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 #include <linux/module.h>
17 #include <linux/slab.h>
18 #include <linux/mempool.h>
19 #include <linux/virtio.h>
20 #include <linux/virtio_ids.h>
21 #include <linux/virtio_config.h>
22 #include <linux/virtio_scsi.h>
23 #include <scsi/scsi_host.h>
24 #include <scsi/scsi_device.h>
25 #include <scsi/scsi_cmnd.h>
27 #define VIRTIO_SCSI_MEMPOOL_SZ 64
29 /* Command queue element */
30 struct virtio_scsi_cmd {
32 struct completion *comp;
34 struct virtio_scsi_cmd_req cmd;
35 struct virtio_scsi_ctrl_tmf_req tmf;
36 struct virtio_scsi_ctrl_an_req an;
39 struct virtio_scsi_cmd_resp cmd;
40 struct virtio_scsi_ctrl_tmf_resp tmf;
41 struct virtio_scsi_ctrl_an_resp an;
42 struct virtio_scsi_event evt;
44 } ____cacheline_aligned_in_smp;
46 /* Driver instance state */
48 /* Protects ctrl_vq, req_vq and sg[] */
51 struct virtio_device *vdev;
52 struct virtqueue *ctrl_vq;
53 struct virtqueue *event_vq;
54 struct virtqueue *req_vq;
56 /* For sglist construction when adding commands to the virtqueue. */
57 struct scatterlist sg[];
60 static struct kmem_cache *virtscsi_cmd_cache;
61 static mempool_t *virtscsi_cmd_pool;
63 static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev)
68 static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid)
73 if (!scsi_bidi_cmnd(sc)) {
74 scsi_set_resid(sc, resid);
78 scsi_in(sc)->resid = min(resid, scsi_in(sc)->length);
79 scsi_out(sc)->resid = resid - scsi_in(sc)->resid;
83 * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done
85 * Called with vq_lock held.
87 static void virtscsi_complete_cmd(void *buf)
89 struct virtio_scsi_cmd *cmd = buf;
90 struct scsi_cmnd *sc = cmd->sc;
91 struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd;
93 dev_dbg(&sc->device->sdev_gendev,
94 "cmd %p response %u status %#02x sense_len %u\n",
95 sc, resp->response, resp->status, resp->sense_len);
97 sc->result = resp->status;
98 virtscsi_compute_resid(sc, resp->resid);
99 switch (resp->response) {
100 case VIRTIO_SCSI_S_OK:
101 set_host_byte(sc, DID_OK);
103 case VIRTIO_SCSI_S_OVERRUN:
104 set_host_byte(sc, DID_ERROR);
106 case VIRTIO_SCSI_S_ABORTED:
107 set_host_byte(sc, DID_ABORT);
109 case VIRTIO_SCSI_S_BAD_TARGET:
110 set_host_byte(sc, DID_BAD_TARGET);
112 case VIRTIO_SCSI_S_RESET:
113 set_host_byte(sc, DID_RESET);
115 case VIRTIO_SCSI_S_BUSY:
116 set_host_byte(sc, DID_BUS_BUSY);
118 case VIRTIO_SCSI_S_TRANSPORT_FAILURE:
119 set_host_byte(sc, DID_TRANSPORT_DISRUPTED);
121 case VIRTIO_SCSI_S_TARGET_FAILURE:
122 set_host_byte(sc, DID_TARGET_FAILURE);
124 case VIRTIO_SCSI_S_NEXUS_FAILURE:
125 set_host_byte(sc, DID_NEXUS_FAILURE);
128 scmd_printk(KERN_WARNING, sc, "Unknown response %d",
131 case VIRTIO_SCSI_S_FAILURE:
132 set_host_byte(sc, DID_ERROR);
136 WARN_ON(resp->sense_len > VIRTIO_SCSI_SENSE_SIZE);
137 if (sc->sense_buffer) {
138 memcpy(sc->sense_buffer, resp->sense,
139 min_t(u32, resp->sense_len, VIRTIO_SCSI_SENSE_SIZE));
141 set_driver_byte(sc, DRIVER_SENSE);
144 mempool_free(cmd, virtscsi_cmd_pool);
148 static void virtscsi_vq_done(struct virtqueue *vq, void (*fn)(void *buf))
150 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
151 struct virtio_scsi *vscsi = shost_priv(sh);
156 spin_lock_irqsave(&vscsi->vq_lock, flags);
159 virtqueue_disable_cb(vq);
160 while ((buf = virtqueue_get_buf(vq, &len)) != NULL)
162 } while (!virtqueue_enable_cb(vq));
164 spin_unlock_irqrestore(&vscsi->vq_lock, flags);
167 static void virtscsi_req_done(struct virtqueue *vq)
169 virtscsi_vq_done(vq, virtscsi_complete_cmd);
172 static void virtscsi_complete_free(void *buf)
174 struct virtio_scsi_cmd *cmd = buf;
177 complete_all(cmd->comp);
179 mempool_free(cmd, virtscsi_cmd_pool);
182 static void virtscsi_ctrl_done(struct virtqueue *vq)
184 virtscsi_vq_done(vq, virtscsi_complete_free);
187 static void virtscsi_event_done(struct virtqueue *vq)
189 virtscsi_vq_done(vq, virtscsi_complete_free);
192 static void virtscsi_map_sgl(struct scatterlist *sg, unsigned int *p_idx,
193 struct scsi_data_buffer *sdb)
195 struct sg_table *table = &sdb->table;
196 struct scatterlist *sg_elem;
197 unsigned int idx = *p_idx;
200 for_each_sg(table->sgl, sg_elem, table->nents, i)
201 sg_set_buf(&sg[idx++], sg_virt(sg_elem), sg_elem->length);
207 * virtscsi_map_cmd - map a scsi_cmd to a virtqueue scatterlist
208 * @vscsi : virtio_scsi state
209 * @cmd : command structure
210 * @out_num : number of read-only elements
211 * @in_num : number of write-only elements
212 * @req_size : size of the request buffer
213 * @resp_size : size of the response buffer
215 * Called with vq_lock held.
217 static void virtscsi_map_cmd(struct virtio_scsi *vscsi,
218 struct virtio_scsi_cmd *cmd,
219 unsigned *out_num, unsigned *in_num,
220 size_t req_size, size_t resp_size)
222 struct scsi_cmnd *sc = cmd->sc;
223 struct scatterlist *sg = vscsi->sg;
224 unsigned int idx = 0;
227 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
228 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize);
230 /* TODO: check feature bit and fail if unsupported? */
231 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL);
234 /* Request header. */
235 sg_set_buf(&sg[idx++], &cmd->req, req_size);
237 /* Data-out buffer. */
238 if (sc && sc->sc_data_direction != DMA_FROM_DEVICE)
239 virtscsi_map_sgl(sg, &idx, scsi_out(sc));
243 /* Response header. */
244 sg_set_buf(&sg[idx++], &cmd->resp, resp_size);
247 if (sc && sc->sc_data_direction != DMA_TO_DEVICE)
248 virtscsi_map_sgl(sg, &idx, scsi_in(sc));
250 *in_num = idx - *out_num;
253 static int virtscsi_kick_cmd(struct virtio_scsi *vscsi, struct virtqueue *vq,
254 struct virtio_scsi_cmd *cmd,
255 size_t req_size, size_t resp_size, gfp_t gfp)
257 unsigned int out_num, in_num;
261 spin_lock_irqsave(&vscsi->vq_lock, flags);
263 virtscsi_map_cmd(vscsi, cmd, &out_num, &in_num, req_size, resp_size);
265 ret = virtqueue_add_buf(vq, vscsi->sg, out_num, in_num, cmd, gfp);
267 ret = virtqueue_kick_prepare(vq);
269 spin_unlock_irqrestore(&vscsi->vq_lock, flags);
271 virtqueue_notify(vq);
275 static int virtscsi_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
277 struct virtio_scsi *vscsi = shost_priv(sh);
278 struct virtio_scsi_cmd *cmd;
281 dev_dbg(&sc->device->sdev_gendev,
282 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]);
284 ret = SCSI_MLQUEUE_HOST_BUSY;
285 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_ATOMIC);
289 memset(cmd, 0, sizeof(*cmd));
291 cmd->req.cmd = (struct virtio_scsi_cmd_req){
293 .lun[1] = sc->device->id,
294 .lun[2] = (sc->device->lun >> 8) | 0x40,
295 .lun[3] = sc->device->lun & 0xff,
296 .tag = (unsigned long)sc,
297 .task_attr = VIRTIO_SCSI_S_SIMPLE,
302 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE);
303 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len);
305 if (virtscsi_kick_cmd(vscsi, vscsi->req_vq, cmd,
306 sizeof cmd->req.cmd, sizeof cmd->resp.cmd,
314 static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd)
316 DECLARE_COMPLETION_ONSTACK(comp);
320 if (virtscsi_kick_cmd(vscsi, vscsi->ctrl_vq, cmd,
321 sizeof cmd->req.tmf, sizeof cmd->resp.tmf,
325 wait_for_completion(&comp);
326 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK ||
327 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED)
331 mempool_free(cmd, virtscsi_cmd_pool);
335 static int virtscsi_device_reset(struct scsi_cmnd *sc)
337 struct virtio_scsi *vscsi = shost_priv(sc->device->host);
338 struct virtio_scsi_cmd *cmd;
340 sdev_printk(KERN_INFO, sc->device, "device reset\n");
341 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
345 memset(cmd, 0, sizeof(*cmd));
347 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
348 .type = VIRTIO_SCSI_T_TMF,
349 .subtype = VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET,
351 .lun[1] = sc->device->id,
352 .lun[2] = (sc->device->lun >> 8) | 0x40,
353 .lun[3] = sc->device->lun & 0xff,
355 return virtscsi_tmf(vscsi, cmd);
358 static int virtscsi_abort(struct scsi_cmnd *sc)
360 struct virtio_scsi *vscsi = shost_priv(sc->device->host);
361 struct virtio_scsi_cmd *cmd;
363 scmd_printk(KERN_INFO, sc, "abort\n");
364 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
368 memset(cmd, 0, sizeof(*cmd));
370 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
371 .type = VIRTIO_SCSI_T_TMF,
372 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK,
374 .lun[1] = sc->device->id,
375 .lun[2] = (sc->device->lun >> 8) | 0x40,
376 .lun[3] = sc->device->lun & 0xff,
377 .tag = (unsigned long)sc,
379 return virtscsi_tmf(vscsi, cmd);
382 static struct scsi_host_template virtscsi_host_template = {
383 .module = THIS_MODULE,
384 .name = "Virtio SCSI HBA",
385 .proc_name = "virtio_scsi",
386 .queuecommand = virtscsi_queuecommand,
388 .eh_abort_handler = virtscsi_abort,
389 .eh_device_reset_handler = virtscsi_device_reset,
392 .dma_boundary = UINT_MAX,
393 .use_clustering = ENABLE_CLUSTERING,
396 #define virtscsi_config_get(vdev, fld) \
398 typeof(((struct virtio_scsi_config *)0)->fld) __val; \
399 vdev->config->get(vdev, \
400 offsetof(struct virtio_scsi_config, fld), \
401 &__val, sizeof(__val)); \
405 #define virtscsi_config_set(vdev, fld, val) \
407 typeof(((struct virtio_scsi_config *)0)->fld) __val = (val); \
408 vdev->config->set(vdev, \
409 offsetof(struct virtio_scsi_config, fld), \
410 &__val, sizeof(__val)); \
413 static int virtscsi_init(struct virtio_device *vdev,
414 struct virtio_scsi *vscsi)
417 struct virtqueue *vqs[3];
418 vq_callback_t *callbacks[] = {
423 const char *names[] = {
429 /* Discover virtqueues and write information to configuration. */
430 err = vdev->config->find_vqs(vdev, 3, vqs, callbacks, names);
434 vscsi->ctrl_vq = vqs[0];
435 vscsi->event_vq = vqs[1];
436 vscsi->req_vq = vqs[2];
438 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE);
439 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE);
443 static int __devinit virtscsi_probe(struct virtio_device *vdev)
445 struct Scsi_Host *shost;
446 struct virtio_scsi *vscsi;
451 /* We need to know how many segments before we allocate.
452 * We need an extra sg elements at head and tail.
454 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
456 /* Allocate memory and link the structs together. */
457 shost = scsi_host_alloc(&virtscsi_host_template,
458 sizeof(*vscsi) + sizeof(vscsi->sg[0]) * (sg_elems + 2));
463 shost->sg_tablesize = sg_elems;
464 vscsi = shost_priv(shost);
468 /* Random initializations. */
469 spin_lock_init(&vscsi->vq_lock);
470 sg_init_table(vscsi->sg, sg_elems + 2);
472 err = virtscsi_init(vdev, vscsi);
474 goto virtscsi_init_failed;
476 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1;
477 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue);
478 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF;
479 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1;
480 shost->max_id = virtscsi_config_get(vdev, max_target) + 1;
481 shost->max_channel = 0;
482 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE;
483 err = scsi_add_host(shost, &vdev->dev);
485 goto scsi_add_host_failed;
487 scsi_scan_host(shost);
491 scsi_add_host_failed:
492 vdev->config->del_vqs(vdev);
493 virtscsi_init_failed:
494 scsi_host_put(shost);
498 static void virtscsi_remove_vqs(struct virtio_device *vdev)
500 /* Stop all the virtqueues. */
501 vdev->config->reset(vdev);
503 vdev->config->del_vqs(vdev);
506 static void __devexit virtscsi_remove(struct virtio_device *vdev)
508 struct Scsi_Host *shost = virtio_scsi_host(vdev);
510 scsi_remove_host(shost);
512 virtscsi_remove_vqs(vdev);
513 scsi_host_put(shost);
517 static int virtscsi_freeze(struct virtio_device *vdev)
519 virtscsi_remove_vqs(vdev);
523 static int virtscsi_restore(struct virtio_device *vdev)
525 struct Scsi_Host *sh = virtio_scsi_host(vdev);
526 struct virtio_scsi *vscsi = shost_priv(sh);
528 return virtscsi_init(vdev, vscsi);
532 static struct virtio_device_id id_table[] = {
533 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID },
537 static struct virtio_driver virtio_scsi_driver = {
538 .driver.name = KBUILD_MODNAME,
539 .driver.owner = THIS_MODULE,
540 .id_table = id_table,
541 .probe = virtscsi_probe,
543 .freeze = virtscsi_freeze,
544 .restore = virtscsi_restore,
546 .remove = __devexit_p(virtscsi_remove),
549 static int __init init(void)
553 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0);
554 if (!virtscsi_cmd_cache) {
555 printk(KERN_ERR "kmem_cache_create() for "
556 "virtscsi_cmd_cache failed\n");
562 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ,
564 if (!virtscsi_cmd_pool) {
565 printk(KERN_ERR "mempool_create() for"
566 "virtscsi_cmd_pool failed\n");
569 ret = register_virtio_driver(&virtio_scsi_driver);
576 if (virtscsi_cmd_pool) {
577 mempool_destroy(virtscsi_cmd_pool);
578 virtscsi_cmd_pool = NULL;
580 if (virtscsi_cmd_cache) {
581 kmem_cache_destroy(virtscsi_cmd_cache);
582 virtscsi_cmd_cache = NULL;
587 static void __exit fini(void)
589 unregister_virtio_driver(&virtio_scsi_driver);
590 mempool_destroy(virtscsi_cmd_pool);
591 kmem_cache_destroy(virtscsi_cmd_cache);
596 MODULE_DEVICE_TABLE(virtio, id_table);
597 MODULE_DESCRIPTION("Virtio SCSI HBA driver");
598 MODULE_LICENSE("GPL");