Since virtio_scsi has supported multi virtqueue already, it is natural to map virtque to hw-queue of blk-mq. Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx> Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxxxxx> --- drivers/scsi/virtio_scsi.c | 154 ++++---------------------------------------- 1 file changed, 14 insertions(+), 140 deletions(-) diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c index b83846f..719adb2 100644 --- a/drivers/scsi/virtio_scsi.c +++ b/drivers/scsi/virtio_scsi.c @@ -65,36 +65,6 @@ struct virtio_scsi_vq { struct virtqueue *vq; }; -/* - * Per-target queue state. - * - * This struct holds the data needed by the queue steering policy. When a - * target is sent multiple requests, we need to drive them to the same queue so - * that FIFO processing order is kept. However, if a target was idle, we can - * choose a queue arbitrarily. In this case the queue is chosen according to - * the current VCPU, so the driver expects the number of request queues to be - * equal to the number of VCPUs. This makes it easy and fast to select the - * queue, and also lets the driver optimize the IRQ affinity for the virtqueues - * (each virtqueue's affinity is set to the CPU that "owns" the queue). - * - * tgt_seq is held to serialize reading and writing req_vq. - * - * Decrements of reqs are never concurrent with writes of req_vq: before the - * decrement reqs will be != 0; after the decrement the virtqueue completion - * routine will not use the req_vq so it can be changed by a new request. - * Thus they can happen outside the tgt_seq, provided of course we make reqs - * an atomic_t. - */ -struct virtio_scsi_target_state { - seqcount_t tgt_seq; - - /* Count of outstanding requests. */ - atomic_t reqs; - - /* Currently active virtqueue for requests sent to this target. */ - struct virtio_scsi_vq *req_vq; -}; - /* Driver instance state */ struct virtio_scsi { struct virtio_device *vdev; @@ -150,8 +120,6 @@ static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf) struct virtio_scsi_cmd *cmd = buf; struct scsi_cmnd *sc = cmd->sc; struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd; - struct virtio_scsi_target_state *tgt = - scsi_target(sc->device)->hostdata; dev_dbg(&sc->device->sdev_gendev, "cmd %p response %u status %#02x sense_len %u\n", @@ -205,8 +173,6 @@ static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf) } sc->scsi_done(sc); - - atomic_dec(&tgt->reqs); } static void virtscsi_vq_done(struct virtio_scsi *vscsi, @@ -514,9 +480,9 @@ static void virtio_scsi_init_hdr_pi(struct virtio_scsi_cmd_req_pi *cmd_pi, cmd_pi->pi_bytesin = blk_rq_sectors(rq) * bi->tuple_size; } -static int virtscsi_queuecommand(struct virtio_scsi *vscsi, - struct virtio_scsi_vq *req_vq, - struct scsi_cmnd *sc) +static int __virtscsi_queuecommand(struct virtio_scsi *vscsi, + struct virtio_scsi_vq *req_vq, + struct scsi_cmnd *sc) { struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc); @@ -550,63 +516,15 @@ static int virtscsi_queuecommand(struct virtio_scsi *vscsi, return 0; } -static int virtscsi_queuecommand_single(struct Scsi_Host *sh, - struct scsi_cmnd *sc) -{ - struct virtio_scsi *vscsi = shost_priv(sh); - struct virtio_scsi_target_state *tgt = - scsi_target(sc->device)->hostdata; - - atomic_inc(&tgt->reqs); - return virtscsi_queuecommand(vscsi, &vscsi->req_vqs[0], sc); -} - -static struct virtio_scsi_vq *virtscsi_pick_vq(struct virtio_scsi *vscsi, - struct virtio_scsi_target_state *tgt) -{ - struct virtio_scsi_vq *vq; - unsigned long flags; - u32 queue_num; - - local_irq_save(flags); - if (atomic_inc_return(&tgt->reqs) > 1) { - unsigned long seq; - - do { - seq = read_seqcount_begin(&tgt->tgt_seq); - vq = tgt->req_vq; - } while (read_seqcount_retry(&tgt->tgt_seq, seq)); - } else { - /* no writes can be concurrent because of atomic_t */ - write_seqcount_begin(&tgt->tgt_seq); - - /* keep previous req_vq if a reader just arrived */ - if (unlikely(atomic_read(&tgt->reqs) > 1)) { - vq = tgt->req_vq; - goto unlock; - } - - queue_num = smp_processor_id(); - while (unlikely(queue_num >= vscsi->num_queues)) - queue_num -= vscsi->num_queues; - tgt->req_vq = vq = &vscsi->req_vqs[queue_num]; - unlock: - write_seqcount_end(&tgt->tgt_seq); - } - local_irq_restore(flags); - - return vq; -} - -static int virtscsi_queuecommand_multi(struct Scsi_Host *sh, - struct scsi_cmnd *sc) +static int virtscsi_queuecommand(struct Scsi_Host *sh, + struct scsi_cmnd *sc) { struct virtio_scsi *vscsi = shost_priv(sh); - struct virtio_scsi_target_state *tgt = - scsi_target(sc->device)->hostdata; - struct virtio_scsi_vq *req_vq = virtscsi_pick_vq(vscsi, tgt); + u32 tag = blk_mq_unique_tag(sc->request); + u16 hwq = blk_mq_unique_tag_to_hwq(tag); + struct virtio_scsi_vq *req_vq = &vscsi->req_vqs[hwq]; - return virtscsi_queuecommand(vscsi, req_vq, sc); + return __virtscsi_queuecommand(vscsi, req_vq, sc); } static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd) @@ -718,37 +636,13 @@ static int virtscsi_abort(struct scsi_cmnd *sc) return virtscsi_tmf(vscsi, cmd); } -static int virtscsi_target_alloc(struct scsi_target *starget) -{ - struct Scsi_Host *sh = dev_to_shost(starget->dev.parent); - struct virtio_scsi *vscsi = shost_priv(sh); - - struct virtio_scsi_target_state *tgt = - kmalloc(sizeof(*tgt), GFP_KERNEL); - if (!tgt) - return -ENOMEM; - - seqcount_init(&tgt->tgt_seq); - atomic_set(&tgt->reqs, 0); - tgt->req_vq = &vscsi->req_vqs[0]; - - starget->hostdata = tgt; - return 0; -} - -static void virtscsi_target_destroy(struct scsi_target *starget) -{ - struct virtio_scsi_target_state *tgt = starget->hostdata; - kfree(tgt); -} - -static struct scsi_host_template virtscsi_host_template_single = { +static struct scsi_host_template virtscsi_host_template = { .module = THIS_MODULE, .name = "Virtio SCSI HBA", .proc_name = "virtio_scsi", .this_id = -1, .cmd_size = sizeof(struct virtio_scsi_cmd), - .queuecommand = virtscsi_queuecommand_single, + .queuecommand = virtscsi_queuecommand, .change_queue_depth = virtscsi_change_queue_depth, .eh_abort_handler = virtscsi_abort, .eh_device_reset_handler = virtscsi_device_reset, @@ -756,26 +650,8 @@ static struct scsi_host_template virtscsi_host_template_single = { .can_queue = 1024, .dma_boundary = UINT_MAX, .use_clustering = ENABLE_CLUSTERING, - .target_alloc = virtscsi_target_alloc, - .target_destroy = virtscsi_target_destroy, -}; -static struct scsi_host_template virtscsi_host_template_multi = { - .module = THIS_MODULE, - .name = "Virtio SCSI HBA", - .proc_name = "virtio_scsi", - .this_id = -1, - .cmd_size = sizeof(struct virtio_scsi_cmd), - .queuecommand = virtscsi_queuecommand_multi, - .change_queue_depth = virtscsi_change_queue_depth, - .eh_abort_handler = virtscsi_abort, - .eh_device_reset_handler = virtscsi_device_reset, - - .can_queue = 1024, - .dma_boundary = UINT_MAX, - .use_clustering = ENABLE_CLUSTERING, - .target_alloc = virtscsi_target_alloc, - .target_destroy = virtscsi_target_destroy, + .force_blk_mq = true, }; #define virtscsi_config_get(vdev, fld) \ @@ -944,10 +820,7 @@ static int virtscsi_probe(struct virtio_device *vdev) num_targets = virtscsi_config_get(vdev, max_target) + 1; - if (num_queues == 1) - hostt = &virtscsi_host_template_single; - else - hostt = &virtscsi_host_template_multi; + hostt = &virtscsi_host_template; shost = scsi_host_alloc(hostt, sizeof(*vscsi) + sizeof(vscsi->req_vqs[0]) * num_queues); @@ -983,6 +856,7 @@ static int virtscsi_probe(struct virtio_device *vdev) shost->max_id = num_targets; shost->max_channel = 0; shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE; + shost->nr_hw_queues = num_queues; if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) { host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION | -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html