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| author | Ming Lei <ming.lei@redhat.com> | 2026-03-31 18:31:54 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2026-04-07 16:39:24 +0300 |
| commit | 08677040a91199175149d1fd465c02e3b3fc768a (patch) | |
| tree | 0596b119af77e071ed4f0acf4067644319a5ae7b /include | |
| parent | 4d4a512a1f87b156f694d25c800e3d525aa56e8a (diff) | |
| download | linux-08677040a91199175149d1fd465c02e3b3fc768a.tar.xz | |
ublk: enable UBLK_F_SHMEM_ZC feature flag
Add UBLK_F_SHMEM_ZC (1ULL << 19) to the UAPI header and UBLK_F_ALL.
Switch ublk_support_shmem_zc() and ublk_dev_support_shmem_zc() from
returning false to checking the actual flag, enabling the shared
memory zero-copy feature for devices that request it.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://patch.msgid.link/20260331153207.3635125-4-ming.lei@redhat.com
[axboe: ublk_buf_reg -> ublk_shmem_buf_reg errors]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'include')
| -rw-r--r-- | include/uapi/linux/ublk_cmd.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h index 5b71c19d3b9c..a7078b798791 100644 --- a/include/uapi/linux/ublk_cmd.h +++ b/include/uapi/linux/ublk_cmd.h @@ -408,6 +408,13 @@ struct ublk_shmem_buf_reg { /* Disable automatic partition scanning when device is started */ #define UBLK_F_NO_AUTO_PART_SCAN (1ULL << 18) +/* + * Enable shared memory zero copy. When enabled, the server can register + * shared memory buffers via UBLK_U_CMD_REG_BUF. If a block request's + * pages match a registered buffer, UBLK_IO_F_SHMEM_ZC is set and addr + * encodes the buffer index + offset instead of a userspace buffer address. + */ +#define UBLK_F_SHMEM_ZC (1ULL << 19) /* device state */ #define UBLK_S_DEV_DEAD 0 |