Merge branch 'for-next' of https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux.git

13 files changed, 275 insertions, 28 deletions

diff --git a/include/linux/bio.h b/include/linux/bio.h
index 17944e44b584..47aef63dba3b 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -80,7 +80,8 @@ static inline bool bio_no_advance_iter(const struct bio *bio)
 {
 	return bio_op(bio) == REQ_OP_DISCARD ||
 	       bio_op(bio) == REQ_OP_SECURE_ERASE ||
-	       bio_op(bio) == REQ_OP_WRITE_ZEROES;
+	       bio_op(bio) == REQ_OP_WRITE_ZEROES ||
+	       op_is_dmabuf(bio->bi_opf);
 }
 
 static inline void *bio_data(struct bio *bio)
@@ -113,11 +114,13 @@ static inline void bio_advance_iter(const struct bio *bio,
 {
 	iter->bi_sector += bytes >> 9;
 
-	if (bio_no_advance_iter(bio))
+	if (bio_no_advance_iter(bio)) {
 		iter->bi_size -= bytes;
-	else
+		iter->bi_offset += bytes;
+	} else {
 		bvec_iter_advance(bio->bi_io_vec, iter, bytes);
 		/* TODO: It is reasonable to complete bio with error here. */
+	}
 }
 
 /* @bytes should be less or equal to bvec[i->bi_idx].bv_len */
@@ -127,10 +130,12 @@ static inline void bio_advance_iter_single(const struct bio *bio,
 {
 	iter->bi_sector += bytes >> 9;
 
-	if (bio_no_advance_iter(bio))
+	if (bio_no_advance_iter(bio)) {
 		iter->bi_size -= bytes;
-	else
+		iter->bi_offset += bytes;
+	} else {
 		bvec_iter_advance_single(bio->bi_io_vec, iter, bytes);
+	}
 }
 
 void __bio_advance(struct bio *, unsigned bytes);
@@ -256,6 +261,12 @@ static inline struct folio *bio_first_folio_all(struct bio *bio)
 	return page_folio(bio_first_page_all(bio));
 }
 
+static inline struct bio_vec *bio_last_bvec_all(struct bio *bio)
+{
+	WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
+	return &bio->bi_io_vec[bio->bi_vcnt - 1];
+}
+
 /**
  * struct folio_iter - State for iterating all folios in a bio.
  * @folio: The current folio we're iterating.  NULL after the last folio.
@@ -434,12 +445,12 @@ static inline void bio_wouldblock_error(struct bio *bio)
 
 /*
  * Calculate number of bvec segments that should be allocated to fit data
- * pointed by @iter. If @iter is backed by bvec it's going to be reused
- * instead of allocating a new one.
+ * pointed by @iter. If @iter is backed by a bvec or a dmabuf, the bvec array /
+ * the dma map are going to be reused, and so no extra allocation is required.
  */
 static inline int bio_iov_vecs_to_alloc(struct iov_iter *iter, int max_segs)
 {
-	if (iov_iter_is_bvec(iter))
+	if (iov_iter_is_bvec(iter) || iov_iter_is_dmabuf_map(iter))
 		return 0;
 	return iov_iter_npages(iter, max_segs);
 }
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index af878597afb8..7c7504c84e09 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -1017,6 +1017,13 @@ static inline void *blk_mq_rq_to_pdu(struct request *rq)
 	return rq + 1;
 }
 
+static inline bool blk_mq_rq_is_dmabuf(struct request *rq)
+{
+	if (!IS_ENABLED(CONFIG_DMA_SHARED_BUFFER))
+		return false;
+	return rq->bio && op_is_dmabuf(rq->bio->bi_opf);
+}
+
 static inline struct blk_mq_hw_ctx *queue_hctx(struct request_queue *q, int id)
 {
 	struct blk_mq_hw_ctx *hctx;
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 98e21b4cbf32..0cc09b975d8f 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -233,7 +233,12 @@ struct bio {
 	atomic_t		__bi_remaining;
 
 	/* The actual vec list, preserved by bio_reset() */
-	struct bio_vec		*bi_io_vec;
+	union {
+		struct bio_vec		*bi_io_vec;
+		/* Driver specific dma map, valid IFF REQ_DMABUF is set */
+		struct dma_buf_io_map	*bi_dmabuf_map;
+	};
+
 	struct bvec_iter	bi_iter;
 
 	union {
@@ -402,6 +407,7 @@ enum req_flag_bits {
 	__REQ_DRV,		/* for driver use */
 	__REQ_FS_PRIVATE,	/* for file system (submitter) use */
 	__REQ_ATOMIC,		/* for atomic write operations */
+	__REQ_DMABUF,		/* Using premmaped dma buffers */
 	/*
 	 * Command specific flags, keep last:
 	 */
@@ -434,6 +440,7 @@ enum req_flag_bits {
 #define REQ_DRV		(__force blk_opf_t)(1ULL << __REQ_DRV)
 #define REQ_FS_PRIVATE	(__force blk_opf_t)(1ULL << __REQ_FS_PRIVATE)
 #define REQ_ATOMIC	(__force blk_opf_t)(1ULL << __REQ_ATOMIC)
+#define REQ_DMABUF	(__force blk_opf_t)(1ULL << __REQ_DMABUF)
 
 #define REQ_NOUNMAP	(__force blk_opf_t)(1ULL << __REQ_NOUNMAP)
 
@@ -487,6 +494,11 @@ static inline bool op_is_discard(blk_opf_t op)
 	return (op & REQ_OP_MASK) == REQ_OP_DISCARD;
 }
 
+static inline bool op_is_dmabuf(blk_opf_t op)
+{
+	return op & REQ_DMABUF;
+}
+
 /*
  * Check if a bio or request operation is a zone management operation.
  */
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 098a65f3e48b..2d5c30823aab 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -191,14 +191,17 @@ struct gendisk {
 #ifdef CONFIG_BLK_DEV_ZONED
 	/*
 	 * Zoned block device information. Reads of this information must be
-	 * protected with blk_queue_enter() / blk_queue_exit(). Modifying this
-	 * information is only allowed while no requests are being processed.
-	 * See also blk_mq_freeze_queue() and blk_mq_unfreeze_queue().
+	 * protected with blk_queue_enter() / blk_queue_exit() or by holding a
+	 * lock on zone_revalidate_mutex. blk_revalidate_disk_zones() may modify
+	 * this information while no requests are being processed (disk queue
+	 * frozen with blk_mq_freeze_queue()) and while holding a lock on
+	 * zone_revalidate_mutex.
 	 */
+	struct mutex		zone_revalidate_mutex;
 	unsigned int		nr_zones;
 	unsigned int		zone_capacity;
 	unsigned int		last_zone_capacity;
-	u8 __rcu		*zones_cond;
+	u8 __rcu		*zones_state;
 	unsigned int		zone_wplugs_hash_bits;
 	atomic_t		nr_zone_wplugs;
 	spinlock_t		zone_wplugs_hash_lock;
@@ -1596,6 +1599,8 @@ struct block_device_operations {
 	/* returns the length of the identifier or a negative errno: */
 	int (*get_unique_id)(struct gendisk *disk, u8 id[16],
 			enum blk_unique_id id_type);
+	int (*init_dma_buf_io_ctx)(struct block_device *,
+				   struct dma_buf_io_ctx *);
 	struct module *owner;
 	const struct pr_ops *pr_ops;
 
diff --git a/include/linux/bvec.h b/include/linux/bvec.h
index df9ce860e787..8decff9484c4 100644
--- a/include/linux/bvec.h
+++ b/include/linux/bvec.h
@@ -108,7 +108,8 @@ struct bvec_iter {
 	unsigned int		bi_idx;
 
 	/*
-	 * Current offset in the bvec entry pointed to by `bi_idx`.
+	 * Current offset in the bvec entry pointed to by `bi_idx` or into
+	 * a dma-buf map.
 	 */
 	unsigned int		bi_offset;
 } __packed __aligned(4);
diff --git a/include/linux/dma-buf-io.h b/include/linux/dma-buf-io.h
new file mode 100644
index 000000000000..8ac338df51ff
--- /dev/null
+++ b/include/linux/dma-buf-io.h
@@ -0,0 +1,105 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __DMA_BUF_IO_H__
+#define __DMA_BUF_IO_H__
+
+#include <linux/dma-buf.h>
+
+struct dma_buf_io_ctx;
+struct dma_buf_io_map;
+
+struct dma_buf_io_ops {
+	/*
+	 * Create a new map for the given ctx. Called with the reservation
+	 * lock held.
+	 */
+	struct dma_buf_io_map *(*map)(struct dma_buf_io_ctx *ctx);
+
+	/*
+	 * Clean up device specific parts of the @map. Called with the
+	 * reservation lock held.
+	 */
+	void (*unmap)(struct dma_buf_io_ctx *ctx, struct dma_buf_io_map *map);
+
+	/*
+	 * The user tries to destroy the ctx. Release all device specific
+	 * parts of the token.
+	 */
+	void (*release)(struct dma_buf_io_ctx *);
+};
+
+struct dma_buf_io_map {
+	/*
+	 * Counts attached requests and other users. Device specific unmapping
+	 * is deferred until all refs are dropped.
+	 */
+	struct percpu_ref		refs;
+	/*
+	 * Shift for the minimum segment size of the mapping.
+	 */
+	unsigned			min_seg_shift;
+
+	struct dma_buf_io_ctx		*ctx;
+	struct completion		drained;
+};
+
+struct dma_buf_io_ctx {
+	struct dma_buf_io_map __rcu		*map;
+	struct dma_buf				*dmabuf;
+	enum dma_data_direction			dir;
+	bool					is_dead;
+
+	void					*dev_priv;
+	const struct dma_buf_io_ops		*dev_ops;
+};
+
+int dma_buf_io_ctx_create(struct file *file,
+			   struct dma_buf *dmabuf,
+			   enum dma_data_direction dir,
+			   struct dma_buf_io_ctx **ctx);
+void dma_buf_io_ctx_release(struct dma_buf_io_ctx *ctx);
+
+struct dma_buf_io_map *dma_buf_io_create_map(struct dma_buf_io_ctx *ctx);
+
+static inline struct dma_buf_io_map *
+__dma_buf_io_get_map(struct dma_buf_io_ctx *ctx)
+{
+	struct dma_buf_io_map *map;
+
+	guard(rcu)();
+
+	map = rcu_dereference(ctx->map);
+	if (unlikely(!map || !percpu_ref_tryget_live_rcu(&map->refs)))
+		return NULL;
+
+	return map;
+}
+
+static inline struct dma_buf_io_map *
+dma_buf_io_get_map(struct dma_buf_io_ctx *ctx, bool nowait)
+{
+	struct dma_buf_io_map *map;
+
+	map = __dma_buf_io_get_map(ctx);
+	if (likely(map))
+		return map;
+
+	if (nowait)
+		return ERR_PTR(-EAGAIN);
+	return dma_buf_io_create_map(ctx);
+}
+
+static inline void dma_buf_io_map_drop(struct dma_buf_io_map *map)
+{
+	percpu_ref_put(&map->refs);
+}
+
+/*
+ * Device API
+ */
+
+void dma_buf_io_invalidate_mappings(struct dma_buf_io_ctx *ctx);
+int dma_buf_io_init_map(struct dma_buf_io_ctx *ctx, struct dma_buf_io_map *map,
+			struct sg_table *sgt);
+void dma_buf_io_detach(struct dma_buf_io_ctx *ctx);
+
+#endif
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 83d41d9f1130..f387c961e0a0 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1914,6 +1914,7 @@ struct dir_context {
 #define COPY_FILE_SPLICE		(1 << 0)
 
 struct io_uring_cmd;
+struct dma_buf_io_ctx;
 struct offset_ctx;
 
 struct file_operations {
@@ -1960,6 +1961,7 @@ struct file_operations {
 	int (*uring_cmd_iopoll)(struct io_uring_cmd *, struct io_comp_batch *,
 				unsigned int poll_flags);
 	int (*mmap_prepare)(struct vm_area_desc *);
+	int (*init_dma_buf_io_ctx)(struct file *, struct dma_buf_io_ctx *);
 } __randomize_layout;
 
 /* Supports async buffered reads */
diff --git a/include/linux/io_uring.h b/include/linux/io_uring.h
index d1aa4edfc2a5..505caa99c621 100644
--- a/include/linux/io_uring.h
+++ b/include/linux/io_uring.h
@@ -2,10 +2,42 @@
 #ifndef _LINUX_IO_URING_H
 #define _LINUX_IO_URING_H
 
+#include <linux/io_uring_types.h>
 #include <linux/sched.h>
 #include <linux/xarray.h>
 #include <uapi/linux/io_uring.h>
 
+static inline void req_set_fail(struct io_kiocb *req)
+{
+	req->flags |= REQ_F_FAIL;
+	if (req->flags & REQ_F_CQE_SKIP) {
+		req->flags &= ~REQ_F_CQE_SKIP;
+		req->flags |= REQ_F_SKIP_LINK_CQES;
+	}
+}
+
+static inline void io_req_set_res(struct io_kiocb *req, s32 res, u32 cflags)
+{
+	req->cqe.res = res;
+	req->cqe.flags = cflags;
+}
+
+static inline u32 ctx_cqe32_flags(struct io_ring_ctx *ctx)
+{
+	if (ctx->flags & IORING_SETUP_CQE_MIXED)
+		return IORING_CQE_F_32;
+	return 0;
+}
+
+static inline void io_req_set_res32(struct io_kiocb *req, s32 res, u32 cflags,
+				    __u64 extra1, __u64 extra2)
+{
+	req->cqe.res = res;
+	req->cqe.flags = cflags | ctx_cqe32_flags(req->ctx);
+	req->big_cqe.extra1 = extra1;
+	req->big_cqe.extra2 = extra2;
+}
+
 #if defined(CONFIG_IO_URING)
 void __io_uring_cancel(bool cancel_all);
 void __io_uring_free(struct task_struct *tsk);
diff --git a/include/linux/io_uring/cmd.h b/include/linux/io_uring/cmd.h
index 42801f0b6456..e18d4af62e1a 100644
--- a/include/linux/io_uring/cmd.h
+++ b/include/linux/io_uring/cmd.h
@@ -3,6 +3,7 @@
 #define _LINUX_IO_URING_CMD_H
 
 #include <uapi/linux/io_uring.h>
+#include <linux/io_uring.h>
 #include <linux/io_uring_types.h>
 #include <linux/blk-mq.h>
 
@@ -41,6 +42,24 @@ static inline void io_uring_cmd_private_sz_check(size_t cmd_sz)
 	((pdu_type *)&(cmd)->pdu) \
 )
 
+static inline void io_uring_cmd_set_res(struct io_uring_cmd *cmd, s32 ret)
+{
+	struct io_kiocb *req = cmd_to_io_kiocb(cmd);
+
+	if (ret < 0)
+		req_set_fail(req);
+	io_req_set_res(req, ret, 0);
+}
+
+static inline void io_uring_cmd_set_res32(struct io_uring_cmd *cmd, s32 ret, u64 res2)
+{
+	struct io_kiocb *req = cmd_to_io_kiocb(cmd);
+
+	if (ret < 0)
+		req_set_fail(req);
+	io_req_set_res32(req, ret, 0, res2, 0);
+}
+
 #if defined(CONFIG_IO_URING)
 int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
 			      struct iov_iter *iter,
@@ -56,11 +75,12 @@ int io_uring_cmd_import_fixed_vec(struct io_uring_cmd *ioucmd,
  * Completes the request, i.e. posts an io_uring CQE and deallocates @ioucmd
  * and the corresponding io_uring request.
  *
+ * io_uring_cmd_set_res()/io_uring_cmd_set_res32() must be called first.
+ *
  * Note: the caller should never hard code @issue_flags and is only allowed
  * to pass the mask provided by the core io_uring code.
  */
-void __io_uring_cmd_done(struct io_uring_cmd *cmd, s32 ret, u64 res2,
-			 unsigned issue_flags, bool is_cqe32);
+void __io_uring_cmd_done(struct io_uring_cmd *, unsigned issue_flags);
 
 void __io_uring_cmd_do_in_task(struct io_uring_cmd *ioucmd,
 			    io_req_tw_func_t task_work_cb,
@@ -116,8 +136,8 @@ static inline int io_uring_cmd_import_fixed_vec(struct io_uring_cmd *ioucmd,
 {
 	return -EOPNOTSUPP;
 }
-static inline void __io_uring_cmd_done(struct io_uring_cmd *cmd, s32 ret,
-		u64 ret2, unsigned issue_flags, bool is_cqe32)
+static inline void __io_uring_cmd_done(struct io_uring_cmd *cmd,
+				       unsigned issue_flags)
 {
 }
 static inline void __io_uring_cmd_do_in_task(struct io_uring_cmd *ioucmd,
@@ -205,13 +225,15 @@ static inline void *io_uring_cmd_ctx_handle(struct io_uring_cmd *cmd)
 static inline void io_uring_cmd_done(struct io_uring_cmd *ioucmd, s32 ret,
 				     unsigned issue_flags)
 {
-	return __io_uring_cmd_done(ioucmd, ret, 0, issue_flags, false);
+	io_uring_cmd_set_res(ioucmd, ret);
+	__io_uring_cmd_done(ioucmd, issue_flags);
 }
 
 static inline void io_uring_cmd_done32(struct io_uring_cmd *ioucmd, s32 ret,
 				       u64 res2, unsigned issue_flags)
 {
-	return __io_uring_cmd_done(ioucmd, ret, res2, issue_flags, true);
+	io_uring_cmd_set_res32(ioucmd, ret, res2);
+	__io_uring_cmd_done(ioucmd, issue_flags);
 }
 
 #endif /* _LINUX_IO_URING_CMD_H */
diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
index 8126af652845..50970b382a9a 100644
--- a/include/linux/io_uring_types.h
+++ b/include/linux/io_uring_types.h
@@ -11,6 +11,7 @@
 
 struct iou_loop_params;
 struct io_uring_bpf_ops;
+struct dma_buf_io_map;
 
 enum {
 	/*
@@ -524,6 +525,8 @@ struct io_ring_ctx {
 
 	/* protected by ->completion_lock */
 	unsigned			nr_req_allocated;
+	/* pending SEND_ZC notifications, protected by ->uring_lock */
+	unsigned			nr_notifs;
 
 #ifdef CONFIG_NET_RX_BUSY_POLL
 	struct list_head	napi_list;	/* track busy poll napi_id */
@@ -610,6 +613,7 @@ enum {
 	REQ_F_IMPORT_BUFFER_BIT,
 	REQ_F_SQE_COPIED_BIT,
 	REQ_F_IOPOLL_BIT,
+	REQ_F_DMABUF_BIT,
 
 	/* not a real bit, just to check we're not overflowing the space */
 	__REQ_F_LAST_BIT,
@@ -705,6 +709,8 @@ enum {
 	REQ_F_SQE_COPIED	= IO_REQ_FLAG(REQ_F_SQE_COPIED_BIT),
 	/* request must be iopolled to completion (set in ->issue()) */
 	REQ_F_IOPOLL		= IO_REQ_FLAG(REQ_F_IOPOLL_BIT),
+	/* there is a dma map attached to request that needs to be dropped */
+	REQ_F_DMABUF		= IO_REQ_FLAG(REQ_F_DMABUF_BIT),
 };
 
 struct io_tw_req {
@@ -827,6 +833,7 @@ struct io_kiocb {
 	/* custom credentials, valid IFF REQ_F_CREDS is set */
 	const struct cred		*creds;
 	struct io_wq_work		work;
+	struct dma_buf_io_map		*dmabuf_map;
 
 	struct io_big_cqe {
 		u64			extra1;
diff --git a/include/linux/iov_iter.h b/include/linux/iov_iter.h
index 39ffd5878f50..e88930af7f36 100644
--- a/include/linux/iov_iter.h
+++ b/include/linux/iov_iter.h
@@ -319,6 +319,8 @@ size_t iterate_and_advance2(struct iov_iter *iter, size_t len, void *priv,
 		return iterate_bvecq(iter, len, priv, priv2, step);
 	if (iov_iter_is_xarray(iter))
 		return iterate_xarray(iter, len, priv, priv2, step);
+	if (WARN_ON_ONCE(iov_iter_is_dmabuf_map(iter)))
+		return 0;
 	return iterate_discard(iter, len, priv, priv2, step);
 }
 
diff --git a/include/linux/uio.h b/include/linux/uio.h
index 8d82a8258ef1..3fc98542922e 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -11,6 +11,7 @@
 #include <uapi/linux/uio.h>
 
 struct page;
+struct dma_buf_io_map;
 
 typedef unsigned int __bitwise iov_iter_extraction_t;
 
@@ -28,6 +29,7 @@ enum iter_type {
 	ITER_BVECQ,
 	ITER_XARRAY,
 	ITER_DISCARD,
+	ITER_DMABUF_MAP,
 };
 
 #define ITER_SOURCE	1	// == WRITE
@@ -70,6 +72,7 @@ struct iov_iter {
 				const struct bvecq *bvecq;
 				struct xarray *xarray;
 				void __user *ubuf;
+				struct dma_buf_io_map *dmabuf_map;
 			};
 			size_t count;
 		};
@@ -154,6 +157,11 @@ static inline bool iov_iter_is_xarray(const struct iov_iter *i)
 	return iov_iter_type(i) == ITER_XARRAY;
 }
 
+static inline bool iov_iter_is_dmabuf_map(const struct iov_iter *i)
+{
+	return iov_iter_type(i) == ITER_DMABUF_MAP;
+}
+
 static inline unsigned char iov_iter_rw(const struct iov_iter *i)
 {
 	return i->data_source ? WRITE : READ;
@@ -299,6 +307,9 @@ void iov_iter_bvec_queue(struct iov_iter *i, unsigned int direction,
 			 unsigned int first_slot, unsigned int offset, size_t count);
 void iov_iter_xarray(struct iov_iter *i, unsigned int direction, struct xarray *xarray,
 		     loff_t start, size_t count);
+void iov_iter_dmabuf_map(struct iov_iter *i, unsigned int direction,
+			struct dma_buf_io_map *map,
+			loff_t off, size_t count);
 ssize_t iov_iter_get_pages2(struct iov_iter *i, struct page **pages,
 			size_t maxsize, unsigned maxpages, size_t *start);
 ssize_t iov_iter_get_pages_alloc2(struct iov_iter *i, struct page ***pages,
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index 909fb7aea638..b456f45fa8de 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -121,14 +121,15 @@ struct io_uring_sqe {
 
 /* sqe->attr_type_mask flags */
 #define IORING_RW_ATTR_FLAG_PI	(1U << 0)
-/* PI attribute information */
+
+/* PI attribute information in sqe->attr_ptr for IORING_RW_ATTR_FLAG_PI: */
 struct io_uring_attr_pi {
-		__u16	flags;
-		__u16	app_tag;
-		__u32	len;
-		__u64	addr;
-		__u64	seed;
-		__u64	rsvd;
+	__u16	flags;
+	__u16	app_tag;
+	__u32	len;
+	__u64	addr;
+	__u64	seed;
+	__u64	rsvd;
 };
 
 /*
@@ -790,13 +791,42 @@ struct io_uring_rsrc_update {
 
 struct io_uring_rsrc_update2 {
 	__u32 offset;
-	__u32 resv;
+	__u32 flags;
 	__aligned_u64 data;
 	__aligned_u64 tags;
 	__u32 nr;
 	__u32 resv2;
 };
 
+/* struct io_uring_rsrc_update2::flags */
+enum io_uring_rsrc_reg_flags {
+	/*
+	 * Use the extended descriptor format for buffer updates,
+	 * see struct io_uring_regbuf_desc
+	 */
+	IORING_RSRC_UPDATE_EXTENDED		= 1U << 1,
+};
+
+/* Buffer registration type, passed in struct io_uring_regbuf_desc::type */
+enum io_uring_regbuf_type {
+	IO_REGBUF_TYPE_EMPTY,
+	IO_REGBUF_TYPE_UADDR,
+	IO_REGBUF_TYPE_DMABUF,
+
+	__IO_REGBUF_TYPE_MAX,
+};
+
+struct io_uring_regbuf_desc {
+	__u32 type; /* enum io_uring_regbuf_type */
+	__u32 flags;
+	__u64 size;
+	__u64 uaddr;
+
+	__s32 dmabuf_fd;
+	__s32 target_fd;
+	__u64 __resv[6];
+};
+
 /* Skip updating fd indexes set to this value in the fd table */
 #define IORING_REGISTER_FILES_SKIP	(-2)