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>
30 #include <scsi/scsi_tcq.h>
31 #include <linux/seqlock.h>
33 #define VIRTIO_SCSI_MEMPOOL_SZ 64
34 #define VIRTIO_SCSI_EVENT_LEN 8
35 #define VIRTIO_SCSI_VQ_BASE 2
37 /* Command queue element */
38 struct virtio_scsi_cmd
{
40 struct completion
*comp
;
42 struct virtio_scsi_cmd_req cmd
;
43 struct virtio_scsi_cmd_req_pi cmd_pi
;
44 struct virtio_scsi_ctrl_tmf_req tmf
;
45 struct virtio_scsi_ctrl_an_req an
;
48 struct virtio_scsi_cmd_resp cmd
;
49 struct virtio_scsi_ctrl_tmf_resp tmf
;
50 struct virtio_scsi_ctrl_an_resp an
;
51 struct virtio_scsi_event evt
;
53 } ____cacheline_aligned_in_smp
;
55 struct virtio_scsi_event_node
{
56 struct virtio_scsi
*vscsi
;
57 struct virtio_scsi_event event
;
58 struct work_struct work
;
61 struct virtio_scsi_vq
{
69 * Per-target queue state.
71 * This struct holds the data needed by the queue steering policy. When a
72 * target is sent multiple requests, we need to drive them to the same queue so
73 * that FIFO processing order is kept. However, if a target was idle, we can
74 * choose a queue arbitrarily. In this case the queue is chosen according to
75 * the current VCPU, so the driver expects the number of request queues to be
76 * equal to the number of VCPUs. This makes it easy and fast to select the
77 * queue, and also lets the driver optimize the IRQ affinity for the virtqueues
78 * (each virtqueue's affinity is set to the CPU that "owns" the queue).
80 * tgt_seq is held to serialize reading and writing req_vq.
82 * Decrements of reqs are never concurrent with writes of req_vq: before the
83 * decrement reqs will be != 0; after the decrement the virtqueue completion
84 * routine will not use the req_vq so it can be changed by a new request.
85 * Thus they can happen outside the tgt_seq, provided of course we make reqs
88 struct virtio_scsi_target_state
{
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 /* Protected by event_vq lock */
116 struct virtio_scsi_vq ctrl_vq
;
117 struct virtio_scsi_vq event_vq
;
118 struct virtio_scsi_vq req_vqs
[];
121 static struct kmem_cache
*virtscsi_cmd_cache
;
122 static mempool_t
*virtscsi_cmd_pool
;
124 static inline struct Scsi_Host
*virtio_scsi_host(struct virtio_device
*vdev
)
129 static void virtscsi_compute_resid(struct scsi_cmnd
*sc
, u32 resid
)
134 if (!scsi_bidi_cmnd(sc
)) {
135 scsi_set_resid(sc
, resid
);
139 scsi_in(sc
)->resid
= min(resid
, scsi_in(sc
)->length
);
140 scsi_out(sc
)->resid
= resid
- scsi_in(sc
)->resid
;
144 * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done
146 * Called with vq_lock held.
148 static void virtscsi_complete_cmd(struct virtio_scsi
*vscsi
, void *buf
)
150 struct virtio_scsi_cmd
*cmd
= buf
;
151 struct scsi_cmnd
*sc
= cmd
->sc
;
152 struct virtio_scsi_cmd_resp
*resp
= &cmd
->resp
.cmd
;
153 struct virtio_scsi_target_state
*tgt
=
154 scsi_target(sc
->device
)->hostdata
;
156 dev_dbg(&sc
->device
->sdev_gendev
,
157 "cmd %p response %u status %#02x sense_len %u\n",
158 sc
, resp
->response
, resp
->status
, resp
->sense_len
);
160 sc
->result
= resp
->status
;
161 virtscsi_compute_resid(sc
, resp
->resid
);
162 switch (resp
->response
) {
163 case VIRTIO_SCSI_S_OK
:
164 set_host_byte(sc
, DID_OK
);
166 case VIRTIO_SCSI_S_OVERRUN
:
167 set_host_byte(sc
, DID_ERROR
);
169 case VIRTIO_SCSI_S_ABORTED
:
170 set_host_byte(sc
, DID_ABORT
);
172 case VIRTIO_SCSI_S_BAD_TARGET
:
173 set_host_byte(sc
, DID_BAD_TARGET
);
175 case VIRTIO_SCSI_S_RESET
:
176 set_host_byte(sc
, DID_RESET
);
178 case VIRTIO_SCSI_S_BUSY
:
179 set_host_byte(sc
, DID_BUS_BUSY
);
181 case VIRTIO_SCSI_S_TRANSPORT_FAILURE
:
182 set_host_byte(sc
, DID_TRANSPORT_DISRUPTED
);
184 case VIRTIO_SCSI_S_TARGET_FAILURE
:
185 set_host_byte(sc
, DID_TARGET_FAILURE
);
187 case VIRTIO_SCSI_S_NEXUS_FAILURE
:
188 set_host_byte(sc
, DID_NEXUS_FAILURE
);
191 scmd_printk(KERN_WARNING
, sc
, "Unknown response %d",
194 case VIRTIO_SCSI_S_FAILURE
:
195 set_host_byte(sc
, DID_ERROR
);
199 WARN_ON(resp
->sense_len
> VIRTIO_SCSI_SENSE_SIZE
);
200 if (sc
->sense_buffer
) {
201 memcpy(sc
->sense_buffer
, resp
->sense
,
202 min_t(u32
, resp
->sense_len
, VIRTIO_SCSI_SENSE_SIZE
));
204 set_driver_byte(sc
, DRIVER_SENSE
);
209 atomic_dec(&tgt
->reqs
);
212 static void virtscsi_vq_done(struct virtio_scsi
*vscsi
,
213 struct virtio_scsi_vq
*virtscsi_vq
,
214 void (*fn
)(struct virtio_scsi
*vscsi
, void *buf
))
219 struct virtqueue
*vq
= virtscsi_vq
->vq
;
221 spin_lock_irqsave(&virtscsi_vq
->vq_lock
, flags
);
223 virtqueue_disable_cb(vq
);
224 while ((buf
= virtqueue_get_buf(vq
, &len
)) != NULL
)
227 if (unlikely(virtqueue_is_broken(vq
)))
229 } while (!virtqueue_enable_cb(vq
));
230 spin_unlock_irqrestore(&virtscsi_vq
->vq_lock
, flags
);
233 static void virtscsi_req_done(struct virtqueue
*vq
)
235 struct Scsi_Host
*sh
= virtio_scsi_host(vq
->vdev
);
236 struct virtio_scsi
*vscsi
= shost_priv(sh
);
237 int index
= vq
->index
- VIRTIO_SCSI_VQ_BASE
;
238 struct virtio_scsi_vq
*req_vq
= &vscsi
->req_vqs
[index
];
240 virtscsi_vq_done(vscsi
, req_vq
, virtscsi_complete_cmd
);
243 static void virtscsi_poll_requests(struct virtio_scsi
*vscsi
)
247 num_vqs
= vscsi
->num_queues
;
248 for (i
= 0; i
< num_vqs
; i
++)
249 virtscsi_vq_done(vscsi
, &vscsi
->req_vqs
[i
],
250 virtscsi_complete_cmd
);
253 static void virtscsi_complete_free(struct virtio_scsi
*vscsi
, void *buf
)
255 struct virtio_scsi_cmd
*cmd
= buf
;
258 complete_all(cmd
->comp
);
261 static void virtscsi_ctrl_done(struct virtqueue
*vq
)
263 struct Scsi_Host
*sh
= virtio_scsi_host(vq
->vdev
);
264 struct virtio_scsi
*vscsi
= shost_priv(sh
);
266 virtscsi_vq_done(vscsi
, &vscsi
->ctrl_vq
, virtscsi_complete_free
);
269 static void virtscsi_handle_event(struct work_struct
*work
);
271 static int virtscsi_kick_event(struct virtio_scsi
*vscsi
,
272 struct virtio_scsi_event_node
*event_node
)
275 struct scatterlist sg
;
278 INIT_WORK(&event_node
->work
, virtscsi_handle_event
);
279 sg_init_one(&sg
, &event_node
->event
, sizeof(struct virtio_scsi_event
));
281 spin_lock_irqsave(&vscsi
->event_vq
.vq_lock
, flags
);
283 err
= virtqueue_add_inbuf(vscsi
->event_vq
.vq
, &sg
, 1, event_node
,
286 virtqueue_kick(vscsi
->event_vq
.vq
);
288 spin_unlock_irqrestore(&vscsi
->event_vq
.vq_lock
, flags
);
293 static int virtscsi_kick_event_all(struct virtio_scsi
*vscsi
)
297 for (i
= 0; i
< VIRTIO_SCSI_EVENT_LEN
; i
++) {
298 vscsi
->event_list
[i
].vscsi
= vscsi
;
299 virtscsi_kick_event(vscsi
, &vscsi
->event_list
[i
]);
305 static void virtscsi_cancel_event_work(struct virtio_scsi
*vscsi
)
309 /* Stop scheduling work before calling cancel_work_sync. */
310 spin_lock_irq(&vscsi
->event_vq
.vq_lock
);
311 vscsi
->stop_events
= true;
312 spin_unlock_irq(&vscsi
->event_vq
.vq_lock
);
314 for (i
= 0; i
< VIRTIO_SCSI_EVENT_LEN
; i
++)
315 cancel_work_sync(&vscsi
->event_list
[i
].work
);
318 static void virtscsi_handle_transport_reset(struct virtio_scsi
*vscsi
,
319 struct virtio_scsi_event
*event
)
321 struct scsi_device
*sdev
;
322 struct Scsi_Host
*shost
= virtio_scsi_host(vscsi
->vdev
);
323 unsigned int target
= event
->lun
[1];
324 unsigned int lun
= (event
->lun
[2] << 8) | event
->lun
[3];
326 switch (event
->reason
) {
327 case VIRTIO_SCSI_EVT_RESET_RESCAN
:
328 scsi_add_device(shost
, 0, target
, lun
);
330 case VIRTIO_SCSI_EVT_RESET_REMOVED
:
331 sdev
= scsi_device_lookup(shost
, 0, target
, lun
);
333 scsi_remove_device(sdev
);
334 scsi_device_put(sdev
);
336 pr_err("SCSI device %d 0 %d %d not found\n",
337 shost
->host_no
, target
, lun
);
341 pr_info("Unsupport virtio scsi event reason %x\n", event
->reason
);
345 static void virtscsi_handle_param_change(struct virtio_scsi
*vscsi
,
346 struct virtio_scsi_event
*event
)
348 struct scsi_device
*sdev
;
349 struct Scsi_Host
*shost
= virtio_scsi_host(vscsi
->vdev
);
350 unsigned int target
= event
->lun
[1];
351 unsigned int lun
= (event
->lun
[2] << 8) | event
->lun
[3];
352 u8 asc
= event
->reason
& 255;
353 u8 ascq
= event
->reason
>> 8;
355 sdev
= scsi_device_lookup(shost
, 0, target
, lun
);
357 pr_err("SCSI device %d 0 %d %d not found\n",
358 shost
->host_no
, target
, lun
);
362 /* Handle "Parameters changed", "Mode parameters changed", and
363 "Capacity data has changed". */
364 if (asc
== 0x2a && (ascq
== 0x00 || ascq
== 0x01 || ascq
== 0x09))
365 scsi_rescan_device(&sdev
->sdev_gendev
);
367 scsi_device_put(sdev
);
370 static void virtscsi_handle_event(struct work_struct
*work
)
372 struct virtio_scsi_event_node
*event_node
=
373 container_of(work
, struct virtio_scsi_event_node
, work
);
374 struct virtio_scsi
*vscsi
= event_node
->vscsi
;
375 struct virtio_scsi_event
*event
= &event_node
->event
;
377 if (event
->event
& VIRTIO_SCSI_T_EVENTS_MISSED
) {
378 event
->event
&= ~VIRTIO_SCSI_T_EVENTS_MISSED
;
379 scsi_scan_host(virtio_scsi_host(vscsi
->vdev
));
382 switch (event
->event
) {
383 case VIRTIO_SCSI_T_NO_EVENT
:
385 case VIRTIO_SCSI_T_TRANSPORT_RESET
:
386 virtscsi_handle_transport_reset(vscsi
, event
);
388 case VIRTIO_SCSI_T_PARAM_CHANGE
:
389 virtscsi_handle_param_change(vscsi
, event
);
392 pr_err("Unsupport virtio scsi event %x\n", event
->event
);
394 virtscsi_kick_event(vscsi
, event_node
);
397 static void virtscsi_complete_event(struct virtio_scsi
*vscsi
, void *buf
)
399 struct virtio_scsi_event_node
*event_node
= buf
;
401 if (!vscsi
->stop_events
)
402 queue_work(system_freezable_wq
, &event_node
->work
);
405 static void virtscsi_event_done(struct virtqueue
*vq
)
407 struct Scsi_Host
*sh
= virtio_scsi_host(vq
->vdev
);
408 struct virtio_scsi
*vscsi
= shost_priv(sh
);
410 virtscsi_vq_done(vscsi
, &vscsi
->event_vq
, virtscsi_complete_event
);
414 * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue
415 * @vq : the struct virtqueue we're talking about
416 * @cmd : command structure
417 * @req_size : size of the request buffer
418 * @resp_size : size of the response buffer
420 static int virtscsi_add_cmd(struct virtqueue
*vq
,
421 struct virtio_scsi_cmd
*cmd
,
422 size_t req_size
, size_t resp_size
)
424 struct scsi_cmnd
*sc
= cmd
->sc
;
425 struct scatterlist
*sgs
[6], req
, resp
;
426 struct sg_table
*out
, *in
;
427 unsigned out_num
= 0, in_num
= 0;
431 if (sc
&& sc
->sc_data_direction
!= DMA_NONE
) {
432 if (sc
->sc_data_direction
!= DMA_FROM_DEVICE
)
433 out
= &scsi_out(sc
)->table
;
434 if (sc
->sc_data_direction
!= DMA_TO_DEVICE
)
435 in
= &scsi_in(sc
)->table
;
438 /* Request header. */
439 sg_init_one(&req
, &cmd
->req
, req_size
);
440 sgs
[out_num
++] = &req
;
442 /* Data-out buffer. */
444 /* Place WRITE protection SGLs before Data OUT payload */
445 if (scsi_prot_sg_count(sc
))
446 sgs
[out_num
++] = scsi_prot_sglist(sc
);
447 sgs
[out_num
++] = out
->sgl
;
450 /* Response header. */
451 sg_init_one(&resp
, &cmd
->resp
, resp_size
);
452 sgs
[out_num
+ in_num
++] = &resp
;
456 /* Place READ protection SGLs before Data IN payload */
457 if (scsi_prot_sg_count(sc
))
458 sgs
[out_num
+ in_num
++] = scsi_prot_sglist(sc
);
459 sgs
[out_num
+ in_num
++] = in
->sgl
;
462 return virtqueue_add_sgs(vq
, sgs
, out_num
, in_num
, cmd
, GFP_ATOMIC
);
465 static int virtscsi_kick_cmd(struct virtio_scsi_vq
*vq
,
466 struct virtio_scsi_cmd
*cmd
,
467 size_t req_size
, size_t resp_size
)
471 bool needs_kick
= false;
473 spin_lock_irqsave(&vq
->vq_lock
, flags
);
474 err
= virtscsi_add_cmd(vq
->vq
, cmd
, req_size
, resp_size
);
476 needs_kick
= virtqueue_kick_prepare(vq
->vq
);
478 spin_unlock_irqrestore(&vq
->vq_lock
, flags
);
481 virtqueue_notify(vq
->vq
);
485 static void virtio_scsi_init_hdr(struct virtio_scsi_cmd_req
*cmd
,
486 struct scsi_cmnd
*sc
)
489 cmd
->lun
[1] = sc
->device
->id
;
490 cmd
->lun
[2] = (sc
->device
->lun
>> 8) | 0x40;
491 cmd
->lun
[3] = sc
->device
->lun
& 0xff;
492 cmd
->tag
= (unsigned long)sc
;
493 cmd
->task_attr
= VIRTIO_SCSI_S_SIMPLE
;
498 static void virtio_scsi_init_hdr_pi(struct virtio_scsi_cmd_req_pi
*cmd_pi
,
499 struct scsi_cmnd
*sc
)
501 struct request
*rq
= sc
->request
;
502 struct blk_integrity
*bi
;
504 virtio_scsi_init_hdr((struct virtio_scsi_cmd_req
*)cmd_pi
, sc
);
506 if (!rq
|| !scsi_prot_sg_count(sc
))
509 bi
= blk_get_integrity(rq
->rq_disk
);
511 if (sc
->sc_data_direction
== DMA_TO_DEVICE
)
512 cmd_pi
->pi_bytesout
= blk_rq_sectors(rq
) * bi
->tuple_size
;
513 else if (sc
->sc_data_direction
== DMA_FROM_DEVICE
)
514 cmd_pi
->pi_bytesin
= blk_rq_sectors(rq
) * bi
->tuple_size
;
517 static int virtscsi_queuecommand(struct virtio_scsi
*vscsi
,
518 struct virtio_scsi_vq
*req_vq
,
519 struct scsi_cmnd
*sc
)
521 struct Scsi_Host
*shost
= virtio_scsi_host(vscsi
->vdev
);
522 struct virtio_scsi_cmd
*cmd
= scsi_cmd_priv(sc
);
525 BUG_ON(scsi_sg_count(sc
) > shost
->sg_tablesize
);
527 /* TODO: check feature bit and fail if unsupported? */
528 BUG_ON(sc
->sc_data_direction
== DMA_BIDIRECTIONAL
);
530 dev_dbg(&sc
->device
->sdev_gendev
,
531 "cmd %p CDB: %#02x\n", sc
, sc
->cmnd
[0]);
533 memset(cmd
, 0, sizeof(*cmd
));
536 BUG_ON(sc
->cmd_len
> VIRTIO_SCSI_CDB_SIZE
);
538 if (virtio_has_feature(vscsi
->vdev
, VIRTIO_SCSI_F_T10_PI
)) {
539 virtio_scsi_init_hdr_pi(&cmd
->req
.cmd_pi
, sc
);
540 memcpy(cmd
->req
.cmd_pi
.cdb
, sc
->cmnd
, sc
->cmd_len
);
541 req_size
= sizeof(cmd
->req
.cmd_pi
);
543 virtio_scsi_init_hdr(&cmd
->req
.cmd
, sc
);
544 memcpy(cmd
->req
.cmd
.cdb
, sc
->cmnd
, sc
->cmd_len
);
545 req_size
= sizeof(cmd
->req
.cmd
);
548 if (virtscsi_kick_cmd(req_vq
, cmd
, req_size
, sizeof(cmd
->resp
.cmd
)) != 0)
549 return SCSI_MLQUEUE_HOST_BUSY
;
553 static int virtscsi_queuecommand_single(struct Scsi_Host
*sh
,
554 struct scsi_cmnd
*sc
)
556 struct virtio_scsi
*vscsi
= shost_priv(sh
);
557 struct virtio_scsi_target_state
*tgt
=
558 scsi_target(sc
->device
)->hostdata
;
560 atomic_inc(&tgt
->reqs
);
561 return virtscsi_queuecommand(vscsi
, &vscsi
->req_vqs
[0], sc
);
564 static struct virtio_scsi_vq
*virtscsi_pick_vq(struct virtio_scsi
*vscsi
,
565 struct virtio_scsi_target_state
*tgt
)
567 struct virtio_scsi_vq
*vq
;
571 local_irq_save(flags
);
572 if (atomic_inc_return(&tgt
->reqs
) > 1) {
576 seq
= read_seqcount_begin(&tgt
->tgt_seq
);
578 } while (read_seqcount_retry(&tgt
->tgt_seq
, seq
));
580 /* no writes can be concurrent because of atomic_t */
581 write_seqcount_begin(&tgt
->tgt_seq
);
583 /* keep previous req_vq if a reader just arrived */
584 if (unlikely(atomic_read(&tgt
->reqs
) > 1)) {
589 queue_num
= smp_processor_id();
590 while (unlikely(queue_num
>= vscsi
->num_queues
))
591 queue_num
-= vscsi
->num_queues
;
592 tgt
->req_vq
= vq
= &vscsi
->req_vqs
[queue_num
];
594 write_seqcount_end(&tgt
->tgt_seq
);
596 local_irq_restore(flags
);
601 static int virtscsi_queuecommand_multi(struct Scsi_Host
*sh
,
602 struct scsi_cmnd
*sc
)
604 struct virtio_scsi
*vscsi
= shost_priv(sh
);
605 struct virtio_scsi_target_state
*tgt
=
606 scsi_target(sc
->device
)->hostdata
;
607 struct virtio_scsi_vq
*req_vq
= virtscsi_pick_vq(vscsi
, tgt
);
609 return virtscsi_queuecommand(vscsi
, req_vq
, sc
);
612 static int virtscsi_tmf(struct virtio_scsi
*vscsi
, struct virtio_scsi_cmd
*cmd
)
614 DECLARE_COMPLETION_ONSTACK(comp
);
618 if (virtscsi_kick_cmd(&vscsi
->ctrl_vq
, cmd
,
619 sizeof cmd
->req
.tmf
, sizeof cmd
->resp
.tmf
) < 0)
622 wait_for_completion(&comp
);
623 if (cmd
->resp
.tmf
.response
== VIRTIO_SCSI_S_OK
||
624 cmd
->resp
.tmf
.response
== VIRTIO_SCSI_S_FUNCTION_SUCCEEDED
)
628 * The spec guarantees that all requests related to the TMF have
629 * been completed, but the callback might not have run yet if
630 * we're using independent interrupts (e.g. MSI). Poll the
633 * In the abort case, sc->scsi_done will do nothing, because
634 * the block layer must have detected a timeout and as a result
635 * REQ_ATOM_COMPLETE has been set.
637 virtscsi_poll_requests(vscsi
);
640 mempool_free(cmd
, virtscsi_cmd_pool
);
644 static int virtscsi_device_reset(struct scsi_cmnd
*sc
)
646 struct virtio_scsi
*vscsi
= shost_priv(sc
->device
->host
);
647 struct virtio_scsi_cmd
*cmd
;
649 sdev_printk(KERN_INFO
, sc
->device
, "device reset\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_LOGICAL_UNIT_RESET
,
660 .lun
[1] = sc
->device
->id
,
661 .lun
[2] = (sc
->device
->lun
>> 8) | 0x40,
662 .lun
[3] = sc
->device
->lun
& 0xff,
664 return virtscsi_tmf(vscsi
, cmd
);
668 * virtscsi_change_queue_depth() - Change a virtscsi target's queue depth
669 * @sdev: Virtscsi target whose queue depth to change
670 * @qdepth: New queue depth
671 * @reason: Reason for the queue depth change.
673 static int virtscsi_change_queue_depth(struct scsi_device
*sdev
,
677 struct Scsi_Host
*shost
= sdev
->host
;
678 int max_depth
= shost
->cmd_per_lun
;
681 case SCSI_QDEPTH_QFULL
: /* Drop qdepth in response to BUSY state */
682 scsi_track_queue_full(sdev
, qdepth
);
684 case SCSI_QDEPTH_RAMP_UP
: /* Raise qdepth after BUSY state resolved */
685 case SCSI_QDEPTH_DEFAULT
: /* Manual change via sysfs */
686 scsi_adjust_queue_depth(sdev
,
687 scsi_get_tag_type(sdev
),
688 min(max_depth
, qdepth
));
694 return sdev
->queue_depth
;
697 static int virtscsi_abort(struct scsi_cmnd
*sc
)
699 struct virtio_scsi
*vscsi
= shost_priv(sc
->device
->host
);
700 struct virtio_scsi_cmd
*cmd
;
702 scmd_printk(KERN_INFO
, sc
, "abort\n");
703 cmd
= mempool_alloc(virtscsi_cmd_pool
, GFP_NOIO
);
707 memset(cmd
, 0, sizeof(*cmd
));
709 cmd
->req
.tmf
= (struct virtio_scsi_ctrl_tmf_req
){
710 .type
= VIRTIO_SCSI_T_TMF
,
711 .subtype
= VIRTIO_SCSI_T_TMF_ABORT_TASK
,
713 .lun
[1] = sc
->device
->id
,
714 .lun
[2] = (sc
->device
->lun
>> 8) | 0x40,
715 .lun
[3] = sc
->device
->lun
& 0xff,
716 .tag
= (unsigned long)sc
,
718 return virtscsi_tmf(vscsi
, cmd
);
721 static int virtscsi_target_alloc(struct scsi_target
*starget
)
723 struct Scsi_Host
*sh
= dev_to_shost(starget
->dev
.parent
);
724 struct virtio_scsi
*vscsi
= shost_priv(sh
);
726 struct virtio_scsi_target_state
*tgt
=
727 kmalloc(sizeof(*tgt
), GFP_KERNEL
);
731 seqcount_init(&tgt
->tgt_seq
);
732 atomic_set(&tgt
->reqs
, 0);
733 tgt
->req_vq
= &vscsi
->req_vqs
[0];
735 starget
->hostdata
= tgt
;
739 static void virtscsi_target_destroy(struct scsi_target
*starget
)
741 struct virtio_scsi_target_state
*tgt
= starget
->hostdata
;
745 static struct scsi_host_template virtscsi_host_template_single
= {
746 .module
= THIS_MODULE
,
747 .name
= "Virtio SCSI HBA",
748 .proc_name
= "virtio_scsi",
750 .cmd_size
= sizeof(struct virtio_scsi_cmd
),
751 .queuecommand
= virtscsi_queuecommand_single
,
752 .change_queue_depth
= virtscsi_change_queue_depth
,
753 .eh_abort_handler
= virtscsi_abort
,
754 .eh_device_reset_handler
= virtscsi_device_reset
,
757 .dma_boundary
= UINT_MAX
,
758 .use_clustering
= ENABLE_CLUSTERING
,
759 .target_alloc
= virtscsi_target_alloc
,
760 .target_destroy
= virtscsi_target_destroy
,
763 static struct scsi_host_template virtscsi_host_template_multi
= {
764 .module
= THIS_MODULE
,
765 .name
= "Virtio SCSI HBA",
766 .proc_name
= "virtio_scsi",
768 .cmd_size
= sizeof(struct virtio_scsi_cmd
),
769 .queuecommand
= virtscsi_queuecommand_multi
,
770 .change_queue_depth
= virtscsi_change_queue_depth
,
771 .eh_abort_handler
= virtscsi_abort
,
772 .eh_device_reset_handler
= virtscsi_device_reset
,
775 .dma_boundary
= UINT_MAX
,
776 .use_clustering
= ENABLE_CLUSTERING
,
777 .target_alloc
= virtscsi_target_alloc
,
778 .target_destroy
= virtscsi_target_destroy
,
781 #define virtscsi_config_get(vdev, fld) \
783 typeof(((struct virtio_scsi_config *)0)->fld) __val; \
784 virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \
788 #define virtscsi_config_set(vdev, fld, val) \
790 typeof(((struct virtio_scsi_config *)0)->fld) __val = (val); \
791 virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \
794 static void __virtscsi_set_affinity(struct virtio_scsi
*vscsi
, bool affinity
)
799 /* In multiqueue mode, when the number of cpu is equal
800 * to the number of request queues, we let the qeueues
801 * to be private to one cpu by setting the affinity hint
802 * to eliminate the contention.
804 if ((vscsi
->num_queues
== 1 ||
805 vscsi
->num_queues
!= num_online_cpus()) && affinity
) {
806 if (vscsi
->affinity_hint_set
)
814 for_each_online_cpu(cpu
) {
815 virtqueue_set_affinity(vscsi
->req_vqs
[i
].vq
, cpu
);
819 vscsi
->affinity_hint_set
= true;
821 for (i
= 0; i
< vscsi
->num_queues
; i
++) {
822 if (!vscsi
->req_vqs
[i
].vq
)
825 virtqueue_set_affinity(vscsi
->req_vqs
[i
].vq
, -1);
828 vscsi
->affinity_hint_set
= false;
832 static void virtscsi_set_affinity(struct virtio_scsi
*vscsi
, bool affinity
)
835 __virtscsi_set_affinity(vscsi
, affinity
);
839 static int virtscsi_cpu_callback(struct notifier_block
*nfb
,
840 unsigned long action
, void *hcpu
)
842 struct virtio_scsi
*vscsi
= container_of(nfb
, struct virtio_scsi
, nb
);
845 case CPU_ONLINE_FROZEN
:
847 case CPU_DEAD_FROZEN
:
848 __virtscsi_set_affinity(vscsi
, true);
856 static void virtscsi_init_vq(struct virtio_scsi_vq
*virtscsi_vq
,
857 struct virtqueue
*vq
)
859 spin_lock_init(&virtscsi_vq
->vq_lock
);
860 virtscsi_vq
->vq
= vq
;
863 static void virtscsi_remove_vqs(struct virtio_device
*vdev
)
865 struct Scsi_Host
*sh
= virtio_scsi_host(vdev
);
866 struct virtio_scsi
*vscsi
= shost_priv(sh
);
868 virtscsi_set_affinity(vscsi
, false);
870 /* Stop all the virtqueues. */
871 vdev
->config
->reset(vdev
);
873 vdev
->config
->del_vqs(vdev
);
876 static int virtscsi_init(struct virtio_device
*vdev
,
877 struct virtio_scsi
*vscsi
)
882 vq_callback_t
**callbacks
;
884 struct virtqueue
**vqs
;
886 num_vqs
= vscsi
->num_queues
+ VIRTIO_SCSI_VQ_BASE
;
887 vqs
= kmalloc(num_vqs
* sizeof(struct virtqueue
*), GFP_KERNEL
);
888 callbacks
= kmalloc(num_vqs
* sizeof(vq_callback_t
*), GFP_KERNEL
);
889 names
= kmalloc(num_vqs
* sizeof(char *), GFP_KERNEL
);
891 if (!callbacks
|| !vqs
|| !names
) {
896 callbacks
[0] = virtscsi_ctrl_done
;
897 callbacks
[1] = virtscsi_event_done
;
898 names
[0] = "control";
900 for (i
= VIRTIO_SCSI_VQ_BASE
; i
< num_vqs
; i
++) {
901 callbacks
[i
] = virtscsi_req_done
;
902 names
[i
] = "request";
905 /* Discover virtqueues and write information to configuration. */
906 err
= vdev
->config
->find_vqs(vdev
, num_vqs
, vqs
, callbacks
, names
);
910 virtscsi_init_vq(&vscsi
->ctrl_vq
, vqs
[0]);
911 virtscsi_init_vq(&vscsi
->event_vq
, vqs
[1]);
912 for (i
= VIRTIO_SCSI_VQ_BASE
; i
< num_vqs
; i
++)
913 virtscsi_init_vq(&vscsi
->req_vqs
[i
- VIRTIO_SCSI_VQ_BASE
],
916 virtscsi_set_affinity(vscsi
, true);
918 virtscsi_config_set(vdev
, cdb_size
, VIRTIO_SCSI_CDB_SIZE
);
919 virtscsi_config_set(vdev
, sense_size
, VIRTIO_SCSI_SENSE_SIZE
);
928 virtscsi_remove_vqs(vdev
);
932 static int virtscsi_probe(struct virtio_device
*vdev
)
934 struct Scsi_Host
*shost
;
935 struct virtio_scsi
*vscsi
;
937 u32 sg_elems
, num_targets
;
940 struct scsi_host_template
*hostt
;
942 /* We need to know how many queues before we allocate. */
943 num_queues
= virtscsi_config_get(vdev
, num_queues
) ? : 1;
945 num_targets
= virtscsi_config_get(vdev
, max_target
) + 1;
948 hostt
= &virtscsi_host_template_single
;
950 hostt
= &virtscsi_host_template_multi
;
952 shost
= scsi_host_alloc(hostt
,
953 sizeof(*vscsi
) + sizeof(vscsi
->req_vqs
[0]) * num_queues
);
957 sg_elems
= virtscsi_config_get(vdev
, seg_max
) ?: 1;
958 shost
->sg_tablesize
= sg_elems
;
959 vscsi
= shost_priv(shost
);
961 vscsi
->num_queues
= num_queues
;
964 err
= virtscsi_init(vdev
, vscsi
);
966 goto virtscsi_init_failed
;
968 vscsi
->nb
.notifier_call
= &virtscsi_cpu_callback
;
969 err
= register_hotcpu_notifier(&vscsi
->nb
);
971 pr_err("registering cpu notifier failed\n");
972 goto scsi_add_host_failed
;
975 cmd_per_lun
= virtscsi_config_get(vdev
, cmd_per_lun
) ?: 1;
976 shost
->cmd_per_lun
= min_t(u32
, cmd_per_lun
, shost
->can_queue
);
977 shost
->max_sectors
= virtscsi_config_get(vdev
, max_sectors
) ?: 0xFFFF;
979 /* LUNs > 256 are reported with format 1, so they go in the range
982 shost
->max_lun
= virtscsi_config_get(vdev
, max_lun
) + 1 + 0x4000;
983 shost
->max_id
= num_targets
;
984 shost
->max_channel
= 0;
985 shost
->max_cmd_len
= VIRTIO_SCSI_CDB_SIZE
;
987 if (virtio_has_feature(vdev
, VIRTIO_SCSI_F_T10_PI
)) {
988 host_prot
= SHOST_DIF_TYPE1_PROTECTION
| SHOST_DIF_TYPE2_PROTECTION
|
989 SHOST_DIF_TYPE3_PROTECTION
| SHOST_DIX_TYPE1_PROTECTION
|
990 SHOST_DIX_TYPE2_PROTECTION
| SHOST_DIX_TYPE3_PROTECTION
;
992 scsi_host_set_prot(shost
, host_prot
);
993 scsi_host_set_guard(shost
, SHOST_DIX_GUARD_CRC
);
996 err
= scsi_add_host(shost
, &vdev
->dev
);
998 goto scsi_add_host_failed
;
1000 virtio_device_ready(vdev
);
1002 if (virtio_has_feature(vdev
, VIRTIO_SCSI_F_HOTPLUG
))
1003 virtscsi_kick_event_all(vscsi
);
1005 scsi_scan_host(shost
);
1008 scsi_add_host_failed
:
1009 vdev
->config
->del_vqs(vdev
);
1010 virtscsi_init_failed
:
1011 scsi_host_put(shost
);
1015 static void virtscsi_remove(struct virtio_device
*vdev
)
1017 struct Scsi_Host
*shost
= virtio_scsi_host(vdev
);
1018 struct virtio_scsi
*vscsi
= shost_priv(shost
);
1020 if (virtio_has_feature(vdev
, VIRTIO_SCSI_F_HOTPLUG
))
1021 virtscsi_cancel_event_work(vscsi
);
1023 scsi_remove_host(shost
);
1025 unregister_hotcpu_notifier(&vscsi
->nb
);
1027 virtscsi_remove_vqs(vdev
);
1028 scsi_host_put(shost
);
1031 #ifdef CONFIG_PM_SLEEP
1032 static int virtscsi_freeze(struct virtio_device
*vdev
)
1034 struct Scsi_Host
*sh
= virtio_scsi_host(vdev
);
1035 struct virtio_scsi
*vscsi
= shost_priv(sh
);
1037 unregister_hotcpu_notifier(&vscsi
->nb
);
1038 virtscsi_remove_vqs(vdev
);
1042 static int virtscsi_restore(struct virtio_device
*vdev
)
1044 struct Scsi_Host
*sh
= virtio_scsi_host(vdev
);
1045 struct virtio_scsi
*vscsi
= shost_priv(sh
);
1048 err
= virtscsi_init(vdev
, vscsi
);
1052 err
= register_hotcpu_notifier(&vscsi
->nb
);
1054 vdev
->config
->del_vqs(vdev
);
1058 virtio_device_ready(vdev
);
1060 if (virtio_has_feature(vdev
, VIRTIO_SCSI_F_HOTPLUG
))
1061 virtscsi_kick_event_all(vscsi
);
1067 static struct virtio_device_id id_table
[] = {
1068 { VIRTIO_ID_SCSI
, VIRTIO_DEV_ANY_ID
},
1072 static unsigned int features
[] = {
1073 VIRTIO_SCSI_F_HOTPLUG
,
1074 VIRTIO_SCSI_F_CHANGE
,
1075 VIRTIO_SCSI_F_T10_PI
,
1078 static struct virtio_driver virtio_scsi_driver
= {
1079 .feature_table
= features
,
1080 .feature_table_size
= ARRAY_SIZE(features
),
1081 .driver
.name
= KBUILD_MODNAME
,
1082 .driver
.owner
= THIS_MODULE
,
1083 .id_table
= id_table
,
1084 .probe
= virtscsi_probe
,
1085 #ifdef CONFIG_PM_SLEEP
1086 .freeze
= virtscsi_freeze
,
1087 .restore
= virtscsi_restore
,
1089 .remove
= virtscsi_remove
,
1092 static int __init
init(void)
1096 virtscsi_cmd_cache
= KMEM_CACHE(virtio_scsi_cmd
, 0);
1097 if (!virtscsi_cmd_cache
) {
1098 pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n");
1104 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ
,
1105 virtscsi_cmd_cache
);
1106 if (!virtscsi_cmd_pool
) {
1107 pr_err("mempool_create() for virtscsi_cmd_pool failed\n");
1110 ret
= register_virtio_driver(&virtio_scsi_driver
);
1117 if (virtscsi_cmd_pool
) {
1118 mempool_destroy(virtscsi_cmd_pool
);
1119 virtscsi_cmd_pool
= NULL
;
1121 if (virtscsi_cmd_cache
) {
1122 kmem_cache_destroy(virtscsi_cmd_cache
);
1123 virtscsi_cmd_cache
= NULL
;
1128 static void __exit
fini(void)
1130 unregister_virtio_driver(&virtio_scsi_driver
);
1131 mempool_destroy(virtscsi_cmd_pool
);
1132 kmem_cache_destroy(virtscsi_cmd_cache
);
1137 MODULE_DEVICE_TABLE(virtio
, id_table
);
1138 MODULE_DESCRIPTION("Virtio SCSI HBA driver");
1139 MODULE_LICENSE("GPL");