xref: /openbmc/qemu/block/iscsi.c (revision c0bea68f9ea48f0dea7a06a259a613bfd3a7e35e)
1 /*
2  * QEMU Block driver for iSCSI images
3  *
4  * Copyright (c) 2010-2011 Ronnie Sahlberg <ronniesahlberg@gmail.com>
5  * Copyright (c) 2012-2015 Peter Lieven <pl@kamp.de>
6  *
7  * Permission is hereby granted, free of charge, to any person obtaining a copy
8  * of this software and associated documentation files (the "Software"), to deal
9  * in the Software without restriction, including without limitation the rights
10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11  * copies of the Software, and to permit persons to whom the Software is
12  * furnished to do so, subject to the following conditions:
13  *
14  * The above copyright notice and this permission notice shall be included in
15  * all copies or substantial portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23  * THE SOFTWARE.
24  */
25 
26 #include "qemu/osdep.h"
27 
28 #include <poll.h>
29 #include <math.h>
30 #include <arpa/inet.h>
31 #include "qemu-common.h"
32 #include "qemu/config-file.h"
33 #include "qemu/error-report.h"
34 #include "qemu/bitops.h"
35 #include "qemu/bitmap.h"
36 #include "block/block_int.h"
37 #include "block/scsi.h"
38 #include "qemu/iov.h"
39 #include "sysemu/sysemu.h"
40 #include "qmp-commands.h"
41 #include "qapi/qmp/qstring.h"
42 #include "crypto/secret.h"
43 
44 #include <iscsi/iscsi.h>
45 #include <iscsi/scsi-lowlevel.h>
46 
47 #ifdef __linux__
48 #include <scsi/sg.h>
49 #include <block/scsi.h>
50 #endif
51 
52 typedef struct IscsiLun {
53     struct iscsi_context *iscsi;
54     AioContext *aio_context;
55     int lun;
56     enum scsi_inquiry_peripheral_device_type type;
57     int block_size;
58     uint64_t num_blocks;
59     int events;
60     QEMUTimer *nop_timer;
61     QEMUTimer *event_timer;
62     struct scsi_inquiry_logical_block_provisioning lbp;
63     struct scsi_inquiry_block_limits bl;
64     unsigned char *zeroblock;
65     unsigned long *allocationmap;
66     int cluster_sectors;
67     bool use_16_for_rw;
68     bool write_protected;
69     bool lbpme;
70     bool lbprz;
71     bool dpofua;
72     bool has_write_same;
73     bool request_timed_out;
74 } IscsiLun;
75 
76 typedef struct IscsiTask {
77     int status;
78     int complete;
79     int retries;
80     int do_retry;
81     struct scsi_task *task;
82     Coroutine *co;
83     QEMUBH *bh;
84     IscsiLun *iscsilun;
85     QEMUTimer retry_timer;
86     int err_code;
87 } IscsiTask;
88 
89 typedef struct IscsiAIOCB {
90     BlockAIOCB common;
91     QEMUIOVector *qiov;
92     QEMUBH *bh;
93     IscsiLun *iscsilun;
94     struct scsi_task *task;
95     uint8_t *buf;
96     int status;
97     int64_t sector_num;
98     int nb_sectors;
99     int ret;
100 #ifdef __linux__
101     sg_io_hdr_t *ioh;
102 #endif
103 } IscsiAIOCB;
104 
105 /* libiscsi uses time_t so its enough to process events every second */
106 #define EVENT_INTERVAL 1000
107 #define NOP_INTERVAL 5000
108 #define MAX_NOP_FAILURES 3
109 #define ISCSI_CMD_RETRIES ARRAY_SIZE(iscsi_retry_times)
110 static const unsigned iscsi_retry_times[] = {8, 32, 128, 512, 2048, 8192, 32768};
111 
112 /* this threshold is a trade-off knob to choose between
113  * the potential additional overhead of an extra GET_LBA_STATUS request
114  * vs. unnecessarily reading a lot of zero sectors over the wire.
115  * If a read request is greater or equal than ISCSI_CHECKALLOC_THRES
116  * sectors we check the allocation status of the area covered by the
117  * request first if the allocationmap indicates that the area might be
118  * unallocated. */
119 #define ISCSI_CHECKALLOC_THRES 64
120 
121 static void
122 iscsi_bh_cb(void *p)
123 {
124     IscsiAIOCB *acb = p;
125 
126     qemu_bh_delete(acb->bh);
127 
128     g_free(acb->buf);
129     acb->buf = NULL;
130 
131     acb->common.cb(acb->common.opaque, acb->status);
132 
133     if (acb->task != NULL) {
134         scsi_free_scsi_task(acb->task);
135         acb->task = NULL;
136     }
137 
138     qemu_aio_unref(acb);
139 }
140 
141 static void
142 iscsi_schedule_bh(IscsiAIOCB *acb)
143 {
144     if (acb->bh) {
145         return;
146     }
147     acb->bh = aio_bh_new(acb->iscsilun->aio_context, iscsi_bh_cb, acb);
148     qemu_bh_schedule(acb->bh);
149 }
150 
151 static void iscsi_co_generic_bh_cb(void *opaque)
152 {
153     struct IscsiTask *iTask = opaque;
154     iTask->complete = 1;
155     qemu_bh_delete(iTask->bh);
156     qemu_coroutine_enter(iTask->co, NULL);
157 }
158 
159 static void iscsi_retry_timer_expired(void *opaque)
160 {
161     struct IscsiTask *iTask = opaque;
162     iTask->complete = 1;
163     if (iTask->co) {
164         qemu_coroutine_enter(iTask->co, NULL);
165     }
166 }
167 
168 static inline unsigned exp_random(double mean)
169 {
170     return -mean * log((double)rand() / RAND_MAX);
171 }
172 
173 /* SCSI_SENSE_ASCQ_INVALID_FIELD_IN_PARAMETER_LIST was introduced in
174  * libiscsi 1.10.0, together with other constants we need.  Use it as
175  * a hint that we have to define them ourselves if needed, to keep the
176  * minimum required libiscsi version at 1.9.0.  We use an ASCQ macro for
177  * the test because SCSI_STATUS_* is an enum.
178  *
179  * To guard against future changes where SCSI_SENSE_ASCQ_* also becomes
180  * an enum, check against the LIBISCSI_API_VERSION macro, which was
181  * introduced in 1.11.0.  If it is present, there is no need to define
182  * anything.
183  */
184 #if !defined(SCSI_SENSE_ASCQ_INVALID_FIELD_IN_PARAMETER_LIST) && \
185     !defined(LIBISCSI_API_VERSION)
186 #define SCSI_STATUS_TASK_SET_FULL                          0x28
187 #define SCSI_STATUS_TIMEOUT                                0x0f000002
188 #define SCSI_SENSE_ASCQ_INVALID_FIELD_IN_PARAMETER_LIST    0x2600
189 #define SCSI_SENSE_ASCQ_PARAMETER_LIST_LENGTH_ERROR        0x1a00
190 #endif
191 
192 static int iscsi_translate_sense(struct scsi_sense *sense)
193 {
194     int ret;
195 
196     switch (sense->key) {
197     case SCSI_SENSE_NOT_READY:
198         return -EBUSY;
199     case SCSI_SENSE_DATA_PROTECTION:
200         return -EACCES;
201     case SCSI_SENSE_COMMAND_ABORTED:
202         return -ECANCELED;
203     case SCSI_SENSE_ILLEGAL_REQUEST:
204         /* Parse ASCQ */
205         break;
206     default:
207         return -EIO;
208     }
209     switch (sense->ascq) {
210     case SCSI_SENSE_ASCQ_PARAMETER_LIST_LENGTH_ERROR:
211     case SCSI_SENSE_ASCQ_INVALID_OPERATION_CODE:
212     case SCSI_SENSE_ASCQ_INVALID_FIELD_IN_CDB:
213     case SCSI_SENSE_ASCQ_INVALID_FIELD_IN_PARAMETER_LIST:
214         ret = -EINVAL;
215         break;
216     case SCSI_SENSE_ASCQ_LBA_OUT_OF_RANGE:
217         ret = -ENOSPC;
218         break;
219     case SCSI_SENSE_ASCQ_LOGICAL_UNIT_NOT_SUPPORTED:
220         ret = -ENOTSUP;
221         break;
222     case SCSI_SENSE_ASCQ_MEDIUM_NOT_PRESENT:
223     case SCSI_SENSE_ASCQ_MEDIUM_NOT_PRESENT_TRAY_CLOSED:
224     case SCSI_SENSE_ASCQ_MEDIUM_NOT_PRESENT_TRAY_OPEN:
225         ret = -ENOMEDIUM;
226         break;
227     case SCSI_SENSE_ASCQ_WRITE_PROTECTED:
228         ret = -EACCES;
229         break;
230     default:
231         ret = -EIO;
232         break;
233     }
234     return ret;
235 }
236 
237 static void
238 iscsi_co_generic_cb(struct iscsi_context *iscsi, int status,
239                         void *command_data, void *opaque)
240 {
241     struct IscsiTask *iTask = opaque;
242     struct scsi_task *task = command_data;
243 
244     iTask->status = status;
245     iTask->do_retry = 0;
246     iTask->task = task;
247 
248     if (status != SCSI_STATUS_GOOD) {
249         if (iTask->retries++ < ISCSI_CMD_RETRIES) {
250             if (status == SCSI_STATUS_CHECK_CONDITION
251                 && task->sense.key == SCSI_SENSE_UNIT_ATTENTION) {
252                 error_report("iSCSI CheckCondition: %s",
253                              iscsi_get_error(iscsi));
254                 iTask->do_retry = 1;
255                 goto out;
256             }
257             if (status == SCSI_STATUS_BUSY ||
258                 status == SCSI_STATUS_TIMEOUT ||
259                 status == SCSI_STATUS_TASK_SET_FULL) {
260                 unsigned retry_time =
261                     exp_random(iscsi_retry_times[iTask->retries - 1]);
262                 if (status == SCSI_STATUS_TIMEOUT) {
263                     /* make sure the request is rescheduled AFTER the
264                      * reconnect is initiated */
265                     retry_time = EVENT_INTERVAL * 2;
266                     iTask->iscsilun->request_timed_out = true;
267                 }
268                 error_report("iSCSI Busy/TaskSetFull/TimeOut"
269                              " (retry #%u in %u ms): %s",
270                              iTask->retries, retry_time,
271                              iscsi_get_error(iscsi));
272                 aio_timer_init(iTask->iscsilun->aio_context,
273                                &iTask->retry_timer, QEMU_CLOCK_REALTIME,
274                                SCALE_MS, iscsi_retry_timer_expired, iTask);
275                 timer_mod(&iTask->retry_timer,
276                           qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + retry_time);
277                 iTask->do_retry = 1;
278                 return;
279             }
280         }
281         iTask->err_code = iscsi_translate_sense(&task->sense);
282         error_report("iSCSI Failure: %s", iscsi_get_error(iscsi));
283     }
284 
285 out:
286     if (iTask->co) {
287         iTask->bh = aio_bh_new(iTask->iscsilun->aio_context,
288                                iscsi_co_generic_bh_cb, iTask);
289         qemu_bh_schedule(iTask->bh);
290     } else {
291         iTask->complete = 1;
292     }
293 }
294 
295 static void iscsi_co_init_iscsitask(IscsiLun *iscsilun, struct IscsiTask *iTask)
296 {
297     *iTask = (struct IscsiTask) {
298         .co         = qemu_coroutine_self(),
299         .iscsilun   = iscsilun,
300     };
301 }
302 
303 static void
304 iscsi_abort_task_cb(struct iscsi_context *iscsi, int status, void *command_data,
305                     void *private_data)
306 {
307     IscsiAIOCB *acb = private_data;
308 
309     acb->status = -ECANCELED;
310     iscsi_schedule_bh(acb);
311 }
312 
313 static void
314 iscsi_aio_cancel(BlockAIOCB *blockacb)
315 {
316     IscsiAIOCB *acb = (IscsiAIOCB *)blockacb;
317     IscsiLun *iscsilun = acb->iscsilun;
318 
319     if (acb->status != -EINPROGRESS) {
320         return;
321     }
322 
323     /* send a task mgmt call to the target to cancel the task on the target */
324     iscsi_task_mgmt_abort_task_async(iscsilun->iscsi, acb->task,
325                                      iscsi_abort_task_cb, acb);
326 
327 }
328 
329 static const AIOCBInfo iscsi_aiocb_info = {
330     .aiocb_size         = sizeof(IscsiAIOCB),
331     .cancel_async       = iscsi_aio_cancel,
332 };
333 
334 
335 static void iscsi_process_read(void *arg);
336 static void iscsi_process_write(void *arg);
337 
338 static void
339 iscsi_set_events(IscsiLun *iscsilun)
340 {
341     struct iscsi_context *iscsi = iscsilun->iscsi;
342     int ev = iscsi_which_events(iscsi);
343 
344     if (ev != iscsilun->events) {
345         aio_set_fd_handler(iscsilun->aio_context, iscsi_get_fd(iscsi),
346                            false,
347                            (ev & POLLIN) ? iscsi_process_read : NULL,
348                            (ev & POLLOUT) ? iscsi_process_write : NULL,
349                            iscsilun);
350         iscsilun->events = ev;
351     }
352 }
353 
354 static void iscsi_timed_check_events(void *opaque)
355 {
356     IscsiLun *iscsilun = opaque;
357 
358     /* check for timed out requests */
359     iscsi_service(iscsilun->iscsi, 0);
360 
361     if (iscsilun->request_timed_out) {
362         iscsilun->request_timed_out = false;
363         iscsi_reconnect(iscsilun->iscsi);
364     }
365 
366     /* newer versions of libiscsi may return zero events. Ensure we are able
367      * to return to service once this situation changes. */
368     iscsi_set_events(iscsilun);
369 
370     timer_mod(iscsilun->event_timer,
371               qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + EVENT_INTERVAL);
372 }
373 
374 static void
375 iscsi_process_read(void *arg)
376 {
377     IscsiLun *iscsilun = arg;
378     struct iscsi_context *iscsi = iscsilun->iscsi;
379 
380     iscsi_service(iscsi, POLLIN);
381     iscsi_set_events(iscsilun);
382 }
383 
384 static void
385 iscsi_process_write(void *arg)
386 {
387     IscsiLun *iscsilun = arg;
388     struct iscsi_context *iscsi = iscsilun->iscsi;
389 
390     iscsi_service(iscsi, POLLOUT);
391     iscsi_set_events(iscsilun);
392 }
393 
394 static int64_t sector_lun2qemu(int64_t sector, IscsiLun *iscsilun)
395 {
396     return sector * iscsilun->block_size / BDRV_SECTOR_SIZE;
397 }
398 
399 static int64_t sector_qemu2lun(int64_t sector, IscsiLun *iscsilun)
400 {
401     return sector * BDRV_SECTOR_SIZE / iscsilun->block_size;
402 }
403 
404 static bool is_request_lun_aligned(int64_t sector_num, int nb_sectors,
405                                       IscsiLun *iscsilun)
406 {
407     if ((sector_num * BDRV_SECTOR_SIZE) % iscsilun->block_size ||
408         (nb_sectors * BDRV_SECTOR_SIZE) % iscsilun->block_size) {
409             error_report("iSCSI misaligned request: "
410                          "iscsilun->block_size %u, sector_num %" PRIi64
411                          ", nb_sectors %d",
412                          iscsilun->block_size, sector_num, nb_sectors);
413             return 0;
414     }
415     return 1;
416 }
417 
418 static unsigned long *iscsi_allocationmap_init(IscsiLun *iscsilun)
419 {
420     return bitmap_try_new(DIV_ROUND_UP(sector_lun2qemu(iscsilun->num_blocks,
421                                                        iscsilun),
422                                        iscsilun->cluster_sectors));
423 }
424 
425 static void iscsi_allocationmap_set(IscsiLun *iscsilun, int64_t sector_num,
426                                     int nb_sectors)
427 {
428     if (iscsilun->allocationmap == NULL) {
429         return;
430     }
431     bitmap_set(iscsilun->allocationmap,
432                sector_num / iscsilun->cluster_sectors,
433                DIV_ROUND_UP(nb_sectors, iscsilun->cluster_sectors));
434 }
435 
436 static void iscsi_allocationmap_clear(IscsiLun *iscsilun, int64_t sector_num,
437                                       int nb_sectors)
438 {
439     int64_t cluster_num, nb_clusters;
440     if (iscsilun->allocationmap == NULL) {
441         return;
442     }
443     cluster_num = DIV_ROUND_UP(sector_num, iscsilun->cluster_sectors);
444     nb_clusters = (sector_num + nb_sectors) / iscsilun->cluster_sectors
445                   - cluster_num;
446     if (nb_clusters > 0) {
447         bitmap_clear(iscsilun->allocationmap, cluster_num, nb_clusters);
448     }
449 }
450 
451 static int coroutine_fn
452 iscsi_co_writev_flags(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
453                       QEMUIOVector *iov, int flags)
454 {
455     IscsiLun *iscsilun = bs->opaque;
456     struct IscsiTask iTask;
457     uint64_t lba;
458     uint32_t num_sectors;
459     bool fua = flags & BDRV_REQ_FUA;
460 
461     if (fua) {
462         assert(iscsilun->dpofua);
463     }
464     if (!is_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
465         return -EINVAL;
466     }
467 
468     if (bs->bl.max_transfer_length && nb_sectors > bs->bl.max_transfer_length) {
469         error_report("iSCSI Error: Write of %d sectors exceeds max_xfer_len "
470                      "of %d sectors", nb_sectors, bs->bl.max_transfer_length);
471         return -EINVAL;
472     }
473 
474     lba = sector_qemu2lun(sector_num, iscsilun);
475     num_sectors = sector_qemu2lun(nb_sectors, iscsilun);
476     iscsi_co_init_iscsitask(iscsilun, &iTask);
477 retry:
478     if (iscsilun->use_16_for_rw) {
479         iTask.task = iscsi_write16_task(iscsilun->iscsi, iscsilun->lun, lba,
480                                         NULL, num_sectors * iscsilun->block_size,
481                                         iscsilun->block_size, 0, 0, fua, 0, 0,
482                                         iscsi_co_generic_cb, &iTask);
483     } else {
484         iTask.task = iscsi_write10_task(iscsilun->iscsi, iscsilun->lun, lba,
485                                         NULL, num_sectors * iscsilun->block_size,
486                                         iscsilun->block_size, 0, 0, fua, 0, 0,
487                                         iscsi_co_generic_cb, &iTask);
488     }
489     if (iTask.task == NULL) {
490         return -ENOMEM;
491     }
492     scsi_task_set_iov_out(iTask.task, (struct scsi_iovec *) iov->iov,
493                           iov->niov);
494     while (!iTask.complete) {
495         iscsi_set_events(iscsilun);
496         qemu_coroutine_yield();
497     }
498 
499     if (iTask.task != NULL) {
500         scsi_free_scsi_task(iTask.task);
501         iTask.task = NULL;
502     }
503 
504     if (iTask.do_retry) {
505         iTask.complete = 0;
506         goto retry;
507     }
508 
509     if (iTask.status != SCSI_STATUS_GOOD) {
510         return iTask.err_code;
511     }
512 
513     iscsi_allocationmap_set(iscsilun, sector_num, nb_sectors);
514 
515     return 0;
516 }
517 
518 
519 static bool iscsi_allocationmap_is_allocated(IscsiLun *iscsilun,
520                                              int64_t sector_num, int nb_sectors)
521 {
522     unsigned long size;
523     if (iscsilun->allocationmap == NULL) {
524         return true;
525     }
526     size = DIV_ROUND_UP(sector_num + nb_sectors, iscsilun->cluster_sectors);
527     return !(find_next_bit(iscsilun->allocationmap, size,
528                            sector_num / iscsilun->cluster_sectors) == size);
529 }
530 
531 static int64_t coroutine_fn iscsi_co_get_block_status(BlockDriverState *bs,
532                                                   int64_t sector_num,
533                                                   int nb_sectors, int *pnum,
534                                                   BlockDriverState **file)
535 {
536     IscsiLun *iscsilun = bs->opaque;
537     struct scsi_get_lba_status *lbas = NULL;
538     struct scsi_lba_status_descriptor *lbasd = NULL;
539     struct IscsiTask iTask;
540     int64_t ret;
541 
542     iscsi_co_init_iscsitask(iscsilun, &iTask);
543 
544     if (!is_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
545         ret = -EINVAL;
546         goto out;
547     }
548 
549     /* default to all sectors allocated */
550     ret = BDRV_BLOCK_DATA;
551     ret |= (sector_num << BDRV_SECTOR_BITS) | BDRV_BLOCK_OFFSET_VALID;
552     *pnum = nb_sectors;
553 
554     /* LUN does not support logical block provisioning */
555     if (!iscsilun->lbpme) {
556         goto out;
557     }
558 
559 retry:
560     if (iscsi_get_lba_status_task(iscsilun->iscsi, iscsilun->lun,
561                                   sector_qemu2lun(sector_num, iscsilun),
562                                   8 + 16, iscsi_co_generic_cb,
563                                   &iTask) == NULL) {
564         ret = -ENOMEM;
565         goto out;
566     }
567 
568     while (!iTask.complete) {
569         iscsi_set_events(iscsilun);
570         qemu_coroutine_yield();
571     }
572 
573     if (iTask.do_retry) {
574         if (iTask.task != NULL) {
575             scsi_free_scsi_task(iTask.task);
576             iTask.task = NULL;
577         }
578         iTask.complete = 0;
579         goto retry;
580     }
581 
582     if (iTask.status != SCSI_STATUS_GOOD) {
583         /* in case the get_lba_status_callout fails (i.e.
584          * because the device is busy or the cmd is not
585          * supported) we pretend all blocks are allocated
586          * for backwards compatibility */
587         goto out;
588     }
589 
590     lbas = scsi_datain_unmarshall(iTask.task);
591     if (lbas == NULL) {
592         ret = -EIO;
593         goto out;
594     }
595 
596     lbasd = &lbas->descriptors[0];
597 
598     if (sector_qemu2lun(sector_num, iscsilun) != lbasd->lba) {
599         ret = -EIO;
600         goto out;
601     }
602 
603     *pnum = sector_lun2qemu(lbasd->num_blocks, iscsilun);
604 
605     if (lbasd->provisioning == SCSI_PROVISIONING_TYPE_DEALLOCATED ||
606         lbasd->provisioning == SCSI_PROVISIONING_TYPE_ANCHORED) {
607         ret &= ~BDRV_BLOCK_DATA;
608         if (iscsilun->lbprz) {
609             ret |= BDRV_BLOCK_ZERO;
610         }
611     }
612 
613     if (ret & BDRV_BLOCK_ZERO) {
614         iscsi_allocationmap_clear(iscsilun, sector_num, *pnum);
615     } else {
616         iscsi_allocationmap_set(iscsilun, sector_num, *pnum);
617     }
618 
619     if (*pnum > nb_sectors) {
620         *pnum = nb_sectors;
621     }
622 out:
623     if (iTask.task != NULL) {
624         scsi_free_scsi_task(iTask.task);
625     }
626     if (ret > 0 && ret & BDRV_BLOCK_OFFSET_VALID) {
627         *file = bs;
628     }
629     return ret;
630 }
631 
632 static int coroutine_fn iscsi_co_readv(BlockDriverState *bs,
633                                        int64_t sector_num, int nb_sectors,
634                                        QEMUIOVector *iov)
635 {
636     IscsiLun *iscsilun = bs->opaque;
637     struct IscsiTask iTask;
638     uint64_t lba;
639     uint32_t num_sectors;
640 
641     if (!is_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
642         return -EINVAL;
643     }
644 
645     if (bs->bl.max_transfer_length && nb_sectors > bs->bl.max_transfer_length) {
646         error_report("iSCSI Error: Read of %d sectors exceeds max_xfer_len "
647                      "of %d sectors", nb_sectors, bs->bl.max_transfer_length);
648         return -EINVAL;
649     }
650 
651     if (iscsilun->lbprz && nb_sectors >= ISCSI_CHECKALLOC_THRES &&
652         !iscsi_allocationmap_is_allocated(iscsilun, sector_num, nb_sectors)) {
653         int64_t ret;
654         int pnum;
655         BlockDriverState *file;
656         ret = iscsi_co_get_block_status(bs, sector_num, INT_MAX, &pnum, &file);
657         if (ret < 0) {
658             return ret;
659         }
660         if (ret & BDRV_BLOCK_ZERO && pnum >= nb_sectors) {
661             qemu_iovec_memset(iov, 0, 0x00, iov->size);
662             return 0;
663         }
664     }
665 
666     lba = sector_qemu2lun(sector_num, iscsilun);
667     num_sectors = sector_qemu2lun(nb_sectors, iscsilun);
668 
669     iscsi_co_init_iscsitask(iscsilun, &iTask);
670 retry:
671     if (iscsilun->use_16_for_rw) {
672         iTask.task = iscsi_read16_task(iscsilun->iscsi, iscsilun->lun, lba,
673                                        num_sectors * iscsilun->block_size,
674                                        iscsilun->block_size, 0, 0, 0, 0, 0,
675                                        iscsi_co_generic_cb, &iTask);
676     } else {
677         iTask.task = iscsi_read10_task(iscsilun->iscsi, iscsilun->lun, lba,
678                                        num_sectors * iscsilun->block_size,
679                                        iscsilun->block_size,
680                                        0, 0, 0, 0, 0,
681                                        iscsi_co_generic_cb, &iTask);
682     }
683     if (iTask.task == NULL) {
684         return -ENOMEM;
685     }
686     scsi_task_set_iov_in(iTask.task, (struct scsi_iovec *) iov->iov, iov->niov);
687 
688     while (!iTask.complete) {
689         iscsi_set_events(iscsilun);
690         qemu_coroutine_yield();
691     }
692 
693     if (iTask.task != NULL) {
694         scsi_free_scsi_task(iTask.task);
695         iTask.task = NULL;
696     }
697 
698     if (iTask.do_retry) {
699         iTask.complete = 0;
700         goto retry;
701     }
702 
703     if (iTask.status != SCSI_STATUS_GOOD) {
704         return iTask.err_code;
705     }
706 
707     return 0;
708 }
709 
710 static int coroutine_fn iscsi_co_flush(BlockDriverState *bs)
711 {
712     IscsiLun *iscsilun = bs->opaque;
713     struct IscsiTask iTask;
714 
715     iscsi_co_init_iscsitask(iscsilun, &iTask);
716 retry:
717     if (iscsi_synchronizecache10_task(iscsilun->iscsi, iscsilun->lun, 0, 0, 0,
718                                       0, iscsi_co_generic_cb, &iTask) == NULL) {
719         return -ENOMEM;
720     }
721 
722     while (!iTask.complete) {
723         iscsi_set_events(iscsilun);
724         qemu_coroutine_yield();
725     }
726 
727     if (iTask.task != NULL) {
728         scsi_free_scsi_task(iTask.task);
729         iTask.task = NULL;
730     }
731 
732     if (iTask.do_retry) {
733         iTask.complete = 0;
734         goto retry;
735     }
736 
737     if (iTask.status != SCSI_STATUS_GOOD) {
738         return iTask.err_code;
739     }
740 
741     return 0;
742 }
743 
744 #ifdef __linux__
745 static void
746 iscsi_aio_ioctl_cb(struct iscsi_context *iscsi, int status,
747                      void *command_data, void *opaque)
748 {
749     IscsiAIOCB *acb = opaque;
750 
751     g_free(acb->buf);
752     acb->buf = NULL;
753 
754     acb->status = 0;
755     if (status < 0) {
756         error_report("Failed to ioctl(SG_IO) to iSCSI lun. %s",
757                      iscsi_get_error(iscsi));
758         acb->status = iscsi_translate_sense(&acb->task->sense);
759     }
760 
761     acb->ioh->driver_status = 0;
762     acb->ioh->host_status   = 0;
763     acb->ioh->resid         = 0;
764     acb->ioh->status        = status;
765 
766 #define SG_ERR_DRIVER_SENSE    0x08
767 
768     if (status == SCSI_STATUS_CHECK_CONDITION && acb->task->datain.size >= 2) {
769         int ss;
770 
771         acb->ioh->driver_status |= SG_ERR_DRIVER_SENSE;
772 
773         acb->ioh->sb_len_wr = acb->task->datain.size - 2;
774         ss = (acb->ioh->mx_sb_len >= acb->ioh->sb_len_wr) ?
775              acb->ioh->mx_sb_len : acb->ioh->sb_len_wr;
776         memcpy(acb->ioh->sbp, &acb->task->datain.data[2], ss);
777     }
778 
779     iscsi_schedule_bh(acb);
780 }
781 
782 static void iscsi_ioctl_bh_completion(void *opaque)
783 {
784     IscsiAIOCB *acb = opaque;
785 
786     qemu_bh_delete(acb->bh);
787     acb->common.cb(acb->common.opaque, acb->ret);
788     qemu_aio_unref(acb);
789 }
790 
791 static void iscsi_ioctl_handle_emulated(IscsiAIOCB *acb, int req, void *buf)
792 {
793     BlockDriverState *bs = acb->common.bs;
794     IscsiLun *iscsilun = bs->opaque;
795     int ret = 0;
796 
797     switch (req) {
798     case SG_GET_VERSION_NUM:
799         *(int *)buf = 30000;
800         break;
801     case SG_GET_SCSI_ID:
802         ((struct sg_scsi_id *)buf)->scsi_type = iscsilun->type;
803         break;
804     default:
805         ret = -EINVAL;
806     }
807     assert(!acb->bh);
808     acb->bh = aio_bh_new(bdrv_get_aio_context(bs),
809                          iscsi_ioctl_bh_completion, acb);
810     acb->ret = ret;
811     qemu_bh_schedule(acb->bh);
812 }
813 
814 static BlockAIOCB *iscsi_aio_ioctl(BlockDriverState *bs,
815         unsigned long int req, void *buf,
816         BlockCompletionFunc *cb, void *opaque)
817 {
818     IscsiLun *iscsilun = bs->opaque;
819     struct iscsi_context *iscsi = iscsilun->iscsi;
820     struct iscsi_data data;
821     IscsiAIOCB *acb;
822 
823     acb = qemu_aio_get(&iscsi_aiocb_info, bs, cb, opaque);
824 
825     acb->iscsilun = iscsilun;
826     acb->bh          = NULL;
827     acb->status      = -EINPROGRESS;
828     acb->buf         = NULL;
829     acb->ioh         = buf;
830 
831     if (req != SG_IO) {
832         iscsi_ioctl_handle_emulated(acb, req, buf);
833         return &acb->common;
834     }
835 
836     acb->task = malloc(sizeof(struct scsi_task));
837     if (acb->task == NULL) {
838         error_report("iSCSI: Failed to allocate task for scsi command. %s",
839                      iscsi_get_error(iscsi));
840         qemu_aio_unref(acb);
841         return NULL;
842     }
843     memset(acb->task, 0, sizeof(struct scsi_task));
844 
845     switch (acb->ioh->dxfer_direction) {
846     case SG_DXFER_TO_DEV:
847         acb->task->xfer_dir = SCSI_XFER_WRITE;
848         break;
849     case SG_DXFER_FROM_DEV:
850         acb->task->xfer_dir = SCSI_XFER_READ;
851         break;
852     default:
853         acb->task->xfer_dir = SCSI_XFER_NONE;
854         break;
855     }
856 
857     acb->task->cdb_size = acb->ioh->cmd_len;
858     memcpy(&acb->task->cdb[0], acb->ioh->cmdp, acb->ioh->cmd_len);
859     acb->task->expxferlen = acb->ioh->dxfer_len;
860 
861     data.size = 0;
862     if (acb->task->xfer_dir == SCSI_XFER_WRITE) {
863         if (acb->ioh->iovec_count == 0) {
864             data.data = acb->ioh->dxferp;
865             data.size = acb->ioh->dxfer_len;
866         } else {
867             scsi_task_set_iov_out(acb->task,
868                                  (struct scsi_iovec *) acb->ioh->dxferp,
869                                  acb->ioh->iovec_count);
870         }
871     }
872 
873     if (iscsi_scsi_command_async(iscsi, iscsilun->lun, acb->task,
874                                  iscsi_aio_ioctl_cb,
875                                  (data.size > 0) ? &data : NULL,
876                                  acb) != 0) {
877         scsi_free_scsi_task(acb->task);
878         qemu_aio_unref(acb);
879         return NULL;
880     }
881 
882     /* tell libiscsi to read straight into the buffer we got from ioctl */
883     if (acb->task->xfer_dir == SCSI_XFER_READ) {
884         if (acb->ioh->iovec_count == 0) {
885             scsi_task_add_data_in_buffer(acb->task,
886                                          acb->ioh->dxfer_len,
887                                          acb->ioh->dxferp);
888         } else {
889             scsi_task_set_iov_in(acb->task,
890                                  (struct scsi_iovec *) acb->ioh->dxferp,
891                                  acb->ioh->iovec_count);
892         }
893     }
894 
895     iscsi_set_events(iscsilun);
896 
897     return &acb->common;
898 }
899 
900 #endif
901 
902 static int64_t
903 iscsi_getlength(BlockDriverState *bs)
904 {
905     IscsiLun *iscsilun = bs->opaque;
906     int64_t len;
907 
908     len  = iscsilun->num_blocks;
909     len *= iscsilun->block_size;
910 
911     return len;
912 }
913 
914 static int
915 coroutine_fn iscsi_co_discard(BlockDriverState *bs, int64_t sector_num,
916                                    int nb_sectors)
917 {
918     IscsiLun *iscsilun = bs->opaque;
919     struct IscsiTask iTask;
920     struct unmap_list list;
921 
922     if (!is_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
923         return -EINVAL;
924     }
925 
926     if (!iscsilun->lbp.lbpu) {
927         /* UNMAP is not supported by the target */
928         return 0;
929     }
930 
931     list.lba = sector_qemu2lun(sector_num, iscsilun);
932     list.num = sector_qemu2lun(nb_sectors, iscsilun);
933 
934     iscsi_co_init_iscsitask(iscsilun, &iTask);
935 retry:
936     if (iscsi_unmap_task(iscsilun->iscsi, iscsilun->lun, 0, 0, &list, 1,
937                      iscsi_co_generic_cb, &iTask) == NULL) {
938         return -ENOMEM;
939     }
940 
941     while (!iTask.complete) {
942         iscsi_set_events(iscsilun);
943         qemu_coroutine_yield();
944     }
945 
946     if (iTask.task != NULL) {
947         scsi_free_scsi_task(iTask.task);
948         iTask.task = NULL;
949     }
950 
951     if (iTask.do_retry) {
952         iTask.complete = 0;
953         goto retry;
954     }
955 
956     if (iTask.status == SCSI_STATUS_CHECK_CONDITION) {
957         /* the target might fail with a check condition if it
958            is not happy with the alignment of the UNMAP request
959            we silently fail in this case */
960         return 0;
961     }
962 
963     if (iTask.status != SCSI_STATUS_GOOD) {
964         return iTask.err_code;
965     }
966 
967     iscsi_allocationmap_clear(iscsilun, sector_num, nb_sectors);
968 
969     return 0;
970 }
971 
972 static int
973 coroutine_fn iscsi_co_write_zeroes(BlockDriverState *bs, int64_t sector_num,
974                                    int nb_sectors, BdrvRequestFlags flags)
975 {
976     IscsiLun *iscsilun = bs->opaque;
977     struct IscsiTask iTask;
978     uint64_t lba;
979     uint32_t nb_blocks;
980     bool use_16_for_ws = iscsilun->use_16_for_rw;
981 
982     if (!is_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
983         return -EINVAL;
984     }
985 
986     if (flags & BDRV_REQ_MAY_UNMAP) {
987         if (!use_16_for_ws && !iscsilun->lbp.lbpws10) {
988             /* WRITESAME10 with UNMAP is unsupported try WRITESAME16 */
989             use_16_for_ws = true;
990         }
991         if (use_16_for_ws && !iscsilun->lbp.lbpws) {
992             /* WRITESAME16 with UNMAP is not supported by the target,
993              * fall back and try WRITESAME10/16 without UNMAP */
994             flags &= ~BDRV_REQ_MAY_UNMAP;
995             use_16_for_ws = iscsilun->use_16_for_rw;
996         }
997     }
998 
999     if (!(flags & BDRV_REQ_MAY_UNMAP) && !iscsilun->has_write_same) {
1000         /* WRITESAME without UNMAP is not supported by the target */
1001         return -ENOTSUP;
1002     }
1003 
1004     lba = sector_qemu2lun(sector_num, iscsilun);
1005     nb_blocks = sector_qemu2lun(nb_sectors, iscsilun);
1006 
1007     if (iscsilun->zeroblock == NULL) {
1008         iscsilun->zeroblock = g_try_malloc0(iscsilun->block_size);
1009         if (iscsilun->zeroblock == NULL) {
1010             return -ENOMEM;
1011         }
1012     }
1013 
1014     iscsi_co_init_iscsitask(iscsilun, &iTask);
1015 retry:
1016     if (use_16_for_ws) {
1017         iTask.task = iscsi_writesame16_task(iscsilun->iscsi, iscsilun->lun, lba,
1018                                             iscsilun->zeroblock, iscsilun->block_size,
1019                                             nb_blocks, 0, !!(flags & BDRV_REQ_MAY_UNMAP),
1020                                             0, 0, iscsi_co_generic_cb, &iTask);
1021     } else {
1022         iTask.task = iscsi_writesame10_task(iscsilun->iscsi, iscsilun->lun, lba,
1023                                             iscsilun->zeroblock, iscsilun->block_size,
1024                                             nb_blocks, 0, !!(flags & BDRV_REQ_MAY_UNMAP),
1025                                             0, 0, iscsi_co_generic_cb, &iTask);
1026     }
1027     if (iTask.task == NULL) {
1028         return -ENOMEM;
1029     }
1030 
1031     while (!iTask.complete) {
1032         iscsi_set_events(iscsilun);
1033         qemu_coroutine_yield();
1034     }
1035 
1036     if (iTask.status == SCSI_STATUS_CHECK_CONDITION &&
1037         iTask.task->sense.key == SCSI_SENSE_ILLEGAL_REQUEST &&
1038         (iTask.task->sense.ascq == SCSI_SENSE_ASCQ_INVALID_OPERATION_CODE ||
1039          iTask.task->sense.ascq == SCSI_SENSE_ASCQ_INVALID_FIELD_IN_CDB)) {
1040         /* WRITE SAME is not supported by the target */
1041         iscsilun->has_write_same = false;
1042         scsi_free_scsi_task(iTask.task);
1043         return -ENOTSUP;
1044     }
1045 
1046     if (iTask.task != NULL) {
1047         scsi_free_scsi_task(iTask.task);
1048         iTask.task = NULL;
1049     }
1050 
1051     if (iTask.do_retry) {
1052         iTask.complete = 0;
1053         goto retry;
1054     }
1055 
1056     if (iTask.status != SCSI_STATUS_GOOD) {
1057         return iTask.err_code;
1058     }
1059 
1060     if (flags & BDRV_REQ_MAY_UNMAP) {
1061         iscsi_allocationmap_clear(iscsilun, sector_num, nb_sectors);
1062     } else {
1063         iscsi_allocationmap_set(iscsilun, sector_num, nb_sectors);
1064     }
1065 
1066     return 0;
1067 }
1068 
1069 static void parse_chap(struct iscsi_context *iscsi, const char *target,
1070                        Error **errp)
1071 {
1072     QemuOptsList *list;
1073     QemuOpts *opts;
1074     const char *user = NULL;
1075     const char *password = NULL;
1076     const char *secretid;
1077     char *secret = NULL;
1078 
1079     list = qemu_find_opts("iscsi");
1080     if (!list) {
1081         return;
1082     }
1083 
1084     opts = qemu_opts_find(list, target);
1085     if (opts == NULL) {
1086         opts = QTAILQ_FIRST(&list->head);
1087         if (!opts) {
1088             return;
1089         }
1090     }
1091 
1092     user = qemu_opt_get(opts, "user");
1093     if (!user) {
1094         return;
1095     }
1096 
1097     secretid = qemu_opt_get(opts, "password-secret");
1098     password = qemu_opt_get(opts, "password");
1099     if (secretid && password) {
1100         error_setg(errp, "'password' and 'password-secret' properties are "
1101                    "mutually exclusive");
1102         return;
1103     }
1104     if (secretid) {
1105         secret = qcrypto_secret_lookup_as_utf8(secretid, errp);
1106         if (!secret) {
1107             return;
1108         }
1109         password = secret;
1110     } else if (!password) {
1111         error_setg(errp, "CHAP username specified but no password was given");
1112         return;
1113     }
1114 
1115     if (iscsi_set_initiator_username_pwd(iscsi, user, password)) {
1116         error_setg(errp, "Failed to set initiator username and password");
1117     }
1118 
1119     g_free(secret);
1120 }
1121 
1122 static void parse_header_digest(struct iscsi_context *iscsi, const char *target,
1123                                 Error **errp)
1124 {
1125     QemuOptsList *list;
1126     QemuOpts *opts;
1127     const char *digest = NULL;
1128 
1129     list = qemu_find_opts("iscsi");
1130     if (!list) {
1131         return;
1132     }
1133 
1134     opts = qemu_opts_find(list, target);
1135     if (opts == NULL) {
1136         opts = QTAILQ_FIRST(&list->head);
1137         if (!opts) {
1138             return;
1139         }
1140     }
1141 
1142     digest = qemu_opt_get(opts, "header-digest");
1143     if (!digest) {
1144         return;
1145     }
1146 
1147     if (!strcmp(digest, "CRC32C")) {
1148         iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_CRC32C);
1149     } else if (!strcmp(digest, "NONE")) {
1150         iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_NONE);
1151     } else if (!strcmp(digest, "CRC32C-NONE")) {
1152         iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_CRC32C_NONE);
1153     } else if (!strcmp(digest, "NONE-CRC32C")) {
1154         iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_NONE_CRC32C);
1155     } else {
1156         error_setg(errp, "Invalid header-digest setting : %s", digest);
1157     }
1158 }
1159 
1160 static char *parse_initiator_name(const char *target)
1161 {
1162     QemuOptsList *list;
1163     QemuOpts *opts;
1164     const char *name;
1165     char *iscsi_name;
1166     UuidInfo *uuid_info;
1167 
1168     list = qemu_find_opts("iscsi");
1169     if (list) {
1170         opts = qemu_opts_find(list, target);
1171         if (!opts) {
1172             opts = QTAILQ_FIRST(&list->head);
1173         }
1174         if (opts) {
1175             name = qemu_opt_get(opts, "initiator-name");
1176             if (name) {
1177                 return g_strdup(name);
1178             }
1179         }
1180     }
1181 
1182     uuid_info = qmp_query_uuid(NULL);
1183     if (strcmp(uuid_info->UUID, UUID_NONE) == 0) {
1184         name = qemu_get_vm_name();
1185     } else {
1186         name = uuid_info->UUID;
1187     }
1188     iscsi_name = g_strdup_printf("iqn.2008-11.org.linux-kvm%s%s",
1189                                  name ? ":" : "", name ? name : "");
1190     qapi_free_UuidInfo(uuid_info);
1191     return iscsi_name;
1192 }
1193 
1194 static int parse_timeout(const char *target)
1195 {
1196     QemuOptsList *list;
1197     QemuOpts *opts;
1198     const char *timeout;
1199 
1200     list = qemu_find_opts("iscsi");
1201     if (list) {
1202         opts = qemu_opts_find(list, target);
1203         if (!opts) {
1204             opts = QTAILQ_FIRST(&list->head);
1205         }
1206         if (opts) {
1207             timeout = qemu_opt_get(opts, "timeout");
1208             if (timeout) {
1209                 return atoi(timeout);
1210             }
1211         }
1212     }
1213 
1214     return 0;
1215 }
1216 
1217 static void iscsi_nop_timed_event(void *opaque)
1218 {
1219     IscsiLun *iscsilun = opaque;
1220 
1221     if (iscsi_get_nops_in_flight(iscsilun->iscsi) >= MAX_NOP_FAILURES) {
1222         error_report("iSCSI: NOP timeout. Reconnecting...");
1223         iscsilun->request_timed_out = true;
1224     } else if (iscsi_nop_out_async(iscsilun->iscsi, NULL, NULL, 0, NULL) != 0) {
1225         error_report("iSCSI: failed to sent NOP-Out. Disabling NOP messages.");
1226         return;
1227     }
1228 
1229     timer_mod(iscsilun->nop_timer, qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + NOP_INTERVAL);
1230     iscsi_set_events(iscsilun);
1231 }
1232 
1233 static void iscsi_readcapacity_sync(IscsiLun *iscsilun, Error **errp)
1234 {
1235     struct scsi_task *task = NULL;
1236     struct scsi_readcapacity10 *rc10 = NULL;
1237     struct scsi_readcapacity16 *rc16 = NULL;
1238     int retries = ISCSI_CMD_RETRIES;
1239 
1240     do {
1241         if (task != NULL) {
1242             scsi_free_scsi_task(task);
1243             task = NULL;
1244         }
1245 
1246         switch (iscsilun->type) {
1247         case TYPE_DISK:
1248             task = iscsi_readcapacity16_sync(iscsilun->iscsi, iscsilun->lun);
1249             if (task != NULL && task->status == SCSI_STATUS_GOOD) {
1250                 rc16 = scsi_datain_unmarshall(task);
1251                 if (rc16 == NULL) {
1252                     error_setg(errp, "iSCSI: Failed to unmarshall readcapacity16 data.");
1253                 } else {
1254                     iscsilun->block_size = rc16->block_length;
1255                     iscsilun->num_blocks = rc16->returned_lba + 1;
1256                     iscsilun->lbpme = !!rc16->lbpme;
1257                     iscsilun->lbprz = !!rc16->lbprz;
1258                     iscsilun->use_16_for_rw = (rc16->returned_lba > 0xffffffff);
1259                 }
1260                 break;
1261             }
1262             if (task != NULL && task->status == SCSI_STATUS_CHECK_CONDITION
1263                 && task->sense.key == SCSI_SENSE_UNIT_ATTENTION) {
1264                 break;
1265             }
1266             /* Fall through and try READ CAPACITY(10) instead.  */
1267         case TYPE_ROM:
1268             task = iscsi_readcapacity10_sync(iscsilun->iscsi, iscsilun->lun, 0, 0);
1269             if (task != NULL && task->status == SCSI_STATUS_GOOD) {
1270                 rc10 = scsi_datain_unmarshall(task);
1271                 if (rc10 == NULL) {
1272                     error_setg(errp, "iSCSI: Failed to unmarshall readcapacity10 data.");
1273                 } else {
1274                     iscsilun->block_size = rc10->block_size;
1275                     if (rc10->lba == 0) {
1276                         /* blank disk loaded */
1277                         iscsilun->num_blocks = 0;
1278                     } else {
1279                         iscsilun->num_blocks = rc10->lba + 1;
1280                     }
1281                 }
1282             }
1283             break;
1284         default:
1285             return;
1286         }
1287     } while (task != NULL && task->status == SCSI_STATUS_CHECK_CONDITION
1288              && task->sense.key == SCSI_SENSE_UNIT_ATTENTION
1289              && retries-- > 0);
1290 
1291     if (task == NULL || task->status != SCSI_STATUS_GOOD) {
1292         error_setg(errp, "iSCSI: failed to send readcapacity10/16 command");
1293     } else if (!iscsilun->block_size ||
1294                iscsilun->block_size % BDRV_SECTOR_SIZE) {
1295         error_setg(errp, "iSCSI: the target returned an invalid "
1296                    "block size of %d.", iscsilun->block_size);
1297     }
1298     if (task) {
1299         scsi_free_scsi_task(task);
1300     }
1301 }
1302 
1303 /* TODO Convert to fine grained options */
1304 static QemuOptsList runtime_opts = {
1305     .name = "iscsi",
1306     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
1307     .desc = {
1308         {
1309             .name = "filename",
1310             .type = QEMU_OPT_STRING,
1311             .help = "URL to the iscsi image",
1312         },
1313         { /* end of list */ }
1314     },
1315 };
1316 
1317 static struct scsi_task *iscsi_do_inquiry(struct iscsi_context *iscsi, int lun,
1318                                           int evpd, int pc, void **inq, Error **errp)
1319 {
1320     int full_size;
1321     struct scsi_task *task = NULL;
1322     task = iscsi_inquiry_sync(iscsi, lun, evpd, pc, 64);
1323     if (task == NULL || task->status != SCSI_STATUS_GOOD) {
1324         goto fail;
1325     }
1326     full_size = scsi_datain_getfullsize(task);
1327     if (full_size > task->datain.size) {
1328         scsi_free_scsi_task(task);
1329 
1330         /* we need more data for the full list */
1331         task = iscsi_inquiry_sync(iscsi, lun, evpd, pc, full_size);
1332         if (task == NULL || task->status != SCSI_STATUS_GOOD) {
1333             goto fail;
1334         }
1335     }
1336 
1337     *inq = scsi_datain_unmarshall(task);
1338     if (*inq == NULL) {
1339         error_setg(errp, "iSCSI: failed to unmarshall inquiry datain blob");
1340         goto fail_with_err;
1341     }
1342 
1343     return task;
1344 
1345 fail:
1346     error_setg(errp, "iSCSI: Inquiry command failed : %s",
1347                iscsi_get_error(iscsi));
1348 fail_with_err:
1349     if (task != NULL) {
1350         scsi_free_scsi_task(task);
1351     }
1352     return NULL;
1353 }
1354 
1355 static void iscsi_detach_aio_context(BlockDriverState *bs)
1356 {
1357     IscsiLun *iscsilun = bs->opaque;
1358 
1359     aio_set_fd_handler(iscsilun->aio_context, iscsi_get_fd(iscsilun->iscsi),
1360                        false, NULL, NULL, NULL);
1361     iscsilun->events = 0;
1362 
1363     if (iscsilun->nop_timer) {
1364         timer_del(iscsilun->nop_timer);
1365         timer_free(iscsilun->nop_timer);
1366         iscsilun->nop_timer = NULL;
1367     }
1368     if (iscsilun->event_timer) {
1369         timer_del(iscsilun->event_timer);
1370         timer_free(iscsilun->event_timer);
1371         iscsilun->event_timer = NULL;
1372     }
1373 }
1374 
1375 static void iscsi_attach_aio_context(BlockDriverState *bs,
1376                                      AioContext *new_context)
1377 {
1378     IscsiLun *iscsilun = bs->opaque;
1379 
1380     iscsilun->aio_context = new_context;
1381     iscsi_set_events(iscsilun);
1382 
1383     /* Set up a timer for sending out iSCSI NOPs */
1384     iscsilun->nop_timer = aio_timer_new(iscsilun->aio_context,
1385                                         QEMU_CLOCK_REALTIME, SCALE_MS,
1386                                         iscsi_nop_timed_event, iscsilun);
1387     timer_mod(iscsilun->nop_timer,
1388               qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + NOP_INTERVAL);
1389 
1390     /* Set up a timer for periodic calls to iscsi_set_events and to
1391      * scan for command timeout */
1392     iscsilun->event_timer = aio_timer_new(iscsilun->aio_context,
1393                                           QEMU_CLOCK_REALTIME, SCALE_MS,
1394                                           iscsi_timed_check_events, iscsilun);
1395     timer_mod(iscsilun->event_timer,
1396               qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + EVENT_INTERVAL);
1397 }
1398 
1399 static void iscsi_modesense_sync(IscsiLun *iscsilun)
1400 {
1401     struct scsi_task *task;
1402     struct scsi_mode_sense *ms = NULL;
1403     iscsilun->write_protected = false;
1404     iscsilun->dpofua = false;
1405 
1406     task = iscsi_modesense6_sync(iscsilun->iscsi, iscsilun->lun,
1407                                  1, SCSI_MODESENSE_PC_CURRENT,
1408                                  0x3F, 0, 255);
1409     if (task == NULL) {
1410         error_report("iSCSI: Failed to send MODE_SENSE(6) command: %s",
1411                      iscsi_get_error(iscsilun->iscsi));
1412         goto out;
1413     }
1414 
1415     if (task->status != SCSI_STATUS_GOOD) {
1416         error_report("iSCSI: Failed MODE_SENSE(6), LUN assumed writable");
1417         goto out;
1418     }
1419     ms = scsi_datain_unmarshall(task);
1420     if (!ms) {
1421         error_report("iSCSI: Failed to unmarshall MODE_SENSE(6) data: %s",
1422                      iscsi_get_error(iscsilun->iscsi));
1423         goto out;
1424     }
1425     iscsilun->write_protected = ms->device_specific_parameter & 0x80;
1426     iscsilun->dpofua          = ms->device_specific_parameter & 0x10;
1427 
1428 out:
1429     if (task) {
1430         scsi_free_scsi_task(task);
1431     }
1432 }
1433 
1434 /*
1435  * We support iscsi url's on the form
1436  * iscsi://[<username>%<password>@]<host>[:<port>]/<targetname>/<lun>
1437  */
1438 static int iscsi_open(BlockDriverState *bs, QDict *options, int flags,
1439                       Error **errp)
1440 {
1441     IscsiLun *iscsilun = bs->opaque;
1442     struct iscsi_context *iscsi = NULL;
1443     struct iscsi_url *iscsi_url = NULL;
1444     struct scsi_task *task = NULL;
1445     struct scsi_inquiry_standard *inq = NULL;
1446     struct scsi_inquiry_supported_pages *inq_vpd;
1447     char *initiator_name = NULL;
1448     QemuOpts *opts;
1449     Error *local_err = NULL;
1450     const char *filename;
1451     int i, ret = 0, timeout = 0;
1452 
1453     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
1454     qemu_opts_absorb_qdict(opts, options, &local_err);
1455     if (local_err) {
1456         error_propagate(errp, local_err);
1457         ret = -EINVAL;
1458         goto out;
1459     }
1460 
1461     filename = qemu_opt_get(opts, "filename");
1462 
1463     iscsi_url = iscsi_parse_full_url(iscsi, filename);
1464     if (iscsi_url == NULL) {
1465         error_setg(errp, "Failed to parse URL : %s", filename);
1466         ret = -EINVAL;
1467         goto out;
1468     }
1469 
1470     memset(iscsilun, 0, sizeof(IscsiLun));
1471 
1472     initiator_name = parse_initiator_name(iscsi_url->target);
1473 
1474     iscsi = iscsi_create_context(initiator_name);
1475     if (iscsi == NULL) {
1476         error_setg(errp, "iSCSI: Failed to create iSCSI context.");
1477         ret = -ENOMEM;
1478         goto out;
1479     }
1480 
1481     if (iscsi_set_targetname(iscsi, iscsi_url->target)) {
1482         error_setg(errp, "iSCSI: Failed to set target name.");
1483         ret = -EINVAL;
1484         goto out;
1485     }
1486 
1487     if (iscsi_url->user[0] != '\0') {
1488         ret = iscsi_set_initiator_username_pwd(iscsi, iscsi_url->user,
1489                                               iscsi_url->passwd);
1490         if (ret != 0) {
1491             error_setg(errp, "Failed to set initiator username and password");
1492             ret = -EINVAL;
1493             goto out;
1494         }
1495     }
1496 
1497     /* check if we got CHAP username/password via the options */
1498     parse_chap(iscsi, iscsi_url->target, &local_err);
1499     if (local_err != NULL) {
1500         error_propagate(errp, local_err);
1501         ret = -EINVAL;
1502         goto out;
1503     }
1504 
1505     if (iscsi_set_session_type(iscsi, ISCSI_SESSION_NORMAL) != 0) {
1506         error_setg(errp, "iSCSI: Failed to set session type to normal.");
1507         ret = -EINVAL;
1508         goto out;
1509     }
1510 
1511     iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_NONE_CRC32C);
1512 
1513     /* check if we got HEADER_DIGEST via the options */
1514     parse_header_digest(iscsi, iscsi_url->target, &local_err);
1515     if (local_err != NULL) {
1516         error_propagate(errp, local_err);
1517         ret = -EINVAL;
1518         goto out;
1519     }
1520 
1521     /* timeout handling is broken in libiscsi before 1.15.0 */
1522     timeout = parse_timeout(iscsi_url->target);
1523 #if defined(LIBISCSI_API_VERSION) && LIBISCSI_API_VERSION >= 20150621
1524     iscsi_set_timeout(iscsi, timeout);
1525 #else
1526     if (timeout) {
1527         error_report("iSCSI: ignoring timeout value for libiscsi <1.15.0");
1528     }
1529 #endif
1530 
1531     if (iscsi_full_connect_sync(iscsi, iscsi_url->portal, iscsi_url->lun) != 0) {
1532         error_setg(errp, "iSCSI: Failed to connect to LUN : %s",
1533             iscsi_get_error(iscsi));
1534         ret = -EINVAL;
1535         goto out;
1536     }
1537 
1538     iscsilun->iscsi = iscsi;
1539     iscsilun->aio_context = bdrv_get_aio_context(bs);
1540     iscsilun->lun   = iscsi_url->lun;
1541     iscsilun->has_write_same = true;
1542 
1543     task = iscsi_do_inquiry(iscsilun->iscsi, iscsilun->lun, 0, 0,
1544                             (void **) &inq, errp);
1545     if (task == NULL) {
1546         ret = -EINVAL;
1547         goto out;
1548     }
1549     iscsilun->type = inq->periperal_device_type;
1550     scsi_free_scsi_task(task);
1551     task = NULL;
1552 
1553     iscsi_modesense_sync(iscsilun);
1554     if (iscsilun->dpofua) {
1555         bs->supported_write_flags = BDRV_REQ_FUA;
1556     }
1557     bs->supported_zero_flags = BDRV_REQ_MAY_UNMAP;
1558 
1559     /* Check the write protect flag of the LUN if we want to write */
1560     if (iscsilun->type == TYPE_DISK && (flags & BDRV_O_RDWR) &&
1561         iscsilun->write_protected) {
1562         error_setg(errp, "Cannot open a write protected LUN as read-write");
1563         ret = -EACCES;
1564         goto out;
1565     }
1566 
1567     iscsi_readcapacity_sync(iscsilun, &local_err);
1568     if (local_err != NULL) {
1569         error_propagate(errp, local_err);
1570         ret = -EINVAL;
1571         goto out;
1572     }
1573     bs->total_sectors = sector_lun2qemu(iscsilun->num_blocks, iscsilun);
1574     bs->request_alignment = iscsilun->block_size;
1575 
1576     /* We don't have any emulation for devices other than disks and CD-ROMs, so
1577      * this must be sg ioctl compatible. We force it to be sg, otherwise qemu
1578      * will try to read from the device to guess the image format.
1579      */
1580     if (iscsilun->type != TYPE_DISK && iscsilun->type != TYPE_ROM) {
1581         bs->sg = 1;
1582     }
1583 
1584     task = iscsi_do_inquiry(iscsilun->iscsi, iscsilun->lun, 1,
1585                             SCSI_INQUIRY_PAGECODE_SUPPORTED_VPD_PAGES,
1586                             (void **) &inq_vpd, errp);
1587     if (task == NULL) {
1588         ret = -EINVAL;
1589         goto out;
1590     }
1591     for (i = 0; i < inq_vpd->num_pages; i++) {
1592         struct scsi_task *inq_task;
1593         struct scsi_inquiry_logical_block_provisioning *inq_lbp;
1594         struct scsi_inquiry_block_limits *inq_bl;
1595         switch (inq_vpd->pages[i]) {
1596         case SCSI_INQUIRY_PAGECODE_LOGICAL_BLOCK_PROVISIONING:
1597             inq_task = iscsi_do_inquiry(iscsilun->iscsi, iscsilun->lun, 1,
1598                                         SCSI_INQUIRY_PAGECODE_LOGICAL_BLOCK_PROVISIONING,
1599                                         (void **) &inq_lbp, errp);
1600             if (inq_task == NULL) {
1601                 ret = -EINVAL;
1602                 goto out;
1603             }
1604             memcpy(&iscsilun->lbp, inq_lbp,
1605                    sizeof(struct scsi_inquiry_logical_block_provisioning));
1606             scsi_free_scsi_task(inq_task);
1607             break;
1608         case SCSI_INQUIRY_PAGECODE_BLOCK_LIMITS:
1609             inq_task = iscsi_do_inquiry(iscsilun->iscsi, iscsilun->lun, 1,
1610                                     SCSI_INQUIRY_PAGECODE_BLOCK_LIMITS,
1611                                     (void **) &inq_bl, errp);
1612             if (inq_task == NULL) {
1613                 ret = -EINVAL;
1614                 goto out;
1615             }
1616             memcpy(&iscsilun->bl, inq_bl,
1617                    sizeof(struct scsi_inquiry_block_limits));
1618             scsi_free_scsi_task(inq_task);
1619             break;
1620         default:
1621             break;
1622         }
1623     }
1624     scsi_free_scsi_task(task);
1625     task = NULL;
1626 
1627     iscsi_attach_aio_context(bs, iscsilun->aio_context);
1628 
1629     /* Guess the internal cluster (page) size of the iscsi target by the means
1630      * of opt_unmap_gran. Transfer the unmap granularity only if it has a
1631      * reasonable size */
1632     if (iscsilun->bl.opt_unmap_gran * iscsilun->block_size >= 4 * 1024 &&
1633         iscsilun->bl.opt_unmap_gran * iscsilun->block_size <= 16 * 1024 * 1024) {
1634         iscsilun->cluster_sectors = (iscsilun->bl.opt_unmap_gran *
1635                                      iscsilun->block_size) >> BDRV_SECTOR_BITS;
1636         if (iscsilun->lbprz) {
1637             iscsilun->allocationmap = iscsi_allocationmap_init(iscsilun);
1638             if (iscsilun->allocationmap == NULL) {
1639                 ret = -ENOMEM;
1640             }
1641         }
1642     }
1643 
1644 out:
1645     qemu_opts_del(opts);
1646     g_free(initiator_name);
1647     if (iscsi_url != NULL) {
1648         iscsi_destroy_url(iscsi_url);
1649     }
1650     if (task != NULL) {
1651         scsi_free_scsi_task(task);
1652     }
1653 
1654     if (ret) {
1655         if (iscsi != NULL) {
1656             if (iscsi_is_logged_in(iscsi)) {
1657                 iscsi_logout_sync(iscsi);
1658             }
1659             iscsi_destroy_context(iscsi);
1660         }
1661         memset(iscsilun, 0, sizeof(IscsiLun));
1662     }
1663     return ret;
1664 }
1665 
1666 static void iscsi_close(BlockDriverState *bs)
1667 {
1668     IscsiLun *iscsilun = bs->opaque;
1669     struct iscsi_context *iscsi = iscsilun->iscsi;
1670 
1671     iscsi_detach_aio_context(bs);
1672     if (iscsi_is_logged_in(iscsi)) {
1673         iscsi_logout_sync(iscsi);
1674     }
1675     iscsi_destroy_context(iscsi);
1676     g_free(iscsilun->zeroblock);
1677     g_free(iscsilun->allocationmap);
1678     memset(iscsilun, 0, sizeof(IscsiLun));
1679 }
1680 
1681 static int sector_limits_lun2qemu(int64_t sector, IscsiLun *iscsilun)
1682 {
1683     return MIN(sector_lun2qemu(sector, iscsilun), INT_MAX / 2 + 1);
1684 }
1685 
1686 static void iscsi_refresh_limits(BlockDriverState *bs, Error **errp)
1687 {
1688     /* We don't actually refresh here, but just return data queried in
1689      * iscsi_open(): iscsi targets don't change their limits. */
1690 
1691     IscsiLun *iscsilun = bs->opaque;
1692     uint32_t max_xfer_len = iscsilun->use_16_for_rw ? 0xffffffff : 0xffff;
1693 
1694     if (iscsilun->bl.max_xfer_len) {
1695         max_xfer_len = MIN(max_xfer_len, iscsilun->bl.max_xfer_len);
1696     }
1697 
1698     bs->bl.max_transfer_length = sector_limits_lun2qemu(max_xfer_len, iscsilun);
1699 
1700     if (iscsilun->lbp.lbpu) {
1701         if (iscsilun->bl.max_unmap < 0xffffffff) {
1702             bs->bl.max_discard =
1703                 sector_limits_lun2qemu(iscsilun->bl.max_unmap, iscsilun);
1704         }
1705         bs->bl.discard_alignment =
1706             sector_limits_lun2qemu(iscsilun->bl.opt_unmap_gran, iscsilun);
1707     }
1708 
1709     if (iscsilun->bl.max_ws_len < 0xffffffff) {
1710         bs->bl.max_write_zeroes =
1711             sector_limits_lun2qemu(iscsilun->bl.max_ws_len, iscsilun);
1712     }
1713     if (iscsilun->lbp.lbpws) {
1714         bs->bl.write_zeroes_alignment =
1715             sector_limits_lun2qemu(iscsilun->bl.opt_unmap_gran, iscsilun);
1716     }
1717     bs->bl.opt_transfer_length =
1718         sector_limits_lun2qemu(iscsilun->bl.opt_xfer_len, iscsilun);
1719 }
1720 
1721 /* Note that this will not re-establish a connection with an iSCSI target - it
1722  * is effectively a NOP.  */
1723 static int iscsi_reopen_prepare(BDRVReopenState *state,
1724                                 BlockReopenQueue *queue, Error **errp)
1725 {
1726     IscsiLun *iscsilun = state->bs->opaque;
1727 
1728     if (state->flags & BDRV_O_RDWR && iscsilun->write_protected) {
1729         error_setg(errp, "Cannot open a write protected LUN as read-write");
1730         return -EACCES;
1731     }
1732     return 0;
1733 }
1734 
1735 static int iscsi_truncate(BlockDriverState *bs, int64_t offset)
1736 {
1737     IscsiLun *iscsilun = bs->opaque;
1738     Error *local_err = NULL;
1739 
1740     if (iscsilun->type != TYPE_DISK) {
1741         return -ENOTSUP;
1742     }
1743 
1744     iscsi_readcapacity_sync(iscsilun, &local_err);
1745     if (local_err != NULL) {
1746         error_free(local_err);
1747         return -EIO;
1748     }
1749 
1750     if (offset > iscsi_getlength(bs)) {
1751         return -EINVAL;
1752     }
1753 
1754     if (iscsilun->allocationmap != NULL) {
1755         g_free(iscsilun->allocationmap);
1756         iscsilun->allocationmap = iscsi_allocationmap_init(iscsilun);
1757     }
1758 
1759     return 0;
1760 }
1761 
1762 static int iscsi_create(const char *filename, QemuOpts *opts, Error **errp)
1763 {
1764     int ret = 0;
1765     int64_t total_size = 0;
1766     BlockDriverState *bs;
1767     IscsiLun *iscsilun = NULL;
1768     QDict *bs_options;
1769 
1770     bs = bdrv_new();
1771 
1772     /* Read out options */
1773     total_size = DIV_ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
1774                               BDRV_SECTOR_SIZE);
1775     bs->opaque = g_new0(struct IscsiLun, 1);
1776     iscsilun = bs->opaque;
1777 
1778     bs_options = qdict_new();
1779     qdict_put(bs_options, "filename", qstring_from_str(filename));
1780     ret = iscsi_open(bs, bs_options, 0, NULL);
1781     QDECREF(bs_options);
1782 
1783     if (ret != 0) {
1784         goto out;
1785     }
1786     iscsi_detach_aio_context(bs);
1787     if (iscsilun->type != TYPE_DISK) {
1788         ret = -ENODEV;
1789         goto out;
1790     }
1791     if (bs->total_sectors < total_size) {
1792         ret = -ENOSPC;
1793         goto out;
1794     }
1795 
1796     ret = 0;
1797 out:
1798     if (iscsilun->iscsi != NULL) {
1799         iscsi_destroy_context(iscsilun->iscsi);
1800     }
1801     g_free(bs->opaque);
1802     bs->opaque = NULL;
1803     bdrv_unref(bs);
1804     return ret;
1805 }
1806 
1807 static int iscsi_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
1808 {
1809     IscsiLun *iscsilun = bs->opaque;
1810     bdi->unallocated_blocks_are_zero = iscsilun->lbprz;
1811     bdi->can_write_zeroes_with_unmap = iscsilun->lbprz && iscsilun->lbp.lbpws;
1812     bdi->cluster_size = iscsilun->cluster_sectors * BDRV_SECTOR_SIZE;
1813     return 0;
1814 }
1815 
1816 static QemuOptsList iscsi_create_opts = {
1817     .name = "iscsi-create-opts",
1818     .head = QTAILQ_HEAD_INITIALIZER(iscsi_create_opts.head),
1819     .desc = {
1820         {
1821             .name = BLOCK_OPT_SIZE,
1822             .type = QEMU_OPT_SIZE,
1823             .help = "Virtual disk size"
1824         },
1825         { /* end of list */ }
1826     }
1827 };
1828 
1829 static BlockDriver bdrv_iscsi = {
1830     .format_name     = "iscsi",
1831     .protocol_name   = "iscsi",
1832 
1833     .instance_size   = sizeof(IscsiLun),
1834     .bdrv_needs_filename = true,
1835     .bdrv_file_open  = iscsi_open,
1836     .bdrv_close      = iscsi_close,
1837     .bdrv_create     = iscsi_create,
1838     .create_opts     = &iscsi_create_opts,
1839     .bdrv_reopen_prepare  = iscsi_reopen_prepare,
1840 
1841     .bdrv_getlength  = iscsi_getlength,
1842     .bdrv_get_info   = iscsi_get_info,
1843     .bdrv_truncate   = iscsi_truncate,
1844     .bdrv_refresh_limits = iscsi_refresh_limits,
1845 
1846     .bdrv_co_get_block_status = iscsi_co_get_block_status,
1847     .bdrv_co_discard      = iscsi_co_discard,
1848     .bdrv_co_write_zeroes = iscsi_co_write_zeroes,
1849     .bdrv_co_readv         = iscsi_co_readv,
1850     .bdrv_co_writev_flags  = iscsi_co_writev_flags,
1851     .bdrv_co_flush_to_disk = iscsi_co_flush,
1852 
1853 #ifdef __linux__
1854     .bdrv_aio_ioctl   = iscsi_aio_ioctl,
1855 #endif
1856 
1857     .bdrv_detach_aio_context = iscsi_detach_aio_context,
1858     .bdrv_attach_aio_context = iscsi_attach_aio_context,
1859 };
1860 
1861 static QemuOptsList qemu_iscsi_opts = {
1862     .name = "iscsi",
1863     .head = QTAILQ_HEAD_INITIALIZER(qemu_iscsi_opts.head),
1864     .desc = {
1865         {
1866             .name = "user",
1867             .type = QEMU_OPT_STRING,
1868             .help = "username for CHAP authentication to target",
1869         },{
1870             .name = "password",
1871             .type = QEMU_OPT_STRING,
1872             .help = "password for CHAP authentication to target",
1873         },{
1874             .name = "password-secret",
1875             .type = QEMU_OPT_STRING,
1876             .help = "ID of the secret providing password for CHAP "
1877                     "authentication to target",
1878         },{
1879             .name = "header-digest",
1880             .type = QEMU_OPT_STRING,
1881             .help = "HeaderDigest setting. "
1882                     "{CRC32C|CRC32C-NONE|NONE-CRC32C|NONE}",
1883         },{
1884             .name = "initiator-name",
1885             .type = QEMU_OPT_STRING,
1886             .help = "Initiator iqn name to use when connecting",
1887         },{
1888             .name = "timeout",
1889             .type = QEMU_OPT_NUMBER,
1890             .help = "Request timeout in seconds (default 0 = no timeout)",
1891         },
1892         { /* end of list */ }
1893     },
1894 };
1895 
1896 static void iscsi_block_init(void)
1897 {
1898     bdrv_register(&bdrv_iscsi);
1899     qemu_add_opts(&qemu_iscsi_opts);
1900 }
1901 
1902 block_init(iscsi_block_init);
1903