diff mbox series

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

Message ID 6b8bb8f2319bf26ead928321f609105e4e5eecf4.1729897278.git.nicolinc@nvidia.com
State New
Headers show
Series iommufd: Add vIOMMU infrastructure (Part-2: vDEVICE) | expand

Commit Message

Nicolin Chen Oct. 25, 2024, 11:50 p.m. UTC 
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 <jgg@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
 include/uapi/linux/iommufd.h            |  9 ++++---
 drivers/iommu/iommufd/hw_pagetable.c    | 32 +++++++++++++++++++------
 tools/testing/selftests/iommu/iommufd.c |  4 ++--
 3 files changed, 33 insertions(+), 12 deletions(-)

Comments

Jason Gunthorpe Oct. 29, 2024, 7:09 p.m. UTC | #1 
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
Nicolin Chen Oct. 29, 2024, 7:45 p.m. UTC | #2 
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
diff mbox series

Patch

diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index b699ecb7aa9c..c2c5f49fdf17 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -730,7 +730,7 @@  struct iommu_hwpt_vtd_s1_invalidate {
 /**
  * struct iommu_hwpt_invalidate - ioctl(IOMMU_HWPT_INVALIDATE)
  * @size: sizeof(struct iommu_hwpt_invalidate)
- * @hwpt_id: ID of a nested HWPT for cache invalidation
+ * @hwpt_id: ID of a nested HWPT or a vIOMMU, for cache invalidation
  * @data_uptr: User pointer to an array of driver-specific cache invalidation
  *             data.
  * @data_type: One of enum iommu_hwpt_invalidate_data_type, defining the data
@@ -741,8 +741,11 @@  struct iommu_hwpt_vtd_s1_invalidate {
  *             Output the number of requests successfully handled by kernel.
  * @__reserved: Must be 0.
  *
- * Invalidate the iommu cache for user-managed page table. Modifications on a
- * user-managed page table should be followed by this operation to sync cache.
+ * Invalidate iommu cache for user-managed page table or vIOMMU. Modifications
+ * on a user-managed page table should be followed by this operation, if a HWPT
+ * is passed in via @hwpt_id. Other caches, such as device cache or descriptor
+ * cache can be flushed if a vIOMMU is passed in via the @hwpt_id field.
+ *
  * Each ioctl can support one or more cache invalidation requests in the array
  * that has a total size of @entry_len * @entry_num.
  *
diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c
index fd260a67b82c..5301ba69fb8a 100644
--- a/drivers/iommu/iommufd/hw_pagetable.c
+++ b/drivers/iommu/iommufd/hw_pagetable.c
@@ -483,7 +483,7 @@  int iommufd_hwpt_invalidate(struct iommufd_ucmd *ucmd)
 		.entry_len = cmd->entry_len,
 		.entry_num = cmd->entry_num,
 	};
-	struct iommufd_hw_pagetable *hwpt;
+	struct iommufd_object *pt_obj;
 	u32 done_num = 0;
 	int rc;
 
@@ -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;
+	}
 
-	rc = hwpt->domain->ops->cache_invalidate_user(hwpt->domain,
-						      &data_array);
 	done_num = data_array.entry_num;
 
-	iommufd_put_object(ucmd->ictx, &hwpt->obj);
+out_put_pt:
+	iommufd_put_object(ucmd->ictx, pt_obj);
 out:
 	cmd->entry_num = done_num;
 	if (iommufd_ucmd_respond(ucmd, sizeof(*cmd)))
diff --git a/tools/testing/selftests/iommu/iommufd.c b/tools/testing/selftests/iommu/iommufd.c
index 93255403dee4..44fbc7e5aa2e 100644
--- a/tools/testing/selftests/iommu/iommufd.c
+++ b/tools/testing/selftests/iommu/iommufd.c
@@ -362,9 +362,9 @@  TEST_F(iommufd_ioas, alloc_hwpt_nested)
 		EXPECT_ERRNO(EBUSY,
 			     _test_ioctl_destroy(self->fd, parent_hwpt_id));
 
-		/* hwpt_invalidate only supports a user-managed hwpt (nested) */
+		/* hwpt_invalidate does not support a parent hwpt */
 		num_inv = 1;
-		test_err_hwpt_invalidate(ENOENT, parent_hwpt_id, inv_reqs,
+		test_err_hwpt_invalidate(EINVAL, parent_hwpt_id, inv_reqs,
 					 IOMMU_HWPT_INVALIDATE_DATA_SELFTEST,
 					 sizeof(*inv_reqs), &num_inv);
 		assert(!num_inv);