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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:45:59 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:45:59 +0000 |
commit | 19fcec84d8d7d21e796c7624e521b60d28ee21ed (patch) | |
tree | 42d26aa27d1e3f7c0b8bd3fd14e7d7082f5008dc /src/spdk/lib/vhost/vhost_blk.c | |
parent | Initial commit. (diff) | |
download | ceph-6d07fdb6bb33b1af39833b850bb6cf8af79fe293.tar.xz ceph-6d07fdb6bb33b1af39833b850bb6cf8af79fe293.zip |
Adding upstream version 16.2.11+ds.upstream/16.2.11+dsupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/spdk/lib/vhost/vhost_blk.c')
-rw-r--r-- | src/spdk/lib/vhost/vhost_blk.c | 1354 |
1 files changed, 1354 insertions, 0 deletions
diff --git a/src/spdk/lib/vhost/vhost_blk.c b/src/spdk/lib/vhost/vhost_blk.c new file mode 100644 index 000000000..d387cb27d --- /dev/null +++ b/src/spdk/lib/vhost/vhost_blk.c @@ -0,0 +1,1354 @@ +/*- + * BSD LICENSE + * + * Copyright(c) Intel Corporation. All rights reserved. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Intel Corporation nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include <linux/virtio_blk.h> + +#include "spdk/env.h" +#include "spdk/bdev.h" +#include "spdk/bdev_module.h" +#include "spdk/conf.h" +#include "spdk/thread.h" +#include "spdk/likely.h" +#include "spdk/string.h" +#include "spdk/util.h" +#include "spdk/vhost.h" + +#include "vhost_internal.h" +#include <rte_version.h> + +/* Minimal set of features supported by every SPDK VHOST-BLK device */ +#define SPDK_VHOST_BLK_FEATURES_BASE (SPDK_VHOST_FEATURES | \ + (1ULL << VIRTIO_BLK_F_SIZE_MAX) | (1ULL << VIRTIO_BLK_F_SEG_MAX) | \ + (1ULL << VIRTIO_BLK_F_GEOMETRY) | (1ULL << VIRTIO_BLK_F_BLK_SIZE) | \ + (1ULL << VIRTIO_BLK_F_TOPOLOGY) | (1ULL << VIRTIO_BLK_F_BARRIER) | \ + (1ULL << VIRTIO_BLK_F_SCSI) | (1ULL << VIRTIO_BLK_F_CONFIG_WCE) | \ + (1ULL << VIRTIO_BLK_F_MQ)) + +/* Not supported features */ +#define SPDK_VHOST_BLK_DISABLED_FEATURES (SPDK_VHOST_DISABLED_FEATURES | \ + (1ULL << VIRTIO_BLK_F_GEOMETRY) | (1ULL << VIRTIO_BLK_F_CONFIG_WCE) | \ + (1ULL << VIRTIO_BLK_F_BARRIER) | (1ULL << VIRTIO_BLK_F_SCSI)) + +/* Vhost-blk support protocol features */ +#ifndef SPDK_CONFIG_VHOST_INTERNAL_LIB +#define SPDK_VHOST_BLK_PROTOCOL_FEATURES ((1ULL << VHOST_USER_PROTOCOL_F_CONFIG) | \ + (1ULL << VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD)) +#else +#define SPDK_VHOST_BLK_PROTOCOL_FEATURES (1ULL << VHOST_USER_PROTOCOL_F_CONFIG) +#endif + +struct spdk_vhost_blk_task { + struct spdk_bdev_io *bdev_io; + struct spdk_vhost_blk_session *bvsession; + struct spdk_vhost_virtqueue *vq; + + volatile uint8_t *status; + + uint16_t req_idx; + uint16_t num_descs; + uint16_t buffer_id; + + /* for io wait */ + struct spdk_bdev_io_wait_entry bdev_io_wait; + + /* If set, the task is currently used for I/O processing. */ + bool used; + + /** Number of bytes that were written. */ + uint32_t used_len; + uint16_t iovcnt; + struct iovec iovs[SPDK_VHOST_IOVS_MAX]; +}; + +struct spdk_vhost_blk_dev { + struct spdk_vhost_dev vdev; + struct spdk_bdev *bdev; + struct spdk_bdev_desc *bdev_desc; + /* dummy_io_channel is used to hold a bdev reference */ + struct spdk_io_channel *dummy_io_channel; + bool readonly; +}; + +struct spdk_vhost_blk_session { + /* The parent session must be the very first field in this struct */ + struct spdk_vhost_session vsession; + struct spdk_vhost_blk_dev *bvdev; + struct spdk_poller *requestq_poller; + struct spdk_io_channel *io_channel; + struct spdk_poller *stop_poller; +}; + +/* forward declaration */ +static const struct spdk_vhost_dev_backend vhost_blk_device_backend; + +static int +process_blk_request(struct spdk_vhost_blk_task *task, + struct spdk_vhost_blk_session *bvsession, + struct spdk_vhost_virtqueue *vq); + +static void +blk_task_finish(struct spdk_vhost_blk_task *task) +{ + assert(task->bvsession->vsession.task_cnt > 0); + task->bvsession->vsession.task_cnt--; + task->used = false; +} + +static void +blk_task_init(struct spdk_vhost_blk_task *task) +{ + task->used = true; + task->iovcnt = SPDK_COUNTOF(task->iovs); + task->status = NULL; + task->used_len = 0; +} + +static void +blk_task_enqueue(struct spdk_vhost_blk_task *task) +{ + if (task->vq->packed.packed_ring) { + vhost_vq_packed_ring_enqueue(&task->bvsession->vsession, task->vq, + task->num_descs, + task->buffer_id, task->used_len); + } else { + vhost_vq_used_ring_enqueue(&task->bvsession->vsession, task->vq, + task->req_idx, task->used_len); + } +} + +static void +invalid_blk_request(struct spdk_vhost_blk_task *task, uint8_t status) +{ + if (task->status) { + *task->status = status; + } + + blk_task_enqueue(task); + blk_task_finish(task); + SPDK_DEBUGLOG(SPDK_LOG_VHOST_BLK_DATA, "Invalid request (status=%" PRIu8")\n", status); +} + +/* + * Process task's descriptor chain and setup data related fields. + * Return + * total size of suplied buffers + * + * FIXME: Make this function return to rd_cnt and wr_cnt + */ +static int +blk_iovs_split_queue_setup(struct spdk_vhost_blk_session *bvsession, + struct spdk_vhost_virtqueue *vq, + uint16_t req_idx, struct iovec *iovs, uint16_t *iovs_cnt, uint32_t *length) +{ + struct spdk_vhost_session *vsession = &bvsession->vsession; + struct spdk_vhost_dev *vdev = vsession->vdev; + struct vring_desc *desc, *desc_table; + uint16_t out_cnt = 0, cnt = 0; + uint32_t desc_table_size, len = 0; + uint32_t desc_handled_cnt; + int rc; + + rc = vhost_vq_get_desc(vsession, vq, req_idx, &desc, &desc_table, &desc_table_size); + if (rc != 0) { + SPDK_ERRLOG("%s: invalid descriptor at index %"PRIu16".\n", vdev->name, req_idx); + return -1; + } + + desc_handled_cnt = 0; + while (1) { + /* + * Maximum cnt reached? + * Should not happen if request is well formatted, otherwise this is a BUG. + */ + if (spdk_unlikely(cnt == *iovs_cnt)) { + SPDK_DEBUGLOG(SPDK_LOG_VHOST_BLK, "%s: max IOVs in request reached (req_idx = %"PRIu16").\n", + vsession->name, req_idx); + return -1; + } + + if (spdk_unlikely(vhost_vring_desc_to_iov(vsession, iovs, &cnt, desc))) { + SPDK_DEBUGLOG(SPDK_LOG_VHOST_BLK, "%s: invalid descriptor %" PRIu16" (req_idx = %"PRIu16").\n", + vsession->name, req_idx, cnt); + return -1; + } + + len += desc->len; + + out_cnt += vhost_vring_desc_is_wr(desc); + + rc = vhost_vring_desc_get_next(&desc, desc_table, desc_table_size); + if (rc != 0) { + SPDK_ERRLOG("%s: descriptor chain at index %"PRIu16" terminated unexpectedly.\n", + vsession->name, req_idx); + return -1; + } else if (desc == NULL) { + break; + } + + desc_handled_cnt++; + if (spdk_unlikely(desc_handled_cnt > desc_table_size)) { + /* Break a cycle and report an error, if any. */ + SPDK_ERRLOG("%s: found a cycle in the descriptor chain: desc_table_size = %d, desc_handled_cnt = %d.\n", + vsession->name, desc_table_size, desc_handled_cnt); + return -1; + } + } + + /* + * There must be least two descriptors. + * First contain request so it must be readable. + * Last descriptor contain buffer for response so it must be writable. + */ + if (spdk_unlikely(out_cnt == 0 || cnt < 2)) { + return -1; + } + + *length = len; + *iovs_cnt = cnt; + return 0; +} + +static int +blk_iovs_packed_queue_setup(struct spdk_vhost_blk_session *bvsession, + struct spdk_vhost_virtqueue *vq, + uint16_t req_idx, struct iovec *iovs, uint16_t *iovs_cnt, uint32_t *length) +{ + struct spdk_vhost_session *vsession = &bvsession->vsession; + struct spdk_vhost_dev *vdev = vsession->vdev; + struct vring_packed_desc *desc = NULL, *desc_table; + uint16_t out_cnt = 0, cnt = 0; + uint32_t desc_table_size, len = 0; + int rc = 0; + + rc = vhost_vq_get_desc_packed(vsession, vq, req_idx, &desc, + &desc_table, &desc_table_size); + if (spdk_unlikely(rc != 0)) { + SPDK_ERRLOG("%s: Invalid descriptor at index %"PRIu16".\n", vdev->name, req_idx); + return rc; + } + + if (desc_table != NULL) { + req_idx = 0; + } + + while (1) { + /* + * Maximum cnt reached? + * Should not happen if request is well formatted, otherwise this is a BUG. + */ + if (spdk_unlikely(cnt == *iovs_cnt)) { + SPDK_ERRLOG("%s: max IOVs in request reached (req_idx = %"PRIu16").\n", + vsession->name, req_idx); + return -EINVAL; + } + + if (spdk_unlikely(vhost_vring_packed_desc_to_iov(vsession, iovs, &cnt, desc))) { + SPDK_ERRLOG("%s: invalid descriptor %" PRIu16" (req_idx = %"PRIu16").\n", + vsession->name, req_idx, cnt); + return -EINVAL; + } + + len += desc->len; + out_cnt += vhost_vring_packed_desc_is_wr(desc); + + /* desc is NULL means we reach the last desc of this request */ + vhost_vring_packed_desc_get_next(&desc, &req_idx, vq, desc_table, desc_table_size); + if (desc == NULL) { + break; + } + } + + /* + * There must be least two descriptors. + * First contain request so it must be readable. + * Last descriptor contain buffer for response so it must be writable. + */ + if (spdk_unlikely(out_cnt == 0 || cnt < 2)) { + return -EINVAL; + } + + *length = len; + *iovs_cnt = cnt; + + return 0; +} + +static void +blk_request_finish(bool success, struct spdk_vhost_blk_task *task) +{ + *task->status = success ? VIRTIO_BLK_S_OK : VIRTIO_BLK_S_IOERR; + + blk_task_enqueue(task); + + SPDK_DEBUGLOG(SPDK_LOG_VHOST_BLK, "Finished task (%p) req_idx=%d\n status: %s\n", task, + task->req_idx, success ? "OK" : "FAIL"); + blk_task_finish(task); +} + +static void +blk_request_complete_cb(struct spdk_bdev_io *bdev_io, bool success, void *cb_arg) +{ + struct spdk_vhost_blk_task *task = cb_arg; + + spdk_bdev_free_io(bdev_io); + blk_request_finish(success, task); +} + +static void +blk_request_resubmit(void *arg) +{ + struct spdk_vhost_blk_task *task = (struct spdk_vhost_blk_task *)arg; + int rc = 0; + + blk_task_init(task); + + rc = process_blk_request(task, task->bvsession, task->vq); + if (rc == 0) { + SPDK_DEBUGLOG(SPDK_LOG_VHOST_BLK, "====== Task %p resubmitted ======\n", task); + } else { + SPDK_DEBUGLOG(SPDK_LOG_VHOST_BLK, "====== Task %p failed ======\n", task); + } +} + +static inline void +blk_request_queue_io(struct spdk_vhost_blk_task *task) +{ + int rc; + struct spdk_vhost_blk_session *bvsession = task->bvsession; + struct spdk_bdev *bdev = bvsession->bvdev->bdev; + + task->bdev_io_wait.bdev = bdev; + task->bdev_io_wait.cb_fn = blk_request_resubmit; + task->bdev_io_wait.cb_arg = task; + + rc = spdk_bdev_queue_io_wait(bdev, bvsession->io_channel, &task->bdev_io_wait); + if (rc != 0) { + SPDK_ERRLOG("%s: failed to queue I/O, rc=%d\n", bvsession->vsession.name, rc); + invalid_blk_request(task, VIRTIO_BLK_S_IOERR); + } +} + +static int +process_blk_request(struct spdk_vhost_blk_task *task, + struct spdk_vhost_blk_session *bvsession, + struct spdk_vhost_virtqueue *vq) +{ + struct spdk_vhost_blk_dev *bvdev = bvsession->bvdev; + const struct virtio_blk_outhdr *req; + struct virtio_blk_discard_write_zeroes *desc; + struct iovec *iov; + uint32_t type; + uint32_t payload_len; + uint64_t flush_bytes; + int rc; + + if (vq->packed.packed_ring) { + rc = blk_iovs_packed_queue_setup(bvsession, vq, task->req_idx, task->iovs, &task->iovcnt, + &payload_len); + } else { + rc = blk_iovs_split_queue_setup(bvsession, vq, task->req_idx, task->iovs, &task->iovcnt, + &payload_len); + } + + if (rc) { + SPDK_DEBUGLOG(SPDK_LOG_VHOST_BLK, "Invalid request (req_idx = %"PRIu16").\n", task->req_idx); + /* Only READ and WRITE are supported for now. */ + invalid_blk_request(task, VIRTIO_BLK_S_UNSUPP); + return -1; + } + + iov = &task->iovs[0]; + if (spdk_unlikely(iov->iov_len != sizeof(*req))) { + SPDK_DEBUGLOG(SPDK_LOG_VHOST_BLK, + "First descriptor size is %zu but expected %zu (req_idx = %"PRIu16").\n", + iov->iov_len, sizeof(*req), task->req_idx); + invalid_blk_request(task, VIRTIO_BLK_S_UNSUPP); + return -1; + } + + req = iov->iov_base; + + iov = &task->iovs[task->iovcnt - 1]; + if (spdk_unlikely(iov->iov_len != 1)) { + SPDK_DEBUGLOG(SPDK_LOG_VHOST_BLK, + "Last descriptor size is %zu but expected %d (req_idx = %"PRIu16").\n", + iov->iov_len, 1, task->req_idx); + invalid_blk_request(task, VIRTIO_BLK_S_UNSUPP); + return -1; + } + + task->status = iov->iov_base; + payload_len -= sizeof(*req) + sizeof(*task->status); + task->iovcnt -= 2; + + type = req->type; +#ifdef VIRTIO_BLK_T_BARRIER + /* Don't care about barier for now (as QEMU's virtio-blk do). */ + type &= ~VIRTIO_BLK_T_BARRIER; +#endif + + switch (type) { + case VIRTIO_BLK_T_IN: + case VIRTIO_BLK_T_OUT: + if (spdk_unlikely(payload_len == 0 || (payload_len & (512 - 1)) != 0)) { + SPDK_ERRLOG("%s - passed IO buffer is not multiple of 512b (req_idx = %"PRIu16").\n", + type ? "WRITE" : "READ", task->req_idx); + invalid_blk_request(task, VIRTIO_BLK_S_UNSUPP); + return -1; + } + + if (type == VIRTIO_BLK_T_IN) { + task->used_len = payload_len + sizeof(*task->status); + rc = spdk_bdev_readv(bvdev->bdev_desc, bvsession->io_channel, + &task->iovs[1], task->iovcnt, req->sector * 512, + payload_len, blk_request_complete_cb, task); + } else if (!bvdev->readonly) { + task->used_len = sizeof(*task->status); + rc = spdk_bdev_writev(bvdev->bdev_desc, bvsession->io_channel, + &task->iovs[1], task->iovcnt, req->sector * 512, + payload_len, blk_request_complete_cb, task); + } else { + SPDK_DEBUGLOG(SPDK_LOG_VHOST_BLK, "Device is in read-only mode!\n"); + rc = -1; + } + + if (rc) { + if (rc == -ENOMEM) { + SPDK_DEBUGLOG(SPDK_LOG_VHOST_BLK, "No memory, start to queue io.\n"); + blk_request_queue_io(task); + } else { + invalid_blk_request(task, VIRTIO_BLK_S_IOERR); + return -1; + } + } + break; + case VIRTIO_BLK_T_DISCARD: + desc = task->iovs[1].iov_base; + if (payload_len != sizeof(*desc)) { + SPDK_NOTICELOG("Invalid discard payload size: %u\n", payload_len); + invalid_blk_request(task, VIRTIO_BLK_S_IOERR); + return -1; + } + + rc = spdk_bdev_unmap(bvdev->bdev_desc, bvsession->io_channel, + desc->sector * 512, desc->num_sectors * 512, + blk_request_complete_cb, task); + if (rc) { + if (rc == -ENOMEM) { + SPDK_DEBUGLOG(SPDK_LOG_VHOST_BLK, "No memory, start to queue io.\n"); + blk_request_queue_io(task); + } else { + invalid_blk_request(task, VIRTIO_BLK_S_IOERR); + return -1; + } + } + break; + case VIRTIO_BLK_T_WRITE_ZEROES: + desc = task->iovs[1].iov_base; + if (payload_len != sizeof(*desc)) { + SPDK_NOTICELOG("Invalid write zeroes payload size: %u\n", payload_len); + invalid_blk_request(task, VIRTIO_BLK_S_IOERR); + return -1; + } + + /* Zeroed and Unmap the range, SPDK doen't support it. */ + if (desc->flags & VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP) { + SPDK_NOTICELOG("Can't support Write Zeroes with Unmap flag\n"); + invalid_blk_request(task, VIRTIO_BLK_S_UNSUPP); + return -1; + } + + rc = spdk_bdev_write_zeroes(bvdev->bdev_desc, bvsession->io_channel, + desc->sector * 512, desc->num_sectors * 512, + blk_request_complete_cb, task); + if (rc) { + if (rc == -ENOMEM) { + SPDK_DEBUGLOG(SPDK_LOG_VHOST_BLK, "No memory, start to queue io.\n"); + blk_request_queue_io(task); + } else { + invalid_blk_request(task, VIRTIO_BLK_S_IOERR); + return -1; + } + } + break; + case VIRTIO_BLK_T_FLUSH: + flush_bytes = spdk_bdev_get_num_blocks(bvdev->bdev) * spdk_bdev_get_block_size(bvdev->bdev); + if (req->sector != 0) { + SPDK_NOTICELOG("sector must be zero for flush command\n"); + invalid_blk_request(task, VIRTIO_BLK_S_IOERR); + return -1; + } + rc = spdk_bdev_flush(bvdev->bdev_desc, bvsession->io_channel, + 0, flush_bytes, + blk_request_complete_cb, task); + if (rc) { + if (rc == -ENOMEM) { + SPDK_DEBUGLOG(SPDK_LOG_VHOST_BLK, "No memory, start to queue io.\n"); + blk_request_queue_io(task); + } else { + invalid_blk_request(task, VIRTIO_BLK_S_IOERR); + return -1; + } + } + break; + case VIRTIO_BLK_T_GET_ID: + if (!task->iovcnt || !payload_len) { + invalid_blk_request(task, VIRTIO_BLK_S_UNSUPP); + return -1; + } + task->used_len = spdk_min((size_t)VIRTIO_BLK_ID_BYTES, task->iovs[1].iov_len); + spdk_strcpy_pad(task->iovs[1].iov_base, spdk_bdev_get_product_name(bvdev->bdev), + task->used_len, ' '); + blk_request_finish(true, task); + break; + default: + SPDK_DEBUGLOG(SPDK_LOG_VHOST_BLK, "Not supported request type '%"PRIu32"'.\n", type); + invalid_blk_request(task, VIRTIO_BLK_S_UNSUPP); + return -1; + } + + return 0; +} + +static void +process_blk_task(struct spdk_vhost_virtqueue *vq, uint16_t req_idx) +{ + struct spdk_vhost_blk_task *task; + uint16_t task_idx = req_idx, num_descs; + + if (vq->packed.packed_ring) { + /* Packed ring used the buffer_id as the task_idx to get task struct. + * In kernel driver, it uses the vq->free_head to set the buffer_id so the value + * must be in the range of 0 ~ vring.size. The free_head value must be unique + * in the outstanding requests. + * We can't use the req_idx as the task_idx because the desc can be reused in + * the next phase even when it's not completed in the previous phase. For example, + * At phase 0, last_used_idx was 2 and desc0 was not completed.Then after moving + * phase 1, last_avail_idx is updated to 1. In this case, req_idx can not be used + * as task_idx because we will know task[0]->used is true at phase 1. + * The split queue is quite different, the desc would insert into the free list when + * device completes the request, the driver gets the desc from the free list which + * ensures the req_idx is unique in the outstanding requests. + */ + task_idx = vhost_vring_packed_desc_get_buffer_id(vq, req_idx, &num_descs); + } + + task = &((struct spdk_vhost_blk_task *)vq->tasks)[task_idx]; + if (spdk_unlikely(task->used)) { + SPDK_ERRLOG("%s: request with idx '%"PRIu16"' is already pending.\n", + task->bvsession->vsession.name, task_idx); + task->used_len = 0; + blk_task_enqueue(task); + return; + } + + if (vq->packed.packed_ring) { + task->req_idx = req_idx; + task->num_descs = num_descs; + task->buffer_id = task_idx; + } + + task->bvsession->vsession.task_cnt++; + + blk_task_init(task); + + if (process_blk_request(task, task->bvsession, vq) == 0) { + SPDK_DEBUGLOG(SPDK_LOG_VHOST_BLK, "====== Task %p req_idx %d submitted ======\n", task, + task_idx); + } else { + SPDK_ERRLOG("====== Task %p req_idx %d failed ======\n", task, task_idx); + } +} + +static void +submit_inflight_desc(struct spdk_vhost_blk_session *bvsession, + struct spdk_vhost_virtqueue *vq) +{ + struct spdk_vhost_session *vsession = &bvsession->vsession; + spdk_vhost_resubmit_info *resubmit = vq->vring_inflight.resubmit_inflight; + spdk_vhost_resubmit_desc *resubmit_list; + uint16_t req_idx; + + if (spdk_likely(resubmit == NULL || resubmit->resubmit_list == NULL)) { + return; + } + + resubmit_list = resubmit->resubmit_list; + while (resubmit->resubmit_num-- > 0) { + req_idx = resubmit_list[resubmit->resubmit_num].index; + SPDK_DEBUGLOG(SPDK_LOG_VHOST_BLK, "====== Start processing request idx %"PRIu16"======\n", + req_idx); + + if (spdk_unlikely(req_idx >= vq->vring.size)) { + SPDK_ERRLOG("%s: request idx '%"PRIu16"' exceeds virtqueue size (%"PRIu16").\n", + vsession->name, req_idx, vq->vring.size); + vhost_vq_used_ring_enqueue(vsession, vq, req_idx, 0); + continue; + } + + process_blk_task(vq, req_idx); + } + + free(resubmit_list); + resubmit->resubmit_list = NULL; +} + +static void +process_vq(struct spdk_vhost_blk_session *bvsession, struct spdk_vhost_virtqueue *vq) +{ + struct spdk_vhost_session *vsession = &bvsession->vsession; + uint16_t reqs[SPDK_VHOST_VQ_MAX_SUBMISSIONS]; + uint16_t reqs_cnt, i; + + submit_inflight_desc(bvsession, vq); + + reqs_cnt = vhost_vq_avail_ring_get(vq, reqs, SPDK_COUNTOF(reqs)); + if (!reqs_cnt) { + return; + } + + for (i = 0; i < reqs_cnt; i++) { + SPDK_DEBUGLOG(SPDK_LOG_VHOST_BLK, "====== Starting processing request idx %"PRIu16"======\n", + reqs[i]); + + if (spdk_unlikely(reqs[i] >= vq->vring.size)) { + SPDK_ERRLOG("%s: request idx '%"PRIu16"' exceeds virtqueue size (%"PRIu16").\n", + vsession->name, reqs[i], vq->vring.size); + vhost_vq_used_ring_enqueue(vsession, vq, reqs[i], 0); + continue; + } + + rte_vhost_set_inflight_desc_split(vsession->vid, vq->vring_idx, reqs[i]); + + process_blk_task(vq, reqs[i]); + } +} + +static void +process_packed_vq(struct spdk_vhost_blk_session *bvsession, struct spdk_vhost_virtqueue *vq) +{ + uint16_t i = 0; + + while (i++ < SPDK_VHOST_VQ_MAX_SUBMISSIONS && + vhost_vq_packed_ring_is_avail(vq)) { + SPDK_DEBUGLOG(SPDK_LOG_VHOST_BLK, "====== Starting processing request idx %"PRIu16"======\n", + vq->last_avail_idx); + + process_blk_task(vq, vq->last_avail_idx); + } +} + +static int +vdev_worker(void *arg) +{ + struct spdk_vhost_blk_session *bvsession = arg; + struct spdk_vhost_session *vsession = &bvsession->vsession; + + uint16_t q_idx; + bool packed_ring; + + /* In a session, every vq supports the same format */ + packed_ring = vsession->virtqueue[0].packed.packed_ring; + for (q_idx = 0; q_idx < vsession->max_queues; q_idx++) { + if (packed_ring) { + process_packed_vq(bvsession, &vsession->virtqueue[q_idx]); + } else { + process_vq(bvsession, &vsession->virtqueue[q_idx]); + } + } + + vhost_session_used_signal(vsession); + + return SPDK_POLLER_BUSY; +} + +static void +no_bdev_process_vq(struct spdk_vhost_blk_session *bvsession, struct spdk_vhost_virtqueue *vq) +{ + struct spdk_vhost_session *vsession = &bvsession->vsession; + struct iovec iovs[SPDK_VHOST_IOVS_MAX]; + uint32_t length; + uint16_t iovcnt, req_idx; + + if (vhost_vq_avail_ring_get(vq, &req_idx, 1) != 1) { + return; + } + + iovcnt = SPDK_COUNTOF(iovs); + if (blk_iovs_split_queue_setup(bvsession, vq, req_idx, iovs, &iovcnt, &length) == 0) { + *(volatile uint8_t *)iovs[iovcnt - 1].iov_base = VIRTIO_BLK_S_IOERR; + SPDK_DEBUGLOG(SPDK_LOG_VHOST_BLK_DATA, "Aborting request %" PRIu16"\n", req_idx); + } + + vhost_vq_used_ring_enqueue(vsession, vq, req_idx, 0); +} + +static void +no_bdev_process_packed_vq(struct spdk_vhost_blk_session *bvsession, struct spdk_vhost_virtqueue *vq) +{ + struct spdk_vhost_session *vsession = &bvsession->vsession; + struct spdk_vhost_blk_task *task; + uint32_t length; + uint16_t req_idx = vq->last_avail_idx; + uint16_t task_idx, num_descs; + + if (!vhost_vq_packed_ring_is_avail(vq)) { + return; + } + + task_idx = vhost_vring_packed_desc_get_buffer_id(vq, req_idx, &num_descs); + task = &((struct spdk_vhost_blk_task *)vq->tasks)[task_idx]; + if (spdk_unlikely(task->used)) { + SPDK_ERRLOG("%s: request with idx '%"PRIu16"' is already pending.\n", + vsession->name, req_idx); + vhost_vq_packed_ring_enqueue(vsession, vq, num_descs, + task->buffer_id, task->used_len); + return; + } + + task->req_idx = req_idx; + task->num_descs = num_descs; + task->buffer_id = task_idx; + blk_task_init(task); + + if (blk_iovs_packed_queue_setup(bvsession, vq, task->req_idx, task->iovs, &task->iovcnt, + &length)) { + *(volatile uint8_t *)(task->iovs[task->iovcnt - 1].iov_base) = VIRTIO_BLK_S_IOERR; + SPDK_DEBUGLOG(SPDK_LOG_VHOST_BLK_DATA, "Aborting request %" PRIu16"\n", req_idx); + } + + task->used = false; + vhost_vq_packed_ring_enqueue(vsession, vq, num_descs, + task->buffer_id, task->used_len); +} + +static int +no_bdev_vdev_worker(void *arg) +{ + struct spdk_vhost_blk_session *bvsession = arg; + struct spdk_vhost_session *vsession = &bvsession->vsession; + uint16_t q_idx; + bool packed_ring; + + /* In a session, every vq supports the same format */ + packed_ring = vsession->virtqueue[0].packed.packed_ring; + for (q_idx = 0; q_idx < vsession->max_queues; q_idx++) { + if (packed_ring) { + no_bdev_process_packed_vq(bvsession, &vsession->virtqueue[q_idx]); + } else { + no_bdev_process_vq(bvsession, &vsession->virtqueue[q_idx]); + } + } + + vhost_session_used_signal(vsession); + + if (vsession->task_cnt == 0 && bvsession->io_channel) { + spdk_put_io_channel(bvsession->io_channel); + bvsession->io_channel = NULL; + } + + return SPDK_POLLER_BUSY; +} + +static struct spdk_vhost_blk_session * +to_blk_session(struct spdk_vhost_session *vsession) +{ + assert(vsession->vdev->backend == &vhost_blk_device_backend); + return (struct spdk_vhost_blk_session *)vsession; +} + +static struct spdk_vhost_blk_dev * +to_blk_dev(struct spdk_vhost_dev *vdev) +{ + if (vdev == NULL) { + return NULL; + } + + if (vdev->backend != &vhost_blk_device_backend) { + SPDK_ERRLOG("%s: not a vhost-blk device\n", vdev->name); + return NULL; + } + + return SPDK_CONTAINEROF(vdev, struct spdk_vhost_blk_dev, vdev); +} + +static int +vhost_session_bdev_resize_cb(struct spdk_vhost_dev *vdev, + struct spdk_vhost_session *vsession, + void *ctx) +{ +#if RTE_VERSION >= RTE_VERSION_NUM(20, 02, 0, 0) + SPDK_NOTICELOG("bdev send slave msg to vid(%d)\n", vsession->vid); + rte_vhost_slave_config_change(vsession->vid, false); +#else + SPDK_NOTICELOG("bdev does not support resize until DPDK submodule version >= 20.02\n"); +#endif + + return 0; +} + +static void +blk_resize_cb(void *resize_ctx) +{ + struct spdk_vhost_blk_dev *bvdev = resize_ctx; + + spdk_vhost_lock(); + vhost_dev_foreach_session(&bvdev->vdev, vhost_session_bdev_resize_cb, + NULL, NULL); + spdk_vhost_unlock(); +} + +static void +vhost_dev_bdev_remove_cpl_cb(struct spdk_vhost_dev *vdev, void *ctx) +{ + + /* All sessions have been notified, time to close the bdev */ + struct spdk_vhost_blk_dev *bvdev = to_blk_dev(vdev); + + assert(bvdev != NULL); + spdk_put_io_channel(bvdev->dummy_io_channel); + spdk_bdev_close(bvdev->bdev_desc); + bvdev->bdev_desc = NULL; + bvdev->bdev = NULL; +} + +static int +vhost_session_bdev_remove_cb(struct spdk_vhost_dev *vdev, + struct spdk_vhost_session *vsession, + void *ctx) +{ + struct spdk_vhost_blk_session *bvsession; + + bvsession = (struct spdk_vhost_blk_session *)vsession; + if (bvsession->requestq_poller) { + spdk_poller_unregister(&bvsession->requestq_poller); + bvsession->requestq_poller = SPDK_POLLER_REGISTER(no_bdev_vdev_worker, bvsession, 0); + } + + return 0; +} + +static void +bdev_remove_cb(void *remove_ctx) +{ + struct spdk_vhost_blk_dev *bvdev = remove_ctx; + + SPDK_WARNLOG("%s: hot-removing bdev - all further requests will fail.\n", + bvdev->vdev.name); + + spdk_vhost_lock(); + vhost_dev_foreach_session(&bvdev->vdev, vhost_session_bdev_remove_cb, + vhost_dev_bdev_remove_cpl_cb, NULL); + spdk_vhost_unlock(); +} + +static void +bdev_event_cb(enum spdk_bdev_event_type type, struct spdk_bdev *bdev, + void *event_ctx) +{ + SPDK_DEBUGLOG(SPDK_LOG_VHOST_BLK, "Bdev event: type %d, name %s\n", + type, + bdev->name); + + switch (type) { + case SPDK_BDEV_EVENT_REMOVE: + SPDK_NOTICELOG("bdev name (%s) received event(SPDK_BDEV_EVENT_REMOVE)\n", bdev->name); + bdev_remove_cb(event_ctx); + break; + case SPDK_BDEV_EVENT_RESIZE: + SPDK_NOTICELOG("bdev name (%s) received event(SPDK_BDEV_EVENT_RESIZE)\n", bdev->name); + blk_resize_cb(event_ctx); + break; + default: + SPDK_NOTICELOG("Unsupported bdev event: type %d\n", type); + break; + } +} + +static void +free_task_pool(struct spdk_vhost_blk_session *bvsession) +{ + struct spdk_vhost_session *vsession = &bvsession->vsession; + struct spdk_vhost_virtqueue *vq; + uint16_t i; + + for (i = 0; i < vsession->max_queues; i++) { + vq = &vsession->virtqueue[i]; + if (vq->tasks == NULL) { + continue; + } + + spdk_free(vq->tasks); + vq->tasks = NULL; + } +} + +static int +alloc_task_pool(struct spdk_vhost_blk_session *bvsession) +{ + struct spdk_vhost_session *vsession = &bvsession->vsession; + struct spdk_vhost_virtqueue *vq; + struct spdk_vhost_blk_task *task; + uint32_t task_cnt; + uint16_t i; + uint32_t j; + + for (i = 0; i < vsession->max_queues; i++) { + vq = &vsession->virtqueue[i]; + if (vq->vring.desc == NULL) { + continue; + } + + task_cnt = vq->vring.size; + if (task_cnt > SPDK_VHOST_MAX_VQ_SIZE) { + /* sanity check */ + SPDK_ERRLOG("%s: virtuque %"PRIu16" is too big. (size = %"PRIu32", max = %"PRIu32")\n", + vsession->name, i, task_cnt, SPDK_VHOST_MAX_VQ_SIZE); + free_task_pool(bvsession); + return -1; + } + vq->tasks = spdk_zmalloc(sizeof(struct spdk_vhost_blk_task) * task_cnt, + SPDK_CACHE_LINE_SIZE, NULL, + SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA); + if (vq->tasks == NULL) { + SPDK_ERRLOG("%s: failed to allocate %"PRIu32" tasks for virtqueue %"PRIu16"\n", + vsession->name, task_cnt, i); + free_task_pool(bvsession); + return -1; + } + + for (j = 0; j < task_cnt; j++) { + task = &((struct spdk_vhost_blk_task *)vq->tasks)[j]; + task->bvsession = bvsession; + task->req_idx = j; + task->vq = vq; + } + } + + return 0; +} + +static int +vhost_blk_start_cb(struct spdk_vhost_dev *vdev, + struct spdk_vhost_session *vsession, void *unused) +{ + struct spdk_vhost_blk_session *bvsession = to_blk_session(vsession); + struct spdk_vhost_blk_dev *bvdev; + int i, rc = 0; + + bvdev = to_blk_dev(vdev); + assert(bvdev != NULL); + bvsession->bvdev = bvdev; + + /* validate all I/O queues are in a contiguous index range */ + for (i = 0; i < vsession->max_queues; i++) { + /* vring.desc and vring.desc_packed are in a union struct + * so q->vring.desc can replace q->vring.desc_packed. + */ + if (vsession->virtqueue[i].vring.desc == NULL) { + SPDK_ERRLOG("%s: queue %"PRIu32" is empty\n", vsession->name, i); + rc = -1; + goto out; + } + } + + rc = alloc_task_pool(bvsession); + if (rc != 0) { + SPDK_ERRLOG("%s: failed to alloc task pool.\n", vsession->name); + goto out; + } + + if (bvdev->bdev) { + bvsession->io_channel = spdk_bdev_get_io_channel(bvdev->bdev_desc); + if (!bvsession->io_channel) { + free_task_pool(bvsession); + SPDK_ERRLOG("%s: I/O channel allocation failed\n", vsession->name); + rc = -1; + goto out; + } + } + + bvsession->requestq_poller = SPDK_POLLER_REGISTER(bvdev->bdev ? vdev_worker : no_bdev_vdev_worker, + bvsession, 0); + SPDK_INFOLOG(SPDK_LOG_VHOST, "%s: started poller on lcore %d\n", + vsession->name, spdk_env_get_current_core()); +out: + vhost_session_start_done(vsession, rc); + return rc; +} + +static int +vhost_blk_start(struct spdk_vhost_session *vsession) +{ + return vhost_session_send_event(vsession, vhost_blk_start_cb, + 3, "start session"); +} + +static int +destroy_session_poller_cb(void *arg) +{ + struct spdk_vhost_blk_session *bvsession = arg; + struct spdk_vhost_session *vsession = &bvsession->vsession; + int i; + + if (vsession->task_cnt > 0) { + return SPDK_POLLER_BUSY; + } + + if (spdk_vhost_trylock() != 0) { + return SPDK_POLLER_BUSY; + } + + for (i = 0; i < vsession->max_queues; i++) { + vsession->virtqueue[i].next_event_time = 0; + vhost_vq_used_signal(vsession, &vsession->virtqueue[i]); + } + + SPDK_INFOLOG(SPDK_LOG_VHOST, "%s: stopping poller on lcore %d\n", + vsession->name, spdk_env_get_current_core()); + + if (bvsession->io_channel) { + spdk_put_io_channel(bvsession->io_channel); + bvsession->io_channel = NULL; + } + + free_task_pool(bvsession); + spdk_poller_unregister(&bvsession->stop_poller); + vhost_session_stop_done(vsession, 0); + + spdk_vhost_unlock(); + return SPDK_POLLER_BUSY; +} + +static int +vhost_blk_stop_cb(struct spdk_vhost_dev *vdev, + struct spdk_vhost_session *vsession, void *unused) +{ + struct spdk_vhost_blk_session *bvsession = to_blk_session(vsession); + + spdk_poller_unregister(&bvsession->requestq_poller); + bvsession->stop_poller = SPDK_POLLER_REGISTER(destroy_session_poller_cb, + bvsession, 1000); + return 0; +} + +static int +vhost_blk_stop(struct spdk_vhost_session *vsession) +{ + return vhost_session_send_event(vsession, vhost_blk_stop_cb, + 3, "stop session"); +} + +static void +vhost_blk_dump_info_json(struct spdk_vhost_dev *vdev, struct spdk_json_write_ctx *w) +{ + struct spdk_vhost_blk_dev *bvdev; + + bvdev = to_blk_dev(vdev); + assert(bvdev != NULL); + + spdk_json_write_named_object_begin(w, "block"); + + spdk_json_write_named_bool(w, "readonly", bvdev->readonly); + + spdk_json_write_name(w, "bdev"); + if (bvdev->bdev) { + spdk_json_write_string(w, spdk_bdev_get_name(bvdev->bdev)); + } else { + spdk_json_write_null(w); + } + + spdk_json_write_object_end(w); +} + +static void +vhost_blk_write_config_json(struct spdk_vhost_dev *vdev, struct spdk_json_write_ctx *w) +{ + struct spdk_vhost_blk_dev *bvdev; + + bvdev = to_blk_dev(vdev); + assert(bvdev != NULL); + + if (!bvdev->bdev) { + return; + } + + spdk_json_write_object_begin(w); + spdk_json_write_named_string(w, "method", "vhost_create_blk_controller"); + + spdk_json_write_named_object_begin(w, "params"); + spdk_json_write_named_string(w, "ctrlr", vdev->name); + spdk_json_write_named_string(w, "dev_name", spdk_bdev_get_name(bvdev->bdev)); + spdk_json_write_named_string(w, "cpumask", + spdk_cpuset_fmt(spdk_thread_get_cpumask(vdev->thread))); + spdk_json_write_named_bool(w, "readonly", bvdev->readonly); + spdk_json_write_object_end(w); + + spdk_json_write_object_end(w); +} + +static int vhost_blk_destroy(struct spdk_vhost_dev *dev); + +static int +vhost_blk_get_config(struct spdk_vhost_dev *vdev, uint8_t *config, + uint32_t len) +{ + struct virtio_blk_config blkcfg; + struct spdk_vhost_blk_dev *bvdev; + struct spdk_bdev *bdev; + uint32_t blk_size; + uint64_t blkcnt; + + memset(&blkcfg, 0, sizeof(blkcfg)); + bvdev = to_blk_dev(vdev); + assert(bvdev != NULL); + bdev = bvdev->bdev; + if (bdev == NULL) { + /* We can't just return -1 here as this GET_CONFIG message might + * be caused by a QEMU VM reboot. Returning -1 will indicate an + * error to QEMU, who might then decide to terminate itself. + * We don't want that. A simple reboot shouldn't break the system. + * + * Presenting a block device with block size 0 and block count 0 + * doesn't cause any problems on QEMU side and the virtio-pci + * device is even still available inside the VM, but there will + * be no block device created for it - the kernel drivers will + * silently reject it. + */ + blk_size = 0; + blkcnt = 0; + } else { + blk_size = spdk_bdev_get_block_size(bdev); + blkcnt = spdk_bdev_get_num_blocks(bdev); + if (spdk_bdev_get_buf_align(bdev) > 1) { + blkcfg.size_max = SPDK_BDEV_LARGE_BUF_MAX_SIZE; + blkcfg.seg_max = spdk_min(SPDK_VHOST_IOVS_MAX - 2 - 1, BDEV_IO_NUM_CHILD_IOV - 2 - 1); + } else { + blkcfg.size_max = 131072; + /* -2 for REQ and RESP and -1 for region boundary splitting */ + blkcfg.seg_max = SPDK_VHOST_IOVS_MAX - 2 - 1; + } + } + + blkcfg.blk_size = blk_size; + /* minimum I/O size in blocks */ + blkcfg.min_io_size = 1; + /* expressed in 512 Bytes sectors */ + blkcfg.capacity = (blkcnt * blk_size) / 512; + /* QEMU can overwrite this value when started */ + blkcfg.num_queues = SPDK_VHOST_MAX_VQUEUES; + + if (bdev && spdk_bdev_io_type_supported(bdev, SPDK_BDEV_IO_TYPE_UNMAP)) { + /* 16MiB, expressed in 512 Bytes */ + blkcfg.max_discard_sectors = 32768; + blkcfg.max_discard_seg = 1; + blkcfg.discard_sector_alignment = blk_size / 512; + } + if (bdev && spdk_bdev_io_type_supported(bdev, SPDK_BDEV_IO_TYPE_WRITE_ZEROES)) { + blkcfg.max_write_zeroes_sectors = 32768; + blkcfg.max_write_zeroes_seg = 1; + } + + memcpy(config, &blkcfg, spdk_min(len, sizeof(blkcfg))); + + return 0; +} + +static const struct spdk_vhost_dev_backend vhost_blk_device_backend = { + .session_ctx_size = sizeof(struct spdk_vhost_blk_session) - sizeof(struct spdk_vhost_session), + .start_session = vhost_blk_start, + .stop_session = vhost_blk_stop, + .vhost_get_config = vhost_blk_get_config, + .dump_info_json = vhost_blk_dump_info_json, + .write_config_json = vhost_blk_write_config_json, + .remove_device = vhost_blk_destroy, +}; + +int +vhost_blk_controller_construct(void) +{ + struct spdk_conf_section *sp; + unsigned ctrlr_num; + char *bdev_name; + char *cpumask; + char *name; + bool readonly; + bool packed_ring; + + for (sp = spdk_conf_first_section(NULL); sp != NULL; sp = spdk_conf_next_section(sp)) { + if (!spdk_conf_section_match_prefix(sp, "VhostBlk")) { + continue; + } + + if (sscanf(spdk_conf_section_get_name(sp), "VhostBlk%u", &ctrlr_num) != 1) { + SPDK_ERRLOG("Section '%s' has non-numeric suffix.\n", + spdk_conf_section_get_name(sp)); + return -1; + } + + name = spdk_conf_section_get_val(sp, "Name"); + if (name == NULL) { + SPDK_ERRLOG("VhostBlk%u: missing Name\n", ctrlr_num); + return -1; + } + + cpumask = spdk_conf_section_get_val(sp, "Cpumask"); + readonly = spdk_conf_section_get_boolval(sp, "ReadOnly", false); + packed_ring = spdk_conf_section_get_boolval(sp, "PackedRing", false); + + bdev_name = spdk_conf_section_get_val(sp, "Dev"); + if (bdev_name == NULL) { + continue; + } + + if (spdk_vhost_blk_construct(name, cpumask, bdev_name, + readonly, packed_ring) < 0) { + return -1; + } + } + + return 0; +} + +int +spdk_vhost_blk_construct(const char *name, const char *cpumask, const char *dev_name, + bool readonly, bool packed_ring) +{ + struct spdk_vhost_blk_dev *bvdev = NULL; + struct spdk_vhost_dev *vdev; + struct spdk_bdev *bdev; + int ret = 0; + + spdk_vhost_lock(); + bdev = spdk_bdev_get_by_name(dev_name); + if (bdev == NULL) { + SPDK_ERRLOG("%s: bdev '%s' not found\n", + name, dev_name); + ret = -ENODEV; + goto out; + } + + bvdev = calloc(1, sizeof(*bvdev)); + if (bvdev == NULL) { + ret = -ENOMEM; + goto out; + } + + vdev = &bvdev->vdev; + vdev->virtio_features = SPDK_VHOST_BLK_FEATURES_BASE; + vdev->disabled_features = SPDK_VHOST_BLK_DISABLED_FEATURES; + vdev->protocol_features = SPDK_VHOST_BLK_PROTOCOL_FEATURES; + + vdev->virtio_features |= (uint64_t)packed_ring << VIRTIO_F_RING_PACKED; + + if (spdk_bdev_io_type_supported(bdev, SPDK_BDEV_IO_TYPE_UNMAP)) { + vdev->virtio_features |= (1ULL << VIRTIO_BLK_F_DISCARD); + } + if (spdk_bdev_io_type_supported(bdev, SPDK_BDEV_IO_TYPE_WRITE_ZEROES)) { + vdev->virtio_features |= (1ULL << VIRTIO_BLK_F_WRITE_ZEROES); + } + if (readonly) { + vdev->virtio_features |= (1ULL << VIRTIO_BLK_F_RO); + } + if (spdk_bdev_io_type_supported(bdev, SPDK_BDEV_IO_TYPE_FLUSH)) { + vdev->virtio_features |= (1ULL << VIRTIO_BLK_F_FLUSH); + } + + ret = spdk_bdev_open_ext(dev_name, true, bdev_event_cb, bvdev, &bvdev->bdev_desc); + if (ret != 0) { + SPDK_ERRLOG("%s: could not open bdev '%s', error=%d\n", + name, dev_name, ret); + goto out; + } + + /* + * When starting qemu with vhost-user-blk multiqueue, the vhost device will + * be started/stopped many times, related to the queues num, as the + * vhost-user backend doesn't know the exact number of queues used for this + * device. The target have to stop and start the device once got a valid + * IO queue. + * When stoping and starting the vhost device, the backend bdev io device + * will be deleted and created repeatedly. + * Hold a bdev reference so that in the struct spdk_vhost_blk_dev, so that + * the io device will not be deleted. + */ + bvdev->dummy_io_channel = spdk_bdev_get_io_channel(bvdev->bdev_desc); + + bvdev->bdev = bdev; + bvdev->readonly = readonly; + ret = vhost_dev_register(vdev, name, cpumask, &vhost_blk_device_backend); + if (ret != 0) { + spdk_put_io_channel(bvdev->dummy_io_channel); + spdk_bdev_close(bvdev->bdev_desc); + goto out; + } + + SPDK_INFOLOG(SPDK_LOG_VHOST, "%s: using bdev '%s'\n", name, dev_name); +out: + if (ret != 0 && bvdev) { + free(bvdev); + } + spdk_vhost_unlock(); + return ret; +} + +static int +vhost_blk_destroy(struct spdk_vhost_dev *vdev) +{ + struct spdk_vhost_blk_dev *bvdev = to_blk_dev(vdev); + int rc; + + assert(bvdev != NULL); + + rc = vhost_dev_unregister(&bvdev->vdev); + if (rc != 0) { + return rc; + } + + /* if the bdev is removed, don't need call spdk_put_io_channel. */ + if (bvdev->bdev) { + spdk_put_io_channel(bvdev->dummy_io_channel); + } + + if (bvdev->bdev_desc) { + spdk_bdev_close(bvdev->bdev_desc); + bvdev->bdev_desc = NULL; + } + bvdev->bdev = NULL; + + free(bvdev); + return 0; +} + +SPDK_LOG_REGISTER_COMPONENT("vhost_blk", SPDK_LOG_VHOST_BLK) +SPDK_LOG_REGISTER_COMPONENT("vhost_blk_data", SPDK_LOG_VHOST_BLK_DATA) |