2 * Virtio SCSI HBA driver
4 * Copyright IBM Corp. 2010
5 * Copyright Red Hat, Inc. 2011
8 * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
9 * Paolo Bonzini <pbonzini@redhat.com>
11 * This work is licensed under the terms of the GNU GPL, version 2 or later.
12 * See the COPYING file in the top-level directory.
16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18 #include <linux/module.h>
19 #include <linux/slab.h>
20 #include <linux/mempool.h>
21 #include <linux/virtio.h>
22 #include <linux/virtio_ids.h>
23 #include <linux/virtio_config.h>
24 #include <linux/virtio_scsi.h>
25 #include <linux/cpu.h>
26 #include <linux/blkdev.h>
27 #include <scsi/scsi_host.h>
28 #include <scsi/scsi_device.h>
29 #include <scsi/scsi_cmnd.h>
31 #define VIRTIO_SCSI_MEMPOOL_SZ 64
32 #define VIRTIO_SCSI_EVENT_LEN 8
33 #define VIRTIO_SCSI_VQ_BASE 2
35 /* Command queue element */
36 struct virtio_scsi_cmd {
38 struct completion *comp;
40 struct virtio_scsi_cmd_req cmd;
41 struct virtio_scsi_cmd_req_pi cmd_pi;
42 struct virtio_scsi_ctrl_tmf_req tmf;
43 struct virtio_scsi_ctrl_an_req an;
46 struct virtio_scsi_cmd_resp cmd;
47 struct virtio_scsi_ctrl_tmf_resp tmf;
48 struct virtio_scsi_ctrl_an_resp an;
49 struct virtio_scsi_event evt;
51 } ____cacheline_aligned_in_smp;
53 struct virtio_scsi_event_node {
54 struct virtio_scsi *vscsi;
55 struct virtio_scsi_event event;
56 struct work_struct work;
59 struct virtio_scsi_vq {
67 * Per-target queue state.
69 * This struct holds the data needed by the queue steering policy. When a
70 * target is sent multiple requests, we need to drive them to the same queue so
71 * that FIFO processing order is kept. However, if a target was idle, we can
72 * choose a queue arbitrarily. In this case the queue is chosen according to
73 * the current VCPU, so the driver expects the number of request queues to be
74 * equal to the number of VCPUs. This makes it easy and fast to select the
75 * queue, and also lets the driver optimize the IRQ affinity for the virtqueues
76 * (each virtqueue's affinity is set to the CPU that "owns" the queue).
78 * tgt_lock is held to serialize reading and writing req_vq. Reading req_vq
79 * could be done locklessly, but we do not do it yet.
81 * Decrements of reqs are never concurrent with writes of req_vq: before the
82 * decrement reqs will be != 0; after the decrement the virtqueue completion
83 * routine will not use the req_vq so it can be changed by a new request.
84 * Thus they can happen outside the tgt_lock, provided of course we make reqs
87 struct virtio_scsi_target_state {
88 /* This spinlock never held at the same time as vq_lock. */
91 /* Count of outstanding requests. */
94 /* Currently active virtqueue for requests sent to this target. */
95 struct virtio_scsi_vq *req_vq;
98 /* Driver instance state */
100 struct virtio_device *vdev;
102 /* Get some buffers ready for event vq */
103 struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN];
107 /* If the affinity hint is set for virtqueues */
108 bool affinity_hint_set;
110 /* CPU hotplug notifier */
111 struct notifier_block nb;
113 struct virtio_scsi_vq ctrl_vq;
114 struct virtio_scsi_vq event_vq;
115 struct virtio_scsi_vq req_vqs[];
118 static struct kmem_cache *virtscsi_cmd_cache;
119 static mempool_t *virtscsi_cmd_pool;
121 static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev)
126 static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid)
131 if (!scsi_bidi_cmnd(sc)) {
132 scsi_set_resid(sc, resid);
136 scsi_in(sc)->resid = min(resid, scsi_in(sc)->length);
137 scsi_out(sc)->resid = resid - scsi_in(sc)->resid;
141 * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done
143 * Called with vq_lock held.
145 static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf)
147 struct virtio_scsi_cmd *cmd = buf;
148 struct scsi_cmnd *sc = cmd->sc;
149 struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd;
150 struct virtio_scsi_target_state *tgt =
151 scsi_target(sc->device)->hostdata;
153 dev_dbg(&sc->device->sdev_gendev,
154 "cmd %p response %u status %#02x sense_len %u\n",
155 sc, resp->response, resp->status, resp->sense_len);
157 sc->result = resp->status;
158 virtscsi_compute_resid(sc, resp->resid);
159 switch (resp->response) {
160 case VIRTIO_SCSI_S_OK:
161 set_host_byte(sc, DID_OK);
163 case VIRTIO_SCSI_S_OVERRUN:
164 set_host_byte(sc, DID_ERROR);
166 case VIRTIO_SCSI_S_ABORTED:
167 set_host_byte(sc, DID_ABORT);
169 case VIRTIO_SCSI_S_BAD_TARGET:
170 set_host_byte(sc, DID_BAD_TARGET);
172 case VIRTIO_SCSI_S_RESET:
173 set_host_byte(sc, DID_RESET);
175 case VIRTIO_SCSI_S_BUSY:
176 set_host_byte(sc, DID_BUS_BUSY);
178 case VIRTIO_SCSI_S_TRANSPORT_FAILURE:
179 set_host_byte(sc, DID_TRANSPORT_DISRUPTED);
181 case VIRTIO_SCSI_S_TARGET_FAILURE:
182 set_host_byte(sc, DID_TARGET_FAILURE);
184 case VIRTIO_SCSI_S_NEXUS_FAILURE:
185 set_host_byte(sc, DID_NEXUS_FAILURE);
188 scmd_printk(KERN_WARNING, sc, "Unknown response %d",
191 case VIRTIO_SCSI_S_FAILURE:
192 set_host_byte(sc, DID_ERROR);
196 WARN_ON(resp->sense_len > VIRTIO_SCSI_SENSE_SIZE);
197 if (sc->sense_buffer) {
198 memcpy(sc->sense_buffer, resp->sense,
199 min_t(u32, resp->sense_len, VIRTIO_SCSI_SENSE_SIZE));
201 set_driver_byte(sc, DRIVER_SENSE);
206 atomic_dec(&tgt->reqs);
209 static void virtscsi_vq_done(struct virtio_scsi *vscsi,
210 struct virtio_scsi_vq *virtscsi_vq,
211 void (*fn)(struct virtio_scsi *vscsi, void *buf))
216 struct virtqueue *vq = virtscsi_vq->vq;
218 spin_lock_irqsave(&virtscsi_vq->vq_lock, flags);
220 virtqueue_disable_cb(vq);
221 while ((buf = virtqueue_get_buf(vq, &len)) != NULL)
224 if (unlikely(virtqueue_is_broken(vq)))
226 } while (!virtqueue_enable_cb(vq));
227 spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags);
230 static void virtscsi_req_done(struct virtqueue *vq)
232 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
233 struct virtio_scsi *vscsi = shost_priv(sh);
234 int index = vq->index - VIRTIO_SCSI_VQ_BASE;
235 struct virtio_scsi_vq *req_vq = &vscsi->req_vqs[index];
237 virtscsi_vq_done(vscsi, req_vq, virtscsi_complete_cmd);
240 static void virtscsi_poll_requests(struct virtio_scsi *vscsi)
244 num_vqs = vscsi->num_queues;
245 for (i = 0; i < num_vqs; i++)
246 virtscsi_vq_done(vscsi, &vscsi->req_vqs[i],
247 virtscsi_complete_cmd);
250 static void virtscsi_complete_free(struct virtio_scsi *vscsi, void *buf)
252 struct virtio_scsi_cmd *cmd = buf;
255 complete_all(cmd->comp);
258 static void virtscsi_ctrl_done(struct virtqueue *vq)
260 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
261 struct virtio_scsi *vscsi = shost_priv(sh);
263 virtscsi_vq_done(vscsi, &vscsi->ctrl_vq, virtscsi_complete_free);
266 static void virtscsi_handle_event(struct work_struct *work);
268 static int virtscsi_kick_event(struct virtio_scsi *vscsi,
269 struct virtio_scsi_event_node *event_node)
272 struct scatterlist sg;
275 INIT_WORK(&event_node->work, virtscsi_handle_event);
276 sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event));
278 spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags);
280 err = virtqueue_add_inbuf(vscsi->event_vq.vq, &sg, 1, event_node,
283 virtqueue_kick(vscsi->event_vq.vq);
285 spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags);
290 static int virtscsi_kick_event_all(struct virtio_scsi *vscsi)
294 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) {
295 vscsi->event_list[i].vscsi = vscsi;
296 virtscsi_kick_event(vscsi, &vscsi->event_list[i]);
302 static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi)
306 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++)
307 cancel_work_sync(&vscsi->event_list[i].work);
310 static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi,
311 struct virtio_scsi_event *event)
313 struct scsi_device *sdev;
314 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
315 unsigned int target = event->lun[1];
316 unsigned int lun = (event->lun[2] << 8) | event->lun[3];
318 switch (event->reason) {
319 case VIRTIO_SCSI_EVT_RESET_RESCAN:
320 scsi_add_device(shost, 0, target, lun);
322 case VIRTIO_SCSI_EVT_RESET_REMOVED:
323 sdev = scsi_device_lookup(shost, 0, target, lun);
325 scsi_remove_device(sdev);
326 scsi_device_put(sdev);
328 pr_err("SCSI device %d 0 %d %d not found\n",
329 shost->host_no, target, lun);
333 pr_info("Unsupport virtio scsi event reason %x\n", event->reason);
337 static void virtscsi_handle_param_change(struct virtio_scsi *vscsi,
338 struct virtio_scsi_event *event)
340 struct scsi_device *sdev;
341 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
342 unsigned int target = event->lun[1];
343 unsigned int lun = (event->lun[2] << 8) | event->lun[3];
344 u8 asc = event->reason & 255;
345 u8 ascq = event->reason >> 8;
347 sdev = scsi_device_lookup(shost, 0, target, lun);
349 pr_err("SCSI device %d 0 %d %d not found\n",
350 shost->host_no, target, lun);
354 /* Handle "Parameters changed", "Mode parameters changed", and
355 "Capacity data has changed". */
356 if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09))
357 scsi_rescan_device(&sdev->sdev_gendev);
359 scsi_device_put(sdev);
362 static void virtscsi_handle_event(struct work_struct *work)
364 struct virtio_scsi_event_node *event_node =
365 container_of(work, struct virtio_scsi_event_node, work);
366 struct virtio_scsi *vscsi = event_node->vscsi;
367 struct virtio_scsi_event *event = &event_node->event;
369 if (event->event & VIRTIO_SCSI_T_EVENTS_MISSED) {
370 event->event &= ~VIRTIO_SCSI_T_EVENTS_MISSED;
371 scsi_scan_host(virtio_scsi_host(vscsi->vdev));
374 switch (event->event) {
375 case VIRTIO_SCSI_T_NO_EVENT:
377 case VIRTIO_SCSI_T_TRANSPORT_RESET:
378 virtscsi_handle_transport_reset(vscsi, event);
380 case VIRTIO_SCSI_T_PARAM_CHANGE:
381 virtscsi_handle_param_change(vscsi, event);
384 pr_err("Unsupport virtio scsi event %x\n", event->event);
386 virtscsi_kick_event(vscsi, event_node);
389 static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf)
391 struct virtio_scsi_event_node *event_node = buf;
393 schedule_work(&event_node->work);
396 static void virtscsi_event_done(struct virtqueue *vq)
398 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
399 struct virtio_scsi *vscsi = shost_priv(sh);
401 virtscsi_vq_done(vscsi, &vscsi->event_vq, virtscsi_complete_event);
405 * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue
406 * @vq : the struct virtqueue we're talking about
407 * @cmd : command structure
408 * @req_size : size of the request buffer
409 * @resp_size : size of the response buffer
411 static int virtscsi_add_cmd(struct virtqueue *vq,
412 struct virtio_scsi_cmd *cmd,
413 size_t req_size, size_t resp_size)
415 struct scsi_cmnd *sc = cmd->sc;
416 struct scatterlist *sgs[6], req, resp;
417 struct sg_table *out, *in;
418 unsigned out_num = 0, in_num = 0;
422 if (sc && sc->sc_data_direction != DMA_NONE) {
423 if (sc->sc_data_direction != DMA_FROM_DEVICE)
424 out = &scsi_out(sc)->table;
425 if (sc->sc_data_direction != DMA_TO_DEVICE)
426 in = &scsi_in(sc)->table;
429 /* Request header. */
430 sg_init_one(&req, &cmd->req, req_size);
431 sgs[out_num++] = &req;
433 /* Data-out buffer. */
435 /* Place WRITE protection SGLs before Data OUT payload */
436 if (scsi_prot_sg_count(sc))
437 sgs[out_num++] = scsi_prot_sglist(sc);
438 sgs[out_num++] = out->sgl;
441 /* Response header. */
442 sg_init_one(&resp, &cmd->resp, resp_size);
443 sgs[out_num + in_num++] = &resp;
447 /* Place READ protection SGLs before Data IN payload */
448 if (scsi_prot_sg_count(sc))
449 sgs[out_num + in_num++] = scsi_prot_sglist(sc);
450 sgs[out_num + in_num++] = in->sgl;
453 return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC);
456 static int virtscsi_kick_cmd(struct virtio_scsi_vq *vq,
457 struct virtio_scsi_cmd *cmd,
458 size_t req_size, size_t resp_size)
462 bool needs_kick = false;
464 spin_lock_irqsave(&vq->vq_lock, flags);
465 err = virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size);
467 needs_kick = virtqueue_kick_prepare(vq->vq);
469 spin_unlock_irqrestore(&vq->vq_lock, flags);
472 virtqueue_notify(vq->vq);
476 static void virtio_scsi_init_hdr(struct virtio_scsi_cmd_req *cmd,
477 struct scsi_cmnd *sc)
480 cmd->lun[1] = sc->device->id;
481 cmd->lun[2] = (sc->device->lun >> 8) | 0x40;
482 cmd->lun[3] = sc->device->lun & 0xff;
483 cmd->tag = (unsigned long)sc;
484 cmd->task_attr = VIRTIO_SCSI_S_SIMPLE;
489 static void virtio_scsi_init_hdr_pi(struct virtio_scsi_cmd_req_pi *cmd_pi,
490 struct scsi_cmnd *sc)
492 struct request *rq = sc->request;
493 struct blk_integrity *bi;
495 virtio_scsi_init_hdr((struct virtio_scsi_cmd_req *)cmd_pi, sc);
497 if (!rq || !scsi_prot_sg_count(sc))
500 bi = blk_get_integrity(rq->rq_disk);
502 if (sc->sc_data_direction == DMA_TO_DEVICE)
503 cmd_pi->pi_bytesout = blk_rq_sectors(rq) * bi->tuple_size;
504 else if (sc->sc_data_direction == DMA_FROM_DEVICE)
505 cmd_pi->pi_bytesin = blk_rq_sectors(rq) * bi->tuple_size;
508 static int virtscsi_queuecommand(struct virtio_scsi *vscsi,
509 struct virtio_scsi_vq *req_vq,
510 struct scsi_cmnd *sc)
512 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
513 struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc);
516 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize);
518 /* TODO: check feature bit and fail if unsupported? */
519 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL);
521 dev_dbg(&sc->device->sdev_gendev,
522 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]);
524 memset(cmd, 0, sizeof(*cmd));
527 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE);
529 if (virtio_has_feature(vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) {
530 virtio_scsi_init_hdr_pi(&cmd->req.cmd_pi, sc);
531 memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len);
532 req_size = sizeof(cmd->req.cmd_pi);
534 virtio_scsi_init_hdr(&cmd->req.cmd, sc);
535 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len);
536 req_size = sizeof(cmd->req.cmd);
539 if (virtscsi_kick_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd)) != 0)
540 return SCSI_MLQUEUE_HOST_BUSY;
544 static int virtscsi_queuecommand_single(struct Scsi_Host *sh,
545 struct scsi_cmnd *sc)
547 struct virtio_scsi *vscsi = shost_priv(sh);
548 struct virtio_scsi_target_state *tgt =
549 scsi_target(sc->device)->hostdata;
551 atomic_inc(&tgt->reqs);
552 return virtscsi_queuecommand(vscsi, &vscsi->req_vqs[0], sc);
555 static struct virtio_scsi_vq *virtscsi_pick_vq(struct virtio_scsi *vscsi,
556 struct virtio_scsi_target_state *tgt)
558 struct virtio_scsi_vq *vq;
562 spin_lock_irqsave(&tgt->tgt_lock, flags);
564 if (atomic_inc_return(&tgt->reqs) > 1)
567 queue_num = smp_processor_id();
568 while (unlikely(queue_num >= vscsi->num_queues))
569 queue_num -= vscsi->num_queues;
571 tgt->req_vq = vq = &vscsi->req_vqs[queue_num];
574 spin_unlock_irqrestore(&tgt->tgt_lock, flags);
578 static int virtscsi_queuecommand_multi(struct Scsi_Host *sh,
579 struct scsi_cmnd *sc)
581 struct virtio_scsi *vscsi = shost_priv(sh);
582 struct virtio_scsi_target_state *tgt =
583 scsi_target(sc->device)->hostdata;
584 struct virtio_scsi_vq *req_vq = virtscsi_pick_vq(vscsi, tgt);
586 return virtscsi_queuecommand(vscsi, req_vq, sc);
589 static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd)
591 DECLARE_COMPLETION_ONSTACK(comp);
595 if (virtscsi_kick_cmd(&vscsi->ctrl_vq, cmd,
596 sizeof cmd->req.tmf, sizeof cmd->resp.tmf) < 0)
599 wait_for_completion(&comp);
600 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK ||
601 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED)
605 * The spec guarantees that all requests related to the TMF have
606 * been completed, but the callback might not have run yet if
607 * we're using independent interrupts (e.g. MSI). Poll the
610 * In the abort case, sc->scsi_done will do nothing, because
611 * the block layer must have detected a timeout and as a result
612 * REQ_ATOM_COMPLETE has been set.
614 virtscsi_poll_requests(vscsi);
617 mempool_free(cmd, virtscsi_cmd_pool);
621 static int virtscsi_device_reset(struct scsi_cmnd *sc)
623 struct virtio_scsi *vscsi = shost_priv(sc->device->host);
624 struct virtio_scsi_cmd *cmd;
626 sdev_printk(KERN_INFO, sc->device, "device reset\n");
627 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
631 memset(cmd, 0, sizeof(*cmd));
633 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
634 .type = VIRTIO_SCSI_T_TMF,
635 .subtype = VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET,
637 .lun[1] = sc->device->id,
638 .lun[2] = (sc->device->lun >> 8) | 0x40,
639 .lun[3] = sc->device->lun & 0xff,
641 return virtscsi_tmf(vscsi, cmd);
644 static int virtscsi_abort(struct scsi_cmnd *sc)
646 struct virtio_scsi *vscsi = shost_priv(sc->device->host);
647 struct virtio_scsi_cmd *cmd;
649 scmd_printk(KERN_INFO, sc, "abort\n");
650 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
654 memset(cmd, 0, sizeof(*cmd));
656 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
657 .type = VIRTIO_SCSI_T_TMF,
658 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK,
660 .lun[1] = sc->device->id,
661 .lun[2] = (sc->device->lun >> 8) | 0x40,
662 .lun[3] = sc->device->lun & 0xff,
663 .tag = (unsigned long)sc,
665 return virtscsi_tmf(vscsi, cmd);
668 static int virtscsi_target_alloc(struct scsi_target *starget)
670 struct virtio_scsi_target_state *tgt =
671 kmalloc(sizeof(*tgt), GFP_KERNEL);
675 spin_lock_init(&tgt->tgt_lock);
676 atomic_set(&tgt->reqs, 0);
679 starget->hostdata = tgt;
683 static void virtscsi_target_destroy(struct scsi_target *starget)
685 struct virtio_scsi_target_state *tgt = starget->hostdata;
689 static struct scsi_host_template virtscsi_host_template_single = {
690 .module = THIS_MODULE,
691 .name = "Virtio SCSI HBA",
692 .proc_name = "virtio_scsi",
694 .cmd_size = sizeof(struct virtio_scsi_cmd),
695 .queuecommand = virtscsi_queuecommand_single,
696 .eh_abort_handler = virtscsi_abort,
697 .eh_device_reset_handler = virtscsi_device_reset,
700 .dma_boundary = UINT_MAX,
701 .use_clustering = ENABLE_CLUSTERING,
702 .target_alloc = virtscsi_target_alloc,
703 .target_destroy = virtscsi_target_destroy,
706 static struct scsi_host_template virtscsi_host_template_multi = {
707 .module = THIS_MODULE,
708 .name = "Virtio SCSI HBA",
709 .proc_name = "virtio_scsi",
711 .cmd_size = sizeof(struct virtio_scsi_cmd),
712 .queuecommand = virtscsi_queuecommand_multi,
713 .eh_abort_handler = virtscsi_abort,
714 .eh_device_reset_handler = virtscsi_device_reset,
717 .dma_boundary = UINT_MAX,
718 .use_clustering = ENABLE_CLUSTERING,
719 .target_alloc = virtscsi_target_alloc,
720 .target_destroy = virtscsi_target_destroy,
723 #define virtscsi_config_get(vdev, fld) \
725 typeof(((struct virtio_scsi_config *)0)->fld) __val; \
726 virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \
730 #define virtscsi_config_set(vdev, fld, val) \
732 typeof(((struct virtio_scsi_config *)0)->fld) __val = (val); \
733 virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \
736 static void __virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity)
741 /* In multiqueue mode, when the number of cpu is equal
742 * to the number of request queues, we let the qeueues
743 * to be private to one cpu by setting the affinity hint
744 * to eliminate the contention.
746 if ((vscsi->num_queues == 1 ||
747 vscsi->num_queues != num_online_cpus()) && affinity) {
748 if (vscsi->affinity_hint_set)
756 for_each_online_cpu(cpu) {
757 virtqueue_set_affinity(vscsi->req_vqs[i].vq, cpu);
761 vscsi->affinity_hint_set = true;
763 for (i = 0; i < vscsi->num_queues; i++) {
764 if (!vscsi->req_vqs[i].vq)
767 virtqueue_set_affinity(vscsi->req_vqs[i].vq, -1);
770 vscsi->affinity_hint_set = false;
774 static void virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity)
777 __virtscsi_set_affinity(vscsi, affinity);
781 static int virtscsi_cpu_callback(struct notifier_block *nfb,
782 unsigned long action, void *hcpu)
784 struct virtio_scsi *vscsi = container_of(nfb, struct virtio_scsi, nb);
787 case CPU_ONLINE_FROZEN:
789 case CPU_DEAD_FROZEN:
790 __virtscsi_set_affinity(vscsi, true);
798 static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq,
799 struct virtqueue *vq)
801 spin_lock_init(&virtscsi_vq->vq_lock);
802 virtscsi_vq->vq = vq;
805 static void virtscsi_scan(struct virtio_device *vdev)
807 struct Scsi_Host *shost = (struct Scsi_Host *)vdev->priv;
809 scsi_scan_host(shost);
812 static void virtscsi_remove_vqs(struct virtio_device *vdev)
814 struct Scsi_Host *sh = virtio_scsi_host(vdev);
815 struct virtio_scsi *vscsi = shost_priv(sh);
817 virtscsi_set_affinity(vscsi, false);
819 /* Stop all the virtqueues. */
820 vdev->config->reset(vdev);
822 vdev->config->del_vqs(vdev);
825 static int virtscsi_init(struct virtio_device *vdev,
826 struct virtio_scsi *vscsi)
831 vq_callback_t **callbacks;
833 struct virtqueue **vqs;
835 num_vqs = vscsi->num_queues + VIRTIO_SCSI_VQ_BASE;
836 vqs = kmalloc(num_vqs * sizeof(struct virtqueue *), GFP_KERNEL);
837 callbacks = kmalloc(num_vqs * sizeof(vq_callback_t *), GFP_KERNEL);
838 names = kmalloc(num_vqs * sizeof(char *), GFP_KERNEL);
840 if (!callbacks || !vqs || !names) {
845 callbacks[0] = virtscsi_ctrl_done;
846 callbacks[1] = virtscsi_event_done;
847 names[0] = "control";
849 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) {
850 callbacks[i] = virtscsi_req_done;
851 names[i] = "request";
854 /* Discover virtqueues and write information to configuration. */
855 err = vdev->config->find_vqs(vdev, num_vqs, vqs, callbacks, names);
859 virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]);
860 virtscsi_init_vq(&vscsi->event_vq, vqs[1]);
861 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++)
862 virtscsi_init_vq(&vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE],
865 virtscsi_set_affinity(vscsi, true);
867 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE);
868 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE);
870 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
871 virtscsi_kick_event_all(vscsi);
880 virtscsi_remove_vqs(vdev);
884 static int virtscsi_probe(struct virtio_device *vdev)
886 struct Scsi_Host *shost;
887 struct virtio_scsi *vscsi;
889 u32 sg_elems, num_targets;
892 struct scsi_host_template *hostt;
894 /* We need to know how many queues before we allocate. */
895 num_queues = virtscsi_config_get(vdev, num_queues) ? : 1;
897 num_targets = virtscsi_config_get(vdev, max_target) + 1;
900 hostt = &virtscsi_host_template_single;
902 hostt = &virtscsi_host_template_multi;
904 shost = scsi_host_alloc(hostt,
905 sizeof(*vscsi) + sizeof(vscsi->req_vqs[0]) * num_queues);
909 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
910 shost->sg_tablesize = sg_elems;
911 vscsi = shost_priv(shost);
913 vscsi->num_queues = num_queues;
916 err = virtscsi_init(vdev, vscsi);
918 goto virtscsi_init_failed;
920 vscsi->nb.notifier_call = &virtscsi_cpu_callback;
921 err = register_hotcpu_notifier(&vscsi->nb);
923 pr_err("registering cpu notifier failed\n");
924 goto scsi_add_host_failed;
927 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1;
928 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue);
929 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF;
931 /* LUNs > 256 are reported with format 1, so they go in the range
934 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000;
935 shost->max_id = num_targets;
936 shost->max_channel = 0;
937 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE;
939 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) {
940 host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION |
941 SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION |
942 SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION;
944 scsi_host_set_prot(shost, host_prot);
945 scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC);
948 err = scsi_add_host(shost, &vdev->dev);
950 goto scsi_add_host_failed;
952 * scsi_scan_host() happens in virtscsi_scan() via virtio_driver->scan()
953 * after VIRTIO_CONFIG_S_DRIVER_OK has been set..
957 scsi_add_host_failed:
958 vdev->config->del_vqs(vdev);
959 virtscsi_init_failed:
960 scsi_host_put(shost);
964 static void virtscsi_remove(struct virtio_device *vdev)
966 struct Scsi_Host *shost = virtio_scsi_host(vdev);
967 struct virtio_scsi *vscsi = shost_priv(shost);
969 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
970 virtscsi_cancel_event_work(vscsi);
972 scsi_remove_host(shost);
974 unregister_hotcpu_notifier(&vscsi->nb);
976 virtscsi_remove_vqs(vdev);
977 scsi_host_put(shost);
980 #ifdef CONFIG_PM_SLEEP
981 static int virtscsi_freeze(struct virtio_device *vdev)
983 struct Scsi_Host *sh = virtio_scsi_host(vdev);
984 struct virtio_scsi *vscsi = shost_priv(sh);
986 unregister_hotcpu_notifier(&vscsi->nb);
987 virtscsi_remove_vqs(vdev);
991 static int virtscsi_restore(struct virtio_device *vdev)
993 struct Scsi_Host *sh = virtio_scsi_host(vdev);
994 struct virtio_scsi *vscsi = shost_priv(sh);
997 err = virtscsi_init(vdev, vscsi);
1001 err = register_hotcpu_notifier(&vscsi->nb);
1003 vdev->config->del_vqs(vdev);
1009 static struct virtio_device_id id_table[] = {
1010 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID },
1014 static unsigned int features[] = {
1015 VIRTIO_SCSI_F_HOTPLUG,
1016 VIRTIO_SCSI_F_CHANGE,
1017 VIRTIO_SCSI_F_T10_PI,
1020 static struct virtio_driver virtio_scsi_driver = {
1021 .feature_table = features,
1022 .feature_table_size = ARRAY_SIZE(features),
1023 .driver.name = KBUILD_MODNAME,
1024 .driver.owner = THIS_MODULE,
1025 .id_table = id_table,
1026 .probe = virtscsi_probe,
1027 .scan = virtscsi_scan,
1028 #ifdef CONFIG_PM_SLEEP
1029 .freeze = virtscsi_freeze,
1030 .restore = virtscsi_restore,
1032 .remove = virtscsi_remove,
1035 static int __init init(void)
1039 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0);
1040 if (!virtscsi_cmd_cache) {
1041 pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n");
1047 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ,
1048 virtscsi_cmd_cache);
1049 if (!virtscsi_cmd_pool) {
1050 pr_err("mempool_create() for virtscsi_cmd_pool failed\n");
1053 ret = register_virtio_driver(&virtio_scsi_driver);
1060 if (virtscsi_cmd_pool) {
1061 mempool_destroy(virtscsi_cmd_pool);
1062 virtscsi_cmd_pool = NULL;
1064 if (virtscsi_cmd_cache) {
1065 kmem_cache_destroy(virtscsi_cmd_cache);
1066 virtscsi_cmd_cache = NULL;
1071 static void __exit fini(void)
1073 unregister_virtio_driver(&virtio_scsi_driver);
1074 mempool_destroy(virtscsi_cmd_pool);
1075 kmem_cache_destroy(virtscsi_cmd_cache);
1080 MODULE_DEVICE_TABLE(virtio, id_table);
1081 MODULE_DESCRIPTION("Virtio SCSI HBA driver");
1082 MODULE_LICENSE("GPL");