Add ->uring_cmd() support for virtio-blk chardev (/dev/vdXc0). According to virtio spec, in addition to passing 'hdr' info into kernel, we also need to pass vaddr & data length of the 'iov' requeired for the writev/readv op.
Signed-off-by: Ferry Meng <[email protected]> --- drivers/block/virtio_blk.c | 228 +++++++++++++++++++++++++++++++- include/uapi/linux/virtio_blk.h | 16 +++ 2 files changed, 240 insertions(+), 4 deletions(-) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 3487aaa67514..1a4bac3dc044 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -18,6 +18,9 @@ #include <linux/vmalloc.h> #include <uapi/linux/virtio_ring.h> #include <linux/cdev.h> +#include <linux/io_uring/cmd.h> +#include <linux/types.h> +#include <linux/uio.h> #define PART_BITS 4 #define VQ_NAME_LEN 16 @@ -54,6 +57,20 @@ static struct class *vd_chr_class; static struct workqueue_struct *virtblk_wq; +struct virtblk_uring_cmd_pdu { + struct request *req; + struct bio *bio; + int status; +}; + +struct virtblk_command { + struct virtio_blk_outhdr out_hdr; + + __u64 data; + __u32 data_len; + __u32 flag; +}; + struct virtio_blk_vq { struct virtqueue *vq; spinlock_t lock; @@ -122,6 +139,16 @@ struct virtblk_req { struct scatterlist sg[]; }; +static bool virtblk_is_write(struct virtblk_command *cmd) +{ + return cmd->out_hdr.type & VIRTIO_BLK_T_OUT; +} + +static void __user *virtblk_to_user_ptr(uintptr_t ptrval) +{ + return (void __user *)ptrval; +} + static inline blk_status_t virtblk_result(u8 status) { switch (status) { @@ -259,9 +286,6 @@ static blk_status_t virtblk_setup_cmd(struct virtio_device *vdev, if (!IS_ENABLED(CONFIG_BLK_DEV_ZONED) && op_is_zone_mgmt(req_op(req))) return BLK_STS_NOTSUPP; - /* Set fields for all request types */ - vbr->out_hdr.ioprio = cpu_to_virtio32(vdev, req_get_ioprio(req)); - switch (req_op(req)) { case REQ_OP_READ: type = VIRTIO_BLK_T_IN; @@ -309,9 +333,11 @@ static blk_status_t virtblk_setup_cmd(struct virtio_device *vdev, type = VIRTIO_BLK_T_ZONE_RESET_ALL; break; case REQ_OP_DRV_IN: + case REQ_OP_DRV_OUT: /* * Out header has already been prepared by the caller (virtblk_get_id() - * or virtblk_submit_zone_report()), nothing to do here. + * virtblk_submit_zone_report() or io_uring passthrough cmd), nothing + * to do here. */ return 0; default: @@ -323,6 +349,7 @@ static blk_status_t virtblk_setup_cmd(struct virtio_device *vdev, vbr->in_hdr_len = in_hdr_len; vbr->out_hdr.type = cpu_to_virtio32(vdev, type); vbr->out_hdr.sector = cpu_to_virtio64(vdev, sector); + vbr->out_hdr.ioprio = cpu_to_virtio32(vdev, req_get_ioprio(req)); if (type == VIRTIO_BLK_T_DISCARD || type == VIRTIO_BLK_T_WRITE_ZEROES || type == VIRTIO_BLK_T_SECURE_ERASE) { @@ -832,6 +859,7 @@ static int virtblk_get_id(struct gendisk *disk, char *id_str) vbr = blk_mq_rq_to_pdu(req); vbr->in_hdr_len = sizeof(vbr->in_hdr.status); vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_GET_ID); + vbr->out_hdr.ioprio = cpu_to_virtio32(vblk->vdev, req_get_ioprio(req)); vbr->out_hdr.sector = 0; err = blk_rq_map_kern(q, req, id_str, VIRTIO_BLK_ID_BYTES, GFP_KERNEL); @@ -1250,6 +1278,197 @@ static const struct blk_mq_ops virtio_mq_ops = { .poll = virtblk_poll, }; +static inline struct virtblk_uring_cmd_pdu *virtblk_get_uring_cmd_pdu( + struct io_uring_cmd *ioucmd) +{ + return (struct virtblk_uring_cmd_pdu *)&ioucmd->pdu; +} + +static void virtblk_uring_task_cb(struct io_uring_cmd *ioucmd, + unsigned int issue_flags) +{ + struct virtblk_uring_cmd_pdu *pdu = virtblk_get_uring_cmd_pdu(ioucmd); + struct virtblk_req *vbr = blk_mq_rq_to_pdu(pdu->req); + u64 result = 0; + + if (pdu->bio) + blk_rq_unmap_user(pdu->bio); + + /* currently result has no use, it should be zero as cqe->res */ + io_uring_cmd_done(ioucmd, vbr->in_hdr.status, result, issue_flags); +} + +static enum rq_end_io_ret virtblk_uring_cmd_end_io(struct request *req, + blk_status_t err) +{ + struct io_uring_cmd *ioucmd = req->end_io_data; + struct virtblk_uring_cmd_pdu *pdu = virtblk_get_uring_cmd_pdu(ioucmd); + + /* + * For iopoll, complete it directly. Note that using the uring_cmd + * helper for this is safe only because we check blk_rq_is_poll(). + * As that returns false if we're NOT on a polled queue, then it's + * safe to use the polled completion helper. + * + * Otherwise, move the completion to task work. + */ + if (blk_rq_is_poll(req)) { + if (pdu->bio) + blk_rq_unmap_user(pdu->bio); + io_uring_cmd_iopoll_done(ioucmd, 0, pdu->status); + } else { + io_uring_cmd_do_in_task_lazy(ioucmd, virtblk_uring_task_cb); + } + + return RQ_END_IO_FREE; +} + +static struct virtblk_req *virtblk_req(struct request *req) +{ + return blk_mq_rq_to_pdu(req); +} + +static enum req_op virtblk_req_op(struct virtblk_command *cmd) +{ + return virtblk_is_write(cmd) ? REQ_OP_DRV_OUT : REQ_OP_DRV_IN; +} + +static struct request *virtblk_alloc_user_request( + struct request_queue *q, struct virtblk_command *cmd, + unsigned int rq_flags, blk_mq_req_flags_t blk_flags) +{ + struct request *req; + + req = blk_mq_alloc_request(q, virtblk_req_op(cmd) | rq_flags, blk_flags); + if (IS_ERR(req)) + return req; + + req->rq_flags |= RQF_DONTPREP; + memcpy(&virtblk_req(req)->out_hdr, &cmd->out_hdr, sizeof(struct virtio_blk_outhdr)); + return req; +} + +static int virtblk_map_user_request(struct request *req, u64 ubuffer, + unsigned int bufflen, struct io_uring_cmd *ioucmd, + bool vec) +{ + struct request_queue *q = req->q; + struct virtio_blk *vblk = q->queuedata; + struct block_device *bdev = vblk ? vblk->disk->part0 : NULL; + struct bio *bio = NULL; + int ret; + + if (ioucmd && (ioucmd->flags & IORING_URING_CMD_FIXED)) { + struct iov_iter iter; + + /* fixedbufs is only for non-vectored io */ + if (WARN_ON_ONCE(vec)) + return -EINVAL; + ret = io_uring_cmd_import_fixed(ubuffer, bufflen, + rq_data_dir(req), &iter, ioucmd); + if (ret < 0) + goto out; + ret = blk_rq_map_user_iov(q, req, NULL, + &iter, GFP_KERNEL); + } else { + ret = blk_rq_map_user_io(req, NULL, + virtblk_to_user_ptr(ubuffer), + bufflen, GFP_KERNEL, vec, 0, + 0, rq_data_dir(req)); + } + if (ret) + goto out; + + bio = req->bio; + if (bdev) + bio_set_dev(bio, bdev); + return 0; + +out: + blk_mq_free_request(req); + return ret; +} + +static int virtblk_uring_cmd_io(struct virtio_blk *vblk, + struct io_uring_cmd *ioucmd, unsigned int issue_flags, bool vec) +{ + struct virtblk_uring_cmd_pdu *pdu = virtblk_get_uring_cmd_pdu(ioucmd); + const struct virtblk_uring_cmd *cmd = io_uring_sqe_cmd(ioucmd->sqe); + struct request_queue *q = vblk->disk->queue; + struct virtblk_req *vbr; + struct virtblk_command d; + struct request *req; + unsigned int rq_flags = 0; + blk_mq_req_flags_t blk_flags = 0; + int ret; + + if (!capable(CAP_SYS_ADMIN)) + return -EACCES; + + d.out_hdr.ioprio = cpu_to_virtio32(vblk->vdev, READ_ONCE(cmd->ioprio)); + d.out_hdr.type = cpu_to_virtio32(vblk->vdev, READ_ONCE(cmd->type)); + d.out_hdr.sector = cpu_to_virtio32(vblk->vdev, READ_ONCE(cmd->sector)); + d.data = READ_ONCE(cmd->data); + d.data_len = READ_ONCE(cmd->data_len); + + if (issue_flags & IO_URING_F_NONBLOCK) { + rq_flags = REQ_NOWAIT; + blk_flags = BLK_MQ_REQ_NOWAIT; + } + if (issue_flags & IO_URING_F_IOPOLL) + rq_flags |= REQ_POLLED; + + req = virtblk_alloc_user_request(q, &d, rq_flags, blk_flags); + if (IS_ERR(req)) + return PTR_ERR(req); + + vbr = virtblk_req(req); + vbr->in_hdr_len = sizeof(vbr->in_hdr.status); + if (d.data && d.data_len) { + ret = virtblk_map_user_request(req, d.data, d.data_len, ioucmd, vec); + if (ret) + return ret; + } + + /* to free bio on completion, as req->bio will be null at that time */ + pdu->bio = req->bio; + pdu->req = req; + req->end_io_data = ioucmd; + req->end_io = virtblk_uring_cmd_end_io; + blk_execute_rq_nowait(req, false); + return -EIOCBQUEUED; +} + + +static int virtblk_uring_cmd(struct virtio_blk *vblk, struct io_uring_cmd *ioucmd, + unsigned int issue_flags) +{ + int ret; + + BUILD_BUG_ON(sizeof(struct virtblk_uring_cmd_pdu) > sizeof(ioucmd->pdu)); + + switch (ioucmd->cmd_op) { + case VIRTBLK_URING_CMD_IO: + ret = virtblk_uring_cmd_io(vblk, ioucmd, issue_flags, false); + break; + case VIRTBLK_URING_CMD_IO_VEC: + ret = virtblk_uring_cmd_io(vblk, ioucmd, issue_flags, true); + break; + default: + ret = -ENOTTY; + } + + return ret; +} + +static int virtblk_chr_uring_cmd(struct io_uring_cmd *ioucmd, unsigned int issue_flags) +{ + struct virtio_blk *vblk = container_of(file_inode(ioucmd->file)->i_cdev, + struct virtio_blk, cdev); + + return virtblk_uring_cmd(vblk, ioucmd, issue_flags); +} + static void virtblk_cdev_rel(struct device *dev) { ida_free(&vd_chr_minor_ida, MINOR(dev->devt)); @@ -1297,6 +1516,7 @@ static int virtblk_cdev_add(struct virtio_blk *vblk, static const struct file_operations virtblk_chr_fops = { .owner = THIS_MODULE, + .uring_cmd = virtblk_chr_uring_cmd, }; static unsigned int virtblk_queue_depth; diff --git a/include/uapi/linux/virtio_blk.h b/include/uapi/linux/virtio_blk.h index 3744e4da1b2a..93b6e1b5b9a4 100644 --- a/include/uapi/linux/virtio_blk.h +++ b/include/uapi/linux/virtio_blk.h @@ -313,6 +313,22 @@ struct virtio_scsi_inhdr { }; #endif /* !VIRTIO_BLK_NO_LEGACY */ +struct virtblk_uring_cmd { + /* VIRTIO_BLK_T* */ + __u32 type; + /* io priority. */ + __u32 ioprio; + /* Sector (ie. 512 byte offset) */ + __u64 sector; + + __u64 data; + __u32 data_len; + __u32 flag; +}; + +#define VIRTBLK_URING_CMD_IO 1 +#define VIRTBLK_URING_CMD_IO_VEC 2 + /* And this is the final byte of the write scatter-gather list. */ #define VIRTIO_BLK_S_OK 0 #define VIRTIO_BLK_S_IOERR 1 -- 2.43.5
