Merge branch 'vfio_mdev_ops' into iommufd.git for-next

Yi Liu says

===================
The .bind_iommufd op of vfio emulated devices are either empty or does
nothing. This is different with the vfio physical devices, to add vfio
device cdev, need to make them act the same.

This series first makes the .bind_iommufd op of vfio emulated devices to
create iommufd_access, this introduces a new iommufd API. Then let the
driver that does not provide .bind_iommufd op to use the vfio emulated
iommufd op set. This makes all vfio device drivers have consistent iommufd
operations, which is good for adding new device uAPIs in the device cdev
===================

* branch 'vfio_mdev_ops':
  vfio: Check the presence for iommufd callbacks in __vfio_register_dev()
  vfio/mdev: Uses the vfio emulated iommufd ops set in the mdev sample drivers
  vfio-iommufd: Make vfio_iommufd_emulated_bind() return iommufd_access ID
  vfio-iommufd: No need to record iommufd_ctx in vfio_device
  iommufd: Create access in vfio_iommufd_emulated_bind()
  iommu/iommufd: Pass iommufd_ctx pointer in iommufd_get_ioas()

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

5 files changed, 51 insertions, 37 deletions

diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c
index c6f4852a8a0c..4f9b2142274c 100644
--- a/drivers/iommu/iommufd/device.c
+++ b/drivers/iommu/iommufd/device.c
@@ -395,17 +395,20 @@ void iommufd_access_destroy_object(struct iommufd_object *obj)
 	struct iommufd_access *access =
 		container_of(obj, struct iommufd_access, obj);
 
-	iopt_remove_access(&access->ioas->iopt, access);
+	if (access->ioas) {
+		iopt_remove_access(&access->ioas->iopt, access);
+		refcount_dec(&access->ioas->obj.users);
+		access->ioas = NULL;
+	}
 	iommufd_ctx_put(access->ictx);
-	refcount_dec(&access->ioas->obj.users);
 }
 
 /**
  * iommufd_access_create - Create an iommufd_access
  * @ictx: iommufd file descriptor
- * @ioas_id: ID for a IOMMUFD_OBJ_IOAS
  * @ops: Driver's ops to associate with the access
  * @data: Opaque data to pass into ops functions
+ * @id: Output ID number to return to userspace for this access
  *
  * An iommufd_access allows a driver to read/write to the IOAS without using
  * DMA. The underlying CPU memory can be accessed using the
@@ -414,12 +417,10 @@ void iommufd_access_destroy_object(struct iommufd_object *obj)
  * The provided ops are required to use iommufd_access_pin_pages().
  */
 struct iommufd_access *
-iommufd_access_create(struct iommufd_ctx *ictx, u32 ioas_id,
-		      const struct iommufd_access_ops *ops, void *data)
+iommufd_access_create(struct iommufd_ctx *ictx,
+		      const struct iommufd_access_ops *ops, void *data, u32 *id)
 {
 	struct iommufd_access *access;
-	struct iommufd_object *obj;
-	int rc;
 
 	/*
 	 * There is no uAPI for the access object, but to keep things symmetric
@@ -432,33 +433,18 @@ iommufd_access_create(struct iommufd_ctx *ictx, u32 ioas_id,
 	access->data = data;
 	access->ops = ops;
 
-	obj = iommufd_get_object(ictx, ioas_id, IOMMUFD_OBJ_IOAS);
-	if (IS_ERR(obj)) {
-		rc = PTR_ERR(obj);
-		goto out_abort;
-	}
-	access->ioas = container_of(obj, struct iommufd_ioas, obj);
-	iommufd_ref_to_users(obj);
-
 	if (ops->needs_pin_pages)
 		access->iova_alignment = PAGE_SIZE;
 	else
 		access->iova_alignment = 1;
-	rc = iopt_add_access(&access->ioas->iopt, access);
-	if (rc)
-		goto out_put_ioas;
 
 	/* The calling driver is a user until iommufd_access_destroy() */
 	refcount_inc(&access->obj.users);
 	access->ictx = ictx;
 	iommufd_ctx_get(ictx);
 	iommufd_object_finalize(ictx, &access->obj);
+	*id = access->obj.id;
 	return access;
-out_put_ioas:
-	refcount_dec(&access->ioas->obj.users);
-out_abort:
-	iommufd_object_abort(ictx, &access->obj);
-	return ERR_PTR(rc);
 }
 EXPORT_SYMBOL_NS_GPL(iommufd_access_create, IOMMUFD);
 
@@ -477,6 +463,30 @@ void iommufd_access_destroy(struct iommufd_access *access)
 }
 EXPORT_SYMBOL_NS_GPL(iommufd_access_destroy, IOMMUFD);
 
+int iommufd_access_attach(struct iommufd_access *access, u32 ioas_id)
+{
+	struct iommufd_ioas *new_ioas;
+	int rc = 0;
+
+	if (access->ioas)
+		return -EINVAL;
+
+	new_ioas = iommufd_get_ioas(access->ictx, ioas_id);
+	if (IS_ERR(new_ioas))
+		return PTR_ERR(new_ioas);
+
+	rc = iopt_add_access(&new_ioas->iopt, access);
+	if (rc) {
+		iommufd_put_object(&new_ioas->obj);
+		return rc;
+	}
+	iommufd_ref_to_users(&new_ioas->obj);
+
+	access->ioas = new_ioas;
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(iommufd_access_attach, IOMMUFD);
+
 /**
  * iommufd_access_notify_unmap - Notify users of an iopt to stop using it
  * @iopt: iopt to work on
diff --git a/drivers/iommu/iommufd/ioas.c b/drivers/iommu/iommufd/ioas.c
index 31577e9d434f..d5624577f79f 100644
--- a/drivers/iommu/iommufd/ioas.c
+++ b/drivers/iommu/iommufd/ioas.c
@@ -71,7 +71,7 @@ int iommufd_ioas_iova_ranges(struct iommufd_ucmd *ucmd)
 	if (cmd->__reserved)
 		return -EOPNOTSUPP;
 
-	ioas = iommufd_get_ioas(ucmd, cmd->ioas_id);
+	ioas = iommufd_get_ioas(ucmd->ictx, cmd->ioas_id);
 	if (IS_ERR(ioas))
 		return PTR_ERR(ioas);
 
@@ -151,7 +151,7 @@ int iommufd_ioas_allow_iovas(struct iommufd_ucmd *ucmd)
 	if (cmd->__reserved)
 		return -EOPNOTSUPP;
 
-	ioas = iommufd_get_ioas(ucmd, cmd->ioas_id);
+	ioas = iommufd_get_ioas(ucmd->ictx, cmd->ioas_id);
 	if (IS_ERR(ioas))
 		return PTR_ERR(ioas);
 	iopt = &ioas->iopt;
@@ -213,7 +213,7 @@ int iommufd_ioas_map(struct iommufd_ucmd *ucmd)
 	if (cmd->iova >= ULONG_MAX || cmd->length >= ULONG_MAX)
 		return -EOVERFLOW;
 
-	ioas = iommufd_get_ioas(ucmd, cmd->ioas_id);
+	ioas = iommufd_get_ioas(ucmd->ictx, cmd->ioas_id);
 	if (IS_ERR(ioas))
 		return PTR_ERR(ioas);
 
@@ -253,7 +253,7 @@ int iommufd_ioas_copy(struct iommufd_ucmd *ucmd)
 	    cmd->dst_iova >= ULONG_MAX)
 		return -EOVERFLOW;
 
-	src_ioas = iommufd_get_ioas(ucmd, cmd->src_ioas_id);
+	src_ioas = iommufd_get_ioas(ucmd->ictx, cmd->src_ioas_id);
 	if (IS_ERR(src_ioas))
 		return PTR_ERR(src_ioas);
 	rc = iopt_get_pages(&src_ioas->iopt, cmd->src_iova, cmd->length,
@@ -262,7 +262,7 @@ int iommufd_ioas_copy(struct iommufd_ucmd *ucmd)
 	if (rc)
 		return rc;
 
-	dst_ioas = iommufd_get_ioas(ucmd, cmd->dst_ioas_id);
+	dst_ioas = iommufd_get_ioas(ucmd->ictx, cmd->dst_ioas_id);
 	if (IS_ERR(dst_ioas)) {
 		rc = PTR_ERR(dst_ioas);
 		goto out_pages;
@@ -292,7 +292,7 @@ int iommufd_ioas_unmap(struct iommufd_ucmd *ucmd)
 	unsigned long unmapped = 0;
 	int rc;
 
-	ioas = iommufd_get_ioas(ucmd, cmd->ioas_id);
+	ioas = iommufd_get_ioas(ucmd->ictx, cmd->ioas_id);
 	if (IS_ERR(ioas))
 		return PTR_ERR(ioas);
 
@@ -381,7 +381,7 @@ int iommufd_ioas_option(struct iommufd_ucmd *ucmd)
 	if (cmd->__reserved)
 		return -EOPNOTSUPP;
 
-	ioas = iommufd_get_ioas(ucmd, cmd->object_id);
+	ioas = iommufd_get_ioas(ucmd->ictx, cmd->object_id);
 	if (IS_ERR(ioas))
 		return PTR_ERR(ioas);
 
diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h
index d523ef12890e..b38e67d1988b 100644
--- a/drivers/iommu/iommufd/iommufd_private.h
+++ b/drivers/iommu/iommufd/iommufd_private.h
@@ -212,10 +212,10 @@ struct iommufd_ioas {
 	struct list_head hwpt_list;
 };
 
-static inline struct iommufd_ioas *iommufd_get_ioas(struct iommufd_ucmd *ucmd,
+static inline struct iommufd_ioas *iommufd_get_ioas(struct iommufd_ctx *ictx,
 						    u32 id)
 {
-	return container_of(iommufd_get_object(ucmd->ictx, id,
+	return container_of(iommufd_get_object(ictx, id,
 					       IOMMUFD_OBJ_IOAS),
 			    struct iommufd_ioas, obj);
 }
diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c
index 58471f9452be..4463060ec84b 100644
--- a/drivers/iommu/iommufd/selftest.c
+++ b/drivers/iommu/iommufd/selftest.c
@@ -75,7 +75,7 @@ void iommufd_test_syz_conv_iova_id(struct iommufd_ucmd *ucmd,
 		return;
 	*flags &= ~(u32)MOCK_FLAGS_ACCESS_SYZ;
 
-	ioas = iommufd_get_ioas(ucmd, ioas_id);
+	ioas = iommufd_get_ioas(ucmd->ictx, ioas_id);
 	if (IS_ERR(ioas))
 		return;
 	*iova = iommufd_test_syz_conv_iova(&ioas->iopt, iova);
@@ -463,7 +463,7 @@ static int iommufd_test_add_reserved(struct iommufd_ucmd *ucmd,
 	struct iommufd_ioas *ioas;
 	int rc;
 
-	ioas = iommufd_get_ioas(ucmd, mockpt_id);
+	ioas = iommufd_get_ioas(ucmd->ictx, mockpt_id);
 	if (IS_ERR(ioas))
 		return PTR_ERR(ioas);
 	down_write(&ioas->iopt.iova_rwsem);
@@ -700,6 +700,7 @@ static int iommufd_test_create_access(struct iommufd_ucmd *ucmd,
 	struct iommu_test_cmd *cmd = ucmd->cmd;
 	struct selftest_access *staccess;
 	struct iommufd_access *access;
+	u32 id;
 	int fdno;
 	int rc;
 
@@ -717,15 +718,18 @@ static int iommufd_test_create_access(struct iommufd_ucmd *ucmd,
 	}
 
 	access = iommufd_access_create(
-		ucmd->ictx, ioas_id,
+		ucmd->ictx,
 		(flags & MOCK_FLAGS_ACCESS_CREATE_NEEDS_PIN_PAGES) ?
 			&selftest_access_ops_pin :
 			&selftest_access_ops,
-		staccess);
+		staccess, &id);
 	if (IS_ERR(access)) {
 		rc = PTR_ERR(access);
 		goto out_put_fdno;
 	}
+	rc = iommufd_access_attach(access, ioas_id);
+	if (rc)
+		goto out_destroy;
 	cmd->create_access.out_access_fd = fdno;
 	rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd));
 	if (rc)
diff --git a/drivers/iommu/iommufd/vfio_compat.c b/drivers/iommu/iommufd/vfio_compat.c
index 514494a0025b..fe02517c73cc 100644
--- a/drivers/iommu/iommufd/vfio_compat.c
+++ b/drivers/iommu/iommufd/vfio_compat.c
@@ -137,7 +137,7 @@ int iommufd_vfio_ioas(struct iommufd_ucmd *ucmd)
 		return iommufd_ucmd_respond(ucmd, sizeof(*cmd));
 
 	case IOMMU_VFIO_IOAS_SET:
-		ioas = iommufd_get_ioas(ucmd, cmd->ioas_id);
+		ioas = iommufd_get_ioas(ucmd->ictx, cmd->ioas_id);
 		if (IS_ERR(ioas))
 			return PTR_ERR(ioas);
 		xa_lock(&ucmd->ictx->objects);