From fc01b96d74b3a9eec2b558d49ec9f5176473766a Mon Sep 17 00:00:00 2001 From: Caleb Sander Mateos Date: Mon, 3 Aug 2026 15:14:38 -0600 Subject: [PATCH] selftests: ublk: add support for --io_desc_size Add an optional --io_desc_size argument to the kublk add/recover commands to enable UBLK_F_IO_DESC on the ublk device. The mmap() arguments and ublk_get_iod() computation are adjusted accordingly. Display the configured io_desc_size in the kublk list output for ublk devices with UBLK_F_IO_DESC. Signed-off-by: Caleb Sander Mateos Link: https://patch.msgid.link/20260803211441.2538144-7-csander@purestorage.com Signed-off-by: Jens Axboe --- tools/testing/selftests/ublk/kublk.c | 29 +++++++++++++++++++--------- tools/testing/selftests/ublk/kublk.h | 6 ++++-- 2 files changed, 24 insertions(+), 11 deletions(-) diff --git a/tools/testing/selftests/ublk/kublk.c b/tools/testing/selftests/ublk/kublk.c index 5c4a1f18d0a3..0e3e2d74cc4d 100644 --- a/tools/testing/selftests/ublk/kublk.c +++ b/tools/testing/selftests/ublk/kublk.c @@ -352,6 +352,8 @@ static void ublk_ctrl_dump(struct ublk_dev *dev) ublk_log("\tmax rq size %d daemon pid %d flags 0x%llx state %s\n", info->max_io_buf_bytes, info->ublksrv_pid, info->flags, ublk_dev_state_desc(dev)); + if (info->flags & UBLK_F_IO_DESC_SIZE) + ublk_log("\tio_desc_size %u\n", info->io_desc_size); if (affinity) { char buf[512]; @@ -400,22 +402,22 @@ static struct ublk_dev *ublk_ctrl_init(void) return dev; } -static int __ublk_queue_cmd_buf_sz(unsigned depth) +static size_t __ublk_queue_cmd_buf_sz(const struct ublk_queue *q, __u16 depth) { - int size = depth * sizeof(struct ublksrv_io_desc); - unsigned int page_sz = getpagesize(); + size_t size = depth * (size_t)q->io_desc_size; + size_t page_sz = getpagesize(); return round_up(size, page_sz); } -static int ublk_queue_max_cmd_buf_sz(void) +static size_t ublk_queue_max_cmd_buf_sz(const struct ublk_queue *q) { - return __ublk_queue_cmd_buf_sz(UBLK_MAX_QUEUE_DEPTH); + return __ublk_queue_cmd_buf_sz(q, UBLK_MAX_QUEUE_DEPTH); } -static int ublk_queue_cmd_buf_sz(struct ublk_queue *q) +static size_t ublk_queue_cmd_buf_sz(const struct ublk_queue *q) { - return __ublk_queue_cmd_buf_sz(q->q_depth); + return __ublk_queue_cmd_buf_sz(q, q->q_depth); } static void ublk_queue_deinit(struct ublk_queue *q) @@ -453,7 +455,7 @@ static int ublk_queue_init(struct ublk_queue *q, unsigned long long extra_flags, struct ublk_dev *dev = q->dev; int depth = dev->dev_info.queue_depth; int i; - int cmd_buf_size, io_buf_size, integrity_size; + size_t cmd_buf_size, io_buf_size, integrity_size; unsigned long off; pthread_spin_init(&q->lock, PTHREAD_PROCESS_PRIVATE); @@ -463,12 +465,13 @@ static int ublk_queue_init(struct ublk_queue *q, unsigned long long extra_flags, q->flags = dev->dev_info.flags; q->flags |= extra_flags; q->metadata_size = metadata_size; + q->io_desc_size = dev->dev_info.io_desc_size; /* Cache fd in queue for fast path access */ q->ublk_fd = dev->fds[0]; cmd_buf_size = ublk_queue_cmd_buf_sz(q); - off = UBLKSRV_CMD_BUF_OFFSET + q->q_id * ublk_queue_max_cmd_buf_sz(); + off = UBLKSRV_CMD_BUF_OFFSET + q->q_id * ublk_queue_max_cmd_buf_sz(q); q->io_cmd_buf = mmap(0, cmd_buf_size, PROT_READ, MAP_SHARED | MAP_POPULATE, dev->fds[0], off); if (q->io_cmd_buf == MAP_FAILED) { @@ -1708,6 +1711,7 @@ static int __cmd_dev_add(const struct dev_ctx *ctx) info->dev_id = ctx->dev_id; info->nr_hw_queues = nr_queues; info->queue_depth = depth; + info->io_desc_size = ctx->io_desc_size; info->flags = ctx->flags; if ((features & UBLK_F_QUIESCE) && (info->flags & UBLK_F_USER_RECOVERY)) @@ -2069,6 +2073,7 @@ static void __cmd_create_help(char *exe, bool recovery) printf("\t[--integrity_capable] [--integrity_reftag] [--metadata_size SIZE] " "[--pi_offset OFFSET] [--csum_type ip|t10dif|nvme] [--tag_size SIZE]\n"); printf("\t[--batch|-b] [--no_auto_part_scan]\n"); + printf("\t[--io_desc_size SIZE]\n"); printf("\t[target options] [backfile1] [backfile2] ...\n"); printf("\tdefault: nr_queues=2(max 32), depth=128(max 1024), dev_id=-1(auto allocation)\n"); printf("\tdefault: nthreads=nr_queues"); @@ -2146,6 +2151,7 @@ int main(int argc, char *argv[]) { "shmem_zc", 0, NULL, 0 }, { "htlb", 1, NULL, 0 }, { "rdonly_shmem_buf", 0, NULL, 0 }, + { "io_desc_size", 1, NULL, 0 }, { 0, 0, 0, 0 } }; const struct ublk_tgt_ops *ops = NULL; @@ -2158,6 +2164,7 @@ int main(int argc, char *argv[]) .dev_id = -1, .tgt_type = "unknown", .csum_type = LBMD_PI_CSUM_NONE, + .io_desc_size = sizeof(struct ublksrv_io_desc), }; int ret = -EINVAL, i; int tgt_argc = 1; @@ -2267,6 +2274,10 @@ int main(int argc, char *argv[]) ctx.htlb_path = strdup(optarg); if (!strcmp(longopts[option_idx].name, "rdonly_shmem_buf")) ctx.rdonly_shmem_buf = 1; + if (!strcmp(longopts[option_idx].name, "io_desc_size")) { + ctx.flags |= UBLK_F_IO_DESC_SIZE; + ctx.io_desc_size = strtoul(optarg, NULL, 0); + } break; case '?': /* diff --git a/tools/testing/selftests/ublk/kublk.h b/tools/testing/selftests/ublk/kublk.h index 742c41d77df1..15b56ff45bb6 100644 --- a/tools/testing/selftests/ublk/kublk.h +++ b/tools/testing/selftests/ublk/kublk.h @@ -87,6 +87,7 @@ struct dev_ctx { __u8 pi_offset; __u8 csum_type; __u8 tag_size; + __u16 io_desc_size; int _evtfd; int _shmid; @@ -187,6 +188,7 @@ struct ublk_queue { __u64 flags; int ublk_fd; /* cached ublk char device fd */ __u8 metadata_size; + __u16 io_desc_size; struct ublk_io ios[UBLK_QUEUE_DEPTH]; /* used for prep io commands */ @@ -461,9 +463,9 @@ static inline void ublk_mark_io_done(struct ublk_io *io, int res) io->result = res; } -static inline const struct ublksrv_io_desc *ublk_get_iod(const struct ublk_queue *q, int tag) +static inline const struct ublksrv_io_desc *ublk_get_iod(const struct ublk_queue *q, __u16 tag) { - return &q->io_cmd_buf[tag]; + return (void *)q->io_cmd_buf + tag * (size_t)q->io_desc_size; } static inline void ublk_set_sqe_cmd_op(struct io_uring_sqe *sqe, __u32 cmd_op)