From 0aa73170eba5eae638c1b96a05eba533f030b5cb Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Sat, 30 Jul 2022 17:27:49 +0800 Subject: ublk_drv: add SET_PARAMS/GET_PARAMS control command Add two commands to set/get parameters generically. One important goal of ublk is to provide generic framework for making block device by userspace flexibly. As one generic block device, there are still lots of block parameters, such as max_sectors, write_cache/fua, discard related limits, zoned parameters, ...., so this patch starts to add generic mechanism for set/get device parameters. Both generic block parameters(all kinds of queue settings) and ublk feature parameters can be covered with this way, then it becomes quite easy to extend in future. Add two parameter types are used so far: basic(covers basic queue setting and misc settings which can't be grouped easily) and discard, basic type must be set, and discard type becomes optional now This way provides mechanism to simulate any kind of generic block device from userspace easily, from both block queue setting viewpoint or ublk feature viewpoint. The style of putting all parameters together is suggested by Christoph. Suggested-by: Christoph Hellwig Signed-off-by: Ming Lei Link: https://lore.kernel.org/r/20220730092750.1118167-4-ming.lei@redhat.com Signed-off-by: Jens Axboe --- include/uapi/linux/ublk_cmd.h | 47 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h index ca33092354ab..54d065426f06 100644 --- a/include/uapi/linux/ublk_cmd.h +++ b/include/uapi/linux/ublk_cmd.h @@ -15,6 +15,8 @@ #define UBLK_CMD_DEL_DEV 0x05 #define UBLK_CMD_START_DEV 0x06 #define UBLK_CMD_STOP_DEV 0x07 +#define UBLK_CMD_SET_PARAMS 0x08 +#define UBLK_CMD_GET_PARAMS 0x09 /* * IO commands, issued by ublk server, and handled by ublk driver. @@ -158,4 +160,49 @@ struct ublksrv_io_cmd { __u64 addr; }; +struct ublk_param_basic { +#define UBLK_ATTR_READ_ONLY (1 << 0) +#define UBLK_ATTR_ROTATIONAL (1 << 1) +#define UBLK_ATTR_VOLATILE_CACHE (1 << 2) +#define UBLK_ATTR_FUA (1 << 3) + __u32 attrs; + __u8 logical_bs_shift; + __u8 physical_bs_shift; + __u8 io_opt_shift; + __u8 io_min_shift; + + __u32 max_sectors; + __u32 chunk_sectors; + + __u64 dev_sectors; + __u64 virt_boundary_mask; +}; + +struct ublk_param_discard { + __u32 discard_alignment; + + __u32 discard_granularity; + __u32 max_discard_sectors; + + __u32 max_write_zeroes_sectors; + __u16 max_discard_segments; + __u16 reserved0; +}; + +struct ublk_params { + /* + * Total length of parameters, userspace has to set 'len' for both + * SET_PARAMS and GET_PARAMS command, and driver may update len + * if two sides use different version of 'ublk_params', same with + * 'types' fields. + */ + __u32 len; +#define UBLK_PARAM_TYPE_BASIC (1 << 0) +#define UBLK_PARAM_TYPE_DISCARD (1 << 1) + __u32 types; /* types of parameter included */ + + struct ublk_param_basic basic; + struct ublk_param_discard discard; +}; + #endif -- cgit v1.2.3 From 4bf9cbf3e93426e9ebe136dabd6ca392ca92cfcb Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Sat, 30 Jul 2022 17:27:50 +0800 Subject: ublk_drv: cleanup ublksrv_ctrl_dev_info Remove all block device related info from ublksrv_ctrl_dev_info, meantime reduce its size into 64 bytes because: 1) ublksrv_ctrl_dev_info becomes cleaner without including any block related info 2) generic set/get parameter command can be used to set block related setting easily and cleanly 3) generic set/get parameter command can be used for extending ublk without needing more info in ublksrv_ctrl_dev_info Signed-off-by: Ming Lei Link: https://lore.kernel.org/r/20220730092750.1118167-5-ming.lei@redhat.com Signed-off-by: Jens Axboe --- drivers/block/ublk_drv.c | 18 +++++++----------- include/uapi/linux/ublk_cmd.h | 15 ++++++++------- 2 files changed, 15 insertions(+), 18 deletions(-) (limited to 'include/uapi/linux') diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 20ad83b25318..2b3cd671a653 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -122,7 +122,6 @@ struct ublk_device { char *__queues; unsigned short queue_size; - unsigned short bs_shift; struct ublksrv_ctrl_dev_info dev_info; struct blk_mq_tag_set tag_set; @@ -223,8 +222,7 @@ static int ublk_validate_params(const struct ublk_device *ub) if (p->logical_bs_shift > p->physical_bs_shift) return -EINVAL; - if (p->max_sectors > (ub->dev_info.rq_max_blocks << - (ub->bs_shift - 9))) + if (p->max_sectors > (ub->dev_info.max_io_buf_bytes >> 9)) return -EINVAL; } else return -EINVAL; @@ -1185,13 +1183,13 @@ static void ublk_stop_work_fn(struct work_struct *work) ublk_stop_dev(ub); } -/* align maximum I/O size to PAGE_SIZE */ +/* align max io buffer size with PAGE_SIZE */ static void ublk_align_max_io_size(struct ublk_device *ub) { - unsigned int max_rq_bytes = ub->dev_info.rq_max_blocks << ub->bs_shift; + unsigned int max_io_bytes = ub->dev_info.max_io_buf_bytes; - ub->dev_info.rq_max_blocks = - round_down(max_rq_bytes, PAGE_SIZE) >> ub->bs_shift; + ub->dev_info.max_io_buf_bytes = + round_down(max_io_bytes, PAGE_SIZE); } static int ublk_add_tag_set(struct ublk_device *ub) @@ -1348,9 +1346,8 @@ static inline void ublk_dump_dev_info(struct ublksrv_ctrl_dev_info *info) { pr_devel("%s: dev id %d flags %llx\n", __func__, info->dev_id, info->flags); - pr_devel("\t nr_hw_queues %d queue_depth %d block size %d dev_capacity %lld\n", - info->nr_hw_queues, info->queue_depth, - info->block_size, info->dev_blocks); + pr_devel("\t nr_hw_queues %d queue_depth %d\n", + info->nr_hw_queues, info->queue_depth); } static int ublk_ctrl_add_dev(struct io_uring_cmd *cmd) @@ -1410,7 +1407,6 @@ static int ublk_ctrl_add_dev(struct io_uring_cmd *cmd) /* We are not ready to support zero copy */ ub->dev_info.flags &= ~UBLK_F_SUPPORT_ZERO_COPY; - ub->bs_shift = ilog2(ub->dev_info.block_size); ub->dev_info.nr_hw_queues = min_t(unsigned int, ub->dev_info.nr_hw_queues, nr_cpu_ids); ublk_align_max_io_size(ub); diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h index 54d065426f06..57d86d0e8c5b 100644 --- a/include/uapi/linux/ublk_cmd.h +++ b/include/uapi/linux/ublk_cmd.h @@ -80,22 +80,23 @@ struct ublksrv_ctrl_cmd { struct ublksrv_ctrl_dev_info { __u16 nr_hw_queues; __u16 queue_depth; - __u16 block_size; __u16 state; + __u16 pad0; - __u32 rq_max_blocks; + __u32 max_io_buf_bytes; __u32 dev_id; - __u64 dev_blocks; - __s32 ublksrv_pid; - __s32 reserved0; + __u32 pad1; + __u64 flags; - __u64 flags_reserved; /* For ublksrv internal use, invisible to ublk driver */ __u64 ublksrv_flags; - __u64 reserved1[9]; + + __u64 reserved0; + __u64 reserved1; + __u64 reserved2; }; #define UBLK_IO_OP_READ 0 -- cgit v1.2.3 From 4e18403d9485a43e1b54397df258b8df7dac9a83 Mon Sep 17 00:00:00 2001 From: ZiyangZhang Date: Thu, 28 Jul 2022 20:39:15 +0800 Subject: ublk_cmd.h: add one new ublk command: UBLK_IO_NEED_GET_DATA Add one new ublk command: UBLK_IO_NEED_GET_DATA. It is prepared for a new feature designed for a user application who wants to allocate IO buffer and set IO buffer address only after it receives an IO request from ublksrv. Reviewed-by: Ming Lei Signed-off-by: ZiyangZhang Link: https://lore.kernel.org/r/c8a64b6b51c78340da7daa9e1054608695e79619.1659011443.git.ZiyangZhang@linux.alibaba.com Signed-off-by: Jens Axboe --- include/uapi/linux/ublk_cmd.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h index 57d86d0e8c5b..677edaab2b66 100644 --- a/include/uapi/linux/ublk_cmd.h +++ b/include/uapi/linux/ublk_cmd.h @@ -30,12 +30,21 @@ * this IO request, request's handling result is committed to ublk * driver, meantime FETCH_REQ is piggyback, and FETCH_REQ has to be * handled before completing io request. + * + * NEED_GET_DATA: only used for write requests to set io addr and copy data + * When NEED_GET_DATA is set, ublksrv has to issue UBLK_IO_NEED_GET_DATA + * command after ublk driver returns UBLK_IO_RES_NEED_GET_DATA. + * + * It is only used if ublksrv set UBLK_F_NEED_GET_DATA flag + * while starting a ublk device. */ #define UBLK_IO_FETCH_REQ 0x20 #define UBLK_IO_COMMIT_AND_FETCH_REQ 0x21 +#define UBLK_IO_NEED_GET_DATA 0x22 /* only ABORT means that no re-fetch */ #define UBLK_IO_RES_OK 0 +#define UBLK_IO_RES_NEED_GET_DATA 1 #define UBLK_IO_RES_ABORT (-ENODEV) #define UBLKSRV_CMD_BUF_OFFSET 0 @@ -56,6 +65,15 @@ */ #define UBLK_F_URING_CMD_COMP_IN_TASK (1ULL << 1) +/* + * User should issue io cmd again for write requests to + * set io buffer address and copy data from bio vectors + * to the userspace io buffer. + * + * In this mode, task_work is not used. + */ +#define UBLK_F_NEED_GET_DATA (1UL << 2) + /* device state */ #define UBLK_S_DEV_DEAD 0 #define UBLK_S_DEV_LIVE 1 -- cgit v1.2.3