xref: /openbmc/qemu/block/iscsi.c (revision 14b61600)
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 "config-host.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 
43 #include <iscsi/iscsi.h>
44 #include <iscsi/scsi-lowlevel.h>
45 
46 #ifdef __linux__
47 #include <scsi/sg.h>
48 #include <block/scsi.h>
49 #endif
50 
51 typedef struct IscsiLun {
52     struct iscsi_context *iscsi;
53     AioContext *aio_context;
54     int lun;
55     enum scsi_inquiry_peripheral_device_type type;
56     int block_size;
57     uint64_t num_blocks;
58     int events;
59     QEMUTimer *nop_timer;
60     QEMUTimer *event_timer;
61     struct scsi_inquiry_logical_block_provisioning lbp;
62     struct scsi_inquiry_block_limits bl;
63     unsigned char *zeroblock;
64     unsigned long *allocationmap;
65     int cluster_sectors;
66     bool use_16_for_rw;
67     bool write_protected;
68     bool lbpme;
69     bool lbprz;
70     bool dpofua;
71     bool has_write_same;
72     bool force_next_flush;
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     bool force_next_flush;
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 #ifdef __linux__
100     sg_io_hdr_t *ioh;
101 #endif
102 } IscsiAIOCB;
103 
104 /* libiscsi uses time_t so its enough to process events every second */
105 #define EVENT_INTERVAL 1000
106 #define NOP_INTERVAL 5000
107 #define MAX_NOP_FAILURES 3
108 #define ISCSI_CMD_RETRIES ARRAY_SIZE(iscsi_retry_times)
109 static const unsigned iscsi_retry_times[] = {8, 32, 128, 512, 2048, 8192, 32768};
110 
111 /* this threshold is a trade-off knob to choose between
112  * the potential additional overhead of an extra GET_LBA_STATUS request
113  * vs. unnecessarily reading a lot of zero sectors over the wire.
114  * If a read request is greater or equal than ISCSI_CHECKALLOC_THRES
115  * sectors we check the allocation status of the area covered by the
116  * request first if the allocationmap indicates that the area might be
117  * unallocated. */
118 #define ISCSI_CHECKALLOC_THRES 64
119 
120 static void
121 iscsi_bh_cb(void *p)
122 {
123     IscsiAIOCB *acb = p;
124 
125     qemu_bh_delete(acb->bh);
126 
127     g_free(acb->buf);
128     acb->buf = NULL;
129 
130     acb->common.cb(acb->common.opaque, acb->status);
131 
132     if (acb->task != NULL) {
133         scsi_free_scsi_task(acb->task);
134         acb->task = NULL;
135     }
136 
137     qemu_aio_unref(acb);
138 }
139 
140 static void
141 iscsi_schedule_bh(IscsiAIOCB *acb)
142 {
143     if (acb->bh) {
144         return;
145     }
146     acb->bh = aio_bh_new(acb->iscsilun->aio_context, iscsi_bh_cb, acb);
147     qemu_bh_schedule(acb->bh);
148 }
149 
150 static void iscsi_co_generic_bh_cb(void *opaque)
151 {
152     struct IscsiTask *iTask = opaque;
153     iTask->complete = 1;
154     qemu_bh_delete(iTask->bh);
155     qemu_coroutine_enter(iTask->co, NULL);
156 }
157 
158 static void iscsi_retry_timer_expired(void *opaque)
159 {
160     struct IscsiTask *iTask = opaque;
161     iTask->complete = 1;
162     if (iTask->co) {
163         qemu_coroutine_enter(iTask->co, NULL);
164     }
165 }
166 
167 static inline unsigned exp_random(double mean)
168 {
169     return -mean * log((double)rand() / RAND_MAX);
170 }
171 
172 /* SCSI_STATUS_TASK_SET_FULL and SCSI_STATUS_TIMEOUT were introduced
173  * in libiscsi 1.10.0 as part of an enum. The LIBISCSI_API_VERSION
174  * macro was introduced in 1.11.0. So use the API_VERSION macro as
175  * a hint that the macros are defined and define them ourselves
176  * otherwise to keep the required libiscsi version at 1.9.0 */
177 #if !defined(LIBISCSI_API_VERSION)
178 #define QEMU_SCSI_STATUS_TASK_SET_FULL  0x28
179 #define QEMU_SCSI_STATUS_TIMEOUT        0x0f000002
180 #else
181 #define QEMU_SCSI_STATUS_TASK_SET_FULL  SCSI_STATUS_TASK_SET_FULL
182 #define QEMU_SCSI_STATUS_TIMEOUT        SCSI_STATUS_TIMEOUT
183 #endif
184 
185 static void
186 iscsi_co_generic_cb(struct iscsi_context *iscsi, int status,
187                         void *command_data, void *opaque)
188 {
189     struct IscsiTask *iTask = opaque;
190     struct scsi_task *task = command_data;
191 
192     iTask->status = status;
193     iTask->do_retry = 0;
194     iTask->task = task;
195 
196     if (status != SCSI_STATUS_GOOD) {
197         if (iTask->retries++ < ISCSI_CMD_RETRIES) {
198             if (status == SCSI_STATUS_CHECK_CONDITION
199                 && task->sense.key == SCSI_SENSE_UNIT_ATTENTION) {
200                 error_report("iSCSI CheckCondition: %s",
201                              iscsi_get_error(iscsi));
202                 iTask->do_retry = 1;
203                 goto out;
204             }
205             if (status == SCSI_STATUS_BUSY ||
206                 status == QEMU_SCSI_STATUS_TIMEOUT ||
207                 status == QEMU_SCSI_STATUS_TASK_SET_FULL) {
208                 unsigned retry_time =
209                     exp_random(iscsi_retry_times[iTask->retries - 1]);
210                 if (status == QEMU_SCSI_STATUS_TIMEOUT) {
211                     /* make sure the request is rescheduled AFTER the
212                      * reconnect is initiated */
213                     retry_time = EVENT_INTERVAL * 2;
214                     iTask->iscsilun->request_timed_out = true;
215                 }
216                 error_report("iSCSI Busy/TaskSetFull/TimeOut"
217                              " (retry #%u in %u ms): %s",
218                              iTask->retries, retry_time,
219                              iscsi_get_error(iscsi));
220                 aio_timer_init(iTask->iscsilun->aio_context,
221                                &iTask->retry_timer, QEMU_CLOCK_REALTIME,
222                                SCALE_MS, iscsi_retry_timer_expired, iTask);
223                 timer_mod(&iTask->retry_timer,
224                           qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + retry_time);
225                 iTask->do_retry = 1;
226                 return;
227             }
228         }
229         error_report("iSCSI Failure: %s", iscsi_get_error(iscsi));
230     } else {
231         iTask->iscsilun->force_next_flush |= iTask->force_next_flush;
232     }
233 
234 out:
235     if (iTask->co) {
236         iTask->bh = aio_bh_new(iTask->iscsilun->aio_context,
237                                iscsi_co_generic_bh_cb, iTask);
238         qemu_bh_schedule(iTask->bh);
239     } else {
240         iTask->complete = 1;
241     }
242 }
243 
244 static void iscsi_co_init_iscsitask(IscsiLun *iscsilun, struct IscsiTask *iTask)
245 {
246     *iTask = (struct IscsiTask) {
247         .co         = qemu_coroutine_self(),
248         .iscsilun   = iscsilun,
249     };
250 }
251 
252 static void
253 iscsi_abort_task_cb(struct iscsi_context *iscsi, int status, void *command_data,
254                     void *private_data)
255 {
256     IscsiAIOCB *acb = private_data;
257 
258     acb->status = -ECANCELED;
259     iscsi_schedule_bh(acb);
260 }
261 
262 static void
263 iscsi_aio_cancel(BlockAIOCB *blockacb)
264 {
265     IscsiAIOCB *acb = (IscsiAIOCB *)blockacb;
266     IscsiLun *iscsilun = acb->iscsilun;
267 
268     if (acb->status != -EINPROGRESS) {
269         return;
270     }
271 
272     /* send a task mgmt call to the target to cancel the task on the target */
273     iscsi_task_mgmt_abort_task_async(iscsilun->iscsi, acb->task,
274                                      iscsi_abort_task_cb, acb);
275 
276 }
277 
278 static const AIOCBInfo iscsi_aiocb_info = {
279     .aiocb_size         = sizeof(IscsiAIOCB),
280     .cancel_async       = iscsi_aio_cancel,
281 };
282 
283 
284 static void iscsi_process_read(void *arg);
285 static void iscsi_process_write(void *arg);
286 
287 static void
288 iscsi_set_events(IscsiLun *iscsilun)
289 {
290     struct iscsi_context *iscsi = iscsilun->iscsi;
291     int ev = iscsi_which_events(iscsi);
292 
293     if (ev != iscsilun->events) {
294         aio_set_fd_handler(iscsilun->aio_context, iscsi_get_fd(iscsi),
295                            false,
296                            (ev & POLLIN) ? iscsi_process_read : NULL,
297                            (ev & POLLOUT) ? iscsi_process_write : NULL,
298                            iscsilun);
299         iscsilun->events = ev;
300     }
301 }
302 
303 static void iscsi_timed_check_events(void *opaque)
304 {
305     IscsiLun *iscsilun = opaque;
306 
307     /* check for timed out requests */
308     iscsi_service(iscsilun->iscsi, 0);
309 
310     if (iscsilun->request_timed_out) {
311         iscsilun->request_timed_out = false;
312         iscsi_reconnect(iscsilun->iscsi);
313     }
314 
315     /* newer versions of libiscsi may return zero events. Ensure we are able
316      * to return to service once this situation changes. */
317     iscsi_set_events(iscsilun);
318 
319     timer_mod(iscsilun->event_timer,
320               qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + EVENT_INTERVAL);
321 }
322 
323 static void
324 iscsi_process_read(void *arg)
325 {
326     IscsiLun *iscsilun = arg;
327     struct iscsi_context *iscsi = iscsilun->iscsi;
328 
329     iscsi_service(iscsi, POLLIN);
330     iscsi_set_events(iscsilun);
331 }
332 
333 static void
334 iscsi_process_write(void *arg)
335 {
336     IscsiLun *iscsilun = arg;
337     struct iscsi_context *iscsi = iscsilun->iscsi;
338 
339     iscsi_service(iscsi, POLLOUT);
340     iscsi_set_events(iscsilun);
341 }
342 
343 static int64_t sector_lun2qemu(int64_t sector, IscsiLun *iscsilun)
344 {
345     return sector * iscsilun->block_size / BDRV_SECTOR_SIZE;
346 }
347 
348 static int64_t sector_qemu2lun(int64_t sector, IscsiLun *iscsilun)
349 {
350     return sector * BDRV_SECTOR_SIZE / iscsilun->block_size;
351 }
352 
353 static bool is_request_lun_aligned(int64_t sector_num, int nb_sectors,
354                                       IscsiLun *iscsilun)
355 {
356     if ((sector_num * BDRV_SECTOR_SIZE) % iscsilun->block_size ||
357         (nb_sectors * BDRV_SECTOR_SIZE) % iscsilun->block_size) {
358             error_report("iSCSI misaligned request: "
359                          "iscsilun->block_size %u, sector_num %" PRIi64
360                          ", nb_sectors %d",
361                          iscsilun->block_size, sector_num, nb_sectors);
362             return 0;
363     }
364     return 1;
365 }
366 
367 static unsigned long *iscsi_allocationmap_init(IscsiLun *iscsilun)
368 {
369     return bitmap_try_new(DIV_ROUND_UP(sector_lun2qemu(iscsilun->num_blocks,
370                                                        iscsilun),
371                                        iscsilun->cluster_sectors));
372 }
373 
374 static void iscsi_allocationmap_set(IscsiLun *iscsilun, int64_t sector_num,
375                                     int nb_sectors)
376 {
377     if (iscsilun->allocationmap == NULL) {
378         return;
379     }
380     bitmap_set(iscsilun->allocationmap,
381                sector_num / iscsilun->cluster_sectors,
382                DIV_ROUND_UP(nb_sectors, iscsilun->cluster_sectors));
383 }
384 
385 static void iscsi_allocationmap_clear(IscsiLun *iscsilun, int64_t sector_num,
386                                       int nb_sectors)
387 {
388     int64_t cluster_num, nb_clusters;
389     if (iscsilun->allocationmap == NULL) {
390         return;
391     }
392     cluster_num = DIV_ROUND_UP(sector_num, iscsilun->cluster_sectors);
393     nb_clusters = (sector_num + nb_sectors) / iscsilun->cluster_sectors
394                   - cluster_num;
395     if (nb_clusters > 0) {
396         bitmap_clear(iscsilun->allocationmap, cluster_num, nb_clusters);
397     }
398 }
399 
400 static int coroutine_fn iscsi_co_writev(BlockDriverState *bs,
401                                         int64_t sector_num, int nb_sectors,
402                                         QEMUIOVector *iov)
403 {
404     IscsiLun *iscsilun = bs->opaque;
405     struct IscsiTask iTask;
406     uint64_t lba;
407     uint32_t num_sectors;
408     int fua;
409 
410     if (!is_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
411         return -EINVAL;
412     }
413 
414     if (bs->bl.max_transfer_length && nb_sectors > bs->bl.max_transfer_length) {
415         error_report("iSCSI Error: Write of %d sectors exceeds max_xfer_len "
416                      "of %d sectors", nb_sectors, bs->bl.max_transfer_length);
417         return -EINVAL;
418     }
419 
420     lba = sector_qemu2lun(sector_num, iscsilun);
421     num_sectors = sector_qemu2lun(nb_sectors, iscsilun);
422     iscsi_co_init_iscsitask(iscsilun, &iTask);
423 retry:
424     fua = iscsilun->dpofua && !bs->enable_write_cache;
425     iTask.force_next_flush = !fua;
426     if (iscsilun->use_16_for_rw) {
427         iTask.task = iscsi_write16_task(iscsilun->iscsi, iscsilun->lun, lba,
428                                         NULL, num_sectors * iscsilun->block_size,
429                                         iscsilun->block_size, 0, 0, fua, 0, 0,
430                                         iscsi_co_generic_cb, &iTask);
431     } else {
432         iTask.task = iscsi_write10_task(iscsilun->iscsi, iscsilun->lun, lba,
433                                         NULL, num_sectors * iscsilun->block_size,
434                                         iscsilun->block_size, 0, 0, fua, 0, 0,
435                                         iscsi_co_generic_cb, &iTask);
436     }
437     if (iTask.task == NULL) {
438         return -ENOMEM;
439     }
440     scsi_task_set_iov_out(iTask.task, (struct scsi_iovec *) iov->iov,
441                           iov->niov);
442     while (!iTask.complete) {
443         iscsi_set_events(iscsilun);
444         qemu_coroutine_yield();
445     }
446 
447     if (iTask.task != NULL) {
448         scsi_free_scsi_task(iTask.task);
449         iTask.task = NULL;
450     }
451 
452     if (iTask.do_retry) {
453         iTask.complete = 0;
454         goto retry;
455     }
456 
457     if (iTask.status != SCSI_STATUS_GOOD) {
458         return -EIO;
459     }
460 
461     iscsi_allocationmap_set(iscsilun, sector_num, nb_sectors);
462 
463     return 0;
464 }
465 
466 
467 static bool iscsi_allocationmap_is_allocated(IscsiLun *iscsilun,
468                                              int64_t sector_num, int nb_sectors)
469 {
470     unsigned long size;
471     if (iscsilun->allocationmap == NULL) {
472         return true;
473     }
474     size = DIV_ROUND_UP(sector_num + nb_sectors, iscsilun->cluster_sectors);
475     return !(find_next_bit(iscsilun->allocationmap, size,
476                            sector_num / iscsilun->cluster_sectors) == size);
477 }
478 
479 static int64_t coroutine_fn iscsi_co_get_block_status(BlockDriverState *bs,
480                                                   int64_t sector_num,
481                                                   int nb_sectors, int *pnum)
482 {
483     IscsiLun *iscsilun = bs->opaque;
484     struct scsi_get_lba_status *lbas = NULL;
485     struct scsi_lba_status_descriptor *lbasd = NULL;
486     struct IscsiTask iTask;
487     int64_t ret;
488 
489     iscsi_co_init_iscsitask(iscsilun, &iTask);
490 
491     if (!is_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
492         ret = -EINVAL;
493         goto out;
494     }
495 
496     /* default to all sectors allocated */
497     ret = BDRV_BLOCK_DATA;
498     ret |= (sector_num << BDRV_SECTOR_BITS) | BDRV_BLOCK_OFFSET_VALID;
499     *pnum = nb_sectors;
500 
501     /* LUN does not support logical block provisioning */
502     if (!iscsilun->lbpme) {
503         goto out;
504     }
505 
506 retry:
507     if (iscsi_get_lba_status_task(iscsilun->iscsi, iscsilun->lun,
508                                   sector_qemu2lun(sector_num, iscsilun),
509                                   8 + 16, iscsi_co_generic_cb,
510                                   &iTask) == NULL) {
511         ret = -ENOMEM;
512         goto out;
513     }
514 
515     while (!iTask.complete) {
516         iscsi_set_events(iscsilun);
517         qemu_coroutine_yield();
518     }
519 
520     if (iTask.do_retry) {
521         if (iTask.task != NULL) {
522             scsi_free_scsi_task(iTask.task);
523             iTask.task = NULL;
524         }
525         iTask.complete = 0;
526         goto retry;
527     }
528 
529     if (iTask.status != SCSI_STATUS_GOOD) {
530         /* in case the get_lba_status_callout fails (i.e.
531          * because the device is busy or the cmd is not
532          * supported) we pretend all blocks are allocated
533          * for backwards compatibility */
534         goto out;
535     }
536 
537     lbas = scsi_datain_unmarshall(iTask.task);
538     if (lbas == NULL) {
539         ret = -EIO;
540         goto out;
541     }
542 
543     lbasd = &lbas->descriptors[0];
544 
545     if (sector_qemu2lun(sector_num, iscsilun) != lbasd->lba) {
546         ret = -EIO;
547         goto out;
548     }
549 
550     *pnum = sector_lun2qemu(lbasd->num_blocks, iscsilun);
551 
552     if (lbasd->provisioning == SCSI_PROVISIONING_TYPE_DEALLOCATED ||
553         lbasd->provisioning == SCSI_PROVISIONING_TYPE_ANCHORED) {
554         ret &= ~BDRV_BLOCK_DATA;
555         if (iscsilun->lbprz) {
556             ret |= BDRV_BLOCK_ZERO;
557         }
558     }
559 
560     if (ret & BDRV_BLOCK_ZERO) {
561         iscsi_allocationmap_clear(iscsilun, sector_num, *pnum);
562     } else {
563         iscsi_allocationmap_set(iscsilun, sector_num, *pnum);
564     }
565 
566     if (*pnum > nb_sectors) {
567         *pnum = nb_sectors;
568     }
569 out:
570     if (iTask.task != NULL) {
571         scsi_free_scsi_task(iTask.task);
572     }
573     return ret;
574 }
575 
576 static int coroutine_fn iscsi_co_readv(BlockDriverState *bs,
577                                        int64_t sector_num, int nb_sectors,
578                                        QEMUIOVector *iov)
579 {
580     IscsiLun *iscsilun = bs->opaque;
581     struct IscsiTask iTask;
582     uint64_t lba;
583     uint32_t num_sectors;
584 
585     if (!is_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
586         return -EINVAL;
587     }
588 
589     if (bs->bl.max_transfer_length && nb_sectors > bs->bl.max_transfer_length) {
590         error_report("iSCSI Error: Read of %d sectors exceeds max_xfer_len "
591                      "of %d sectors", nb_sectors, bs->bl.max_transfer_length);
592         return -EINVAL;
593     }
594 
595     if (iscsilun->lbprz && nb_sectors >= ISCSI_CHECKALLOC_THRES &&
596         !iscsi_allocationmap_is_allocated(iscsilun, sector_num, nb_sectors)) {
597         int64_t ret;
598         int pnum;
599         ret = iscsi_co_get_block_status(bs, sector_num, INT_MAX, &pnum);
600         if (ret < 0) {
601             return ret;
602         }
603         if (ret & BDRV_BLOCK_ZERO && pnum >= nb_sectors) {
604             qemu_iovec_memset(iov, 0, 0x00, iov->size);
605             return 0;
606         }
607     }
608 
609     lba = sector_qemu2lun(sector_num, iscsilun);
610     num_sectors = sector_qemu2lun(nb_sectors, iscsilun);
611 
612     iscsi_co_init_iscsitask(iscsilun, &iTask);
613 retry:
614     if (iscsilun->use_16_for_rw) {
615         iTask.task = iscsi_read16_task(iscsilun->iscsi, iscsilun->lun, lba,
616                                        num_sectors * iscsilun->block_size,
617                                        iscsilun->block_size, 0, 0, 0, 0, 0,
618                                        iscsi_co_generic_cb, &iTask);
619     } else {
620         iTask.task = iscsi_read10_task(iscsilun->iscsi, iscsilun->lun, lba,
621                                        num_sectors * iscsilun->block_size,
622                                        iscsilun->block_size,
623                                        0, 0, 0, 0, 0,
624                                        iscsi_co_generic_cb, &iTask);
625     }
626     if (iTask.task == NULL) {
627         return -ENOMEM;
628     }
629     scsi_task_set_iov_in(iTask.task, (struct scsi_iovec *) iov->iov, iov->niov);
630 
631     while (!iTask.complete) {
632         iscsi_set_events(iscsilun);
633         qemu_coroutine_yield();
634     }
635 
636     if (iTask.task != NULL) {
637         scsi_free_scsi_task(iTask.task);
638         iTask.task = NULL;
639     }
640 
641     if (iTask.do_retry) {
642         iTask.complete = 0;
643         goto retry;
644     }
645 
646     if (iTask.status != SCSI_STATUS_GOOD) {
647         return -EIO;
648     }
649 
650     return 0;
651 }
652 
653 static int coroutine_fn iscsi_co_flush(BlockDriverState *bs)
654 {
655     IscsiLun *iscsilun = bs->opaque;
656     struct IscsiTask iTask;
657 
658     if (!iscsilun->force_next_flush) {
659         return 0;
660     }
661     iscsilun->force_next_flush = false;
662 
663     iscsi_co_init_iscsitask(iscsilun, &iTask);
664 retry:
665     if (iscsi_synchronizecache10_task(iscsilun->iscsi, iscsilun->lun, 0, 0, 0,
666                                       0, iscsi_co_generic_cb, &iTask) == NULL) {
667         return -ENOMEM;
668     }
669 
670     while (!iTask.complete) {
671         iscsi_set_events(iscsilun);
672         qemu_coroutine_yield();
673     }
674 
675     if (iTask.task != NULL) {
676         scsi_free_scsi_task(iTask.task);
677         iTask.task = NULL;
678     }
679 
680     if (iTask.do_retry) {
681         iTask.complete = 0;
682         goto retry;
683     }
684 
685     if (iTask.status != SCSI_STATUS_GOOD) {
686         return -EIO;
687     }
688 
689     return 0;
690 }
691 
692 #ifdef __linux__
693 static void
694 iscsi_aio_ioctl_cb(struct iscsi_context *iscsi, int status,
695                      void *command_data, void *opaque)
696 {
697     IscsiAIOCB *acb = opaque;
698 
699     g_free(acb->buf);
700     acb->buf = NULL;
701 
702     acb->status = 0;
703     if (status < 0) {
704         error_report("Failed to ioctl(SG_IO) to iSCSI lun. %s",
705                      iscsi_get_error(iscsi));
706         acb->status = -EIO;
707     }
708 
709     acb->ioh->driver_status = 0;
710     acb->ioh->host_status   = 0;
711     acb->ioh->resid         = 0;
712 
713 #define SG_ERR_DRIVER_SENSE    0x08
714 
715     if (status == SCSI_STATUS_CHECK_CONDITION && acb->task->datain.size >= 2) {
716         int ss;
717 
718         acb->ioh->driver_status |= SG_ERR_DRIVER_SENSE;
719 
720         acb->ioh->sb_len_wr = acb->task->datain.size - 2;
721         ss = (acb->ioh->mx_sb_len >= acb->ioh->sb_len_wr) ?
722              acb->ioh->mx_sb_len : acb->ioh->sb_len_wr;
723         memcpy(acb->ioh->sbp, &acb->task->datain.data[2], ss);
724     }
725 
726     iscsi_schedule_bh(acb);
727 }
728 
729 static BlockAIOCB *iscsi_aio_ioctl(BlockDriverState *bs,
730         unsigned long int req, void *buf,
731         BlockCompletionFunc *cb, void *opaque)
732 {
733     IscsiLun *iscsilun = bs->opaque;
734     struct iscsi_context *iscsi = iscsilun->iscsi;
735     struct iscsi_data data;
736     IscsiAIOCB *acb;
737 
738     assert(req == SG_IO);
739 
740     acb = qemu_aio_get(&iscsi_aiocb_info, bs, cb, opaque);
741 
742     acb->iscsilun = iscsilun;
743     acb->bh          = NULL;
744     acb->status      = -EINPROGRESS;
745     acb->buf         = NULL;
746     acb->ioh         = buf;
747 
748     acb->task = malloc(sizeof(struct scsi_task));
749     if (acb->task == NULL) {
750         error_report("iSCSI: Failed to allocate task for scsi command. %s",
751                      iscsi_get_error(iscsi));
752         qemu_aio_unref(acb);
753         return NULL;
754     }
755     memset(acb->task, 0, sizeof(struct scsi_task));
756 
757     switch (acb->ioh->dxfer_direction) {
758     case SG_DXFER_TO_DEV:
759         acb->task->xfer_dir = SCSI_XFER_WRITE;
760         break;
761     case SG_DXFER_FROM_DEV:
762         acb->task->xfer_dir = SCSI_XFER_READ;
763         break;
764     default:
765         acb->task->xfer_dir = SCSI_XFER_NONE;
766         break;
767     }
768 
769     acb->task->cdb_size = acb->ioh->cmd_len;
770     memcpy(&acb->task->cdb[0], acb->ioh->cmdp, acb->ioh->cmd_len);
771     acb->task->expxferlen = acb->ioh->dxfer_len;
772 
773     data.size = 0;
774     if (acb->task->xfer_dir == SCSI_XFER_WRITE) {
775         if (acb->ioh->iovec_count == 0) {
776             data.data = acb->ioh->dxferp;
777             data.size = acb->ioh->dxfer_len;
778         } else {
779             scsi_task_set_iov_out(acb->task,
780                                  (struct scsi_iovec *) acb->ioh->dxferp,
781                                  acb->ioh->iovec_count);
782         }
783     }
784 
785     if (iscsi_scsi_command_async(iscsi, iscsilun->lun, acb->task,
786                                  iscsi_aio_ioctl_cb,
787                                  (data.size > 0) ? &data : NULL,
788                                  acb) != 0) {
789         scsi_free_scsi_task(acb->task);
790         qemu_aio_unref(acb);
791         return NULL;
792     }
793 
794     /* tell libiscsi to read straight into the buffer we got from ioctl */
795     if (acb->task->xfer_dir == SCSI_XFER_READ) {
796         if (acb->ioh->iovec_count == 0) {
797             scsi_task_add_data_in_buffer(acb->task,
798                                          acb->ioh->dxfer_len,
799                                          acb->ioh->dxferp);
800         } else {
801             scsi_task_set_iov_in(acb->task,
802                                  (struct scsi_iovec *) acb->ioh->dxferp,
803                                  acb->ioh->iovec_count);
804         }
805     }
806 
807     iscsi_set_events(iscsilun);
808 
809     return &acb->common;
810 }
811 
812 static void ioctl_cb(void *opaque, int status)
813 {
814     int *p_status = opaque;
815     *p_status = status;
816 }
817 
818 static int iscsi_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
819 {
820     IscsiLun *iscsilun = bs->opaque;
821     int status;
822 
823     switch (req) {
824     case SG_GET_VERSION_NUM:
825         *(int *)buf = 30000;
826         break;
827     case SG_GET_SCSI_ID:
828         ((struct sg_scsi_id *)buf)->scsi_type = iscsilun->type;
829         break;
830     case SG_IO:
831         status = -EINPROGRESS;
832         iscsi_aio_ioctl(bs, req, buf, ioctl_cb, &status);
833 
834         while (status == -EINPROGRESS) {
835             aio_poll(iscsilun->aio_context, true);
836         }
837 
838         return 0;
839     default:
840         return -1;
841     }
842     return 0;
843 }
844 #endif
845 
846 static int64_t
847 iscsi_getlength(BlockDriverState *bs)
848 {
849     IscsiLun *iscsilun = bs->opaque;
850     int64_t len;
851 
852     len  = iscsilun->num_blocks;
853     len *= iscsilun->block_size;
854 
855     return len;
856 }
857 
858 static int
859 coroutine_fn iscsi_co_discard(BlockDriverState *bs, int64_t sector_num,
860                                    int nb_sectors)
861 {
862     IscsiLun *iscsilun = bs->opaque;
863     struct IscsiTask iTask;
864     struct unmap_list list;
865 
866     if (!is_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
867         return -EINVAL;
868     }
869 
870     if (!iscsilun->lbp.lbpu) {
871         /* UNMAP is not supported by the target */
872         return 0;
873     }
874 
875     list.lba = sector_qemu2lun(sector_num, iscsilun);
876     list.num = sector_qemu2lun(nb_sectors, iscsilun);
877 
878     iscsi_co_init_iscsitask(iscsilun, &iTask);
879 retry:
880     if (iscsi_unmap_task(iscsilun->iscsi, iscsilun->lun, 0, 0, &list, 1,
881                      iscsi_co_generic_cb, &iTask) == NULL) {
882         return -ENOMEM;
883     }
884 
885     while (!iTask.complete) {
886         iscsi_set_events(iscsilun);
887         qemu_coroutine_yield();
888     }
889 
890     if (iTask.task != NULL) {
891         scsi_free_scsi_task(iTask.task);
892         iTask.task = NULL;
893     }
894 
895     if (iTask.do_retry) {
896         iTask.complete = 0;
897         goto retry;
898     }
899 
900     if (iTask.status == SCSI_STATUS_CHECK_CONDITION) {
901         /* the target might fail with a check condition if it
902            is not happy with the alignment of the UNMAP request
903            we silently fail in this case */
904         return 0;
905     }
906 
907     if (iTask.status != SCSI_STATUS_GOOD) {
908         return -EIO;
909     }
910 
911     iscsi_allocationmap_clear(iscsilun, sector_num, nb_sectors);
912 
913     return 0;
914 }
915 
916 static int
917 coroutine_fn iscsi_co_write_zeroes(BlockDriverState *bs, int64_t sector_num,
918                                    int nb_sectors, BdrvRequestFlags flags)
919 {
920     IscsiLun *iscsilun = bs->opaque;
921     struct IscsiTask iTask;
922     uint64_t lba;
923     uint32_t nb_blocks;
924     bool use_16_for_ws = iscsilun->use_16_for_rw;
925 
926     if (!is_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
927         return -EINVAL;
928     }
929 
930     if (flags & BDRV_REQ_MAY_UNMAP) {
931         if (!use_16_for_ws && !iscsilun->lbp.lbpws10) {
932             /* WRITESAME10 with UNMAP is unsupported try WRITESAME16 */
933             use_16_for_ws = true;
934         }
935         if (use_16_for_ws && !iscsilun->lbp.lbpws) {
936             /* WRITESAME16 with UNMAP is not supported by the target,
937              * fall back and try WRITESAME10/16 without UNMAP */
938             flags &= ~BDRV_REQ_MAY_UNMAP;
939             use_16_for_ws = iscsilun->use_16_for_rw;
940         }
941     }
942 
943     if (!(flags & BDRV_REQ_MAY_UNMAP) && !iscsilun->has_write_same) {
944         /* WRITESAME without UNMAP is not supported by the target */
945         return -ENOTSUP;
946     }
947 
948     lba = sector_qemu2lun(sector_num, iscsilun);
949     nb_blocks = sector_qemu2lun(nb_sectors, iscsilun);
950 
951     if (iscsilun->zeroblock == NULL) {
952         iscsilun->zeroblock = g_try_malloc0(iscsilun->block_size);
953         if (iscsilun->zeroblock == NULL) {
954             return -ENOMEM;
955         }
956     }
957 
958     iscsi_co_init_iscsitask(iscsilun, &iTask);
959     iTask.force_next_flush = true;
960 retry:
961     if (use_16_for_ws) {
962         iTask.task = iscsi_writesame16_task(iscsilun->iscsi, iscsilun->lun, lba,
963                                             iscsilun->zeroblock, iscsilun->block_size,
964                                             nb_blocks, 0, !!(flags & BDRV_REQ_MAY_UNMAP),
965                                             0, 0, iscsi_co_generic_cb, &iTask);
966     } else {
967         iTask.task = iscsi_writesame10_task(iscsilun->iscsi, iscsilun->lun, lba,
968                                             iscsilun->zeroblock, iscsilun->block_size,
969                                             nb_blocks, 0, !!(flags & BDRV_REQ_MAY_UNMAP),
970                                             0, 0, iscsi_co_generic_cb, &iTask);
971     }
972     if (iTask.task == NULL) {
973         return -ENOMEM;
974     }
975 
976     while (!iTask.complete) {
977         iscsi_set_events(iscsilun);
978         qemu_coroutine_yield();
979     }
980 
981     if (iTask.status == SCSI_STATUS_CHECK_CONDITION &&
982         iTask.task->sense.key == SCSI_SENSE_ILLEGAL_REQUEST &&
983         (iTask.task->sense.ascq == SCSI_SENSE_ASCQ_INVALID_OPERATION_CODE ||
984          iTask.task->sense.ascq == SCSI_SENSE_ASCQ_INVALID_FIELD_IN_CDB)) {
985         /* WRITE SAME is not supported by the target */
986         iscsilun->has_write_same = false;
987         scsi_free_scsi_task(iTask.task);
988         return -ENOTSUP;
989     }
990 
991     if (iTask.task != NULL) {
992         scsi_free_scsi_task(iTask.task);
993         iTask.task = NULL;
994     }
995 
996     if (iTask.do_retry) {
997         iTask.complete = 0;
998         goto retry;
999     }
1000 
1001     if (iTask.status != SCSI_STATUS_GOOD) {
1002         return -EIO;
1003     }
1004 
1005     if (flags & BDRV_REQ_MAY_UNMAP) {
1006         iscsi_allocationmap_clear(iscsilun, sector_num, nb_sectors);
1007     } else {
1008         iscsi_allocationmap_set(iscsilun, sector_num, nb_sectors);
1009     }
1010 
1011     return 0;
1012 }
1013 
1014 static void parse_chap(struct iscsi_context *iscsi, const char *target,
1015                        Error **errp)
1016 {
1017     QemuOptsList *list;
1018     QemuOpts *opts;
1019     const char *user = NULL;
1020     const char *password = NULL;
1021 
1022     list = qemu_find_opts("iscsi");
1023     if (!list) {
1024         return;
1025     }
1026 
1027     opts = qemu_opts_find(list, target);
1028     if (opts == NULL) {
1029         opts = QTAILQ_FIRST(&list->head);
1030         if (!opts) {
1031             return;
1032         }
1033     }
1034 
1035     user = qemu_opt_get(opts, "user");
1036     if (!user) {
1037         return;
1038     }
1039 
1040     password = qemu_opt_get(opts, "password");
1041     if (!password) {
1042         error_setg(errp, "CHAP username specified but no password was given");
1043         return;
1044     }
1045 
1046     if (iscsi_set_initiator_username_pwd(iscsi, user, password)) {
1047         error_setg(errp, "Failed to set initiator username and password");
1048     }
1049 }
1050 
1051 static void parse_header_digest(struct iscsi_context *iscsi, const char *target,
1052                                 Error **errp)
1053 {
1054     QemuOptsList *list;
1055     QemuOpts *opts;
1056     const char *digest = NULL;
1057 
1058     list = qemu_find_opts("iscsi");
1059     if (!list) {
1060         return;
1061     }
1062 
1063     opts = qemu_opts_find(list, target);
1064     if (opts == NULL) {
1065         opts = QTAILQ_FIRST(&list->head);
1066         if (!opts) {
1067             return;
1068         }
1069     }
1070 
1071     digest = qemu_opt_get(opts, "header-digest");
1072     if (!digest) {
1073         return;
1074     }
1075 
1076     if (!strcmp(digest, "CRC32C")) {
1077         iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_CRC32C);
1078     } else if (!strcmp(digest, "NONE")) {
1079         iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_NONE);
1080     } else if (!strcmp(digest, "CRC32C-NONE")) {
1081         iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_CRC32C_NONE);
1082     } else if (!strcmp(digest, "NONE-CRC32C")) {
1083         iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_NONE_CRC32C);
1084     } else {
1085         error_setg(errp, "Invalid header-digest setting : %s", digest);
1086     }
1087 }
1088 
1089 static char *parse_initiator_name(const char *target)
1090 {
1091     QemuOptsList *list;
1092     QemuOpts *opts;
1093     const char *name;
1094     char *iscsi_name;
1095     UuidInfo *uuid_info;
1096 
1097     list = qemu_find_opts("iscsi");
1098     if (list) {
1099         opts = qemu_opts_find(list, target);
1100         if (!opts) {
1101             opts = QTAILQ_FIRST(&list->head);
1102         }
1103         if (opts) {
1104             name = qemu_opt_get(opts, "initiator-name");
1105             if (name) {
1106                 return g_strdup(name);
1107             }
1108         }
1109     }
1110 
1111     uuid_info = qmp_query_uuid(NULL);
1112     if (strcmp(uuid_info->UUID, UUID_NONE) == 0) {
1113         name = qemu_get_vm_name();
1114     } else {
1115         name = uuid_info->UUID;
1116     }
1117     iscsi_name = g_strdup_printf("iqn.2008-11.org.linux-kvm%s%s",
1118                                  name ? ":" : "", name ? name : "");
1119     qapi_free_UuidInfo(uuid_info);
1120     return iscsi_name;
1121 }
1122 
1123 static int parse_timeout(const char *target)
1124 {
1125     QemuOptsList *list;
1126     QemuOpts *opts;
1127     const char *timeout;
1128 
1129     list = qemu_find_opts("iscsi");
1130     if (list) {
1131         opts = qemu_opts_find(list, target);
1132         if (!opts) {
1133             opts = QTAILQ_FIRST(&list->head);
1134         }
1135         if (opts) {
1136             timeout = qemu_opt_get(opts, "timeout");
1137             if (timeout) {
1138                 return atoi(timeout);
1139             }
1140         }
1141     }
1142 
1143     return 0;
1144 }
1145 
1146 static void iscsi_nop_timed_event(void *opaque)
1147 {
1148     IscsiLun *iscsilun = opaque;
1149 
1150     if (iscsi_get_nops_in_flight(iscsilun->iscsi) >= MAX_NOP_FAILURES) {
1151         error_report("iSCSI: NOP timeout. Reconnecting...");
1152         iscsilun->request_timed_out = true;
1153     } else if (iscsi_nop_out_async(iscsilun->iscsi, NULL, NULL, 0, NULL) != 0) {
1154         error_report("iSCSI: failed to sent NOP-Out. Disabling NOP messages.");
1155         return;
1156     }
1157 
1158     timer_mod(iscsilun->nop_timer, qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + NOP_INTERVAL);
1159     iscsi_set_events(iscsilun);
1160 }
1161 
1162 static void iscsi_readcapacity_sync(IscsiLun *iscsilun, Error **errp)
1163 {
1164     struct scsi_task *task = NULL;
1165     struct scsi_readcapacity10 *rc10 = NULL;
1166     struct scsi_readcapacity16 *rc16 = NULL;
1167     int retries = ISCSI_CMD_RETRIES;
1168 
1169     do {
1170         if (task != NULL) {
1171             scsi_free_scsi_task(task);
1172             task = NULL;
1173         }
1174 
1175         switch (iscsilun->type) {
1176         case TYPE_DISK:
1177             task = iscsi_readcapacity16_sync(iscsilun->iscsi, iscsilun->lun);
1178             if (task != NULL && task->status == SCSI_STATUS_GOOD) {
1179                 rc16 = scsi_datain_unmarshall(task);
1180                 if (rc16 == NULL) {
1181                     error_setg(errp, "iSCSI: Failed to unmarshall readcapacity16 data.");
1182                 } else {
1183                     iscsilun->block_size = rc16->block_length;
1184                     iscsilun->num_blocks = rc16->returned_lba + 1;
1185                     iscsilun->lbpme = !!rc16->lbpme;
1186                     iscsilun->lbprz = !!rc16->lbprz;
1187                     iscsilun->use_16_for_rw = (rc16->returned_lba > 0xffffffff);
1188                 }
1189             }
1190             break;
1191         case TYPE_ROM:
1192             task = iscsi_readcapacity10_sync(iscsilun->iscsi, iscsilun->lun, 0, 0);
1193             if (task != NULL && task->status == SCSI_STATUS_GOOD) {
1194                 rc10 = scsi_datain_unmarshall(task);
1195                 if (rc10 == NULL) {
1196                     error_setg(errp, "iSCSI: Failed to unmarshall readcapacity10 data.");
1197                 } else {
1198                     iscsilun->block_size = rc10->block_size;
1199                     if (rc10->lba == 0) {
1200                         /* blank disk loaded */
1201                         iscsilun->num_blocks = 0;
1202                     } else {
1203                         iscsilun->num_blocks = rc10->lba + 1;
1204                     }
1205                 }
1206             }
1207             break;
1208         default:
1209             return;
1210         }
1211     } while (task != NULL && task->status == SCSI_STATUS_CHECK_CONDITION
1212              && task->sense.key == SCSI_SENSE_UNIT_ATTENTION
1213              && retries-- > 0);
1214 
1215     if (task == NULL || task->status != SCSI_STATUS_GOOD) {
1216         error_setg(errp, "iSCSI: failed to send readcapacity10 command.");
1217     } else if (!iscsilun->block_size ||
1218                iscsilun->block_size % BDRV_SECTOR_SIZE) {
1219         error_setg(errp, "iSCSI: the target returned an invalid "
1220                    "block size of %d.", iscsilun->block_size);
1221     }
1222     if (task) {
1223         scsi_free_scsi_task(task);
1224     }
1225 }
1226 
1227 /* TODO Convert to fine grained options */
1228 static QemuOptsList runtime_opts = {
1229     .name = "iscsi",
1230     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
1231     .desc = {
1232         {
1233             .name = "filename",
1234             .type = QEMU_OPT_STRING,
1235             .help = "URL to the iscsi image",
1236         },
1237         { /* end of list */ }
1238     },
1239 };
1240 
1241 static struct scsi_task *iscsi_do_inquiry(struct iscsi_context *iscsi, int lun,
1242                                           int evpd, int pc, void **inq, Error **errp)
1243 {
1244     int full_size;
1245     struct scsi_task *task = NULL;
1246     task = iscsi_inquiry_sync(iscsi, lun, evpd, pc, 64);
1247     if (task == NULL || task->status != SCSI_STATUS_GOOD) {
1248         goto fail;
1249     }
1250     full_size = scsi_datain_getfullsize(task);
1251     if (full_size > task->datain.size) {
1252         scsi_free_scsi_task(task);
1253 
1254         /* we need more data for the full list */
1255         task = iscsi_inquiry_sync(iscsi, lun, evpd, pc, full_size);
1256         if (task == NULL || task->status != SCSI_STATUS_GOOD) {
1257             goto fail;
1258         }
1259     }
1260 
1261     *inq = scsi_datain_unmarshall(task);
1262     if (*inq == NULL) {
1263         error_setg(errp, "iSCSI: failed to unmarshall inquiry datain blob");
1264         goto fail_with_err;
1265     }
1266 
1267     return task;
1268 
1269 fail:
1270     error_setg(errp, "iSCSI: Inquiry command failed : %s",
1271                iscsi_get_error(iscsi));
1272 fail_with_err:
1273     if (task != NULL) {
1274         scsi_free_scsi_task(task);
1275     }
1276     return NULL;
1277 }
1278 
1279 static void iscsi_detach_aio_context(BlockDriverState *bs)
1280 {
1281     IscsiLun *iscsilun = bs->opaque;
1282 
1283     aio_set_fd_handler(iscsilun->aio_context, iscsi_get_fd(iscsilun->iscsi),
1284                        false, NULL, NULL, NULL);
1285     iscsilun->events = 0;
1286 
1287     if (iscsilun->nop_timer) {
1288         timer_del(iscsilun->nop_timer);
1289         timer_free(iscsilun->nop_timer);
1290         iscsilun->nop_timer = NULL;
1291     }
1292     if (iscsilun->event_timer) {
1293         timer_del(iscsilun->event_timer);
1294         timer_free(iscsilun->event_timer);
1295         iscsilun->event_timer = NULL;
1296     }
1297 }
1298 
1299 static void iscsi_attach_aio_context(BlockDriverState *bs,
1300                                      AioContext *new_context)
1301 {
1302     IscsiLun *iscsilun = bs->opaque;
1303 
1304     iscsilun->aio_context = new_context;
1305     iscsi_set_events(iscsilun);
1306 
1307     /* Set up a timer for sending out iSCSI NOPs */
1308     iscsilun->nop_timer = aio_timer_new(iscsilun->aio_context,
1309                                         QEMU_CLOCK_REALTIME, SCALE_MS,
1310                                         iscsi_nop_timed_event, iscsilun);
1311     timer_mod(iscsilun->nop_timer,
1312               qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + NOP_INTERVAL);
1313 
1314     /* Set up a timer for periodic calls to iscsi_set_events and to
1315      * scan for command timeout */
1316     iscsilun->event_timer = aio_timer_new(iscsilun->aio_context,
1317                                           QEMU_CLOCK_REALTIME, SCALE_MS,
1318                                           iscsi_timed_check_events, iscsilun);
1319     timer_mod(iscsilun->event_timer,
1320               qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + EVENT_INTERVAL);
1321 }
1322 
1323 static void iscsi_modesense_sync(IscsiLun *iscsilun)
1324 {
1325     struct scsi_task *task;
1326     struct scsi_mode_sense *ms = NULL;
1327     iscsilun->write_protected = false;
1328     iscsilun->dpofua = false;
1329 
1330     task = iscsi_modesense6_sync(iscsilun->iscsi, iscsilun->lun,
1331                                  1, SCSI_MODESENSE_PC_CURRENT,
1332                                  0x3F, 0, 255);
1333     if (task == NULL) {
1334         error_report("iSCSI: Failed to send MODE_SENSE(6) command: %s",
1335                      iscsi_get_error(iscsilun->iscsi));
1336         goto out;
1337     }
1338 
1339     if (task->status != SCSI_STATUS_GOOD) {
1340         error_report("iSCSI: Failed MODE_SENSE(6), LUN assumed writable");
1341         goto out;
1342     }
1343     ms = scsi_datain_unmarshall(task);
1344     if (!ms) {
1345         error_report("iSCSI: Failed to unmarshall MODE_SENSE(6) data: %s",
1346                      iscsi_get_error(iscsilun->iscsi));
1347         goto out;
1348     }
1349     iscsilun->write_protected = ms->device_specific_parameter & 0x80;
1350     iscsilun->dpofua          = ms->device_specific_parameter & 0x10;
1351 
1352 out:
1353     if (task) {
1354         scsi_free_scsi_task(task);
1355     }
1356 }
1357 
1358 /*
1359  * We support iscsi url's on the form
1360  * iscsi://[<username>%<password>@]<host>[:<port>]/<targetname>/<lun>
1361  */
1362 static int iscsi_open(BlockDriverState *bs, QDict *options, int flags,
1363                       Error **errp)
1364 {
1365     IscsiLun *iscsilun = bs->opaque;
1366     struct iscsi_context *iscsi = NULL;
1367     struct iscsi_url *iscsi_url = NULL;
1368     struct scsi_task *task = NULL;
1369     struct scsi_inquiry_standard *inq = NULL;
1370     struct scsi_inquiry_supported_pages *inq_vpd;
1371     char *initiator_name = NULL;
1372     QemuOpts *opts;
1373     Error *local_err = NULL;
1374     const char *filename;
1375     int i, ret = 0, timeout = 0;
1376 
1377     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
1378     qemu_opts_absorb_qdict(opts, options, &local_err);
1379     if (local_err) {
1380         error_propagate(errp, local_err);
1381         ret = -EINVAL;
1382         goto out;
1383     }
1384 
1385     filename = qemu_opt_get(opts, "filename");
1386 
1387     iscsi_url = iscsi_parse_full_url(iscsi, filename);
1388     if (iscsi_url == NULL) {
1389         error_setg(errp, "Failed to parse URL : %s", filename);
1390         ret = -EINVAL;
1391         goto out;
1392     }
1393 
1394     memset(iscsilun, 0, sizeof(IscsiLun));
1395 
1396     initiator_name = parse_initiator_name(iscsi_url->target);
1397 
1398     iscsi = iscsi_create_context(initiator_name);
1399     if (iscsi == NULL) {
1400         error_setg(errp, "iSCSI: Failed to create iSCSI context.");
1401         ret = -ENOMEM;
1402         goto out;
1403     }
1404 
1405     if (iscsi_set_targetname(iscsi, iscsi_url->target)) {
1406         error_setg(errp, "iSCSI: Failed to set target name.");
1407         ret = -EINVAL;
1408         goto out;
1409     }
1410 
1411     if (iscsi_url->user[0] != '\0') {
1412         ret = iscsi_set_initiator_username_pwd(iscsi, iscsi_url->user,
1413                                               iscsi_url->passwd);
1414         if (ret != 0) {
1415             error_setg(errp, "Failed to set initiator username and password");
1416             ret = -EINVAL;
1417             goto out;
1418         }
1419     }
1420 
1421     /* check if we got CHAP username/password via the options */
1422     parse_chap(iscsi, iscsi_url->target, &local_err);
1423     if (local_err != NULL) {
1424         error_propagate(errp, local_err);
1425         ret = -EINVAL;
1426         goto out;
1427     }
1428 
1429     if (iscsi_set_session_type(iscsi, ISCSI_SESSION_NORMAL) != 0) {
1430         error_setg(errp, "iSCSI: Failed to set session type to normal.");
1431         ret = -EINVAL;
1432         goto out;
1433     }
1434 
1435     iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_NONE_CRC32C);
1436 
1437     /* check if we got HEADER_DIGEST via the options */
1438     parse_header_digest(iscsi, iscsi_url->target, &local_err);
1439     if (local_err != NULL) {
1440         error_propagate(errp, local_err);
1441         ret = -EINVAL;
1442         goto out;
1443     }
1444 
1445     /* timeout handling is broken in libiscsi before 1.15.0 */
1446     timeout = parse_timeout(iscsi_url->target);
1447 #if defined(LIBISCSI_API_VERSION) && LIBISCSI_API_VERSION >= 20150621
1448     iscsi_set_timeout(iscsi, timeout);
1449 #else
1450     if (timeout) {
1451         error_report("iSCSI: ignoring timeout value for libiscsi <1.15.0");
1452     }
1453 #endif
1454 
1455     if (iscsi_full_connect_sync(iscsi, iscsi_url->portal, iscsi_url->lun) != 0) {
1456         error_setg(errp, "iSCSI: Failed to connect to LUN : %s",
1457             iscsi_get_error(iscsi));
1458         ret = -EINVAL;
1459         goto out;
1460     }
1461 
1462     iscsilun->iscsi = iscsi;
1463     iscsilun->aio_context = bdrv_get_aio_context(bs);
1464     iscsilun->lun   = iscsi_url->lun;
1465     iscsilun->has_write_same = true;
1466 
1467     task = iscsi_do_inquiry(iscsilun->iscsi, iscsilun->lun, 0, 0,
1468                             (void **) &inq, errp);
1469     if (task == NULL) {
1470         ret = -EINVAL;
1471         goto out;
1472     }
1473     iscsilun->type = inq->periperal_device_type;
1474     scsi_free_scsi_task(task);
1475     task = NULL;
1476 
1477     iscsi_modesense_sync(iscsilun);
1478 
1479     /* Check the write protect flag of the LUN if we want to write */
1480     if (iscsilun->type == TYPE_DISK && (flags & BDRV_O_RDWR) &&
1481         iscsilun->write_protected) {
1482         error_setg(errp, "Cannot open a write protected LUN as read-write");
1483         ret = -EACCES;
1484         goto out;
1485     }
1486 
1487     iscsi_readcapacity_sync(iscsilun, &local_err);
1488     if (local_err != NULL) {
1489         error_propagate(errp, local_err);
1490         ret = -EINVAL;
1491         goto out;
1492     }
1493     bs->total_sectors = sector_lun2qemu(iscsilun->num_blocks, iscsilun);
1494     bs->request_alignment = iscsilun->block_size;
1495 
1496     /* We don't have any emulation for devices other than disks and CD-ROMs, so
1497      * this must be sg ioctl compatible. We force it to be sg, otherwise qemu
1498      * will try to read from the device to guess the image format.
1499      */
1500     if (iscsilun->type != TYPE_DISK && iscsilun->type != TYPE_ROM) {
1501         bs->sg = 1;
1502     }
1503 
1504     task = iscsi_do_inquiry(iscsilun->iscsi, iscsilun->lun, 1,
1505                             SCSI_INQUIRY_PAGECODE_SUPPORTED_VPD_PAGES,
1506                             (void **) &inq_vpd, errp);
1507     if (task == NULL) {
1508         ret = -EINVAL;
1509         goto out;
1510     }
1511     for (i = 0; i < inq_vpd->num_pages; i++) {
1512         struct scsi_task *inq_task;
1513         struct scsi_inquiry_logical_block_provisioning *inq_lbp;
1514         struct scsi_inquiry_block_limits *inq_bl;
1515         switch (inq_vpd->pages[i]) {
1516         case SCSI_INQUIRY_PAGECODE_LOGICAL_BLOCK_PROVISIONING:
1517             inq_task = iscsi_do_inquiry(iscsilun->iscsi, iscsilun->lun, 1,
1518                                         SCSI_INQUIRY_PAGECODE_LOGICAL_BLOCK_PROVISIONING,
1519                                         (void **) &inq_lbp, errp);
1520             if (inq_task == NULL) {
1521                 ret = -EINVAL;
1522                 goto out;
1523             }
1524             memcpy(&iscsilun->lbp, inq_lbp,
1525                    sizeof(struct scsi_inquiry_logical_block_provisioning));
1526             scsi_free_scsi_task(inq_task);
1527             break;
1528         case SCSI_INQUIRY_PAGECODE_BLOCK_LIMITS:
1529             inq_task = iscsi_do_inquiry(iscsilun->iscsi, iscsilun->lun, 1,
1530                                     SCSI_INQUIRY_PAGECODE_BLOCK_LIMITS,
1531                                     (void **) &inq_bl, errp);
1532             if (inq_task == NULL) {
1533                 ret = -EINVAL;
1534                 goto out;
1535             }
1536             memcpy(&iscsilun->bl, inq_bl,
1537                    sizeof(struct scsi_inquiry_block_limits));
1538             scsi_free_scsi_task(inq_task);
1539             break;
1540         default:
1541             break;
1542         }
1543     }
1544     scsi_free_scsi_task(task);
1545     task = NULL;
1546 
1547     iscsi_attach_aio_context(bs, iscsilun->aio_context);
1548 
1549     /* Guess the internal cluster (page) size of the iscsi target by the means
1550      * of opt_unmap_gran. Transfer the unmap granularity only if it has a
1551      * reasonable size */
1552     if (iscsilun->bl.opt_unmap_gran * iscsilun->block_size >= 4 * 1024 &&
1553         iscsilun->bl.opt_unmap_gran * iscsilun->block_size <= 16 * 1024 * 1024) {
1554         iscsilun->cluster_sectors = (iscsilun->bl.opt_unmap_gran *
1555                                      iscsilun->block_size) >> BDRV_SECTOR_BITS;
1556         if (iscsilun->lbprz) {
1557             iscsilun->allocationmap = iscsi_allocationmap_init(iscsilun);
1558             if (iscsilun->allocationmap == NULL) {
1559                 ret = -ENOMEM;
1560             }
1561         }
1562     }
1563 
1564 out:
1565     qemu_opts_del(opts);
1566     g_free(initiator_name);
1567     if (iscsi_url != NULL) {
1568         iscsi_destroy_url(iscsi_url);
1569     }
1570     if (task != NULL) {
1571         scsi_free_scsi_task(task);
1572     }
1573 
1574     if (ret) {
1575         if (iscsi != NULL) {
1576             if (iscsi_is_logged_in(iscsi)) {
1577                 iscsi_logout_sync(iscsi);
1578             }
1579             iscsi_destroy_context(iscsi);
1580         }
1581         memset(iscsilun, 0, sizeof(IscsiLun));
1582     }
1583     return ret;
1584 }
1585 
1586 static void iscsi_close(BlockDriverState *bs)
1587 {
1588     IscsiLun *iscsilun = bs->opaque;
1589     struct iscsi_context *iscsi = iscsilun->iscsi;
1590 
1591     iscsi_detach_aio_context(bs);
1592     if (iscsi_is_logged_in(iscsi)) {
1593         iscsi_logout_sync(iscsi);
1594     }
1595     iscsi_destroy_context(iscsi);
1596     g_free(iscsilun->zeroblock);
1597     g_free(iscsilun->allocationmap);
1598     memset(iscsilun, 0, sizeof(IscsiLun));
1599 }
1600 
1601 static int sector_limits_lun2qemu(int64_t sector, IscsiLun *iscsilun)
1602 {
1603     return MIN(sector_lun2qemu(sector, iscsilun), INT_MAX / 2 + 1);
1604 }
1605 
1606 static void iscsi_refresh_limits(BlockDriverState *bs, Error **errp)
1607 {
1608     /* We don't actually refresh here, but just return data queried in
1609      * iscsi_open(): iscsi targets don't change their limits. */
1610 
1611     IscsiLun *iscsilun = bs->opaque;
1612     uint32_t max_xfer_len = iscsilun->use_16_for_rw ? 0xffffffff : 0xffff;
1613 
1614     if (iscsilun->bl.max_xfer_len) {
1615         max_xfer_len = MIN(max_xfer_len, iscsilun->bl.max_xfer_len);
1616     }
1617 
1618     bs->bl.max_transfer_length = sector_limits_lun2qemu(max_xfer_len, iscsilun);
1619 
1620     if (iscsilun->lbp.lbpu) {
1621         if (iscsilun->bl.max_unmap < 0xffffffff) {
1622             bs->bl.max_discard =
1623                 sector_limits_lun2qemu(iscsilun->bl.max_unmap, iscsilun);
1624         }
1625         bs->bl.discard_alignment =
1626             sector_limits_lun2qemu(iscsilun->bl.opt_unmap_gran, iscsilun);
1627     }
1628 
1629     if (iscsilun->bl.max_ws_len < 0xffffffff) {
1630         bs->bl.max_write_zeroes =
1631             sector_limits_lun2qemu(iscsilun->bl.max_ws_len, iscsilun);
1632     }
1633     if (iscsilun->lbp.lbpws) {
1634         bs->bl.write_zeroes_alignment =
1635             sector_limits_lun2qemu(iscsilun->bl.opt_unmap_gran, iscsilun);
1636     }
1637     bs->bl.opt_transfer_length =
1638         sector_limits_lun2qemu(iscsilun->bl.opt_xfer_len, iscsilun);
1639 }
1640 
1641 /* Note that this will not re-establish a connection with an iSCSI target - it
1642  * is effectively a NOP.  */
1643 static int iscsi_reopen_prepare(BDRVReopenState *state,
1644                                 BlockReopenQueue *queue, Error **errp)
1645 {
1646     IscsiLun *iscsilun = state->bs->opaque;
1647 
1648     if (state->flags & BDRV_O_RDWR && iscsilun->write_protected) {
1649         error_setg(errp, "Cannot open a write protected LUN as read-write");
1650         return -EACCES;
1651     }
1652     return 0;
1653 }
1654 
1655 static int iscsi_truncate(BlockDriverState *bs, int64_t offset)
1656 {
1657     IscsiLun *iscsilun = bs->opaque;
1658     Error *local_err = NULL;
1659 
1660     if (iscsilun->type != TYPE_DISK) {
1661         return -ENOTSUP;
1662     }
1663 
1664     iscsi_readcapacity_sync(iscsilun, &local_err);
1665     if (local_err != NULL) {
1666         error_free(local_err);
1667         return -EIO;
1668     }
1669 
1670     if (offset > iscsi_getlength(bs)) {
1671         return -EINVAL;
1672     }
1673 
1674     if (iscsilun->allocationmap != NULL) {
1675         g_free(iscsilun->allocationmap);
1676         iscsilun->allocationmap = iscsi_allocationmap_init(iscsilun);
1677     }
1678 
1679     return 0;
1680 }
1681 
1682 static int iscsi_create(const char *filename, QemuOpts *opts, Error **errp)
1683 {
1684     int ret = 0;
1685     int64_t total_size = 0;
1686     BlockDriverState *bs;
1687     IscsiLun *iscsilun = NULL;
1688     QDict *bs_options;
1689 
1690     bs = bdrv_new();
1691 
1692     /* Read out options */
1693     total_size = DIV_ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
1694                               BDRV_SECTOR_SIZE);
1695     bs->opaque = g_new0(struct IscsiLun, 1);
1696     iscsilun = bs->opaque;
1697 
1698     bs_options = qdict_new();
1699     qdict_put(bs_options, "filename", qstring_from_str(filename));
1700     ret = iscsi_open(bs, bs_options, 0, NULL);
1701     QDECREF(bs_options);
1702 
1703     if (ret != 0) {
1704         goto out;
1705     }
1706     iscsi_detach_aio_context(bs);
1707     if (iscsilun->type != TYPE_DISK) {
1708         ret = -ENODEV;
1709         goto out;
1710     }
1711     if (bs->total_sectors < total_size) {
1712         ret = -ENOSPC;
1713         goto out;
1714     }
1715 
1716     ret = 0;
1717 out:
1718     if (iscsilun->iscsi != NULL) {
1719         iscsi_destroy_context(iscsilun->iscsi);
1720     }
1721     g_free(bs->opaque);
1722     bs->opaque = NULL;
1723     bdrv_unref(bs);
1724     return ret;
1725 }
1726 
1727 static int iscsi_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
1728 {
1729     IscsiLun *iscsilun = bs->opaque;
1730     bdi->unallocated_blocks_are_zero = iscsilun->lbprz;
1731     bdi->can_write_zeroes_with_unmap = iscsilun->lbprz && iscsilun->lbp.lbpws;
1732     bdi->cluster_size = iscsilun->cluster_sectors * BDRV_SECTOR_SIZE;
1733     return 0;
1734 }
1735 
1736 static QemuOptsList iscsi_create_opts = {
1737     .name = "iscsi-create-opts",
1738     .head = QTAILQ_HEAD_INITIALIZER(iscsi_create_opts.head),
1739     .desc = {
1740         {
1741             .name = BLOCK_OPT_SIZE,
1742             .type = QEMU_OPT_SIZE,
1743             .help = "Virtual disk size"
1744         },
1745         { /* end of list */ }
1746     }
1747 };
1748 
1749 static BlockDriver bdrv_iscsi = {
1750     .format_name     = "iscsi",
1751     .protocol_name   = "iscsi",
1752 
1753     .instance_size   = sizeof(IscsiLun),
1754     .bdrv_needs_filename = true,
1755     .bdrv_file_open  = iscsi_open,
1756     .bdrv_close      = iscsi_close,
1757     .bdrv_create     = iscsi_create,
1758     .create_opts     = &iscsi_create_opts,
1759     .bdrv_reopen_prepare  = iscsi_reopen_prepare,
1760 
1761     .bdrv_getlength  = iscsi_getlength,
1762     .bdrv_get_info   = iscsi_get_info,
1763     .bdrv_truncate   = iscsi_truncate,
1764     .bdrv_refresh_limits = iscsi_refresh_limits,
1765 
1766     .bdrv_co_get_block_status = iscsi_co_get_block_status,
1767     .bdrv_co_discard      = iscsi_co_discard,
1768     .bdrv_co_write_zeroes = iscsi_co_write_zeroes,
1769     .bdrv_co_readv         = iscsi_co_readv,
1770     .bdrv_co_writev        = iscsi_co_writev,
1771     .bdrv_co_flush_to_disk = iscsi_co_flush,
1772 
1773 #ifdef __linux__
1774     .bdrv_ioctl       = iscsi_ioctl,
1775     .bdrv_aio_ioctl   = iscsi_aio_ioctl,
1776 #endif
1777 
1778     .bdrv_detach_aio_context = iscsi_detach_aio_context,
1779     .bdrv_attach_aio_context = iscsi_attach_aio_context,
1780 };
1781 
1782 static QemuOptsList qemu_iscsi_opts = {
1783     .name = "iscsi",
1784     .head = QTAILQ_HEAD_INITIALIZER(qemu_iscsi_opts.head),
1785     .desc = {
1786         {
1787             .name = "user",
1788             .type = QEMU_OPT_STRING,
1789             .help = "username for CHAP authentication to target",
1790         },{
1791             .name = "password",
1792             .type = QEMU_OPT_STRING,
1793             .help = "password for CHAP authentication to target",
1794         },{
1795             .name = "header-digest",
1796             .type = QEMU_OPT_STRING,
1797             .help = "HeaderDigest setting. "
1798                     "{CRC32C|CRC32C-NONE|NONE-CRC32C|NONE}",
1799         },{
1800             .name = "initiator-name",
1801             .type = QEMU_OPT_STRING,
1802             .help = "Initiator iqn name to use when connecting",
1803         },{
1804             .name = "timeout",
1805             .type = QEMU_OPT_NUMBER,
1806             .help = "Request timeout in seconds (default 0 = no timeout)",
1807         },
1808         { /* end of list */ }
1809     },
1810 };
1811 
1812 static void iscsi_block_init(void)
1813 {
1814     bdrv_register(&bdrv_iscsi);
1815     qemu_add_opts(&qemu_iscsi_opts);
1816 }
1817 
1818 block_init(iscsi_block_init);
1819