->ictx, cmd->hwpt_id, IOMMUFD_OBJ_ANY);
> > +   if (IS_ERR(pt_obj)) {
> > +   rc = PTR_ERR(pt_obj);
> > goto out;
> > }
> > +   if (pt_obj->type == IOMMUFD_OBJ_HWPT_NESTED) {
> > +   struct iommufd_hw_pagetable *hwpt =
> > +   container_of(pt_obj, struct iommufd_hw_pagetable, obj);
> > +
> > +   rc = hwpt->domain->ops->cache_invalidate_user(hwpt->domain,
> > + &data_array);
> > +   } else if (pt_obj->type == IOMMUFD_OBJ_VIOMMU) {
> > +   struct iommufd_viommu *viommu =
> > +   container_of(pt_obj, struct iommufd_viommu, obj);
> > +
> > +   if (!viommu->ops || !viommu->ops->cache_invalidate) {
> > +   rc = -EOPNOTSUPP;
> > +   goto out_put_pt;
> > +   }
> > +   rc = viommu->ops->cache_invalidate(viommu, &data_array);
> > +   } else {
> > +   rc = -EINVAL;
> > +   goto out_put_pt;
> > +   }
> 
> Given the test in iommufd_viommu_alloc_hwpt_nested() is:
> 
>   if (WARN_ON_ONCE(hwpt->domain->type != IOMMU_DOMAIN_NESTED ||
>(!viommu->ops->cache_invalidate &&
> !hwpt->domain->ops->cache_invalidate_user)))
> {
> 
> We will crash if the user passes a viommu allocated domain as
> IOMMUFD_OBJ_HWPT_NESTED since the above doesn't check it.

Ah, that was missed.

> I suggest we put the required if (ops..) -EOPNOTSUPP above and remove
> the ops->cache_invalidate checks from both WARN_ONs.

Ack. I will add hwpt->domain->ops check:
-
if (pt_obj->type == IOMMUFD_OBJ_HWPT_NESTED) {
struct iommufd_hw_pagetable *hwpt =
container_of(pt_obj, struct iommufd_hw_pagetable, obj);

if (!hwpt->domain->ops ||
!hwpt->domain->ops->cache_invalidate_user) {
rc = -EOPNOTSUPP;
goto out_put_pt;
}
rc = hwpt->domain->ops->cache_invalidate_user(hwpt->domain,
  &data_array);
} else if (pt_obj->type == IOMMUFD_OBJ_VIOMMU) {
struct iommufd_viommu *viommu =
container_of(pt_obj, struct iommufd_viommu, obj);

if (!viommu->ops || !viommu->ops->cache_invalidate) {
rc = -EOPNOTSUPP;
goto out_put_pt;
}
rc = viommu->ops->cache_invalidate(viommu, &data_array);
} else {
-

Thanks
Nicolin

Re: [PATCH v5 05/13] iommufd: Allow hwpt_id to carry viommu_id for IOMMU_HWPT_INVALIDATE

[Jason Gunthorpe]

On Fri, Oct 25, 2024 at 04:50:34PM -0700, Nicolin Chen wrote:
> @@ -497,17 +497,35 @@ int iommufd_hwpt_invalidate(struct iommufd_ucmd *ucmd)
>   goto out;
>   }
>  
> - hwpt = iommufd_get_hwpt_nested(ucmd, cmd->hwpt_id);
> - if (IS_ERR(hwpt)) {
> - rc = PTR_ERR(hwpt);
> + pt_obj = iommufd_get_object(ucmd->ictx, cmd->hwpt_id, IOMMUFD_OBJ_ANY);
> + if (IS_ERR(pt_obj)) {
> + rc = PTR_ERR(pt_obj);
>   goto out;
>   }
> + if (pt_obj->type == IOMMUFD_OBJ_HWPT_NESTED) {
> + struct iommufd_hw_pagetable *hwpt =
> + container_of(pt_obj, struct iommufd_hw_pagetable, obj);
> +
> + rc = hwpt->domain->ops->cache_invalidate_user(hwpt->domain,
> +   &data_array);
> + } else if (pt_obj->type == IOMMUFD_OBJ_VIOMMU) {
> + struct iommufd_viommu *viommu =
> + container_of(pt_obj, struct iommufd_viommu, obj);
> +
> + if (!viommu->ops || !viommu->ops->cache_invalidate) {
> + rc = -EOPNOTSUPP;
> + goto out_put_pt;
> + }
> + rc = viommu->ops->cache_invalidate(viommu, &data_array);
> + } else {
> + rc = -EINVAL;
> + goto out_put_pt;
> + }

Given the test in iommufd_viommu_alloc_hwpt_nested() is:

if (WARN_ON_ONCE(hwpt->domain->type != IOMMU_DOMAIN_NESTED ||
 (!viommu->ops->cache_invalidate &&
  !hwpt->domain->ops->cache_invalidate_user)))
  {

We will crash if the user passes a viommu allocated domain as
IOMMUFD_OBJ_HWPT_NESTED since the above doesn't check it.

I suggest we put the required if (ops..) -EOPNOTSUPP above and remove
the ops->cache_invalidate checks from both WARN_ONs.

Jason

RE: [PATCH v5 05/13] iommufd: Allow hwpt_id to carry viommu_id for IOMMU_HWPT_INVALIDATE

[Tian, Kevin]

> From: Nicolin Chen 
> Sent: Saturday, October 26, 2024 7:51 AM
> 
> With a vIOMMU object, use space can flush any IOMMU related cache that
> can
> be directed via a vIOMMU object. It is similar to the
> IOMMU_HWPT_INVALIDATE
> uAPI, but can cover a wider range than IOTLB, e.g. device/desciprtor cache.
> 
> Allow hwpt_id of the iommu_hwpt_invalidate structure to carry a viommu_id,
> and reuse the IOMMU_HWPT_INVALIDATE uAPI for vIOMMU invalidations.
> Drivers
> can define different structures for vIOMMU invalidations v.s. HWPT ones.
> 
> Update the uAPI, kdoc, and selftest case accordingly.
> 
> Reviewed-by: Jason Gunthorpe 
> Signed-off-by: Nicolin Chen 

Reviewed-by: Kevin Tian