xref: /openbmc/qemu/hw/s390x/virtio-ccw.c (revision 5f333d79)
1 /*
2  * virtio ccw target implementation
3  *
4  * Copyright 2012,2015 IBM Corp.
5  * Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
6  *            Pierre Morel <pmorel@linux.vnet.ibm.com>
7  *
8  * This work is licensed under the terms of the GNU GPL, version 2 or (at
9  * your option) any later version. See the COPYING file in the top-level
10  * directory.
11  */
12 
13 #include "qemu/osdep.h"
14 #include "qapi/error.h"
15 #include "hw/hw.h"
16 #include "sysemu/block-backend.h"
17 #include "sysemu/blockdev.h"
18 #include "sysemu/sysemu.h"
19 #include "sysemu/kvm.h"
20 #include "net/net.h"
21 #include "hw/virtio/virtio.h"
22 #include "hw/virtio/virtio-serial.h"
23 #include "hw/virtio/virtio-net.h"
24 #include "hw/sysbus.h"
25 #include "qemu/bitops.h"
26 #include "qemu/error-report.h"
27 #include "hw/virtio/virtio-access.h"
28 #include "hw/virtio/virtio-bus.h"
29 #include "hw/s390x/adapter.h"
30 #include "hw/s390x/s390_flic.h"
31 
32 #include "hw/s390x/ioinst.h"
33 #include "hw/s390x/css.h"
34 #include "virtio-ccw.h"
35 #include "trace.h"
36 #include "hw/s390x/css-bridge.h"
37 
38 static void virtio_ccw_bus_new(VirtioBusState *bus, size_t bus_size,
39                                VirtioCcwDevice *dev);
40 
41 VirtIODevice *virtio_ccw_get_vdev(SubchDev *sch)
42 {
43     VirtIODevice *vdev = NULL;
44     VirtioCcwDevice *dev = sch->driver_data;
45 
46     if (dev) {
47         vdev = virtio_bus_get_device(&dev->bus);
48     }
49     return vdev;
50 }
51 
52 static void virtio_ccw_start_ioeventfd(VirtioCcwDevice *dev)
53 {
54     virtio_bus_start_ioeventfd(&dev->bus);
55 }
56 
57 static void virtio_ccw_stop_ioeventfd(VirtioCcwDevice *dev)
58 {
59     virtio_bus_stop_ioeventfd(&dev->bus);
60 }
61 
62 static bool virtio_ccw_ioeventfd_started(DeviceState *d)
63 {
64     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
65 
66     return dev->ioeventfd_started;
67 }
68 
69 static void virtio_ccw_ioeventfd_set_started(DeviceState *d, bool started,
70                                              bool err)
71 {
72     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
73 
74     dev->ioeventfd_started = started;
75     if (err) {
76         /* Disable ioeventfd for this device. */
77         dev->flags &= ~VIRTIO_CCW_FLAG_USE_IOEVENTFD;
78     }
79 }
80 
81 static bool virtio_ccw_ioeventfd_disabled(DeviceState *d)
82 {
83     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
84 
85     return dev->ioeventfd_disabled ||
86         !(dev->flags & VIRTIO_CCW_FLAG_USE_IOEVENTFD);
87 }
88 
89 static void virtio_ccw_ioeventfd_set_disabled(DeviceState *d, bool disabled)
90 {
91     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
92 
93     dev->ioeventfd_disabled = disabled;
94 }
95 
96 static int virtio_ccw_ioeventfd_assign(DeviceState *d, EventNotifier *notifier,
97                                        int n, bool assign)
98 {
99     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
100     CcwDevice *ccw_dev = CCW_DEVICE(dev);
101     SubchDev *sch = ccw_dev->sch;
102     uint32_t sch_id = (css_build_subchannel_id(sch) << 16) | sch->schid;
103 
104     return s390_assign_subch_ioeventfd(notifier, sch_id, n, assign);
105 }
106 
107 /* Communication blocks used by several channel commands. */
108 typedef struct VqInfoBlockLegacy {
109     uint64_t queue;
110     uint32_t align;
111     uint16_t index;
112     uint16_t num;
113 } QEMU_PACKED VqInfoBlockLegacy;
114 
115 typedef struct VqInfoBlock {
116     uint64_t desc;
117     uint32_t res0;
118     uint16_t index;
119     uint16_t num;
120     uint64_t avail;
121     uint64_t used;
122 } QEMU_PACKED VqInfoBlock;
123 
124 typedef struct VqConfigBlock {
125     uint16_t index;
126     uint16_t num_max;
127 } QEMU_PACKED VqConfigBlock;
128 
129 typedef struct VirtioFeatDesc {
130     uint32_t features;
131     uint8_t index;
132 } QEMU_PACKED VirtioFeatDesc;
133 
134 typedef struct VirtioThinintInfo {
135     hwaddr summary_indicator;
136     hwaddr device_indicator;
137     uint64_t ind_bit;
138     uint8_t isc;
139 } QEMU_PACKED VirtioThinintInfo;
140 
141 typedef struct VirtioRevInfo {
142     uint16_t revision;
143     uint16_t length;
144     uint8_t data[0];
145 } QEMU_PACKED VirtioRevInfo;
146 
147 /* Specify where the virtqueues for the subchannel are in guest memory. */
148 static int virtio_ccw_set_vqs(SubchDev *sch, VqInfoBlock *info,
149                               VqInfoBlockLegacy *linfo)
150 {
151     VirtIODevice *vdev = virtio_ccw_get_vdev(sch);
152     uint16_t index = info ? info->index : linfo->index;
153     uint16_t num = info ? info->num : linfo->num;
154     uint64_t desc = info ? info->desc : linfo->queue;
155 
156     if (index >= VIRTIO_CCW_QUEUE_MAX) {
157         return -EINVAL;
158     }
159 
160     /* Current code in virtio.c relies on 4K alignment. */
161     if (linfo && desc && (linfo->align != 4096)) {
162         return -EINVAL;
163     }
164 
165     if (!vdev) {
166         return -EINVAL;
167     }
168 
169     if (info) {
170         virtio_queue_set_rings(vdev, index, desc, info->avail, info->used);
171     } else {
172         virtio_queue_set_addr(vdev, index, desc);
173     }
174     if (!desc) {
175         virtio_queue_set_vector(vdev, index, VIRTIO_NO_VECTOR);
176     } else {
177         if (info) {
178             /* virtio-1 allows changing the ring size. */
179             if (virtio_queue_get_num(vdev, index) < num) {
180                 /* Fail if we exceed the maximum number. */
181                 return -EINVAL;
182             }
183             virtio_queue_set_num(vdev, index, num);
184         } else if (virtio_queue_get_num(vdev, index) > num) {
185             /* Fail if we don't have a big enough queue. */
186             return -EINVAL;
187         }
188         /* We ignore possible increased num for legacy for compatibility. */
189         virtio_queue_set_vector(vdev, index, index);
190     }
191     /* tell notify handler in case of config change */
192     vdev->config_vector = VIRTIO_CCW_QUEUE_MAX;
193     return 0;
194 }
195 
196 static void virtio_ccw_reset_virtio(VirtioCcwDevice *dev, VirtIODevice *vdev)
197 {
198     CcwDevice *ccw_dev = CCW_DEVICE(dev);
199 
200     virtio_ccw_stop_ioeventfd(dev);
201     virtio_reset(vdev);
202     if (dev->indicators) {
203         release_indicator(&dev->routes.adapter, dev->indicators);
204         dev->indicators = NULL;
205     }
206     if (dev->indicators2) {
207         release_indicator(&dev->routes.adapter, dev->indicators2);
208         dev->indicators2 = NULL;
209     }
210     if (dev->summary_indicator) {
211         release_indicator(&dev->routes.adapter, dev->summary_indicator);
212         dev->summary_indicator = NULL;
213     }
214     ccw_dev->sch->thinint_active = false;
215 }
216 
217 static int virtio_ccw_handle_set_vq(SubchDev *sch, CCW1 ccw, bool check_len,
218                                     bool is_legacy)
219 {
220     int ret;
221     VqInfoBlock info;
222     VqInfoBlockLegacy linfo;
223     size_t info_len = is_legacy ? sizeof(linfo) : sizeof(info);
224 
225     if (check_len) {
226         if (ccw.count != info_len) {
227             return -EINVAL;
228         }
229     } else if (ccw.count < info_len) {
230         /* Can't execute command. */
231         return -EINVAL;
232     }
233     if (!ccw.cda) {
234         return -EFAULT;
235     }
236     if (is_legacy) {
237         linfo.queue = address_space_ldq_be(&address_space_memory, ccw.cda,
238                                            MEMTXATTRS_UNSPECIFIED, NULL);
239         linfo.align = address_space_ldl_be(&address_space_memory,
240                                            ccw.cda + sizeof(linfo.queue),
241                                            MEMTXATTRS_UNSPECIFIED,
242                                            NULL);
243         linfo.index = address_space_lduw_be(&address_space_memory,
244                                             ccw.cda + sizeof(linfo.queue)
245                                             + sizeof(linfo.align),
246                                             MEMTXATTRS_UNSPECIFIED,
247                                             NULL);
248         linfo.num = address_space_lduw_be(&address_space_memory,
249                                           ccw.cda + sizeof(linfo.queue)
250                                           + sizeof(linfo.align)
251                                           + sizeof(linfo.index),
252                                           MEMTXATTRS_UNSPECIFIED,
253                                           NULL);
254         ret = virtio_ccw_set_vqs(sch, NULL, &linfo);
255     } else {
256         info.desc = address_space_ldq_be(&address_space_memory, ccw.cda,
257                                            MEMTXATTRS_UNSPECIFIED, NULL);
258         info.index = address_space_lduw_be(&address_space_memory,
259                                            ccw.cda + sizeof(info.desc)
260                                            + sizeof(info.res0),
261                                            MEMTXATTRS_UNSPECIFIED, NULL);
262         info.num = address_space_lduw_be(&address_space_memory,
263                                          ccw.cda + sizeof(info.desc)
264                                          + sizeof(info.res0)
265                                          + sizeof(info.index),
266                                          MEMTXATTRS_UNSPECIFIED, NULL);
267         info.avail = address_space_ldq_be(&address_space_memory,
268                                           ccw.cda + sizeof(info.desc)
269                                           + sizeof(info.res0)
270                                           + sizeof(info.index)
271                                           + sizeof(info.num),
272                                           MEMTXATTRS_UNSPECIFIED, NULL);
273         info.used = address_space_ldq_be(&address_space_memory,
274                                          ccw.cda + sizeof(info.desc)
275                                          + sizeof(info.res0)
276                                          + sizeof(info.index)
277                                          + sizeof(info.num)
278                                          + sizeof(info.avail),
279                                          MEMTXATTRS_UNSPECIFIED, NULL);
280         ret = virtio_ccw_set_vqs(sch, &info, NULL);
281     }
282     sch->curr_status.scsw.count = 0;
283     return ret;
284 }
285 
286 static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
287 {
288     int ret;
289     VirtioRevInfo revinfo;
290     uint8_t status;
291     VirtioFeatDesc features;
292     void *config;
293     hwaddr indicators;
294     VqConfigBlock vq_config;
295     VirtioCcwDevice *dev = sch->driver_data;
296     VirtIODevice *vdev = virtio_ccw_get_vdev(sch);
297     bool check_len;
298     int len;
299     hwaddr hw_len;
300     VirtioThinintInfo *thinint;
301 
302     if (!dev) {
303         return -EINVAL;
304     }
305 
306     trace_virtio_ccw_interpret_ccw(sch->cssid, sch->ssid, sch->schid,
307                                    ccw.cmd_code);
308     check_len = !((ccw.flags & CCW_FLAG_SLI) && !(ccw.flags & CCW_FLAG_DC));
309 
310     /* Look at the command. */
311     switch (ccw.cmd_code) {
312     case CCW_CMD_SET_VQ:
313         ret = virtio_ccw_handle_set_vq(sch, ccw, check_len, dev->revision < 1);
314         break;
315     case CCW_CMD_VDEV_RESET:
316         virtio_ccw_reset_virtio(dev, vdev);
317         ret = 0;
318         break;
319     case CCW_CMD_READ_FEAT:
320         if (check_len) {
321             if (ccw.count != sizeof(features)) {
322                 ret = -EINVAL;
323                 break;
324             }
325         } else if (ccw.count < sizeof(features)) {
326             /* Can't execute command. */
327             ret = -EINVAL;
328             break;
329         }
330         if (!ccw.cda) {
331             ret = -EFAULT;
332         } else {
333             features.index = address_space_ldub(&address_space_memory,
334                                                 ccw.cda
335                                                 + sizeof(features.features),
336                                                 MEMTXATTRS_UNSPECIFIED,
337                                                 NULL);
338             if (features.index == 0) {
339                 if (dev->revision >= 1) {
340                     /* Don't offer legacy features for modern devices. */
341                     features.features = (uint32_t)
342                         (vdev->host_features & ~VIRTIO_LEGACY_FEATURES);
343                 } else {
344                     features.features = (uint32_t)vdev->host_features;
345                 }
346             } else if ((features.index == 1) && (dev->revision >= 1)) {
347                 /*
348                  * Only offer feature bits beyond 31 if the guest has
349                  * negotiated at least revision 1.
350                  */
351                 features.features = (uint32_t)(vdev->host_features >> 32);
352             } else {
353                 /* Return zeroes if the guest supports more feature bits. */
354                 features.features = 0;
355             }
356             address_space_stl_le(&address_space_memory, ccw.cda,
357                                  features.features, MEMTXATTRS_UNSPECIFIED,
358                                  NULL);
359             sch->curr_status.scsw.count = ccw.count - sizeof(features);
360             ret = 0;
361         }
362         break;
363     case CCW_CMD_WRITE_FEAT:
364         if (check_len) {
365             if (ccw.count != sizeof(features)) {
366                 ret = -EINVAL;
367                 break;
368             }
369         } else if (ccw.count < sizeof(features)) {
370             /* Can't execute command. */
371             ret = -EINVAL;
372             break;
373         }
374         if (!ccw.cda) {
375             ret = -EFAULT;
376         } else {
377             features.index = address_space_ldub(&address_space_memory,
378                                                 ccw.cda
379                                                 + sizeof(features.features),
380                                                 MEMTXATTRS_UNSPECIFIED,
381                                                 NULL);
382             features.features = address_space_ldl_le(&address_space_memory,
383                                                      ccw.cda,
384                                                      MEMTXATTRS_UNSPECIFIED,
385                                                      NULL);
386             if (features.index == 0) {
387                 virtio_set_features(vdev,
388                                     (vdev->guest_features & 0xffffffff00000000ULL) |
389                                     features.features);
390             } else if ((features.index == 1) && (dev->revision >= 1)) {
391                 /*
392                  * If the guest did not negotiate at least revision 1,
393                  * we did not offer it any feature bits beyond 31. Such a
394                  * guest passing us any bit here is therefore buggy.
395                  */
396                 virtio_set_features(vdev,
397                                     (vdev->guest_features & 0x00000000ffffffffULL) |
398                                     ((uint64_t)features.features << 32));
399             } else {
400                 /*
401                  * If the guest supports more feature bits, assert that it
402                  * passes us zeroes for those we don't support.
403                  */
404                 if (features.features) {
405                     fprintf(stderr, "Guest bug: features[%i]=%x (expected 0)\n",
406                             features.index, features.features);
407                     /* XXX: do a unit check here? */
408                 }
409             }
410             sch->curr_status.scsw.count = ccw.count - sizeof(features);
411             ret = 0;
412         }
413         break;
414     case CCW_CMD_READ_CONF:
415         if (check_len) {
416             if (ccw.count > vdev->config_len) {
417                 ret = -EINVAL;
418                 break;
419             }
420         }
421         len = MIN(ccw.count, vdev->config_len);
422         if (!ccw.cda) {
423             ret = -EFAULT;
424         } else {
425             virtio_bus_get_vdev_config(&dev->bus, vdev->config);
426             /* XXX config space endianness */
427             cpu_physical_memory_write(ccw.cda, vdev->config, len);
428             sch->curr_status.scsw.count = ccw.count - len;
429             ret = 0;
430         }
431         break;
432     case CCW_CMD_WRITE_CONF:
433         if (check_len) {
434             if (ccw.count > vdev->config_len) {
435                 ret = -EINVAL;
436                 break;
437             }
438         }
439         len = MIN(ccw.count, vdev->config_len);
440         hw_len = len;
441         if (!ccw.cda) {
442             ret = -EFAULT;
443         } else {
444             config = cpu_physical_memory_map(ccw.cda, &hw_len, 0);
445             if (!config) {
446                 ret = -EFAULT;
447             } else {
448                 len = hw_len;
449                 /* XXX config space endianness */
450                 memcpy(vdev->config, config, len);
451                 cpu_physical_memory_unmap(config, hw_len, 0, hw_len);
452                 virtio_bus_set_vdev_config(&dev->bus, vdev->config);
453                 sch->curr_status.scsw.count = ccw.count - len;
454                 ret = 0;
455             }
456         }
457         break;
458     case CCW_CMD_READ_STATUS:
459         if (check_len) {
460             if (ccw.count != sizeof(status)) {
461                 ret = -EINVAL;
462                 break;
463             }
464         } else if (ccw.count < sizeof(status)) {
465             /* Can't execute command. */
466             ret = -EINVAL;
467             break;
468         }
469         if (!ccw.cda) {
470             ret = -EFAULT;
471         } else {
472             address_space_stb(&address_space_memory, ccw.cda, vdev->status,
473                                         MEMTXATTRS_UNSPECIFIED, NULL);
474             sch->curr_status.scsw.count = ccw.count - sizeof(vdev->status);;
475             ret = 0;
476         }
477         break;
478     case CCW_CMD_WRITE_STATUS:
479         if (check_len) {
480             if (ccw.count != sizeof(status)) {
481                 ret = -EINVAL;
482                 break;
483             }
484         } else if (ccw.count < sizeof(status)) {
485             /* Can't execute command. */
486             ret = -EINVAL;
487             break;
488         }
489         if (!ccw.cda) {
490             ret = -EFAULT;
491         } else {
492             status = address_space_ldub(&address_space_memory, ccw.cda,
493                                         MEMTXATTRS_UNSPECIFIED, NULL);
494             if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
495                 virtio_ccw_stop_ioeventfd(dev);
496             }
497             if (virtio_set_status(vdev, status) == 0) {
498                 if (vdev->status == 0) {
499                     virtio_ccw_reset_virtio(dev, vdev);
500                 }
501                 if (status & VIRTIO_CONFIG_S_DRIVER_OK) {
502                     virtio_ccw_start_ioeventfd(dev);
503                 }
504                 sch->curr_status.scsw.count = ccw.count - sizeof(status);
505                 ret = 0;
506             } else {
507                 /* Trigger a command reject. */
508                 ret = -ENOSYS;
509             }
510         }
511         break;
512     case CCW_CMD_SET_IND:
513         if (check_len) {
514             if (ccw.count != sizeof(indicators)) {
515                 ret = -EINVAL;
516                 break;
517             }
518         } else if (ccw.count < sizeof(indicators)) {
519             /* Can't execute command. */
520             ret = -EINVAL;
521             break;
522         }
523         if (sch->thinint_active) {
524             /* Trigger a command reject. */
525             ret = -ENOSYS;
526             break;
527         }
528         if (!ccw.cda) {
529             ret = -EFAULT;
530         } else {
531             indicators = address_space_ldq_be(&address_space_memory, ccw.cda,
532                                               MEMTXATTRS_UNSPECIFIED, NULL);
533             dev->indicators = get_indicator(indicators, sizeof(uint64_t));
534             sch->curr_status.scsw.count = ccw.count - sizeof(indicators);
535             ret = 0;
536         }
537         break;
538     case CCW_CMD_SET_CONF_IND:
539         if (check_len) {
540             if (ccw.count != sizeof(indicators)) {
541                 ret = -EINVAL;
542                 break;
543             }
544         } else if (ccw.count < sizeof(indicators)) {
545             /* Can't execute command. */
546             ret = -EINVAL;
547             break;
548         }
549         if (!ccw.cda) {
550             ret = -EFAULT;
551         } else {
552             indicators = address_space_ldq_be(&address_space_memory, ccw.cda,
553                                               MEMTXATTRS_UNSPECIFIED, NULL);
554             dev->indicators2 = get_indicator(indicators, sizeof(uint64_t));
555             sch->curr_status.scsw.count = ccw.count - sizeof(indicators);
556             ret = 0;
557         }
558         break;
559     case CCW_CMD_READ_VQ_CONF:
560         if (check_len) {
561             if (ccw.count != sizeof(vq_config)) {
562                 ret = -EINVAL;
563                 break;
564             }
565         } else if (ccw.count < sizeof(vq_config)) {
566             /* Can't execute command. */
567             ret = -EINVAL;
568             break;
569         }
570         if (!ccw.cda) {
571             ret = -EFAULT;
572         } else {
573             vq_config.index = address_space_lduw_be(&address_space_memory,
574                                                     ccw.cda,
575                                                     MEMTXATTRS_UNSPECIFIED,
576                                                     NULL);
577             if (vq_config.index >= VIRTIO_CCW_QUEUE_MAX) {
578                 ret = -EINVAL;
579                 break;
580             }
581             vq_config.num_max = virtio_queue_get_num(vdev,
582                                                      vq_config.index);
583             address_space_stw_be(&address_space_memory,
584                                  ccw.cda + sizeof(vq_config.index),
585                                  vq_config.num_max,
586                                  MEMTXATTRS_UNSPECIFIED,
587                                  NULL);
588             sch->curr_status.scsw.count = ccw.count - sizeof(vq_config);
589             ret = 0;
590         }
591         break;
592     case CCW_CMD_SET_IND_ADAPTER:
593         if (check_len) {
594             if (ccw.count != sizeof(*thinint)) {
595                 ret = -EINVAL;
596                 break;
597             }
598         } else if (ccw.count < sizeof(*thinint)) {
599             /* Can't execute command. */
600             ret = -EINVAL;
601             break;
602         }
603         len = sizeof(*thinint);
604         hw_len = len;
605         if (!ccw.cda) {
606             ret = -EFAULT;
607         } else if (dev->indicators && !sch->thinint_active) {
608             /* Trigger a command reject. */
609             ret = -ENOSYS;
610         } else {
611             thinint = cpu_physical_memory_map(ccw.cda, &hw_len, 0);
612             if (!thinint) {
613                 ret = -EFAULT;
614             } else {
615                 uint64_t ind_bit = ldq_be_p(&thinint->ind_bit);
616 
617                 len = hw_len;
618                 dev->summary_indicator =
619                     get_indicator(ldq_be_p(&thinint->summary_indicator),
620                                   sizeof(uint8_t));
621                 dev->indicators =
622                     get_indicator(ldq_be_p(&thinint->device_indicator),
623                                   ind_bit / 8 + 1);
624                 dev->thinint_isc = thinint->isc;
625                 dev->routes.adapter.ind_offset = ind_bit;
626                 dev->routes.adapter.summary_offset = 7;
627                 cpu_physical_memory_unmap(thinint, hw_len, 0, hw_len);
628                 ret = css_register_io_adapter(CSS_IO_ADAPTER_VIRTIO,
629                                               dev->thinint_isc, true, false,
630                                               &dev->routes.adapter.adapter_id);
631                 assert(ret == 0);
632                 sch->thinint_active = ((dev->indicators != NULL) &&
633                                        (dev->summary_indicator != NULL));
634                 sch->curr_status.scsw.count = ccw.count - len;
635                 ret = 0;
636             }
637         }
638         break;
639     case CCW_CMD_SET_VIRTIO_REV:
640         len = sizeof(revinfo);
641         if (ccw.count < len) {
642             ret = -EINVAL;
643             break;
644         }
645         if (!ccw.cda) {
646             ret = -EFAULT;
647             break;
648         }
649         revinfo.revision =
650             address_space_lduw_be(&address_space_memory, ccw.cda,
651                                   MEMTXATTRS_UNSPECIFIED, NULL);
652         revinfo.length =
653             address_space_lduw_be(&address_space_memory,
654                                   ccw.cda + sizeof(revinfo.revision),
655                                   MEMTXATTRS_UNSPECIFIED, NULL);
656         if (ccw.count < len + revinfo.length ||
657             (check_len && ccw.count > len + revinfo.length)) {
658             ret = -EINVAL;
659             break;
660         }
661         /*
662          * Once we start to support revisions with additional data, we'll
663          * need to fetch it here. Nothing to do for now, though.
664          */
665         if (dev->revision >= 0 ||
666             revinfo.revision > virtio_ccw_rev_max(dev)) {
667             ret = -ENOSYS;
668             break;
669         }
670         ret = 0;
671         dev->revision = revinfo.revision;
672         break;
673     default:
674         ret = -ENOSYS;
675         break;
676     }
677     return ret;
678 }
679 
680 static void virtio_sch_disable_cb(SubchDev *sch)
681 {
682     VirtioCcwDevice *dev = sch->driver_data;
683 
684     dev->revision = -1;
685 }
686 
687 static void virtio_ccw_device_realize(VirtioCcwDevice *dev, Error **errp)
688 {
689     VirtIOCCWDeviceClass *k = VIRTIO_CCW_DEVICE_GET_CLASS(dev);
690     CcwDevice *ccw_dev = CCW_DEVICE(dev);
691     SubchDev *sch = css_create_virtual_sch(ccw_dev->bus_id, errp);
692     Error *err = NULL;
693 
694     if (!sch) {
695         return;
696     }
697 
698     sch->driver_data = dev;
699     sch->ccw_cb = virtio_ccw_cb;
700     sch->disable_cb = virtio_sch_disable_cb;
701     sch->id.reserved = 0xff;
702     sch->id.cu_type = VIRTIO_CCW_CU_TYPE;
703     ccw_dev->sch = sch;
704     dev->indicators = NULL;
705     dev->revision = -1;
706     css_sch_build_virtual_schib(sch, 0, VIRTIO_CCW_CHPID_TYPE);
707 
708     trace_virtio_ccw_new_device(
709         sch->cssid, sch->ssid, sch->schid, sch->devno,
710         ccw_dev->bus_id.valid ? "user-configured" : "auto-configured");
711 
712     if (k->realize) {
713         k->realize(dev, &err);
714     }
715     if (err) {
716         error_propagate(errp, err);
717         css_subch_assign(sch->cssid, sch->ssid, sch->schid, sch->devno, NULL);
718         ccw_dev->sch = NULL;
719         g_free(sch);
720     }
721 }
722 
723 static int virtio_ccw_exit(VirtioCcwDevice *dev)
724 {
725     CcwDevice *ccw_dev = CCW_DEVICE(dev);
726     SubchDev *sch = ccw_dev->sch;
727 
728     if (sch) {
729         css_subch_assign(sch->cssid, sch->ssid, sch->schid, sch->devno, NULL);
730         g_free(sch);
731     }
732     if (dev->indicators) {
733         release_indicator(&dev->routes.adapter, dev->indicators);
734         dev->indicators = NULL;
735     }
736     return 0;
737 }
738 
739 static void virtio_ccw_net_realize(VirtioCcwDevice *ccw_dev, Error **errp)
740 {
741     DeviceState *qdev = DEVICE(ccw_dev);
742     VirtIONetCcw *dev = VIRTIO_NET_CCW(ccw_dev);
743     DeviceState *vdev = DEVICE(&dev->vdev);
744 
745     virtio_net_set_netclient_name(&dev->vdev, qdev->id,
746                                   object_get_typename(OBJECT(qdev)));
747     qdev_set_parent_bus(vdev, BUS(&ccw_dev->bus));
748     object_property_set_bool(OBJECT(vdev), true, "realized", errp);
749 }
750 
751 static void virtio_ccw_net_instance_init(Object *obj)
752 {
753     VirtIONetCcw *dev = VIRTIO_NET_CCW(obj);
754 
755     virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
756                                 TYPE_VIRTIO_NET);
757     object_property_add_alias(obj, "bootindex", OBJECT(&dev->vdev),
758                               "bootindex", &error_abort);
759 }
760 
761 static void virtio_ccw_blk_realize(VirtioCcwDevice *ccw_dev, Error **errp)
762 {
763     VirtIOBlkCcw *dev = VIRTIO_BLK_CCW(ccw_dev);
764     DeviceState *vdev = DEVICE(&dev->vdev);
765 
766     qdev_set_parent_bus(vdev, BUS(&ccw_dev->bus));
767     object_property_set_bool(OBJECT(vdev), true, "realized", errp);
768 }
769 
770 static void virtio_ccw_blk_instance_init(Object *obj)
771 {
772     VirtIOBlkCcw *dev = VIRTIO_BLK_CCW(obj);
773 
774     virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
775                                 TYPE_VIRTIO_BLK);
776     object_property_add_alias(obj, "iothread", OBJECT(&dev->vdev),"iothread",
777                               &error_abort);
778     object_property_add_alias(obj, "bootindex", OBJECT(&dev->vdev),
779                               "bootindex", &error_abort);
780 }
781 
782 static void virtio_ccw_serial_realize(VirtioCcwDevice *ccw_dev, Error **errp)
783 {
784     VirtioSerialCcw *dev = VIRTIO_SERIAL_CCW(ccw_dev);
785     DeviceState *vdev = DEVICE(&dev->vdev);
786     DeviceState *proxy = DEVICE(ccw_dev);
787     char *bus_name;
788 
789     /*
790      * For command line compatibility, this sets the virtio-serial-device bus
791      * name as before.
792      */
793     if (proxy->id) {
794         bus_name = g_strdup_printf("%s.0", proxy->id);
795         virtio_device_set_child_bus_name(VIRTIO_DEVICE(vdev), bus_name);
796         g_free(bus_name);
797     }
798 
799     qdev_set_parent_bus(vdev, BUS(&ccw_dev->bus));
800     object_property_set_bool(OBJECT(vdev), true, "realized", errp);
801 }
802 
803 
804 static void virtio_ccw_serial_instance_init(Object *obj)
805 {
806     VirtioSerialCcw *dev = VIRTIO_SERIAL_CCW(obj);
807 
808     virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
809                                 TYPE_VIRTIO_SERIAL);
810 }
811 
812 static void virtio_ccw_balloon_realize(VirtioCcwDevice *ccw_dev, Error **errp)
813 {
814     VirtIOBalloonCcw *dev = VIRTIO_BALLOON_CCW(ccw_dev);
815     DeviceState *vdev = DEVICE(&dev->vdev);
816 
817     qdev_set_parent_bus(vdev, BUS(&ccw_dev->bus));
818     object_property_set_bool(OBJECT(vdev), true, "realized", errp);
819 }
820 
821 static void virtio_ccw_balloon_instance_init(Object *obj)
822 {
823     VirtIOBalloonCcw *dev = VIRTIO_BALLOON_CCW(obj);
824 
825     virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
826                                 TYPE_VIRTIO_BALLOON);
827     object_property_add_alias(obj, "guest-stats", OBJECT(&dev->vdev),
828                               "guest-stats", &error_abort);
829     object_property_add_alias(obj, "guest-stats-polling-interval",
830                               OBJECT(&dev->vdev),
831                               "guest-stats-polling-interval", &error_abort);
832 }
833 
834 static void virtio_ccw_scsi_realize(VirtioCcwDevice *ccw_dev, Error **errp)
835 {
836     VirtIOSCSICcw *dev = VIRTIO_SCSI_CCW(ccw_dev);
837     DeviceState *vdev = DEVICE(&dev->vdev);
838     DeviceState *qdev = DEVICE(ccw_dev);
839     char *bus_name;
840 
841     /*
842      * For command line compatibility, this sets the virtio-scsi-device bus
843      * name as before.
844      */
845     if (qdev->id) {
846         bus_name = g_strdup_printf("%s.0", qdev->id);
847         virtio_device_set_child_bus_name(VIRTIO_DEVICE(vdev), bus_name);
848         g_free(bus_name);
849     }
850 
851     qdev_set_parent_bus(vdev, BUS(&ccw_dev->bus));
852     object_property_set_bool(OBJECT(vdev), true, "realized", errp);
853 }
854 
855 static void virtio_ccw_scsi_instance_init(Object *obj)
856 {
857     VirtIOSCSICcw *dev = VIRTIO_SCSI_CCW(obj);
858 
859     virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
860                                 TYPE_VIRTIO_SCSI);
861     object_property_add_alias(obj, "iothread", OBJECT(&dev->vdev), "iothread",
862                               &error_abort);
863 }
864 
865 #ifdef CONFIG_VHOST_SCSI
866 static void vhost_ccw_scsi_realize(VirtioCcwDevice *ccw_dev, Error **errp)
867 {
868     VHostSCSICcw *dev = VHOST_SCSI_CCW(ccw_dev);
869     DeviceState *vdev = DEVICE(&dev->vdev);
870 
871     qdev_set_parent_bus(vdev, BUS(&ccw_dev->bus));
872     object_property_set_bool(OBJECT(vdev), true, "realized", errp);
873 }
874 
875 static void vhost_ccw_scsi_instance_init(Object *obj)
876 {
877     VHostSCSICcw *dev = VHOST_SCSI_CCW(obj);
878 
879     virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
880                                 TYPE_VHOST_SCSI);
881 }
882 #endif
883 
884 static void virtio_ccw_rng_realize(VirtioCcwDevice *ccw_dev, Error **errp)
885 {
886     VirtIORNGCcw *dev = VIRTIO_RNG_CCW(ccw_dev);
887     DeviceState *vdev = DEVICE(&dev->vdev);
888     Error *err = NULL;
889 
890     qdev_set_parent_bus(vdev, BUS(&ccw_dev->bus));
891     object_property_set_bool(OBJECT(vdev), true, "realized", &err);
892     if (err) {
893         error_propagate(errp, err);
894         return;
895     }
896 
897     object_property_set_link(OBJECT(dev),
898                              OBJECT(dev->vdev.conf.rng), "rng",
899                              NULL);
900 }
901 
902 /* DeviceState to VirtioCcwDevice. Note: used on datapath,
903  * be careful and test performance if you change this.
904  */
905 static inline VirtioCcwDevice *to_virtio_ccw_dev_fast(DeviceState *d)
906 {
907     CcwDevice *ccw_dev = to_ccw_dev_fast(d);
908 
909     return container_of(ccw_dev, VirtioCcwDevice, parent_obj);
910 }
911 
912 static uint8_t virtio_set_ind_atomic(SubchDev *sch, uint64_t ind_loc,
913                                      uint8_t to_be_set)
914 {
915     uint8_t ind_old, ind_new;
916     hwaddr len = 1;
917     uint8_t *ind_addr;
918 
919     ind_addr = cpu_physical_memory_map(ind_loc, &len, 1);
920     if (!ind_addr) {
921         error_report("%s(%x.%x.%04x): unable to access indicator",
922                      __func__, sch->cssid, sch->ssid, sch->schid);
923         return -1;
924     }
925     do {
926         ind_old = *ind_addr;
927         ind_new = ind_old | to_be_set;
928     } while (atomic_cmpxchg(ind_addr, ind_old, ind_new) != ind_old);
929     trace_virtio_ccw_set_ind(ind_loc, ind_old, ind_new);
930     cpu_physical_memory_unmap(ind_addr, len, 1, len);
931 
932     return ind_old;
933 }
934 
935 static void virtio_ccw_notify(DeviceState *d, uint16_t vector)
936 {
937     VirtioCcwDevice *dev = to_virtio_ccw_dev_fast(d);
938     CcwDevice *ccw_dev = to_ccw_dev_fast(d);
939     SubchDev *sch = ccw_dev->sch;
940     uint64_t indicators;
941 
942     /* queue indicators + secondary indicators */
943     if (vector >= VIRTIO_CCW_QUEUE_MAX + 64) {
944         return;
945     }
946 
947     if (vector < VIRTIO_CCW_QUEUE_MAX) {
948         if (!dev->indicators) {
949             return;
950         }
951         if (sch->thinint_active) {
952             /*
953              * In the adapter interrupt case, indicators points to a
954              * memory area that may be (way) larger than 64 bit and
955              * ind_bit indicates the start of the indicators in a big
956              * endian notation.
957              */
958             uint64_t ind_bit = dev->routes.adapter.ind_offset;
959 
960             virtio_set_ind_atomic(sch, dev->indicators->addr +
961                                   (ind_bit + vector) / 8,
962                                   0x80 >> ((ind_bit + vector) % 8));
963             if (!virtio_set_ind_atomic(sch, dev->summary_indicator->addr,
964                                        0x01)) {
965                 css_adapter_interrupt(dev->thinint_isc);
966             }
967         } else {
968             indicators = address_space_ldq(&address_space_memory,
969                                            dev->indicators->addr,
970                                            MEMTXATTRS_UNSPECIFIED,
971                                            NULL);
972             indicators |= 1ULL << vector;
973             address_space_stq(&address_space_memory, dev->indicators->addr,
974                               indicators, MEMTXATTRS_UNSPECIFIED, NULL);
975             css_conditional_io_interrupt(sch);
976         }
977     } else {
978         if (!dev->indicators2) {
979             return;
980         }
981         vector = 0;
982         indicators = address_space_ldq(&address_space_memory,
983                                        dev->indicators2->addr,
984                                        MEMTXATTRS_UNSPECIFIED,
985                                        NULL);
986         indicators |= 1ULL << vector;
987         address_space_stq(&address_space_memory, dev->indicators2->addr,
988                           indicators, MEMTXATTRS_UNSPECIFIED, NULL);
989         css_conditional_io_interrupt(sch);
990     }
991 }
992 
993 static void virtio_ccw_reset(DeviceState *d)
994 {
995     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
996     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
997     CcwDevice *ccw_dev = CCW_DEVICE(d);
998 
999     virtio_ccw_reset_virtio(dev, vdev);
1000     css_reset_sch(ccw_dev->sch);
1001 }
1002 
1003 static void virtio_ccw_vmstate_change(DeviceState *d, bool running)
1004 {
1005     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
1006 
1007     if (running) {
1008         virtio_ccw_start_ioeventfd(dev);
1009     } else {
1010         virtio_ccw_stop_ioeventfd(dev);
1011     }
1012 }
1013 
1014 static bool virtio_ccw_query_guest_notifiers(DeviceState *d)
1015 {
1016     CcwDevice *dev = CCW_DEVICE(d);
1017 
1018     return !!(dev->sch->curr_status.pmcw.flags & PMCW_FLAGS_MASK_ENA);
1019 }
1020 
1021 static int virtio_ccw_get_mappings(VirtioCcwDevice *dev)
1022 {
1023     int r;
1024     CcwDevice *ccw_dev = CCW_DEVICE(dev);
1025 
1026     if (!ccw_dev->sch->thinint_active) {
1027         return -EINVAL;
1028     }
1029 
1030     r = map_indicator(&dev->routes.adapter, dev->summary_indicator);
1031     if (r) {
1032         return r;
1033     }
1034     r = map_indicator(&dev->routes.adapter, dev->indicators);
1035     if (r) {
1036         return r;
1037     }
1038     dev->routes.adapter.summary_addr = dev->summary_indicator->map;
1039     dev->routes.adapter.ind_addr = dev->indicators->map;
1040 
1041     return 0;
1042 }
1043 
1044 static int virtio_ccw_setup_irqroutes(VirtioCcwDevice *dev, int nvqs)
1045 {
1046     int i;
1047     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
1048     int ret;
1049     S390FLICState *fs = s390_get_flic();
1050     S390FLICStateClass *fsc = S390_FLIC_COMMON_GET_CLASS(fs);
1051 
1052     ret = virtio_ccw_get_mappings(dev);
1053     if (ret) {
1054         return ret;
1055     }
1056     for (i = 0; i < nvqs; i++) {
1057         if (!virtio_queue_get_num(vdev, i)) {
1058             break;
1059         }
1060     }
1061     dev->routes.num_routes = i;
1062     return fsc->add_adapter_routes(fs, &dev->routes);
1063 }
1064 
1065 static void virtio_ccw_release_irqroutes(VirtioCcwDevice *dev, int nvqs)
1066 {
1067     S390FLICState *fs = s390_get_flic();
1068     S390FLICStateClass *fsc = S390_FLIC_COMMON_GET_CLASS(fs);
1069 
1070     fsc->release_adapter_routes(fs, &dev->routes);
1071 }
1072 
1073 static int virtio_ccw_add_irqfd(VirtioCcwDevice *dev, int n)
1074 {
1075     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
1076     VirtQueue *vq = virtio_get_queue(vdev, n);
1077     EventNotifier *notifier = virtio_queue_get_guest_notifier(vq);
1078 
1079     return kvm_irqchip_add_irqfd_notifier_gsi(kvm_state, notifier, NULL,
1080                                               dev->routes.gsi[n]);
1081 }
1082 
1083 static void virtio_ccw_remove_irqfd(VirtioCcwDevice *dev, int n)
1084 {
1085     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
1086     VirtQueue *vq = virtio_get_queue(vdev, n);
1087     EventNotifier *notifier = virtio_queue_get_guest_notifier(vq);
1088     int ret;
1089 
1090     ret = kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state, notifier,
1091                                                 dev->routes.gsi[n]);
1092     assert(ret == 0);
1093 }
1094 
1095 static int virtio_ccw_set_guest_notifier(VirtioCcwDevice *dev, int n,
1096                                          bool assign, bool with_irqfd)
1097 {
1098     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
1099     VirtQueue *vq = virtio_get_queue(vdev, n);
1100     EventNotifier *notifier = virtio_queue_get_guest_notifier(vq);
1101     VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
1102 
1103     if (assign) {
1104         int r = event_notifier_init(notifier, 0);
1105 
1106         if (r < 0) {
1107             return r;
1108         }
1109         virtio_queue_set_guest_notifier_fd_handler(vq, true, with_irqfd);
1110         if (with_irqfd) {
1111             r = virtio_ccw_add_irqfd(dev, n);
1112             if (r) {
1113                 virtio_queue_set_guest_notifier_fd_handler(vq, false,
1114                                                            with_irqfd);
1115                 return r;
1116             }
1117         }
1118         /*
1119          * We do not support individual masking for channel devices, so we
1120          * need to manually trigger any guest masking callbacks here.
1121          */
1122         if (k->guest_notifier_mask) {
1123             k->guest_notifier_mask(vdev, n, false);
1124         }
1125         /* get lost events and re-inject */
1126         if (k->guest_notifier_pending &&
1127             k->guest_notifier_pending(vdev, n)) {
1128             event_notifier_set(notifier);
1129         }
1130     } else {
1131         if (k->guest_notifier_mask) {
1132             k->guest_notifier_mask(vdev, n, true);
1133         }
1134         if (with_irqfd) {
1135             virtio_ccw_remove_irqfd(dev, n);
1136         }
1137         virtio_queue_set_guest_notifier_fd_handler(vq, false, with_irqfd);
1138         event_notifier_cleanup(notifier);
1139     }
1140     return 0;
1141 }
1142 
1143 static int virtio_ccw_set_guest_notifiers(DeviceState *d, int nvqs,
1144                                           bool assigned)
1145 {
1146     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
1147     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
1148     CcwDevice *ccw_dev = CCW_DEVICE(d);
1149     bool with_irqfd = ccw_dev->sch->thinint_active && kvm_irqfds_enabled();
1150     int r, n;
1151 
1152     if (with_irqfd && assigned) {
1153         /* irq routes need to be set up before assigning irqfds */
1154         r = virtio_ccw_setup_irqroutes(dev, nvqs);
1155         if (r < 0) {
1156             goto irqroute_error;
1157         }
1158     }
1159     for (n = 0; n < nvqs; n++) {
1160         if (!virtio_queue_get_num(vdev, n)) {
1161             break;
1162         }
1163         r = virtio_ccw_set_guest_notifier(dev, n, assigned, with_irqfd);
1164         if (r < 0) {
1165             goto assign_error;
1166         }
1167     }
1168     if (with_irqfd && !assigned) {
1169         /* release irq routes after irqfds have been released */
1170         virtio_ccw_release_irqroutes(dev, nvqs);
1171     }
1172     return 0;
1173 
1174 assign_error:
1175     while (--n >= 0) {
1176         virtio_ccw_set_guest_notifier(dev, n, !assigned, false);
1177     }
1178 irqroute_error:
1179     if (with_irqfd && assigned) {
1180         virtio_ccw_release_irqroutes(dev, nvqs);
1181     }
1182     return r;
1183 }
1184 
1185 static void virtio_ccw_save_queue(DeviceState *d, int n, QEMUFile *f)
1186 {
1187     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
1188     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
1189 
1190     qemu_put_be16(f, virtio_queue_vector(vdev, n));
1191 }
1192 
1193 static int virtio_ccw_load_queue(DeviceState *d, int n, QEMUFile *f)
1194 {
1195     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
1196     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
1197     uint16_t vector;
1198 
1199     qemu_get_be16s(f, &vector);
1200     virtio_queue_set_vector(vdev, n , vector);
1201 
1202     return 0;
1203 }
1204 
1205 static void virtio_ccw_save_config(DeviceState *d, QEMUFile *f)
1206 {
1207     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
1208     CcwDevice *ccw_dev = CCW_DEVICE(d);
1209     SubchDev *s = ccw_dev->sch;
1210     VirtIODevice *vdev = virtio_ccw_get_vdev(s);
1211 
1212     subch_device_save(s, f);
1213     if (dev->indicators != NULL) {
1214         qemu_put_be32(f, dev->indicators->len);
1215         qemu_put_be64(f, dev->indicators->addr);
1216     } else {
1217         qemu_put_be32(f, 0);
1218         qemu_put_be64(f, 0UL);
1219     }
1220     if (dev->indicators2 != NULL) {
1221         qemu_put_be32(f, dev->indicators2->len);
1222         qemu_put_be64(f, dev->indicators2->addr);
1223     } else {
1224         qemu_put_be32(f, 0);
1225         qemu_put_be64(f, 0UL);
1226     }
1227     if (dev->summary_indicator != NULL) {
1228         qemu_put_be32(f, dev->summary_indicator->len);
1229         qemu_put_be64(f, dev->summary_indicator->addr);
1230     } else {
1231         qemu_put_be32(f, 0);
1232         qemu_put_be64(f, 0UL);
1233     }
1234     qemu_put_be16(f, vdev->config_vector);
1235     qemu_put_be64(f, dev->routes.adapter.ind_offset);
1236     qemu_put_byte(f, dev->thinint_isc);
1237     qemu_put_be32(f, dev->revision);
1238 }
1239 
1240 static int virtio_ccw_load_config(DeviceState *d, QEMUFile *f)
1241 {
1242     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
1243     CcwDevice *ccw_dev = CCW_DEVICE(d);
1244     SubchDev *s = ccw_dev->sch;
1245     VirtIODevice *vdev = virtio_ccw_get_vdev(s);
1246     int len;
1247 
1248     s->driver_data = dev;
1249     subch_device_load(s, f);
1250     len = qemu_get_be32(f);
1251     if (len != 0) {
1252         dev->indicators = get_indicator(qemu_get_be64(f), len);
1253     } else {
1254         qemu_get_be64(f);
1255         dev->indicators = NULL;
1256     }
1257     len = qemu_get_be32(f);
1258     if (len != 0) {
1259         dev->indicators2 = get_indicator(qemu_get_be64(f), len);
1260     } else {
1261         qemu_get_be64(f);
1262         dev->indicators2 = NULL;
1263     }
1264     len = qemu_get_be32(f);
1265     if (len != 0) {
1266         dev->summary_indicator = get_indicator(qemu_get_be64(f), len);
1267     } else {
1268         qemu_get_be64(f);
1269         dev->summary_indicator = NULL;
1270     }
1271     qemu_get_be16s(f, &vdev->config_vector);
1272     dev->routes.adapter.ind_offset = qemu_get_be64(f);
1273     dev->thinint_isc = qemu_get_byte(f);
1274     dev->revision = qemu_get_be32(f);
1275     if (s->thinint_active) {
1276         return css_register_io_adapter(CSS_IO_ADAPTER_VIRTIO,
1277                                        dev->thinint_isc, true, false,
1278                                        &dev->routes.adapter.adapter_id);
1279     }
1280 
1281     return 0;
1282 }
1283 
1284 static void virtio_ccw_pre_plugged(DeviceState *d, Error **errp)
1285 {
1286    VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
1287    VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
1288 
1289     if (dev->max_rev >= 1) {
1290         virtio_add_feature(&vdev->host_features, VIRTIO_F_VERSION_1);
1291     }
1292 }
1293 
1294 /* This is called by virtio-bus just after the device is plugged. */
1295 static void virtio_ccw_device_plugged(DeviceState *d, Error **errp)
1296 {
1297     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
1298     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
1299     CcwDevice *ccw_dev = CCW_DEVICE(d);
1300     SubchDev *sch = ccw_dev->sch;
1301     int n = virtio_get_num_queues(vdev);
1302 
1303     if (!virtio_has_feature(vdev->host_features, VIRTIO_F_VERSION_1)) {
1304         dev->max_rev = 0;
1305     }
1306 
1307     if (virtio_get_num_queues(vdev) > VIRTIO_CCW_QUEUE_MAX) {
1308         error_setg(errp, "The number of virtqueues %d "
1309                    "exceeds ccw limit %d", n,
1310                    VIRTIO_CCW_QUEUE_MAX);
1311         return;
1312     }
1313 
1314     if (!kvm_eventfds_enabled()) {
1315         dev->flags &= ~VIRTIO_CCW_FLAG_USE_IOEVENTFD;
1316     }
1317 
1318     sch->id.cu_model = virtio_bus_get_vdev_id(&dev->bus);
1319 
1320 
1321     css_generate_sch_crws(sch->cssid, sch->ssid, sch->schid,
1322                           d->hotplugged, 1);
1323 }
1324 
1325 static void virtio_ccw_device_unplugged(DeviceState *d)
1326 {
1327     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
1328 
1329     virtio_ccw_stop_ioeventfd(dev);
1330 }
1331 /**************** Virtio-ccw Bus Device Descriptions *******************/
1332 
1333 static Property virtio_ccw_net_properties[] = {
1334     DEFINE_PROP_CSS_DEV_ID("devno", VirtioCcwDevice, parent_obj.bus_id),
1335     DEFINE_PROP_BIT("ioeventfd", VirtioCcwDevice, flags,
1336                     VIRTIO_CCW_FLAG_USE_IOEVENTFD_BIT, true),
1337     DEFINE_PROP_UINT32("max_revision", VirtioCcwDevice, max_rev,
1338                        VIRTIO_CCW_MAX_REV),
1339     DEFINE_PROP_END_OF_LIST(),
1340 };
1341 
1342 static void virtio_ccw_net_class_init(ObjectClass *klass, void *data)
1343 {
1344     DeviceClass *dc = DEVICE_CLASS(klass);
1345     VirtIOCCWDeviceClass *k = VIRTIO_CCW_DEVICE_CLASS(klass);
1346 
1347     k->realize = virtio_ccw_net_realize;
1348     k->exit = virtio_ccw_exit;
1349     dc->reset = virtio_ccw_reset;
1350     dc->props = virtio_ccw_net_properties;
1351     set_bit(DEVICE_CATEGORY_NETWORK, dc->categories);
1352 }
1353 
1354 static const TypeInfo virtio_ccw_net = {
1355     .name          = TYPE_VIRTIO_NET_CCW,
1356     .parent        = TYPE_VIRTIO_CCW_DEVICE,
1357     .instance_size = sizeof(VirtIONetCcw),
1358     .instance_init = virtio_ccw_net_instance_init,
1359     .class_init    = virtio_ccw_net_class_init,
1360 };
1361 
1362 static Property virtio_ccw_blk_properties[] = {
1363     DEFINE_PROP_CSS_DEV_ID("devno", VirtioCcwDevice, parent_obj.bus_id),
1364     DEFINE_PROP_BIT("ioeventfd", VirtioCcwDevice, flags,
1365                     VIRTIO_CCW_FLAG_USE_IOEVENTFD_BIT, true),
1366     DEFINE_PROP_UINT32("max_revision", VirtioCcwDevice, max_rev,
1367                        VIRTIO_CCW_MAX_REV),
1368     DEFINE_PROP_END_OF_LIST(),
1369 };
1370 
1371 static void virtio_ccw_blk_class_init(ObjectClass *klass, void *data)
1372 {
1373     DeviceClass *dc = DEVICE_CLASS(klass);
1374     VirtIOCCWDeviceClass *k = VIRTIO_CCW_DEVICE_CLASS(klass);
1375 
1376     k->realize = virtio_ccw_blk_realize;
1377     k->exit = virtio_ccw_exit;
1378     dc->reset = virtio_ccw_reset;
1379     dc->props = virtio_ccw_blk_properties;
1380     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1381 }
1382 
1383 static const TypeInfo virtio_ccw_blk = {
1384     .name          = TYPE_VIRTIO_BLK_CCW,
1385     .parent        = TYPE_VIRTIO_CCW_DEVICE,
1386     .instance_size = sizeof(VirtIOBlkCcw),
1387     .instance_init = virtio_ccw_blk_instance_init,
1388     .class_init    = virtio_ccw_blk_class_init,
1389 };
1390 
1391 static Property virtio_ccw_serial_properties[] = {
1392     DEFINE_PROP_CSS_DEV_ID("devno", VirtioCcwDevice, parent_obj.bus_id),
1393     DEFINE_PROP_BIT("ioeventfd", VirtioCcwDevice, flags,
1394                     VIRTIO_CCW_FLAG_USE_IOEVENTFD_BIT, true),
1395     DEFINE_PROP_UINT32("max_revision", VirtioCcwDevice, max_rev,
1396                        VIRTIO_CCW_MAX_REV),
1397     DEFINE_PROP_END_OF_LIST(),
1398 };
1399 
1400 static void virtio_ccw_serial_class_init(ObjectClass *klass, void *data)
1401 {
1402     DeviceClass *dc = DEVICE_CLASS(klass);
1403     VirtIOCCWDeviceClass *k = VIRTIO_CCW_DEVICE_CLASS(klass);
1404 
1405     k->realize = virtio_ccw_serial_realize;
1406     k->exit = virtio_ccw_exit;
1407     dc->reset = virtio_ccw_reset;
1408     dc->props = virtio_ccw_serial_properties;
1409     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
1410 }
1411 
1412 static const TypeInfo virtio_ccw_serial = {
1413     .name          = TYPE_VIRTIO_SERIAL_CCW,
1414     .parent        = TYPE_VIRTIO_CCW_DEVICE,
1415     .instance_size = sizeof(VirtioSerialCcw),
1416     .instance_init = virtio_ccw_serial_instance_init,
1417     .class_init    = virtio_ccw_serial_class_init,
1418 };
1419 
1420 static Property virtio_ccw_balloon_properties[] = {
1421     DEFINE_PROP_CSS_DEV_ID("devno", VirtioCcwDevice, parent_obj.bus_id),
1422     DEFINE_PROP_BIT("ioeventfd", VirtioCcwDevice, flags,
1423                     VIRTIO_CCW_FLAG_USE_IOEVENTFD_BIT, true),
1424     DEFINE_PROP_UINT32("max_revision", VirtioCcwDevice, max_rev,
1425                        VIRTIO_CCW_MAX_REV),
1426     DEFINE_PROP_END_OF_LIST(),
1427 };
1428 
1429 static void virtio_ccw_balloon_class_init(ObjectClass *klass, void *data)
1430 {
1431     DeviceClass *dc = DEVICE_CLASS(klass);
1432     VirtIOCCWDeviceClass *k = VIRTIO_CCW_DEVICE_CLASS(klass);
1433 
1434     k->realize = virtio_ccw_balloon_realize;
1435     k->exit = virtio_ccw_exit;
1436     dc->reset = virtio_ccw_reset;
1437     dc->props = virtio_ccw_balloon_properties;
1438     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
1439 }
1440 
1441 static const TypeInfo virtio_ccw_balloon = {
1442     .name          = TYPE_VIRTIO_BALLOON_CCW,
1443     .parent        = TYPE_VIRTIO_CCW_DEVICE,
1444     .instance_size = sizeof(VirtIOBalloonCcw),
1445     .instance_init = virtio_ccw_balloon_instance_init,
1446     .class_init    = virtio_ccw_balloon_class_init,
1447 };
1448 
1449 static Property virtio_ccw_scsi_properties[] = {
1450     DEFINE_PROP_CSS_DEV_ID("devno", VirtioCcwDevice, parent_obj.bus_id),
1451     DEFINE_PROP_BIT("ioeventfd", VirtioCcwDevice, flags,
1452                     VIRTIO_CCW_FLAG_USE_IOEVENTFD_BIT, true),
1453     DEFINE_PROP_UINT32("max_revision", VirtioCcwDevice, max_rev,
1454                        VIRTIO_CCW_MAX_REV),
1455     DEFINE_PROP_END_OF_LIST(),
1456 };
1457 
1458 static void virtio_ccw_scsi_class_init(ObjectClass *klass, void *data)
1459 {
1460     DeviceClass *dc = DEVICE_CLASS(klass);
1461     VirtIOCCWDeviceClass *k = VIRTIO_CCW_DEVICE_CLASS(klass);
1462 
1463     k->realize = virtio_ccw_scsi_realize;
1464     k->exit = virtio_ccw_exit;
1465     dc->reset = virtio_ccw_reset;
1466     dc->props = virtio_ccw_scsi_properties;
1467     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1468 }
1469 
1470 static const TypeInfo virtio_ccw_scsi = {
1471     .name          = TYPE_VIRTIO_SCSI_CCW,
1472     .parent        = TYPE_VIRTIO_CCW_DEVICE,
1473     .instance_size = sizeof(VirtIOSCSICcw),
1474     .instance_init = virtio_ccw_scsi_instance_init,
1475     .class_init    = virtio_ccw_scsi_class_init,
1476 };
1477 
1478 #ifdef CONFIG_VHOST_SCSI
1479 static Property vhost_ccw_scsi_properties[] = {
1480     DEFINE_PROP_CSS_DEV_ID("devno", VirtioCcwDevice, parent_obj.bus_id),
1481     DEFINE_PROP_UINT32("max_revision", VirtioCcwDevice, max_rev,
1482                        VIRTIO_CCW_MAX_REV),
1483     DEFINE_PROP_END_OF_LIST(),
1484 };
1485 
1486 static void vhost_ccw_scsi_class_init(ObjectClass *klass, void *data)
1487 {
1488     DeviceClass *dc = DEVICE_CLASS(klass);
1489     VirtIOCCWDeviceClass *k = VIRTIO_CCW_DEVICE_CLASS(klass);
1490 
1491     k->realize = vhost_ccw_scsi_realize;
1492     k->exit = virtio_ccw_exit;
1493     dc->reset = virtio_ccw_reset;
1494     dc->props = vhost_ccw_scsi_properties;
1495     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1496 }
1497 
1498 static const TypeInfo vhost_ccw_scsi = {
1499     .name          = TYPE_VHOST_SCSI_CCW,
1500     .parent        = TYPE_VIRTIO_CCW_DEVICE,
1501     .instance_size = sizeof(VHostSCSICcw),
1502     .instance_init = vhost_ccw_scsi_instance_init,
1503     .class_init    = vhost_ccw_scsi_class_init,
1504 };
1505 #endif
1506 
1507 static void virtio_ccw_rng_instance_init(Object *obj)
1508 {
1509     VirtIORNGCcw *dev = VIRTIO_RNG_CCW(obj);
1510 
1511     virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
1512                                 TYPE_VIRTIO_RNG);
1513     object_property_add_alias(obj, "rng", OBJECT(&dev->vdev),
1514                               "rng", &error_abort);
1515 }
1516 
1517 static Property virtio_ccw_rng_properties[] = {
1518     DEFINE_PROP_CSS_DEV_ID("devno", VirtioCcwDevice, parent_obj.bus_id),
1519     DEFINE_PROP_BIT("ioeventfd", VirtioCcwDevice, flags,
1520                     VIRTIO_CCW_FLAG_USE_IOEVENTFD_BIT, true),
1521     DEFINE_PROP_UINT32("max_revision", VirtioCcwDevice, max_rev,
1522                        VIRTIO_CCW_MAX_REV),
1523     DEFINE_PROP_END_OF_LIST(),
1524 };
1525 
1526 static void virtio_ccw_rng_class_init(ObjectClass *klass, void *data)
1527 {
1528     DeviceClass *dc = DEVICE_CLASS(klass);
1529     VirtIOCCWDeviceClass *k = VIRTIO_CCW_DEVICE_CLASS(klass);
1530 
1531     k->realize = virtio_ccw_rng_realize;
1532     k->exit = virtio_ccw_exit;
1533     dc->reset = virtio_ccw_reset;
1534     dc->props = virtio_ccw_rng_properties;
1535     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
1536 }
1537 
1538 static const TypeInfo virtio_ccw_rng = {
1539     .name          = TYPE_VIRTIO_RNG_CCW,
1540     .parent        = TYPE_VIRTIO_CCW_DEVICE,
1541     .instance_size = sizeof(VirtIORNGCcw),
1542     .instance_init = virtio_ccw_rng_instance_init,
1543     .class_init    = virtio_ccw_rng_class_init,
1544 };
1545 
1546 static void virtio_ccw_busdev_realize(DeviceState *dev, Error **errp)
1547 {
1548     VirtioCcwDevice *_dev = (VirtioCcwDevice *)dev;
1549 
1550     virtio_ccw_bus_new(&_dev->bus, sizeof(_dev->bus), _dev);
1551     virtio_ccw_device_realize(_dev, errp);
1552 }
1553 
1554 static int virtio_ccw_busdev_exit(DeviceState *dev)
1555 {
1556     VirtioCcwDevice *_dev = (VirtioCcwDevice *)dev;
1557     VirtIOCCWDeviceClass *_info = VIRTIO_CCW_DEVICE_GET_CLASS(dev);
1558 
1559     return _info->exit(_dev);
1560 }
1561 
1562 static void virtio_ccw_busdev_unplug(HotplugHandler *hotplug_dev,
1563                                      DeviceState *dev, Error **errp)
1564 {
1565     VirtioCcwDevice *_dev = to_virtio_ccw_dev_fast(dev);
1566 
1567     virtio_ccw_stop_ioeventfd(_dev);
1568 }
1569 
1570 static void virtio_ccw_device_class_init(ObjectClass *klass, void *data)
1571 {
1572     DeviceClass *dc = DEVICE_CLASS(klass);
1573     CCWDeviceClass *k = CCW_DEVICE_CLASS(dc);
1574 
1575     k->unplug = virtio_ccw_busdev_unplug;
1576     dc->realize = virtio_ccw_busdev_realize;
1577     dc->exit = virtio_ccw_busdev_exit;
1578     dc->bus_type = TYPE_VIRTUAL_CSS_BUS;
1579 }
1580 
1581 static const TypeInfo virtio_ccw_device_info = {
1582     .name = TYPE_VIRTIO_CCW_DEVICE,
1583     .parent = TYPE_CCW_DEVICE,
1584     .instance_size = sizeof(VirtioCcwDevice),
1585     .class_init = virtio_ccw_device_class_init,
1586     .class_size = sizeof(VirtIOCCWDeviceClass),
1587     .abstract = true,
1588 };
1589 
1590 /* virtio-ccw-bus */
1591 
1592 static void virtio_ccw_bus_new(VirtioBusState *bus, size_t bus_size,
1593                                VirtioCcwDevice *dev)
1594 {
1595     DeviceState *qdev = DEVICE(dev);
1596     char virtio_bus_name[] = "virtio-bus";
1597 
1598     qbus_create_inplace(bus, bus_size, TYPE_VIRTIO_CCW_BUS,
1599                         qdev, virtio_bus_name);
1600 }
1601 
1602 static void virtio_ccw_bus_class_init(ObjectClass *klass, void *data)
1603 {
1604     VirtioBusClass *k = VIRTIO_BUS_CLASS(klass);
1605     BusClass *bus_class = BUS_CLASS(klass);
1606 
1607     bus_class->max_dev = 1;
1608     k->notify = virtio_ccw_notify;
1609     k->vmstate_change = virtio_ccw_vmstate_change;
1610     k->query_guest_notifiers = virtio_ccw_query_guest_notifiers;
1611     k->set_guest_notifiers = virtio_ccw_set_guest_notifiers;
1612     k->save_queue = virtio_ccw_save_queue;
1613     k->load_queue = virtio_ccw_load_queue;
1614     k->save_config = virtio_ccw_save_config;
1615     k->load_config = virtio_ccw_load_config;
1616     k->pre_plugged = virtio_ccw_pre_plugged;
1617     k->device_plugged = virtio_ccw_device_plugged;
1618     k->device_unplugged = virtio_ccw_device_unplugged;
1619     k->ioeventfd_started = virtio_ccw_ioeventfd_started;
1620     k->ioeventfd_set_started = virtio_ccw_ioeventfd_set_started;
1621     k->ioeventfd_disabled = virtio_ccw_ioeventfd_disabled;
1622     k->ioeventfd_set_disabled = virtio_ccw_ioeventfd_set_disabled;
1623     k->ioeventfd_assign = virtio_ccw_ioeventfd_assign;
1624 }
1625 
1626 static const TypeInfo virtio_ccw_bus_info = {
1627     .name = TYPE_VIRTIO_CCW_BUS,
1628     .parent = TYPE_VIRTIO_BUS,
1629     .instance_size = sizeof(VirtioCcwBusState),
1630     .class_init = virtio_ccw_bus_class_init,
1631 };
1632 
1633 #ifdef CONFIG_VIRTFS
1634 static Property virtio_ccw_9p_properties[] = {
1635     DEFINE_PROP_CSS_DEV_ID("devno", VirtioCcwDevice, parent_obj.bus_id),
1636     DEFINE_PROP_BIT("ioeventfd", VirtioCcwDevice, flags,
1637             VIRTIO_CCW_FLAG_USE_IOEVENTFD_BIT, true),
1638     DEFINE_PROP_UINT32("max_revision", VirtioCcwDevice, max_rev,
1639                        VIRTIO_CCW_MAX_REV),
1640     DEFINE_PROP_END_OF_LIST(),
1641 };
1642 
1643 static void virtio_ccw_9p_realize(VirtioCcwDevice *ccw_dev, Error **errp)
1644 {
1645     V9fsCCWState *dev = VIRTIO_9P_CCW(ccw_dev);
1646     DeviceState *vdev = DEVICE(&dev->vdev);
1647 
1648     qdev_set_parent_bus(vdev, BUS(&ccw_dev->bus));
1649     object_property_set_bool(OBJECT(vdev), true, "realized", errp);
1650 }
1651 
1652 static void virtio_ccw_9p_class_init(ObjectClass *klass, void *data)
1653 {
1654     DeviceClass *dc = DEVICE_CLASS(klass);
1655     VirtIOCCWDeviceClass *k = VIRTIO_CCW_DEVICE_CLASS(klass);
1656 
1657     k->exit = virtio_ccw_exit;
1658     k->realize = virtio_ccw_9p_realize;
1659     dc->reset = virtio_ccw_reset;
1660     dc->props = virtio_ccw_9p_properties;
1661     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1662 }
1663 
1664 static void virtio_ccw_9p_instance_init(Object *obj)
1665 {
1666     V9fsCCWState *dev = VIRTIO_9P_CCW(obj);
1667 
1668     virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
1669                                 TYPE_VIRTIO_9P);
1670 }
1671 
1672 static const TypeInfo virtio_ccw_9p_info = {
1673     .name          = TYPE_VIRTIO_9P_CCW,
1674     .parent        = TYPE_VIRTIO_CCW_DEVICE,
1675     .instance_size = sizeof(V9fsCCWState),
1676     .instance_init = virtio_ccw_9p_instance_init,
1677     .class_init    = virtio_ccw_9p_class_init,
1678 };
1679 #endif
1680 
1681 #ifdef CONFIG_VHOST_VSOCK
1682 
1683 static Property vhost_vsock_ccw_properties[] = {
1684     DEFINE_PROP_CSS_DEV_ID("devno", VirtioCcwDevice, parent_obj.bus_id),
1685     DEFINE_PROP_UINT32("max_revision", VirtioCcwDevice, max_rev,
1686                        VIRTIO_CCW_MAX_REV),
1687     DEFINE_PROP_END_OF_LIST(),
1688 };
1689 
1690 static void vhost_vsock_ccw_realize(VirtioCcwDevice *ccw_dev, Error **errp)
1691 {
1692     VHostVSockCCWState *dev = VHOST_VSOCK_CCW(ccw_dev);
1693     DeviceState *vdev = DEVICE(&dev->vdev);
1694     Error *err = NULL;
1695 
1696     qdev_set_parent_bus(vdev, BUS(&ccw_dev->bus));
1697     object_property_set_bool(OBJECT(vdev), true, "realized", &err);
1698     if (err) {
1699         error_propagate(errp, err);
1700     }
1701 }
1702 
1703 static void vhost_vsock_ccw_class_init(ObjectClass *klass, void *data)
1704 {
1705     DeviceClass *dc = DEVICE_CLASS(klass);
1706     VirtIOCCWDeviceClass *k = VIRTIO_CCW_DEVICE_CLASS(klass);
1707 
1708     k->realize = vhost_vsock_ccw_realize;
1709     k->exit = virtio_ccw_exit;
1710     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
1711     dc->props = vhost_vsock_ccw_properties;
1712     dc->reset = virtio_ccw_reset;
1713 }
1714 
1715 static void vhost_vsock_ccw_instance_init(Object *obj)
1716 {
1717     VHostVSockCCWState *dev = VHOST_VSOCK_CCW(obj);
1718 
1719     virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
1720                                 TYPE_VHOST_VSOCK);
1721 }
1722 
1723 static const TypeInfo vhost_vsock_ccw_info = {
1724     .name          = TYPE_VHOST_VSOCK_CCW,
1725     .parent        = TYPE_VIRTIO_CCW_DEVICE,
1726     .instance_size = sizeof(VHostVSockCCWState),
1727     .instance_init = vhost_vsock_ccw_instance_init,
1728     .class_init    = vhost_vsock_ccw_class_init,
1729 };
1730 #endif
1731 
1732 static void virtio_ccw_register(void)
1733 {
1734     type_register_static(&virtio_ccw_bus_info);
1735     type_register_static(&virtio_ccw_device_info);
1736     type_register_static(&virtio_ccw_serial);
1737     type_register_static(&virtio_ccw_blk);
1738     type_register_static(&virtio_ccw_net);
1739     type_register_static(&virtio_ccw_balloon);
1740     type_register_static(&virtio_ccw_scsi);
1741 #ifdef CONFIG_VHOST_SCSI
1742     type_register_static(&vhost_ccw_scsi);
1743 #endif
1744     type_register_static(&virtio_ccw_rng);
1745 #ifdef CONFIG_VIRTFS
1746     type_register_static(&virtio_ccw_9p_info);
1747 #endif
1748 #ifdef CONFIG_VHOST_VSOCK
1749     type_register_static(&vhost_vsock_ccw_info);
1750 #endif
1751 }
1752 
1753 type_init(virtio_ccw_register)
1754