diff options
| author | Ming Lei <ming.lei@redhat.com> | 2025-08-21 12:02:07 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2025-08-24 11:41:12 -0600 |
| commit | 620a50c927004f5c9420a7ca9b1a55673dbf3941 (patch) | |
| tree | 1408d7c5c7246376ef6702a8002d44032bcb93eb /include/linux | |
| parent | d589bcddaa3f8b1668499c3f0466863df3abe37a (diff) | |
io_uring: uring_cmd: add multishot support
Add UAPI flag IORING_URING_CMD_MULTISHOT for supporting multishot
uring_cmd operations with provided buffer.
This enables drivers to post multiple completion events from a single
uring_cmd submission, which is useful for:
- Notifying userspace of device events (e.g., interrupt handling)
- Supporting devices with multiple event sources (e.g., multi-queue devices)
- Avoiding the need for device poll() support when events originate
from multiple sources device-wide
The implementation adds two new APIs:
- io_uring_cmd_select_buffer(): selects a buffer from the provided
buffer group for multishot uring_cmd
- io_uring_mshot_cmd_post_cqe(): posts a CQE after event data is
pushed to the provided buffer
Multishot uring_cmd must be used with buffer select (IOSQE_BUFFER_SELECT)
and is mutually exclusive with IORING_URING_CMD_FIXED for now.
The ublk driver will be the first user of this functionality:
https://github.com/ming1/linux/commits/ublk-devel/
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250821040210.1152145-3-ming.lei@redhat.com
[axboe: fold in fix for !CONFIG_IO_URING]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/io_uring/cmd.h | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/include/linux/io_uring/cmd.h b/include/linux/io_uring/cmd.h index cfa6d0c0c322..4bd3a7339243 100644 --- a/include/linux/io_uring/cmd.h +++ b/include/linux/io_uring/cmd.h @@ -70,6 +70,21 @@ void io_uring_cmd_mark_cancelable(struct io_uring_cmd *cmd, /* Execute the request from a blocking context */ void io_uring_cmd_issue_blocking(struct io_uring_cmd *ioucmd); +/* + * Select a buffer from the provided buffer group for multishot uring_cmd. + * Returns the selected buffer address and size. + */ +struct io_br_sel io_uring_cmd_buffer_select(struct io_uring_cmd *ioucmd, + unsigned buf_group, size_t *len, + unsigned int issue_flags); + +/* + * Complete a multishot uring_cmd event. This will post a CQE to the completion + * queue and update the provided buffer. + */ +bool io_uring_mshot_cmd_post_cqe(struct io_uring_cmd *ioucmd, + struct io_br_sel *sel, unsigned int issue_flags); + #else static inline int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw, @@ -102,6 +117,17 @@ static inline void io_uring_cmd_mark_cancelable(struct io_uring_cmd *cmd, static inline void io_uring_cmd_issue_blocking(struct io_uring_cmd *ioucmd) { } +static inline struct io_br_sel +io_uring_cmd_buffer_select(struct io_uring_cmd *ioucmd, unsigned buf_group, + size_t *len, unsigned int issue_flags) +{ + return (struct io_br_sel) { .val = -EOPNOTSUPP }; +} +static inline bool io_uring_mshot_cmd_post_cqe(struct io_uring_cmd *ioucmd, + ssize_t ret, unsigned int issue_flags) +{ + return true; +} #endif /* |