iommufd: Add vIOMMU infrastructure (Part-3: vEVENTQ)

index 97c5e3567d33..49be19305d98 100644
@@ -307,9 +307,9 @@ union ucmd_buffer {
 	struct iommu_ioas_map map;
 	struct iommu_ioas_unmap unmap;
 	struct iommu_option option;
+	struct iommu_vdevice_alloc vdev;
 	struct iommu_vfio_ioas vfio_ioas;
 	struct iommu_viommu_alloc viommu;
-	struct iommu_vdevice_alloc vdev;
 #ifdef CONFIG_IOMMUFD_TEST
 	struct iommu_test_cmd test;
 #endif

@@ -333,8 +333,8 @@ struct iommufd_ioctl_op {
 	}
 static const struct iommufd_ioctl_op iommufd_ioctl_ops[] = {
 	IOCTL_OP(IOMMU_DESTROY, iommufd_destroy, struct iommu_destroy, id),
-	IOCTL_OP(IOMMU_FAULT_QUEUE_ALLOC, iommufd_fault_alloc, struct iommu_fault_alloc,
-		 out_fault_fd),
+	IOCTL_OP(IOMMU_FAULT_QUEUE_ALLOC, iommufd_fault_alloc,
+		 struct iommu_fault_alloc, out_fault_fd),
 	IOCTL_OP(IOMMU_GET_HW_INFO, iommufd_get_hw_info, struct iommu_hw_info,
 		 __reserved),
 	IOCTL_OP(IOMMU_HWPT_ALLOC, iommufd_hwpt_alloc, struct iommu_hwpt_alloc,

@@ -355,20 +355,18 @@ static const struct iommufd_ioctl_op iommufd_ioctl_ops[] = {
 		 src_iova),
 	IOCTL_OP(IOMMU_IOAS_IOVA_RANGES, iommufd_ioas_iova_ranges,
 		 struct iommu_ioas_iova_ranges, out_iova_alignment),
-	IOCTL_OP(IOMMU_IOAS_MAP, iommufd_ioas_map, struct iommu_ioas_map,
-		 iova),
+	IOCTL_OP(IOMMU_IOAS_MAP, iommufd_ioas_map, struct iommu_ioas_map, iova),
 	IOCTL_OP(IOMMU_IOAS_MAP_FILE, iommufd_ioas_map_file,
 		 struct iommu_ioas_map_file, iova),
 	IOCTL_OP(IOMMU_IOAS_UNMAP, iommufd_ioas_unmap, struct iommu_ioas_unmap,
 		 length),
-	IOCTL_OP(IOMMU_OPTION, iommufd_option, struct iommu_option,
-		 val64),
+	IOCTL_OP(IOMMU_OPTION, iommufd_option, struct iommu_option, val64),
+	IOCTL_OP(IOMMU_VDEVICE_ALLOC, iommufd_vdevice_alloc_ioctl,
+		 struct iommu_vdevice_alloc, virt_id),
 	IOCTL_OP(IOMMU_VFIO_IOAS, iommufd_vfio_ioas, struct iommu_vfio_ioas,
 		 __reserved),
 	IOCTL_OP(IOMMU_VIOMMU_ALLOC, iommufd_viommu_alloc_ioctl,
 		 struct iommu_viommu_alloc, out_viommu_id),
-	IOCTL_OP(IOMMU_VDEVICE_ALLOC, iommufd_vdevice_alloc_ioctl,
-		 struct iommu_vdevice_alloc, virt_id),
 #ifdef CONFIG_IOMMUFD_TEST
 	IOCTL_OP(IOMMU_TEST_CMD, iommufd_test, struct iommu_test_cmd, last),
 #endif

index 1fe804e28a86..1d1095fc8224 100644
@@ -367,11 +367,35 @@ static const struct file_operations iommufd_fault_fops = {
 	.release	= iommufd_fault_fops_release,
 };
 
+static int iommufd_fault_init(struct iommufd_fault *fault, char *name,
+			      struct iommufd_ctx *ictx)
+{
+	struct file *filep;
+	int fdno;
+
+	mutex_init(&fault->mutex);
+	INIT_LIST_HEAD(&fault->deliver);
+	init_waitqueue_head(&fault->wait_queue);
+
+	filep = anon_inode_getfile(name, &iommufd_fault_fops, fault, O_RDWR);
+	if (IS_ERR(filep))
+		return PTR_ERR(filep);
+
+	fault->ictx = ictx;
+	iommufd_ctx_get(fault->ictx);
+	fault->filep = filep;
+	refcount_inc(&fault->obj.users);
+
+	fdno = get_unused_fd_flags(O_CLOEXEC);
+	if (fdno < 0)
+		fput(filep);
+	return fdno;
+}
+
 int iommufd_fault_alloc(struct iommufd_ucmd *ucmd)
 {
 	struct iommu_fault_alloc *cmd = ucmd->cmd;
 	struct iommufd_fault *fault;
-	struct file *filep;
 	int fdno;
 	int rc;
 

@@ -382,27 +406,12 @@ int iommufd_fault_alloc(struct iommufd_ucmd *ucmd)
 	if (IS_ERR(fault))
 		return PTR_ERR(fault);
 
-	fault->ictx = ucmd->ictx;
-	INIT_LIST_HEAD(&fault->deliver);
 	xa_init_flags(&fault->response, XA_FLAGS_ALLOC1);
-	mutex_init(&fault->mutex);
-	init_waitqueue_head(&fault->wait_queue);
-
-	filep = anon_inode_getfile("[iommufd-pgfault]", &iommufd_fault_fops,
-				   fault, O_RDWR);
-	if (IS_ERR(filep)) {
-		rc = PTR_ERR(filep);
-		goto out_abort;
-	}
 
-	refcount_inc(&fault->obj.users);
-	iommufd_ctx_get(fault->ictx);
-	fault->filep = filep;
-
-	fdno = get_unused_fd_flags(O_CLOEXEC);
+	fdno = iommufd_fault_init(fault, "[iommufd-pgfault]", ucmd->ictx);
 	if (fdno < 0) {
 		rc = fdno;
-		goto out_fput;
+		goto out_abort;
 	}
 
 	cmd->out_fault_id = fault->obj.id;

@@ -418,8 +427,7 @@ int iommufd_fault_alloc(struct iommufd_ucmd *ucmd)
 	return 0;
 out_put_fdno:
 	put_unused_fd(fdno);
-out_fput:
-	fput(filep);
+	fput(fault->filep);
 out_abort:
 	iommufd_object_abort_and_destroy(ucmd->ictx, &fault->obj);
 

index b6d706cf2c66..8b378705ee71 100644
@@ -451,6 +451,17 @@ struct iommufd_fault {
 	struct wait_queue_head wait_queue;
 };
 
+static inline int iommufd_fault_notify(struct iommufd_fault *fault,
+				       struct list_head *new_fault)
+{
+	mutex_lock(&fault->mutex);
+	list_add_tail(new_fault, &fault->deliver);
+	mutex_unlock(&fault->mutex);
+
+	wake_up_interruptible(&fault->wait_queue);
+	return 0;
+}
+
 struct iommufd_attach_handle {
 	struct iommu_attach_handle handle;
 	struct iommufd_device *idev;

@@ -469,7 +480,14 @@ iommufd_get_fault(struct iommufd_ucmd *ucmd, u32 id)
 
 int iommufd_fault_alloc(struct iommufd_ucmd *ucmd);
 void iommufd_fault_destroy(struct iommufd_object *obj);
-int iommufd_fault_iopf_handler(struct iopf_group *group);
+
+static inline int iommufd_fault_iopf_handler(struct iopf_group *group)
+{
+	struct iommufd_hw_pagetable *hwpt =
+		group->attach_handle->domain->fault_data;
+
+	return iommufd_fault_notify(hwpt->fault, &group->node);
+}
 
 int iommufd_fault_domain_attach_dev(struct iommufd_hw_pagetable *hwpt,
 				    struct iommufd_device *idev);

index 1d1095fc8224..d188994e4e84 100644
@@ -433,20 +433,3 @@ int iommufd_fault_alloc(struct iommufd_ucmd *ucmd)
 
 	return rc;
 }
-
-int iommufd_fault_iopf_handler(struct iopf_group *group)
-{
-	struct iommufd_hw_pagetable *hwpt;
-	struct iommufd_fault *fault;
-
-	hwpt = group->attach_handle->domain->fault_data;
-	fault = hwpt->fault;
-
-	mutex_lock(&fault->mutex);
-	list_add_tail(&group->node, &fault->deliver);
-	mutex_unlock(&fault->mutex);
-
-	wake_up_interruptible(&fault->wait_queue);
-
-	return 0;
-}

index 8b378705ee71..dfbc5cfbd164 100644
@@ -18,6 +18,7 @@ struct iommu_domain;
 struct iommu_group;
 struct iommu_option;
 struct iommufd_device;
+struct iommufd_eventq;
 
 struct iommufd_ctx {
 	struct file *file;

@@ -433,32 +434,35 @@ void iopt_remove_access(struct io_pagetable *iopt,
 			u32 iopt_access_list_id);
 void iommufd_access_destroy_object(struct iommufd_object *obj);
 
-/*
- * An iommufd_fault object represents an interface to deliver I/O page faults
- * to the user space. These objects are created/destroyed by the user space and
- * associated with hardware page table objects during page-table allocation.
- */
-struct iommufd_fault {
+struct iommufd_eventq_ops {
+	ssize_t (*read)(struct iommufd_eventq *eventq, char __user *buf,
+			size_t count, loff_t *ppos); /* Mandatory op */
+	ssize_t (*write)(struct iommufd_eventq *eventq, const char __user *buf,
+			 size_t count, loff_t *ppos); /* Optional op */
+};
+
+struct iommufd_eventq {
 	struct iommufd_object obj;
 	struct iommufd_ctx *ictx;
 	struct file *filep;
 
-	/* The lists of outstanding faults protected by below mutex. */
+	const struct iommufd_eventq_ops *ops;
+
+	/* The lists of outstanding events protected by below mutex. */
 	struct mutex mutex;
 	struct list_head deliver;
-	struct xarray response;
 
 	struct wait_queue_head wait_queue;
 };
 
-static inline int iommufd_fault_notify(struct iommufd_fault *fault,
-				       struct list_head *new_fault)
+static inline int iommufd_eventq_notify(struct iommufd_eventq *eventq,
+					struct list_head *new_event)
 {
-	mutex_lock(&fault->mutex);
-	list_add_tail(new_fault, &fault->deliver);
-	mutex_unlock(&fault->mutex);
+	mutex_lock(&eventq->mutex);
+	list_add_tail(new_event, &eventq->deliver);
+	mutex_unlock(&eventq->mutex);
 
-	wake_up_interruptible(&fault->wait_queue);
+	wake_up_interruptible(&eventq->wait_queue);
 	return 0;
 }
 

@@ -470,12 +474,28 @@ struct iommufd_attach_handle {
 /* Convert an iommu attach handle to iommufd handle. */
 #define to_iommufd_handle(hdl)	container_of(hdl, struct iommufd_attach_handle, handle)
 
+/*
+ * An iommufd_fault object represents an interface to deliver I/O page faults
+ * to the user space. These objects are created/destroyed by the user space and
+ * associated with hardware page table objects during page-table allocation.
+ */
+struct iommufd_fault {
+	struct iommufd_eventq common;
+	struct xarray response;
+};
+
+static inline struct iommufd_fault *
+eventq_to_fault(struct iommufd_eventq *eventq)
+{
+	return container_of(eventq, struct iommufd_fault, common);
+}
+
 static inline struct iommufd_fault *
 iommufd_get_fault(struct iommufd_ucmd *ucmd, u32 id)
 {
 	return container_of(iommufd_get_object(ucmd->ictx, id,
 					       IOMMUFD_OBJ_FAULT),
-			    struct iommufd_fault, obj);
+			    struct iommufd_fault, common.obj);
 }
 
 int iommufd_fault_alloc(struct iommufd_ucmd *ucmd);

@@ -486,7 +506,7 @@ static inline int iommufd_fault_iopf_handler(struct iopf_group *group)
 	struct iommufd_hw_pagetable *hwpt =
 		group->attach_handle->domain->fault_data;
 
-	return iommufd_fault_notify(hwpt->fault, &group->node);
+	return iommufd_eventq_notify(&hwpt->fault->common, &group->node);
 }
 
 int iommufd_fault_domain_attach_dev(struct iommufd_hw_pagetable *hwpt,

270 lines not on this page · raw message

index ce03c3804651..12a576f1f13d 100644
@@ -14,7 +14,7 @@ static void __iommufd_hwpt_destroy(struct iommufd_hw_pagetable *hwpt)
 		iommu_domain_free(hwpt->domain);
 
 	if (hwpt->fault)
-		refcount_dec(&hwpt->fault->obj.users);
+		refcount_dec(&hwpt->fault->common.obj.users);
 }
 
 void iommufd_hwpt_paging_destroy(struct iommufd_object *obj)

@@ -403,8 +403,8 @@ int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd)
 		hwpt->fault = fault;
 		hwpt->domain->iopf_handler = iommufd_fault_iopf_handler;
 		hwpt->domain->fault_data = hwpt;
-		refcount_inc(&fault->obj.users);
-		iommufd_put_object(ucmd->ictx, &fault->obj);
+		refcount_inc(&fault->common.obj.users);
+		iommufd_put_object(ucmd->ictx, &fault->common.obj);
 	}
 
 	cmd->out_hwpt_id = hwpt->obj.id;

similarity index 100%
rename from drivers/iommu/iommufd/fault.c
rename to drivers/iommu/iommufd/eventq.c

index dfbc5cfbd164..9410f6275b5a 100644
@@ -547,6 +547,50 @@ static inline int iommufd_hwpt_replace_device(struct iommufd_device *idev,
 	return iommu_group_replace_domain(idev->igroup->group, hwpt->domain);
 }
 
+/*
+ * An iommufd_veventq object represents an interface to deliver vIOMMU events to
+ * the user space. It is created/destroyed by the user space and associated with
+ * vIOMMU object(s) during the allocations.
+ */
+struct iommufd_veventq {
+	struct iommufd_eventq common;
+	struct iommufd_viommu *viommu;
+	struct list_head node; /* for iommufd_viommu::veventqs */
+
+	unsigned int type;
+};
+
+static inline struct iommufd_veventq *
+eventq_to_veventq(struct iommufd_eventq *eventq)
+{
+	return container_of(eventq, struct iommufd_veventq, common);
+}
+
+static inline struct iommufd_veventq *
+iommufd_get_veventq(struct iommufd_ucmd *ucmd, u32 id)
+{
+	return container_of(iommufd_get_object(ucmd->ictx, id,
+					       IOMMUFD_OBJ_VEVENTQ),
+			    struct iommufd_veventq, common.obj);
+}
+
+int iommufd_veventq_alloc(struct iommufd_ucmd *ucmd);
+void iommufd_veventq_destroy(struct iommufd_object *obj);
+void iommufd_veventq_abort(struct iommufd_object *obj);
+
+/* An iommufd_vevent represents a vIOMMU event in an iommufd_veventq */
+struct iommufd_vevent {
+	struct list_head node; /* for iommufd_eventq::deliver */
+	ssize_t data_len;
+	u64 event_data[] __counted_by(data_len);
+};
+
+static inline int iommufd_vevent_handler(struct iommufd_veventq *veventq,
+					  struct iommufd_vevent *vevent)
+{
+	return iommufd_eventq_notify(&veventq->common, &vevent->node);
+}
+
 static inline struct iommufd_viommu *
 iommufd_get_viommu(struct iommufd_ucmd *ucmd, u32 id)
 {

@@ -555,6 +599,20 @@ iommufd_get_viommu(struct iommufd_ucmd *ucmd, u32 id)
 			    struct iommufd_viommu, obj);
 }
 
+static inline struct iommufd_veventq *
+iommufd_viommu_find_veventq(struct iommufd_viommu *viommu, u32 type)
+{
+	struct iommufd_veventq *veventq, *next;
+
+	lockdep_assert_held(&viommu->veventqs_rwsem);
+
+	list_for_each_entry_safe(veventq, next, &viommu->veventqs, node) {
+		if (veventq->type == type)
+			return veventq;
+	}
+	return NULL;
+}
+
 int iommufd_viommu_alloc_ioctl(struct iommufd_ucmd *ucmd);
 void iommufd_viommu_destroy(struct iommufd_object *obj);
 int iommufd_vdevice_alloc_ioctl(struct iommufd_ucmd *ucmd);

index 11110c749200..8948b1836940 100644
@@ -34,6 +34,7 @@ enum iommufd_object_type {
 	IOMMUFD_OBJ_FAULT,
 	IOMMUFD_OBJ_VIOMMU,
 	IOMMUFD_OBJ_VDEVICE,
+	IOMMUFD_OBJ_VEVENTQ,
 #ifdef CONFIG_IOMMUFD_TEST
 	IOMMUFD_OBJ_SELFTEST,
 #endif

@@ -93,6 +94,8 @@ struct iommufd_viommu {
 	const struct iommufd_viommu_ops *ops;
 
 	struct xarray vdevs;
+	struct list_head veventqs;
+	struct rw_semaphore veventqs_rwsem;
 
 	unsigned int type;
 };

index 34810f6ae2b5..0a08aa82e7cc 100644
@@ -55,6 +55,7 @@ enum {
 	IOMMUFD_CMD_VIOMMU_ALLOC = 0x90,
 	IOMMUFD_CMD_VDEVICE_ALLOC = 0x91,
 	IOMMUFD_CMD_IOAS_CHANGE_PROCESS = 0x92,
+	IOMMUFD_CMD_VEVENTQ_ALLOC = 0x93,
 };
 
 /**

@@ -1012,4 +1013,34 @@ struct iommu_ioas_change_process {
 #define IOMMU_IOAS_CHANGE_PROCESS \
 	_IO(IOMMUFD_TYPE, IOMMUFD_CMD_IOAS_CHANGE_PROCESS)
 
+/**
+ * enum iommu_veventq_type - Virtual Event Queue Type
+ * @IOMMU_VEVENTQ_TYPE_DEFAULT: Reserved for future use
+ */
+enum iommu_veventq_type {
+	IOMMU_VEVENTQ_TYPE_DEFAULT = 0,
+};
+
+/**
+ * struct iommu_veventq_alloc - ioctl(IOMMU_VEVENTQ_ALLOC)
+ * @size: sizeof(struct iommu_veventq_alloc)
+ * @flags: Must be 0
+ * @viommu: virtual IOMMU ID to associate the vEVENTQ with
+ * @type: Type of the vEVENTQ. Must be defined in enum iommu_veventq_type
+ * @out_veventq_id: The ID of the new vEVENTQ
+ * @out_veventq_fd: The fd of the new vEVENTQ. User space must close the
+ *                  successfully returned fd after using it
+ *
+ * Explicitly allocate a virtual event queue interface for a vIOMMU. A vIOMMU
+ * can have multiple FDs for different types, but is confined to one per @type.
+ */
+struct iommu_veventq_alloc {
+	__u32 size;
+	__u32 flags;
+	__u32 viommu_id;
+	__u32 type;
+	__u32 out_veventq_id;
+	__u32 out_veventq_fd;
+};
+#define IOMMU_VEVENTQ_ALLOC _IO(IOMMUFD_TYPE, IOMMUFD_CMD_VEVENTQ_ALLOC)
 #endif

138 lines not on this page · raw message

index 49be19305d98..985661a4af07 100644
@@ -310,6 +310,7 @@ union ucmd_buffer {
 	struct iommu_vdevice_alloc vdev;
 	struct iommu_vfio_ioas vfio_ioas;
 	struct iommu_viommu_alloc viommu;
+	struct iommu_veventq_alloc veventq;
 #ifdef CONFIG_IOMMUFD_TEST
 	struct iommu_test_cmd test;
 #endif

@@ -367,6 +368,8 @@ static const struct iommufd_ioctl_op iommufd_ioctl_ops[] = {
 		 __reserved),
 	IOCTL_OP(IOMMU_VIOMMU_ALLOC, iommufd_viommu_alloc_ioctl,
 		 struct iommu_viommu_alloc, out_viommu_id),
+	IOCTL_OP(IOMMU_VEVENTQ_ALLOC, iommufd_veventq_alloc,
+		 struct iommu_veventq_alloc, out_veventq_fd),
 #ifdef CONFIG_IOMMUFD_TEST
 	IOCTL_OP(IOMMU_TEST_CMD, iommufd_test, struct iommu_test_cmd, last),
 #endif

@@ -502,6 +505,10 @@ static const struct iommufd_object_ops iommufd_object_ops[] = {
 	[IOMMUFD_OBJ_FAULT] = {
 		.destroy = iommufd_fault_destroy,
 	},
+	[IOMMUFD_OBJ_VEVENTQ] = {
+		.destroy = iommufd_veventq_destroy,
+		.abort = iommufd_veventq_abort,
+	},
 	[IOMMUFD_OBJ_VIOMMU] = {
 		.destroy = iommufd_viommu_destroy,
 	},

index 69b88e8c7c26..01df2b985f02 100644
@@ -59,6 +59,8 @@ int iommufd_viommu_alloc_ioctl(struct iommufd_ucmd *ucmd)
 	viommu->ictx = ucmd->ictx;
 	viommu->hwpt = hwpt_paging;
 	refcount_inc(&viommu->hwpt->common.obj.users);
+	INIT_LIST_HEAD(&viommu->veventqs);
+	init_rwsem(&viommu->veventqs_rwsem);
 	/*
 	 * It is the most likely case that a physical IOMMU is unpluggable. A
 	 * pluggable IOMMU instance (if exists) is responsible for refcounting

index 8948b1836940..9c6ba7df3994 100644
@@ -190,6 +190,8 @@ struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx,
 					     enum iommufd_object_type type);
 struct device *iommufd_viommu_find_dev(struct iommufd_viommu *viommu,
 				       unsigned long vdev_id);
+unsigned long iommufd_viommu_get_vdev_id(struct iommufd_viommu *viommu,
+					 struct device *dev);
 #else /* !CONFIG_IOMMUFD_DRIVER_CORE */
 static inline struct iommufd_object *
 _iommufd_object_alloc(struct iommufd_ctx *ictx, size_t size,

@@ -203,6 +205,12 @@ iommufd_viommu_find_dev(struct iommufd_viommu *viommu, unsigned long vdev_id)
 {
 	return NULL;
 }
+
+static inline unsigned long
+iommufd_viommu_get_vdev_id(struct iommufd_viommu *viommu, struct device *dev)
+{
+	return 0;
+}
 #endif /* CONFIG_IOMMUFD_DRIVER_CORE */
 
 /*

index 2d98b04ff1cb..e5d7397c0a6c 100644
@@ -49,5 +49,25 @@ struct device *iommufd_viommu_find_dev(struct iommufd_viommu *viommu,
 }
 EXPORT_SYMBOL_NS_GPL(iommufd_viommu_find_dev, "IOMMUFD");
 
+/* Return 0 if device is not associated to the vIOMMU */
+unsigned long iommufd_viommu_get_vdev_id(struct iommufd_viommu *viommu,
+					 struct device *dev)
+{
+	struct iommufd_vdevice *vdev;
+	unsigned long vdev_id = 0;
+	unsigned long index;
+
+	xa_lock(&viommu->vdevs);
+	xa_for_each(&viommu->vdevs, index, vdev) {
+		if (vdev && vdev->dev == dev) {
+			vdev_id = (unsigned long)vdev->id;
+			break;
+		}
+	}
+	xa_unlock(&viommu->vdevs);
+	return vdev_id;
+}
+EXPORT_SYMBOL_NS_GPL(iommufd_viommu_get_vdev_id, "IOMMUFD");
+
 MODULE_DESCRIPTION("iommufd code shared with builtin modules");
 MODULE_LICENSE("GPL");

index 9c6ba7df3994..6b3b46e382f8 100644
@@ -11,6 +11,7 @@
 #include <linux/refcount.h>
 #include <linux/types.h>
 #include <linux/xarray.h>
+#include <uapi/linux/iommufd.h>
 
 struct device;
 struct file;

@@ -192,6 +193,9 @@ struct device *iommufd_viommu_find_dev(struct iommufd_viommu *viommu,
 				       unsigned long vdev_id);
 unsigned long iommufd_viommu_get_vdev_id(struct iommufd_viommu *viommu,
 					 struct device *dev);
+int iommufd_viommu_report_event(struct iommufd_viommu *viommu,
+				enum iommu_veventq_type type, void *event_data,
+				size_t data_len);
 #else /* !CONFIG_IOMMUFD_DRIVER_CORE */
 static inline struct iommufd_object *
 _iommufd_object_alloc(struct iommufd_ctx *ictx, size_t size,

@@ -211,6 +215,13 @@ iommufd_viommu_get_vdev_id(struct iommufd_viommu *viommu, struct device *dev)
 {
 	return 0;
 }
+
+static inline int iommufd_viommu_report_event(struct iommufd_viommu *viommu,
+					      enum iommu_veventq_type type,
+					      void *event_data, size_t data_len)
+{
+	return -EOPNOTSUPP;
+}
 #endif /* CONFIG_IOMMUFD_DRIVER_CORE */
 
 /*

index e5d7397c0a6c..77c34f8791ef 100644
@@ -69,5 +69,45 @@ unsigned long iommufd_viommu_get_vdev_id(struct iommufd_viommu *viommu,
 }
 EXPORT_SYMBOL_NS_GPL(iommufd_viommu_get_vdev_id, "IOMMUFD");
 
+/*
+ * Typically called in driver's threaded IRQ handler.
+ * The @type and @event_data must be defined in include/uapi/linux/iommufd.h
+ */
+int iommufd_viommu_report_event(struct iommufd_viommu *viommu,
+				enum iommu_veventq_type type, void *event_data,
+				size_t data_len)
+{
+	struct iommufd_veventq *veventq;
+	struct iommufd_vevent *vevent;
+	int rc = 0;
+
+	if (!viommu)
+		return -ENODEV;
+	if (WARN_ON_ONCE(!data_len || !event_data))
+		return -EINVAL;
+
+	down_read(&viommu->veventqs_rwsem);
+
+	veventq = iommufd_viommu_find_veventq(viommu, type);
+	if (!veventq) {
+		rc = -EOPNOTSUPP;
+		goto out_unlock_veventqs;
+	}
+
+	vevent = kmalloc(struct_size(vevent, event_data, data_len), GFP_KERNEL);
+	if (!vevent) {
+		rc = -ENOMEM;
+		goto out_unlock_veventqs;
+	}
+	memcpy(vevent->event_data, event_data, data_len);
+	vevent->data_len = data_len;
+
+	iommufd_vevent_handler(veventq, vevent);
+out_unlock_veventqs:
+	up_read(&viommu->veventqs_rwsem);
+	return rc;
+}
+EXPORT_SYMBOL_NS_GPL(iommufd_viommu_report_event, "IOMMUFD");
+
 MODULE_DESCRIPTION("iommufd code shared with builtin modules");
 MODULE_LICENSE("GPL");

index a0de6d6d4e68..d1438d81e664 100644
@@ -161,7 +161,10 @@ enum selftest_obj_type {
 
 struct mock_dev {
 	struct device dev;
+	struct mock_viommu *viommu;
+	struct rw_semaphore viommu_rwsem;
 	unsigned long flags;
+	unsigned long vdev_id;
 	int id;
 	u32 cache[MOCK_DEV_CACHE_NUM];
 };

@@ -193,10 +196,29 @@ static int mock_domain_nop_attach(struct iommu_domain *domain,
 				  struct device *dev)
 {
 	struct mock_dev *mdev = to_mock_dev(dev);
+	struct mock_viommu *new_viommu = NULL;
+	unsigned long vdev_id = 0;
 
 	if (domain->dirty_ops && (mdev->flags & MOCK_FLAGS_DEVICE_NO_DIRTY))
 		return -EINVAL;
 
+	iommu_group_mutex_assert(dev);
+	if (domain->type == IOMMU_DOMAIN_NESTED) {
+		new_viommu = to_mock_nested(domain)->mock_viommu;
+		if (new_viommu) {
+			vdev_id = iommufd_viommu_get_vdev_id(&new_viommu->core,
+							     dev);
+			if (!vdev_id)
+				return -ENOENT;
+		}
+	}
+	if (new_viommu != mdev->viommu) {
+		down_write(&mdev->viommu_rwsem);
+		mdev->viommu = new_viommu;
+		mdev->vdev_id = vdev_id;
+		up_write(&mdev->viommu_rwsem);
+	}
+
 	return 0;
 }
 

@@ -861,6 +883,7 @@ static struct mock_dev *mock_dev_create(unsigned long dev_flags)
 	if (!mdev)
 		return ERR_PTR(-ENOMEM);
 
+	init_rwsem(&mdev->viommu_rwsem);
 	device_initialize(&mdev->dev);
 	mdev->flags = dev_flags;
 	mdev->dev.release = mock_dev_release;

index a1b2b657999d..212e5d62e13d 100644
@@ -2736,6 +2736,7 @@ TEST_F(iommufd_viommu, viommu_alloc_nested_iopf)
 	uint32_t iopf_hwpt_id;
 	uint32_t fault_id;
 	uint32_t fault_fd;
+	uint32_t vdev_id;
 
 	if (self->device_id) {
 		test_ioctl_fault_alloc(&fault_id, &fault_fd);

@@ -2752,6 +2753,10 @@ TEST_F(iommufd_viommu, viommu_alloc_nested_iopf)
 			&iopf_hwpt_id, IOMMU_HWPT_DATA_SELFTEST, &data,
 			sizeof(data));
 
+		/* Must allocate vdevice before attaching to a nested hwpt */
+		test_err_mock_domain_replace(ENOENT, self->stdev_id,
+					     iopf_hwpt_id);
+		test_cmd_vdevice_alloc(viommu_id, dev_id, 0x99, &vdev_id);
 		test_cmd_mock_domain_replace(self->stdev_id, iopf_hwpt_id);
 		EXPECT_ERRNO(EBUSY,
 			     _test_ioctl_destroy(self->fd, iopf_hwpt_id));

index a6b7a163f636..87e9165cea27 100644
@@ -24,6 +24,7 @@ enum {
 	IOMMU_TEST_OP_MD_CHECK_IOTLB,
 	IOMMU_TEST_OP_TRIGGER_IOPF,
 	IOMMU_TEST_OP_DEV_CHECK_CACHE,
+	IOMMU_TEST_OP_TRIGGER_VEVENT,
 };
 
 enum {

@@ -145,6 +146,9 @@ struct iommu_test_cmd {
 			__u32 id;
 			__u32 cache;
 		} check_dev_cache;
+		struct {
+			__u32 dev_id;
+		} trigger_vevent;
 	};
 	__u32 last;
 };

@@ -212,4 +216,10 @@ struct iommu_viommu_invalidate_selftest {
 	__u32 cache_id;
 };
 
+#define IOMMU_VEVENTQ_TYPE_SELFTEST 0xbeefbeef
+
+struct iommu_viommu_event_selftest {
+	__u32 virt_id;
+};
+
 #endif

index d1438d81e664..7c20a85ed142 100644
@@ -1631,6 +1631,34 @@ static int iommufd_test_trigger_iopf(struct iommufd_ucmd *ucmd,
 	return 0;
 }
 
+static int iommufd_test_trigger_vevent(struct iommufd_ucmd *ucmd,
+				       struct iommu_test_cmd *cmd)
+{
+	struct iommu_viommu_event_selftest test = {};
+	struct iommufd_device *idev;
+	struct mock_dev *mdev;
+	int rc = -ENOENT;
+
+	idev = iommufd_get_device(ucmd, cmd->trigger_vevent.dev_id);
+	if (IS_ERR(idev))
+		return PTR_ERR(idev);
+	mdev = to_mock_dev(idev->dev);
+
+	down_read(&mdev->viommu_rwsem);
+	if (!mdev->viommu || !mdev->vdev_id)
+		goto out_unlock;
+
+	test.virt_id = mdev->vdev_id;
+	rc = iommufd_viommu_report_event(&mdev->viommu->core,
+					 IOMMU_VEVENTQ_TYPE_SELFTEST, &test,
+					 sizeof(test));
+out_unlock:
+	up_read(&mdev->viommu_rwsem);
+	iommufd_put_object(ucmd->ictx, &idev->obj);
+
+	return rc;
+}
+
 void iommufd_selftest_destroy(struct iommufd_object *obj)
 {
 	struct selftest_obj *sobj = to_selftest_obj(obj);

@@ -1712,6 +1740,8 @@ int iommufd_test(struct iommufd_ucmd *ucmd)
 					  cmd->dirty.flags);
 	case IOMMU_TEST_OP_TRIGGER_IOPF:
 		return iommufd_test_trigger_iopf(ucmd, cmd);
+	case IOMMU_TEST_OP_TRIGGER_VEVENT:
+		return iommufd_test_trigger_vevent(ucmd, cmd);
 	default:
 		return -EOPNOTSUPP;
 	}

index d979f5b0efe8..15cf28b88332 100644
@@ -9,6 +9,7 @@
 #include <sys/ioctl.h>
 #include <stdint.h>
 #include <assert.h>
+#include <poll.h>
 
 #include "../kselftest_harness.h"
 #include "../../../../drivers/iommu/iommufd/iommufd_test.h"

@@ -936,3 +937,67 @@ static int _test_cmd_vdevice_alloc(int fd, __u32 viommu_id, __u32 idev_id,
 	EXPECT_ERRNO(_errno,                                                 \
 		     _test_cmd_vdevice_alloc(self->fd, viommu_id, idev_id,   \
 					     virt_id, vdev_id))
+
+static int _test_cmd_veventq_alloc(int fd, __u32 viommu_id, __u32 type,
+				   __u32 *veventq_id, __u32 *veventq_fd)
+{
+	struct iommu_veventq_alloc cmd = {
+		.size = sizeof(cmd),
+		.type = type,
+		.viommu_id = viommu_id,
+	};
+	int ret;
+
+	ret = ioctl(fd, IOMMU_VEVENTQ_ALLOC, &cmd);
+	if (ret)
+		return ret;
+	if (veventq_id)
+		*veventq_id = cmd.out_veventq_id;
+	if (veventq_fd)
+		*veventq_fd = cmd.out_veventq_fd;
+	return 0;
+}
+
+#define test_cmd_veventq_alloc(viommu_id, type, veventq_id, veventq_fd) \
+	ASSERT_EQ(0, _test_cmd_veventq_alloc(self->fd, viommu_id, type, \
+					     veventq_id, veventq_fd))
+#define test_err_veventq_alloc(_errno, viommu_id, type, veventq_id,     \
+			       veventq_fd)                              \
+	EXPECT_ERRNO(_errno,                                            \
+		     _test_cmd_veventq_alloc(self->fd, viommu_id, type, \
+					     veventq_id, veventq_fd))
+
+static int _test_cmd_trigger_vevent(int fd, __u32 dev_id, __u32 event_fd,
+				    __u32 virt_id)
+{
+	struct iommu_test_cmd trigger_vevent_cmd = {
+		.size = sizeof(trigger_vevent_cmd),
+		.op = IOMMU_TEST_OP_TRIGGER_VEVENT,
+		.trigger_vevent = {
+			.dev_id = dev_id,
+		},
+	};
+	struct pollfd pollfd = { .fd = event_fd, .events = POLLIN };
+	struct iommu_viommu_event_selftest event;
+	ssize_t bytes;
+	int ret;
+
+	ret = ioctl(fd, _IOMMU_TEST_CMD(IOMMU_TEST_OP_TRIGGER_VEVENT),
+		    &trigger_vevent_cmd);
+	if (ret)
+		return ret;
+
+	ret = poll(&pollfd, 1, 1000);
+	if (ret < 0)
+		return ret;
+
+	bytes = read(event_fd, &event, sizeof(event));
+	if (bytes <= 0)
+		return -EIO;
+
+	return event.virt_id == virt_id ? 0 : -EINVAL;
+}
+
+#define test_cmd_trigger_vevent(dev_id, event_fd, virt_id)                \
+	ASSERT_EQ(0, _test_cmd_trigger_vevent(self->fd, dev_id, event_fd, \
+					      virt_id))

index 212e5d62e13d..c225f6e5108d 100644
@@ -2774,15 +2774,37 @@ TEST_F(iommufd_viommu, vdevice_alloc)
 	uint32_t viommu_id = self->viommu_id;
 	uint32_t dev_id = self->device_id;
 	uint32_t vdev_id = 0;
+	uint32_t veventq_id;
+	uint32_t veventq_fd;
 
 	if (dev_id) {
+		/* Must allocate vdevice before attaching to a nested hwpt */
+		test_err_mock_domain_replace(ENOENT, self->stdev_id,
+					     self->nested_hwpt_id);
+
+		test_cmd_veventq_alloc(viommu_id, IOMMU_VEVENTQ_TYPE_SELFTEST,
+				       &veventq_id, &veventq_fd);
+		test_err_veventq_alloc(EEXIST, viommu_id,
+				       IOMMU_VEVENTQ_TYPE_SELFTEST, NULL, NULL);
 		/* Set vdev_id to 0x99, unset it, and set to 0x88 */
 		test_cmd_vdevice_alloc(viommu_id, dev_id, 0x99, &vdev_id);
+		test_cmd_mock_domain_replace(self->stdev_id,
+					     self->nested_hwpt_id);
+		test_cmd_trigger_vevent(dev_id, veventq_fd, 0x99);
 		test_err_vdevice_alloc(EEXIST, viommu_id, dev_id, 0x99,
 				       &vdev_id);
+		test_cmd_mock_domain_replace(self->stdev_id, self->ioas_id);
 		test_ioctl_destroy(vdev_id);
+
+		/* Try again with 0x88 */
 		test_cmd_vdevice_alloc(viommu_id, dev_id, 0x88, &vdev_id);
+		test_cmd_mock_domain_replace(self->stdev_id,
+					     self->nested_hwpt_id);
+		test_cmd_trigger_vevent(dev_id, veventq_fd, 0x88);
+		close(veventq_fd);
+		test_cmd_mock_domain_replace(self->stdev_id, self->ioas_id);
 		test_ioctl_destroy(vdev_id);
+		test_ioctl_destroy(veventq_id);
 	} else {
 		test_err_vdevice_alloc(ENOENT, viommu_id, dev_id, 0x99, NULL);
 	}

index 64b1f8e1b0cf..99a7f7897bb2 100644
@@ -620,6 +620,7 @@ TEST_FAIL_NTH(basic_fail_nth, device)
 	};
 	struct iommu_test_hw_info info;
 	uint32_t fault_id, fault_fd;
+	uint32_t veventq_id, veventq_fd;
 	uint32_t fault_hwpt_id;
 	uint32_t ioas_id;
 	uint32_t ioas_id2;

@@ -692,6 +693,12 @@ TEST_FAIL_NTH(basic_fail_nth, device)
 				 IOMMU_HWPT_DATA_SELFTEST, &data, sizeof(data)))
 		return -1;
 
+	if (_test_cmd_veventq_alloc(self->fd, viommu_id,
+				    IOMMU_VEVENTQ_TYPE_SELFTEST, &veventq_id,
+				    &veventq_fd))
+		return -1;
+	close(veventq_fd);
+
 	return 0;
 }
 

index bd9d7c85576a..4435ad7db776 100644
@@ -799,6 +799,11 @@ struct arm_smmu_stream {
 	struct rb_node			node;
 };
 
+struct arm_smmu_vmaster {
+	struct arm_vsmmu		*vsmmu;
+	unsigned long			vsid;
+};
+
 struct arm_smmu_event {
 	u8				stall : 1,
 					ssv : 1,

@@ -824,6 +829,8 @@ struct arm_smmu_master {
 	struct arm_smmu_device		*smmu;
 	struct device			*dev;
 	struct arm_smmu_stream		*streams;
+	struct arm_smmu_vmaster		*vmaster;
+	struct rw_semaphore		vmaster_rwsem;
 	/* Locked by the iommu core using the group mutex */
 	struct arm_smmu_ctx_desc_cfg	cd_table;
 	unsigned int			num_streams;

@@ -972,6 +979,7 @@ struct arm_smmu_attach_state {
 	bool disable_ats;
 	ioasid_t ssid;
 	/* Resulting state */
+	struct arm_smmu_vmaster *vmaster;
 	bool ats_enabled;
 };
 

@@ -1055,9 +1063,24 @@ struct iommufd_viommu *arm_vsmmu_alloc(struct device *dev,
 				       struct iommu_domain *parent,
 				       struct iommufd_ctx *ictx,
 				       unsigned int viommu_type);
+int arm_smmu_attach_prepare_vmaster(struct arm_smmu_attach_state *state,
+				    struct iommu_domain *domain);
+void arm_smmu_attach_commit_vmaster(struct arm_smmu_attach_state *state);
 #else
 #define arm_smmu_hw_info NULL
 #define arm_vsmmu_alloc NULL
+
+static inline int
+arm_smmu_attach_prepare_vmaster(struct arm_smmu_attach_state *state,
+				struct iommu_domain *domain)
+{
+	return 0; /* NOP */
+}
+
+static inline void
+arm_smmu_attach_commit_vmaster(struct arm_smmu_attach_state *state)
+{
+}
 #endif /* CONFIG_ARM_SMMU_V3_IOMMUFD */
 
 #endif /* _ARM_SMMU_V3_H */

55 lines not on this page · raw message

index ea76f25c0661..686c171dd273 100644
@@ -2802,6 +2802,7 @@ int arm_smmu_attach_prepare(struct arm_smmu_attach_state *state,
 	struct arm_smmu_domain *smmu_domain =
 		to_smmu_domain_devices(new_domain);
 	unsigned long flags;
+	int ret;
 
 	/*
 	 * arm_smmu_share_asid() must not see two domains pointing to the same

@@ -2831,9 +2832,15 @@ int arm_smmu_attach_prepare(struct arm_smmu_attach_state *state,
 	}
 
 	if (smmu_domain) {
+		ret = arm_smmu_attach_prepare_vmaster(state, new_domain);
+		if (ret)
+			return ret;
+
 		master_domain = kzalloc(sizeof(*master_domain), GFP_KERNEL);
-		if (!master_domain)
+		if (!master_domain) {
+			kfree(state->vmaster);
 			return -ENOMEM;
+		}
 		master_domain->master = master;
 		master_domain->ssid = state->ssid;
 		if (new_domain->type == IOMMU_DOMAIN_NESTED)

@@ -2860,6 +2867,7 @@ int arm_smmu_attach_prepare(struct arm_smmu_attach_state *state,
 			spin_unlock_irqrestore(&smmu_domain->devices_lock,
 					       flags);
 			kfree(master_domain);
+			kfree(state->vmaster);
 			return -EINVAL;
 		}
 

@@ -2892,6 +2900,8 @@ void arm_smmu_attach_commit(struct arm_smmu_attach_state *state)
 
 	lockdep_assert_held(&arm_smmu_asid_lock);
 
+	arm_smmu_attach_commit_vmaster(state);
+
 	if (state->ats_enabled && !master->ats_enabled) {
 		arm_smmu_enable_ats(master);
 	} else if (state->ats_enabled && master->ats_enabled) {

@@ -3158,8 +3168,17 @@ static void arm_smmu_attach_dev_ste(struct iommu_domain *domain,
 static int arm_smmu_attach_dev_identity(struct iommu_domain *domain,
 					struct device *dev)
 {
+	int ret;
 	struct arm_smmu_ste ste;
 	struct arm_smmu_master *master = dev_iommu_priv_get(dev);
+	struct arm_smmu_attach_state state = {
+		.master = master,
+	};
+
+	ret = arm_smmu_attach_prepare_vmaster(&state, domain);
+	if (ret)
+		return ret;
+	arm_smmu_attach_commit_vmaster(&state);
 
 	arm_smmu_make_bypass_ste(master->smmu, &ste);
 	arm_smmu_attach_dev_ste(domain, dev, &ste, STRTAB_STE_1_S1DSS_BYPASS);

@@ -3178,7 +3197,17 @@ static struct iommu_domain arm_smmu_identity_domain = {
 static int arm_smmu_attach_dev_blocked(struct iommu_domain *domain,
 					struct device *dev)
 {
+	int ret;
 	struct arm_smmu_ste ste;
+	struct arm_smmu_master *master = dev_iommu_priv_get(dev);
+	struct arm_smmu_attach_state state = {
+		.master = master,
+	};
+
+	ret = arm_smmu_attach_prepare_vmaster(&state, domain);
+	if (ret)
+		return ret;
+	arm_smmu_attach_commit_vmaster(&state);
 
 	arm_smmu_make_abort_ste(&ste);
 	arm_smmu_attach_dev_ste(domain, dev, &ste,

@@ -3428,6 +3457,7 @@ static struct iommu_device *arm_smmu_probe_device(struct device *dev)
 
 	master->dev = dev;
 	master->smmu = smmu;
+	init_rwsem(&master->vmaster_rwsem);
 	dev_iommu_priv_set(dev, master);
 
 	ret = arm_smmu_insert_master(smmu, master);

index 4435ad7db776..d24c3d8ee397 100644
@@ -1066,6 +1066,7 @@ struct iommufd_viommu *arm_vsmmu_alloc(struct device *dev,
 int arm_smmu_attach_prepare_vmaster(struct arm_smmu_attach_state *state,
 				    struct iommu_domain *domain);
 void arm_smmu_attach_commit_vmaster(struct arm_smmu_attach_state *state);
+int arm_vmaster_report_event(struct arm_smmu_vmaster *vmaster, u64 *evt);
 #else
 #define arm_smmu_hw_info NULL
 #define arm_vsmmu_alloc NULL

@@ -1081,6 +1082,12 @@ static inline void
 arm_smmu_attach_commit_vmaster(struct arm_smmu_attach_state *state)
 {
 }
+
+static inline int arm_vmaster_report_event(struct arm_smmu_vmaster *vmaster,
+					   u64 *evt)
+{
+	return -EOPNOTSUPP;
+}
 #endif /* CONFIG_ARM_SMMU_V3_IOMMUFD */
 
 #endif /* _ARM_SMMU_V3_H */

index 0a08aa82e7cc..55e3d5a14cca 100644
@@ -1016,9 +1016,24 @@ struct iommu_ioas_change_process {
 /**
  * enum iommu_veventq_type - Virtual Event Queue Type
  * @IOMMU_VEVENTQ_TYPE_DEFAULT: Reserved for future use
+ * @IOMMU_VEVENTQ_TYPE_ARM_SMMUV3: ARM SMMUv3 Virtual Event Queue
  */
 enum iommu_veventq_type {
 	IOMMU_VEVENTQ_TYPE_DEFAULT = 0,
+	IOMMU_VEVENTQ_TYPE_ARM_SMMUV3 = 1,
+};
+
+/**
+ * struct iommu_vevent_arm_smmuv3 - ARM SMMUv3 Virtual Event
+ *                                  (IOMMU_VEVENTQ_TYPE_ARM_SMMUV3)
+ * @evt: 256-bit ARM SMMUv3 Event record, little-endian.
+ *       (Refer to "7.3 Event records" in SMMUv3 HW Spec)
+ *
+ * StreamID field reports a virtual device ID. To receive a virtual event for a
+ * device, a vDEVICE must be allocated via IOMMU_VDEVICE_ALLOC.
+ */
+struct iommu_vevent_arm_smmuv3 {
+	__aligned_le64 evt[4];
 };
 
 /**

index 2b6253ef0e8f..f88fd2f5cae8 100644
@@ -447,4 +447,20 @@ struct iommufd_viommu *arm_vsmmu_alloc(struct device *dev,
 	return &vsmmu->core;
 }
 
+int arm_vmaster_report_event(struct arm_smmu_vmaster *vmaster, u64 *evt)
+{
+	struct iommu_vevent_arm_smmuv3 vevt =
+		*(struct iommu_vevent_arm_smmuv3 *)evt;
+
+	vevt.evt[0] &= ~EVTQ_0_SID;
+	vevt.evt[0] |= FIELD_PREP(EVTQ_0_SID, vmaster->vsid);
+
+	vevt.evt[0] = cpu_to_le64(vevt.evt[0]);
+	vevt.evt[1] = cpu_to_le64(vevt.evt[1]);
+
+	return iommufd_viommu_report_event(&vmaster->vsmmu->core,
+					   IOMMU_VEVENTQ_TYPE_ARM_SMMUV3, &vevt,
+					   sizeof(vevt));
+}
+
 MODULE_IMPORT_NS("IOMMUFD");

86 lines not on this page · raw message

index 0c7a5894ba07..348179f3cf2a 100644
@@ -399,9 +399,15 @@ static int arm_vsmmu_cache_invalidate(struct iommufd_viommu *viommu,
 	return ret;
 }
 
+static bool arm_vsmmu_supports_veventq(unsigned int type)
+{
+	return type == IOMMU_VIOMMU_TYPE_ARM_SMMUV3;
+}
+
 static const struct iommufd_viommu_ops arm_vsmmu_ops = {
 	.alloc_domain_nested = arm_vsmmu_alloc_domain_nested,
 	.cache_invalidate = arm_vsmmu_cache_invalidate,
+	.supports_veventq = arm_vsmmu_supports_veventq,
 };
 
 struct iommufd_viommu *arm_vsmmu_alloc(struct device *dev,

index bf0c04f571a7..b5be629f38ed 100644
@@ -555,6 +555,11 @@ int iommufd_veventq_alloc(struct iommufd_ucmd *ucmd)
 	viommu = iommufd_get_viommu(ucmd, cmd->viommu_id);
 	if (IS_ERR(viommu))
 		return PTR_ERR(viommu);
+
+	if (!viommu->ops || !viommu->ops->supports_veventq ||
+	    !viommu->ops->supports_veventq(cmd->type))
+		return -EOPNOTSUPP;
+
 	down_write(&viommu->veventqs_rwsem);
 
 	if (iommufd_viommu_find_veventq(viommu, cmd->type)) {

index 6b3b46e382f8..55e71dca3664 100644
@@ -117,6 +117,7 @@ struct iommufd_viommu {
  *                    array->entry_num to report the number of handled requests.
  *                    The data structure of the array entry must be defined in
  *                    include/uapi/linux/iommufd.h
+ * @supports_veventq: Whether the vIOMMU supports a given vEVENTQ type
  */
 struct iommufd_viommu_ops {
 	void (*destroy)(struct iommufd_viommu *viommu);

@@ -125,6 +126,7 @@ struct iommufd_viommu_ops {
 		const struct iommu_user_data *user_data);
 	int (*cache_invalidate)(struct iommufd_viommu *viommu,
 				struct iommu_user_data_array *array);
+	bool (*supports_veventq)(unsigned int type);
 };
 
 #if IS_ENABLED(CONFIG_IOMMUFD)