Merge tag 'for-7.4/io_uring-dmabuf-20261023' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux

Pull io_uring dma-buf support from Jens Axboe:
 "This adds native dma-buf support to the I/O path, exposed through
  io_uring. It's been in development for a while and should be ready to
  go now.

   - dma-buf file I/O infrastructure: a dma_buf_io_ctx created through a
     new ->init_dma_buf_io_ctx file operation, and a dma_buf_io_map
     holding the device DMA mapping. The two are split so a mapping can
     be invalidated and re-established underneath a live context, with
     the map counting in-flight requests so it can be torn down safely.

   - A new iov_iter type for dmabuf maps, and a dma map backed bio type
     for the block layer, with raw block device support on top.

   - nvme-pci backend implementing dma-buf backed requests, including
     SGL support.

   - io_uring dmabuf backed registered buffers, built on a reworked
     buffer registration structure with an extended update path, regbuf
     import flags, an uncloneable flag for buffer types that can't be
     cloned, and cloning support for registered dma-bufs"

* tag 'for-7.4/io_uring-dmabuf-20261023' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  io_uring/dma-buf: don't fail fixed buffers without dma-buf support
  nvme-pci: detach dma-bufs only on removal
  block: reject dma-bufs larger than 4GiB
  io_uring/dma-buf: allow cloning registered dma-bufs
  dma-buf-io: document dma_buf_io_init_map
  dma-buf-io: fix typos in kernel docs
  block: fix indention for dma-buf checks
  io_uring/rsrc: add dmabuf backed registered buffers
  io_uring/rsrc: add regbuf import flags
  io_uring/rsrc: add uncloneable regbuf flag
  io_uring/rsrc: extend buffer update
  io_uring/rsrc: introduce buf registration structure
  nvme-pci: add SGL support for the dmabuf path
  nvme-pci: implement dma-buf backed requests
  nvme-pci: rename nvme_pci_sgl_set_data to nvme_pci_dma_iter_set_sgl
  block: add dma-buf support for raw bdev
  block: introduce dma map backed bio type
  block: always adjust bi_offset on bio_advance_iter
  iov_iter: add iterator type for dmabuf maps
  dma-buf: introduce initial file I/O infrastructure

1 files changed, 30 insertions, 1 deletions

diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index b42b66b424a7..b456f45fa8de 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -791,13 +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)