xref: /openbmc/qemu/hw/s390x/virtio-ccw.c (revision 3d9569b8)
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/sysemu.h"
17 #include "sysemu/kvm.h"
18 #include "net/net.h"
19 #include "hw/virtio/virtio.h"
20 #include "hw/virtio/virtio-net.h"
21 #include "hw/sysbus.h"
22 #include "qemu/bitops.h"
23 #include "qemu/error-report.h"
24 #include "qemu/module.h"
25 #include "hw/virtio/virtio-access.h"
26 #include "hw/virtio/virtio-bus.h"
27 #include "hw/s390x/adapter.h"
28 #include "hw/s390x/s390_flic.h"
29 
30 #include "hw/s390x/ioinst.h"
31 #include "hw/s390x/css.h"
32 #include "virtio-ccw.h"
33 #include "trace.h"
34 #include "hw/s390x/css-bridge.h"
35 #include "hw/s390x/s390-virtio-ccw.h"
36 
37 #define NR_CLASSIC_INDICATOR_BITS 64
38 
39 static int virtio_ccw_dev_post_load(void *opaque, int version_id)
40 {
41     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(opaque);
42     CcwDevice *ccw_dev = CCW_DEVICE(dev);
43     CCWDeviceClass *ck = CCW_DEVICE_GET_CLASS(ccw_dev);
44 
45     ccw_dev->sch->driver_data = dev;
46     if (ccw_dev->sch->thinint_active) {
47         dev->routes.adapter.adapter_id = css_get_adapter_id(
48                                          CSS_IO_ADAPTER_VIRTIO,
49                                          dev->thinint_isc);
50     }
51     /* Re-fill subch_id after loading the subchannel states.*/
52     if (ck->refill_ids) {
53         ck->refill_ids(ccw_dev);
54     }
55     return 0;
56 }
57 
58 typedef struct VirtioCcwDeviceTmp {
59     VirtioCcwDevice *parent;
60     uint16_t config_vector;
61 } VirtioCcwDeviceTmp;
62 
63 static int virtio_ccw_dev_tmp_pre_save(void *opaque)
64 {
65     VirtioCcwDeviceTmp *tmp = opaque;
66     VirtioCcwDevice *dev = tmp->parent;
67     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
68 
69     tmp->config_vector = vdev->config_vector;
70 
71     return 0;
72 }
73 
74 static int virtio_ccw_dev_tmp_post_load(void *opaque, int version_id)
75 {
76     VirtioCcwDeviceTmp *tmp = opaque;
77     VirtioCcwDevice *dev = tmp->parent;
78     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
79 
80     vdev->config_vector = tmp->config_vector;
81     return 0;
82 }
83 
84 const VMStateDescription vmstate_virtio_ccw_dev_tmp = {
85     .name = "s390_virtio_ccw_dev_tmp",
86     .pre_save = virtio_ccw_dev_tmp_pre_save,
87     .post_load = virtio_ccw_dev_tmp_post_load,
88     .fields = (VMStateField[]) {
89         VMSTATE_UINT16(config_vector, VirtioCcwDeviceTmp),
90         VMSTATE_END_OF_LIST()
91     }
92 };
93 
94 const VMStateDescription vmstate_virtio_ccw_dev = {
95     .name = "s390_virtio_ccw_dev",
96     .version_id = 1,
97     .minimum_version_id = 1,
98     .post_load = virtio_ccw_dev_post_load,
99     .fields = (VMStateField[]) {
100         VMSTATE_CCW_DEVICE(parent_obj, VirtioCcwDevice),
101         VMSTATE_PTR_TO_IND_ADDR(indicators, VirtioCcwDevice),
102         VMSTATE_PTR_TO_IND_ADDR(indicators2, VirtioCcwDevice),
103         VMSTATE_PTR_TO_IND_ADDR(summary_indicator, VirtioCcwDevice),
104         /*
105          * Ugly hack because VirtIODevice does not migrate itself.
106          * This also makes legacy via vmstate_save_state possible.
107          */
108         VMSTATE_WITH_TMP(VirtioCcwDevice, VirtioCcwDeviceTmp,
109                          vmstate_virtio_ccw_dev_tmp),
110         VMSTATE_STRUCT(routes, VirtioCcwDevice, 1, vmstate_adapter_routes,
111                        AdapterRoutes),
112         VMSTATE_UINT8(thinint_isc, VirtioCcwDevice),
113         VMSTATE_INT32(revision, VirtioCcwDevice),
114         VMSTATE_END_OF_LIST()
115     }
116 };
117 
118 static void virtio_ccw_bus_new(VirtioBusState *bus, size_t bus_size,
119                                VirtioCcwDevice *dev);
120 
121 VirtIODevice *virtio_ccw_get_vdev(SubchDev *sch)
122 {
123     VirtIODevice *vdev = NULL;
124     VirtioCcwDevice *dev = sch->driver_data;
125 
126     if (dev) {
127         vdev = virtio_bus_get_device(&dev->bus);
128     }
129     return vdev;
130 }
131 
132 static void virtio_ccw_start_ioeventfd(VirtioCcwDevice *dev)
133 {
134     virtio_bus_start_ioeventfd(&dev->bus);
135 }
136 
137 static void virtio_ccw_stop_ioeventfd(VirtioCcwDevice *dev)
138 {
139     virtio_bus_stop_ioeventfd(&dev->bus);
140 }
141 
142 static bool virtio_ccw_ioeventfd_enabled(DeviceState *d)
143 {
144     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
145 
146     return (dev->flags & VIRTIO_CCW_FLAG_USE_IOEVENTFD) != 0;
147 }
148 
149 static int virtio_ccw_ioeventfd_assign(DeviceState *d, EventNotifier *notifier,
150                                        int n, bool assign)
151 {
152     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
153     CcwDevice *ccw_dev = CCW_DEVICE(dev);
154     SubchDev *sch = ccw_dev->sch;
155     uint32_t sch_id = (css_build_subchannel_id(sch) << 16) | sch->schid;
156 
157     return s390_assign_subch_ioeventfd(notifier, sch_id, n, assign);
158 }
159 
160 /* Communication blocks used by several channel commands. */
161 typedef struct VqInfoBlockLegacy {
162     uint64_t queue;
163     uint32_t align;
164     uint16_t index;
165     uint16_t num;
166 } QEMU_PACKED VqInfoBlockLegacy;
167 
168 typedef struct VqInfoBlock {
169     uint64_t desc;
170     uint32_t res0;
171     uint16_t index;
172     uint16_t num;
173     uint64_t avail;
174     uint64_t used;
175 } QEMU_PACKED VqInfoBlock;
176 
177 typedef struct VqConfigBlock {
178     uint16_t index;
179     uint16_t num_max;
180 } QEMU_PACKED VqConfigBlock;
181 
182 typedef struct VirtioFeatDesc {
183     uint32_t features;
184     uint8_t index;
185 } QEMU_PACKED VirtioFeatDesc;
186 
187 typedef struct VirtioThinintInfo {
188     hwaddr summary_indicator;
189     hwaddr device_indicator;
190     uint64_t ind_bit;
191     uint8_t isc;
192 } QEMU_PACKED VirtioThinintInfo;
193 
194 typedef struct VirtioRevInfo {
195     uint16_t revision;
196     uint16_t length;
197     uint8_t data[0];
198 } QEMU_PACKED VirtioRevInfo;
199 
200 /* Specify where the virtqueues for the subchannel are in guest memory. */
201 static int virtio_ccw_set_vqs(SubchDev *sch, VqInfoBlock *info,
202                               VqInfoBlockLegacy *linfo)
203 {
204     VirtIODevice *vdev = virtio_ccw_get_vdev(sch);
205     uint16_t index = info ? info->index : linfo->index;
206     uint16_t num = info ? info->num : linfo->num;
207     uint64_t desc = info ? info->desc : linfo->queue;
208 
209     if (index >= VIRTIO_QUEUE_MAX) {
210         return -EINVAL;
211     }
212 
213     /* Current code in virtio.c relies on 4K alignment. */
214     if (linfo && desc && (linfo->align != 4096)) {
215         return -EINVAL;
216     }
217 
218     if (!vdev) {
219         return -EINVAL;
220     }
221 
222     if (info) {
223         virtio_queue_set_rings(vdev, index, desc, info->avail, info->used);
224     } else {
225         virtio_queue_set_addr(vdev, index, desc);
226     }
227     if (!desc) {
228         virtio_queue_set_vector(vdev, index, VIRTIO_NO_VECTOR);
229     } else {
230         if (info) {
231             /* virtio-1 allows changing the ring size. */
232             if (virtio_queue_get_max_num(vdev, index) < num) {
233                 /* Fail if we exceed the maximum number. */
234                 return -EINVAL;
235             }
236             virtio_queue_set_num(vdev, index, num);
237         } else if (virtio_queue_get_num(vdev, index) > num) {
238             /* Fail if we don't have a big enough queue. */
239             return -EINVAL;
240         }
241         /* We ignore possible increased num for legacy for compatibility. */
242         virtio_queue_set_vector(vdev, index, index);
243     }
244     /* tell notify handler in case of config change */
245     vdev->config_vector = VIRTIO_QUEUE_MAX;
246     return 0;
247 }
248 
249 static void virtio_ccw_reset_virtio(VirtioCcwDevice *dev, VirtIODevice *vdev)
250 {
251     CcwDevice *ccw_dev = CCW_DEVICE(dev);
252 
253     virtio_ccw_stop_ioeventfd(dev);
254     virtio_reset(vdev);
255     if (dev->indicators) {
256         release_indicator(&dev->routes.adapter, dev->indicators);
257         dev->indicators = NULL;
258     }
259     if (dev->indicators2) {
260         release_indicator(&dev->routes.adapter, dev->indicators2);
261         dev->indicators2 = NULL;
262     }
263     if (dev->summary_indicator) {
264         release_indicator(&dev->routes.adapter, dev->summary_indicator);
265         dev->summary_indicator = NULL;
266     }
267     ccw_dev->sch->thinint_active = false;
268 }
269 
270 static int virtio_ccw_handle_set_vq(SubchDev *sch, CCW1 ccw, bool check_len,
271                                     bool is_legacy)
272 {
273     int ret;
274     VqInfoBlock info;
275     VqInfoBlockLegacy linfo;
276     size_t info_len = is_legacy ? sizeof(linfo) : sizeof(info);
277 
278     if (check_len) {
279         if (ccw.count != info_len) {
280             return -EINVAL;
281         }
282     } else if (ccw.count < info_len) {
283         /* Can't execute command. */
284         return -EINVAL;
285     }
286     if (!ccw.cda) {
287         return -EFAULT;
288     }
289     if (is_legacy) {
290         ccw_dstream_read(&sch->cds, linfo);
291         linfo.queue = be64_to_cpu(linfo.queue);
292         linfo.align = be32_to_cpu(linfo.align);
293         linfo.index = be16_to_cpu(linfo.index);
294         linfo.num = be16_to_cpu(linfo.num);
295         ret = virtio_ccw_set_vqs(sch, NULL, &linfo);
296     } else {
297         ccw_dstream_read(&sch->cds, info);
298         info.desc = be64_to_cpu(info.desc);
299         info.index = be16_to_cpu(info.index);
300         info.num = be16_to_cpu(info.num);
301         info.avail = be64_to_cpu(info.avail);
302         info.used = be64_to_cpu(info.used);
303         ret = virtio_ccw_set_vqs(sch, &info, NULL);
304     }
305     sch->curr_status.scsw.count = 0;
306     return ret;
307 }
308 
309 static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
310 {
311     int ret;
312     VirtioRevInfo revinfo;
313     uint8_t status;
314     VirtioFeatDesc features;
315     hwaddr indicators;
316     VqConfigBlock vq_config;
317     VirtioCcwDevice *dev = sch->driver_data;
318     VirtIODevice *vdev = virtio_ccw_get_vdev(sch);
319     bool check_len;
320     int len;
321     VirtioThinintInfo thinint;
322 
323     if (!dev) {
324         return -EINVAL;
325     }
326 
327     trace_virtio_ccw_interpret_ccw(sch->cssid, sch->ssid, sch->schid,
328                                    ccw.cmd_code);
329     check_len = !((ccw.flags & CCW_FLAG_SLI) && !(ccw.flags & CCW_FLAG_DC));
330 
331     if (dev->force_revision_1 && dev->revision < 0 &&
332         ccw.cmd_code != CCW_CMD_SET_VIRTIO_REV) {
333         /*
334          * virtio-1 drivers must start with negotiating to a revision >= 1,
335          * so post a command reject for all other commands
336          */
337         return -ENOSYS;
338     }
339 
340     /* Look at the command. */
341     switch (ccw.cmd_code) {
342     case CCW_CMD_SET_VQ:
343         ret = virtio_ccw_handle_set_vq(sch, ccw, check_len, dev->revision < 1);
344         break;
345     case CCW_CMD_VDEV_RESET:
346         virtio_ccw_reset_virtio(dev, vdev);
347         ret = 0;
348         break;
349     case CCW_CMD_READ_FEAT:
350         if (check_len) {
351             if (ccw.count != sizeof(features)) {
352                 ret = -EINVAL;
353                 break;
354             }
355         } else if (ccw.count < sizeof(features)) {
356             /* Can't execute command. */
357             ret = -EINVAL;
358             break;
359         }
360         if (!ccw.cda) {
361             ret = -EFAULT;
362         } else {
363             VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
364 
365             ccw_dstream_advance(&sch->cds, sizeof(features.features));
366             ccw_dstream_read(&sch->cds, features.index);
367             if (features.index == 0) {
368                 if (dev->revision >= 1) {
369                     /* Don't offer legacy features for modern devices. */
370                     features.features = (uint32_t)
371                         (vdev->host_features & ~vdc->legacy_features);
372                 } else {
373                     features.features = (uint32_t)vdev->host_features;
374                 }
375             } else if ((features.index == 1) && (dev->revision >= 1)) {
376                 /*
377                  * Only offer feature bits beyond 31 if the guest has
378                  * negotiated at least revision 1.
379                  */
380                 features.features = (uint32_t)(vdev->host_features >> 32);
381             } else {
382                 /* Return zeroes if the guest supports more feature bits. */
383                 features.features = 0;
384             }
385             ccw_dstream_rewind(&sch->cds);
386             features.features = cpu_to_le32(features.features);
387             ccw_dstream_write(&sch->cds, features.features);
388             sch->curr_status.scsw.count = ccw.count - sizeof(features);
389             ret = 0;
390         }
391         break;
392     case CCW_CMD_WRITE_FEAT:
393         if (check_len) {
394             if (ccw.count != sizeof(features)) {
395                 ret = -EINVAL;
396                 break;
397             }
398         } else if (ccw.count < sizeof(features)) {
399             /* Can't execute command. */
400             ret = -EINVAL;
401             break;
402         }
403         if (!ccw.cda) {
404             ret = -EFAULT;
405         } else {
406             ccw_dstream_read(&sch->cds, features);
407             features.features = le32_to_cpu(features.features);
408             if (features.index == 0) {
409                 virtio_set_features(vdev,
410                                     (vdev->guest_features & 0xffffffff00000000ULL) |
411                                     features.features);
412             } else if ((features.index == 1) && (dev->revision >= 1)) {
413                 /*
414                  * If the guest did not negotiate at least revision 1,
415                  * we did not offer it any feature bits beyond 31. Such a
416                  * guest passing us any bit here is therefore buggy.
417                  */
418                 virtio_set_features(vdev,
419                                     (vdev->guest_features & 0x00000000ffffffffULL) |
420                                     ((uint64_t)features.features << 32));
421             } else {
422                 /*
423                  * If the guest supports more feature bits, assert that it
424                  * passes us zeroes for those we don't support.
425                  */
426                 if (features.features) {
427                     qemu_log_mask(LOG_GUEST_ERROR,
428                                   "Guest bug: features[%i]=%x (expected 0)",
429                                   features.index, features.features);
430                     /* XXX: do a unit check here? */
431                 }
432             }
433             sch->curr_status.scsw.count = ccw.count - sizeof(features);
434             ret = 0;
435         }
436         break;
437     case CCW_CMD_READ_CONF:
438         if (check_len) {
439             if (ccw.count > vdev->config_len) {
440                 ret = -EINVAL;
441                 break;
442             }
443         }
444         len = MIN(ccw.count, vdev->config_len);
445         if (!ccw.cda) {
446             ret = -EFAULT;
447         } else {
448             virtio_bus_get_vdev_config(&dev->bus, vdev->config);
449             ccw_dstream_write_buf(&sch->cds, vdev->config, len);
450             sch->curr_status.scsw.count = ccw.count - len;
451             ret = 0;
452         }
453         break;
454     case CCW_CMD_WRITE_CONF:
455         if (check_len) {
456             if (ccw.count > vdev->config_len) {
457                 ret = -EINVAL;
458                 break;
459             }
460         }
461         len = MIN(ccw.count, vdev->config_len);
462         if (!ccw.cda) {
463             ret = -EFAULT;
464         } else {
465             ret = ccw_dstream_read_buf(&sch->cds, vdev->config, len);
466             if (!ret) {
467                 virtio_bus_set_vdev_config(&dev->bus, vdev->config);
468                 sch->curr_status.scsw.count = ccw.count - len;
469             }
470         }
471         break;
472     case CCW_CMD_READ_STATUS:
473         if (check_len) {
474             if (ccw.count != sizeof(status)) {
475                 ret = -EINVAL;
476                 break;
477             }
478         } else if (ccw.count < sizeof(status)) {
479             /* Can't execute command. */
480             ret = -EINVAL;
481             break;
482         }
483         if (!ccw.cda) {
484             ret = -EFAULT;
485         } else {
486             address_space_stb(&address_space_memory, ccw.cda, vdev->status,
487                                         MEMTXATTRS_UNSPECIFIED, NULL);
488             sch->curr_status.scsw.count = ccw.count - sizeof(vdev->status);
489             ret = 0;
490         }
491         break;
492     case CCW_CMD_WRITE_STATUS:
493         if (check_len) {
494             if (ccw.count != sizeof(status)) {
495                 ret = -EINVAL;
496                 break;
497             }
498         } else if (ccw.count < sizeof(status)) {
499             /* Can't execute command. */
500             ret = -EINVAL;
501             break;
502         }
503         if (!ccw.cda) {
504             ret = -EFAULT;
505         } else {
506             ccw_dstream_read(&sch->cds, status);
507             if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
508                 virtio_ccw_stop_ioeventfd(dev);
509             }
510             if (virtio_set_status(vdev, status) == 0) {
511                 if (vdev->status == 0) {
512                     virtio_ccw_reset_virtio(dev, vdev);
513                 }
514                 if (status & VIRTIO_CONFIG_S_DRIVER_OK) {
515                     virtio_ccw_start_ioeventfd(dev);
516                 }
517                 sch->curr_status.scsw.count = ccw.count - sizeof(status);
518                 ret = 0;
519             } else {
520                 /* Trigger a command reject. */
521                 ret = -ENOSYS;
522             }
523         }
524         break;
525     case CCW_CMD_SET_IND:
526         if (check_len) {
527             if (ccw.count != sizeof(indicators)) {
528                 ret = -EINVAL;
529                 break;
530             }
531         } else if (ccw.count < sizeof(indicators)) {
532             /* Can't execute command. */
533             ret = -EINVAL;
534             break;
535         }
536         if (sch->thinint_active) {
537             /* Trigger a command reject. */
538             ret = -ENOSYS;
539             break;
540         }
541         if (virtio_get_num_queues(vdev) > NR_CLASSIC_INDICATOR_BITS) {
542             /* More queues than indicator bits --> trigger a reject */
543             ret = -ENOSYS;
544             break;
545         }
546         if (!ccw.cda) {
547             ret = -EFAULT;
548         } else {
549             ccw_dstream_read(&sch->cds, indicators);
550             indicators = be64_to_cpu(indicators);
551             dev->indicators = get_indicator(indicators, sizeof(uint64_t));
552             sch->curr_status.scsw.count = ccw.count - sizeof(indicators);
553             ret = 0;
554         }
555         break;
556     case CCW_CMD_SET_CONF_IND:
557         if (check_len) {
558             if (ccw.count != sizeof(indicators)) {
559                 ret = -EINVAL;
560                 break;
561             }
562         } else if (ccw.count < sizeof(indicators)) {
563             /* Can't execute command. */
564             ret = -EINVAL;
565             break;
566         }
567         if (!ccw.cda) {
568             ret = -EFAULT;
569         } else {
570             ccw_dstream_read(&sch->cds, indicators);
571             indicators = be64_to_cpu(indicators);
572             dev->indicators2 = get_indicator(indicators, sizeof(uint64_t));
573             sch->curr_status.scsw.count = ccw.count - sizeof(indicators);
574             ret = 0;
575         }
576         break;
577     case CCW_CMD_READ_VQ_CONF:
578         if (check_len) {
579             if (ccw.count != sizeof(vq_config)) {
580                 ret = -EINVAL;
581                 break;
582             }
583         } else if (ccw.count < sizeof(vq_config)) {
584             /* Can't execute command. */
585             ret = -EINVAL;
586             break;
587         }
588         if (!ccw.cda) {
589             ret = -EFAULT;
590         } else {
591             ccw_dstream_read(&sch->cds, vq_config.index);
592             vq_config.index = be16_to_cpu(vq_config.index);
593             if (vq_config.index >= VIRTIO_QUEUE_MAX) {
594                 ret = -EINVAL;
595                 break;
596             }
597             vq_config.num_max = virtio_queue_get_num(vdev,
598                                                      vq_config.index);
599             vq_config.num_max = cpu_to_be16(vq_config.num_max);
600             ccw_dstream_write(&sch->cds, vq_config.num_max);
601             sch->curr_status.scsw.count = ccw.count - sizeof(vq_config);
602             ret = 0;
603         }
604         break;
605     case CCW_CMD_SET_IND_ADAPTER:
606         if (check_len) {
607             if (ccw.count != sizeof(thinint)) {
608                 ret = -EINVAL;
609                 break;
610             }
611         } else if (ccw.count < sizeof(thinint)) {
612             /* Can't execute command. */
613             ret = -EINVAL;
614             break;
615         }
616         if (!ccw.cda) {
617             ret = -EFAULT;
618         } else if (dev->indicators && !sch->thinint_active) {
619             /* Trigger a command reject. */
620             ret = -ENOSYS;
621         } else {
622             if (ccw_dstream_read(&sch->cds, thinint)) {
623                 ret = -EFAULT;
624             } else {
625                 thinint.ind_bit = be64_to_cpu(thinint.ind_bit);
626                 thinint.summary_indicator =
627                     be64_to_cpu(thinint.summary_indicator);
628                 thinint.device_indicator =
629                     be64_to_cpu(thinint.device_indicator);
630 
631                 dev->summary_indicator =
632                     get_indicator(thinint.summary_indicator, sizeof(uint8_t));
633                 dev->indicators =
634                     get_indicator(thinint.device_indicator,
635                                   thinint.ind_bit / 8 + 1);
636                 dev->thinint_isc = thinint.isc;
637                 dev->routes.adapter.ind_offset = thinint.ind_bit;
638                 dev->routes.adapter.summary_offset = 7;
639                 dev->routes.adapter.adapter_id = css_get_adapter_id(
640                                                  CSS_IO_ADAPTER_VIRTIO,
641                                                  dev->thinint_isc);
642                 sch->thinint_active = ((dev->indicators != NULL) &&
643                                        (dev->summary_indicator != NULL));
644                 sch->curr_status.scsw.count = ccw.count - sizeof(thinint);
645                 ret = 0;
646             }
647         }
648         break;
649     case CCW_CMD_SET_VIRTIO_REV:
650         len = sizeof(revinfo);
651         if (ccw.count < len) {
652             ret = -EINVAL;
653             break;
654         }
655         if (!ccw.cda) {
656             ret = -EFAULT;
657             break;
658         }
659         ccw_dstream_read_buf(&sch->cds, &revinfo, 4);
660         revinfo.revision = be16_to_cpu(revinfo.revision);
661         revinfo.length = be16_to_cpu(revinfo.length);
662         if (ccw.count < len + revinfo.length ||
663             (check_len && ccw.count > len + revinfo.length)) {
664             ret = -EINVAL;
665             break;
666         }
667         /*
668          * Once we start to support revisions with additional data, we'll
669          * need to fetch it here. Nothing to do for now, though.
670          */
671         if (dev->revision >= 0 ||
672             revinfo.revision > virtio_ccw_rev_max(dev) ||
673             (dev->force_revision_1 && !revinfo.revision)) {
674             ret = -ENOSYS;
675             break;
676         }
677         ret = 0;
678         dev->revision = revinfo.revision;
679         break;
680     default:
681         ret = -ENOSYS;
682         break;
683     }
684     return ret;
685 }
686 
687 static void virtio_sch_disable_cb(SubchDev *sch)
688 {
689     VirtioCcwDevice *dev = sch->driver_data;
690 
691     dev->revision = -1;
692 }
693 
694 static void virtio_ccw_device_realize(VirtioCcwDevice *dev, Error **errp)
695 {
696     VirtIOCCWDeviceClass *k = VIRTIO_CCW_DEVICE_GET_CLASS(dev);
697     CcwDevice *ccw_dev = CCW_DEVICE(dev);
698     CCWDeviceClass *ck = CCW_DEVICE_GET_CLASS(ccw_dev);
699     SubchDev *sch;
700     Error *err = NULL;
701 
702     sch = css_create_sch(ccw_dev->devno, errp);
703     if (!sch) {
704         return;
705     }
706     if (!virtio_ccw_rev_max(dev) && dev->force_revision_1) {
707         error_setg(&err, "Invalid value of property max_rev "
708                    "(is %d expected >= 1)", virtio_ccw_rev_max(dev));
709         goto out_err;
710     }
711 
712     sch->driver_data = dev;
713     sch->ccw_cb = virtio_ccw_cb;
714     sch->disable_cb = virtio_sch_disable_cb;
715     sch->id.reserved = 0xff;
716     sch->id.cu_type = VIRTIO_CCW_CU_TYPE;
717     sch->do_subchannel_work = do_subchannel_work_virtual;
718     ccw_dev->sch = sch;
719     dev->indicators = NULL;
720     dev->revision = -1;
721     css_sch_build_virtual_schib(sch, 0, VIRTIO_CCW_CHPID_TYPE);
722 
723     trace_virtio_ccw_new_device(
724         sch->cssid, sch->ssid, sch->schid, sch->devno,
725         ccw_dev->devno.valid ? "user-configured" : "auto-configured");
726 
727     if (kvm_enabled() && !kvm_eventfds_enabled()) {
728         dev->flags &= ~VIRTIO_CCW_FLAG_USE_IOEVENTFD;
729     }
730 
731     if (k->realize) {
732         k->realize(dev, &err);
733         if (err) {
734             goto out_err;
735         }
736     }
737 
738     ck->realize(ccw_dev, &err);
739     if (err) {
740         goto out_err;
741     }
742 
743     return;
744 
745 out_err:
746     error_propagate(errp, err);
747     css_subch_assign(sch->cssid, sch->ssid, sch->schid, sch->devno, NULL);
748     ccw_dev->sch = NULL;
749     g_free(sch);
750 }
751 
752 static void virtio_ccw_device_unrealize(VirtioCcwDevice *dev, Error **errp)
753 {
754     VirtIOCCWDeviceClass *dc = VIRTIO_CCW_DEVICE_GET_CLASS(dev);
755     CcwDevice *ccw_dev = CCW_DEVICE(dev);
756     SubchDev *sch = ccw_dev->sch;
757 
758     if (dc->unrealize) {
759         dc->unrealize(dev, errp);
760     }
761 
762     if (sch) {
763         css_subch_assign(sch->cssid, sch->ssid, sch->schid, sch->devno, NULL);
764         g_free(sch);
765         ccw_dev->sch = NULL;
766     }
767     if (dev->indicators) {
768         release_indicator(&dev->routes.adapter, dev->indicators);
769         dev->indicators = NULL;
770     }
771 }
772 
773 /* DeviceState to VirtioCcwDevice. Note: used on datapath,
774  * be careful and test performance if you change this.
775  */
776 static inline VirtioCcwDevice *to_virtio_ccw_dev_fast(DeviceState *d)
777 {
778     CcwDevice *ccw_dev = to_ccw_dev_fast(d);
779 
780     return container_of(ccw_dev, VirtioCcwDevice, parent_obj);
781 }
782 
783 static uint8_t virtio_set_ind_atomic(SubchDev *sch, uint64_t ind_loc,
784                                      uint8_t to_be_set)
785 {
786     uint8_t ind_old, ind_new;
787     hwaddr len = 1;
788     uint8_t *ind_addr;
789 
790     ind_addr = cpu_physical_memory_map(ind_loc, &len, 1);
791     if (!ind_addr) {
792         error_report("%s(%x.%x.%04x): unable to access indicator",
793                      __func__, sch->cssid, sch->ssid, sch->schid);
794         return -1;
795     }
796     do {
797         ind_old = *ind_addr;
798         ind_new = ind_old | to_be_set;
799     } while (atomic_cmpxchg(ind_addr, ind_old, ind_new) != ind_old);
800     trace_virtio_ccw_set_ind(ind_loc, ind_old, ind_new);
801     cpu_physical_memory_unmap(ind_addr, len, 1, len);
802 
803     return ind_old;
804 }
805 
806 static void virtio_ccw_notify(DeviceState *d, uint16_t vector)
807 {
808     VirtioCcwDevice *dev = to_virtio_ccw_dev_fast(d);
809     CcwDevice *ccw_dev = to_ccw_dev_fast(d);
810     SubchDev *sch = ccw_dev->sch;
811     uint64_t indicators;
812 
813     if (vector == VIRTIO_NO_VECTOR) {
814         return;
815     }
816     /*
817      * vector < VIRTIO_QUEUE_MAX: notification for a virtqueue
818      * vector == VIRTIO_QUEUE_MAX: configuration change notification
819      * bits beyond that are unused and should never be notified for
820      */
821     assert(vector <= VIRTIO_QUEUE_MAX);
822 
823     if (vector < VIRTIO_QUEUE_MAX) {
824         if (!dev->indicators) {
825             return;
826         }
827         if (sch->thinint_active) {
828             /*
829              * In the adapter interrupt case, indicators points to a
830              * memory area that may be (way) larger than 64 bit and
831              * ind_bit indicates the start of the indicators in a big
832              * endian notation.
833              */
834             uint64_t ind_bit = dev->routes.adapter.ind_offset;
835 
836             virtio_set_ind_atomic(sch, dev->indicators->addr +
837                                   (ind_bit + vector) / 8,
838                                   0x80 >> ((ind_bit + vector) % 8));
839             if (!virtio_set_ind_atomic(sch, dev->summary_indicator->addr,
840                                        0x01)) {
841                 css_adapter_interrupt(CSS_IO_ADAPTER_VIRTIO, dev->thinint_isc);
842             }
843         } else {
844             assert(vector < NR_CLASSIC_INDICATOR_BITS);
845             indicators = address_space_ldq(&address_space_memory,
846                                            dev->indicators->addr,
847                                            MEMTXATTRS_UNSPECIFIED,
848                                            NULL);
849             indicators |= 1ULL << vector;
850             address_space_stq(&address_space_memory, dev->indicators->addr,
851                               indicators, MEMTXATTRS_UNSPECIFIED, NULL);
852             css_conditional_io_interrupt(sch);
853         }
854     } else {
855         if (!dev->indicators2) {
856             return;
857         }
858         indicators = address_space_ldq(&address_space_memory,
859                                        dev->indicators2->addr,
860                                        MEMTXATTRS_UNSPECIFIED,
861                                        NULL);
862         indicators |= 1ULL;
863         address_space_stq(&address_space_memory, dev->indicators2->addr,
864                           indicators, MEMTXATTRS_UNSPECIFIED, NULL);
865         css_conditional_io_interrupt(sch);
866     }
867 }
868 
869 static void virtio_ccw_reset(DeviceState *d)
870 {
871     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
872     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
873     VirtIOCCWDeviceClass *vdc = VIRTIO_CCW_DEVICE_GET_CLASS(dev);
874 
875     virtio_ccw_reset_virtio(dev, vdev);
876     if (vdc->parent_reset) {
877         vdc->parent_reset(d);
878     }
879 }
880 
881 static void virtio_ccw_vmstate_change(DeviceState *d, bool running)
882 {
883     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
884 
885     if (running) {
886         virtio_ccw_start_ioeventfd(dev);
887     } else {
888         virtio_ccw_stop_ioeventfd(dev);
889     }
890 }
891 
892 static bool virtio_ccw_query_guest_notifiers(DeviceState *d)
893 {
894     CcwDevice *dev = CCW_DEVICE(d);
895 
896     return !!(dev->sch->curr_status.pmcw.flags & PMCW_FLAGS_MASK_ENA);
897 }
898 
899 static int virtio_ccw_get_mappings(VirtioCcwDevice *dev)
900 {
901     int r;
902     CcwDevice *ccw_dev = CCW_DEVICE(dev);
903 
904     if (!ccw_dev->sch->thinint_active) {
905         return -EINVAL;
906     }
907 
908     r = map_indicator(&dev->routes.adapter, dev->summary_indicator);
909     if (r) {
910         return r;
911     }
912     r = map_indicator(&dev->routes.adapter, dev->indicators);
913     if (r) {
914         return r;
915     }
916     dev->routes.adapter.summary_addr = dev->summary_indicator->map;
917     dev->routes.adapter.ind_addr = dev->indicators->map;
918 
919     return 0;
920 }
921 
922 static int virtio_ccw_setup_irqroutes(VirtioCcwDevice *dev, int nvqs)
923 {
924     int i;
925     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
926     int ret;
927     S390FLICState *fs = s390_get_flic();
928     S390FLICStateClass *fsc = s390_get_flic_class(fs);
929 
930     ret = virtio_ccw_get_mappings(dev);
931     if (ret) {
932         return ret;
933     }
934     for (i = 0; i < nvqs; i++) {
935         if (!virtio_queue_get_num(vdev, i)) {
936             break;
937         }
938     }
939     dev->routes.num_routes = i;
940     return fsc->add_adapter_routes(fs, &dev->routes);
941 }
942 
943 static void virtio_ccw_release_irqroutes(VirtioCcwDevice *dev, int nvqs)
944 {
945     S390FLICState *fs = s390_get_flic();
946     S390FLICStateClass *fsc = s390_get_flic_class(fs);
947 
948     fsc->release_adapter_routes(fs, &dev->routes);
949 }
950 
951 static int virtio_ccw_add_irqfd(VirtioCcwDevice *dev, int n)
952 {
953     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
954     VirtQueue *vq = virtio_get_queue(vdev, n);
955     EventNotifier *notifier = virtio_queue_get_guest_notifier(vq);
956 
957     return kvm_irqchip_add_irqfd_notifier_gsi(kvm_state, notifier, NULL,
958                                               dev->routes.gsi[n]);
959 }
960 
961 static void virtio_ccw_remove_irqfd(VirtioCcwDevice *dev, int n)
962 {
963     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
964     VirtQueue *vq = virtio_get_queue(vdev, n);
965     EventNotifier *notifier = virtio_queue_get_guest_notifier(vq);
966     int ret;
967 
968     ret = kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state, notifier,
969                                                 dev->routes.gsi[n]);
970     assert(ret == 0);
971 }
972 
973 static int virtio_ccw_set_guest_notifier(VirtioCcwDevice *dev, int n,
974                                          bool assign, bool with_irqfd)
975 {
976     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
977     VirtQueue *vq = virtio_get_queue(vdev, n);
978     EventNotifier *notifier = virtio_queue_get_guest_notifier(vq);
979     VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
980 
981     if (assign) {
982         int r = event_notifier_init(notifier, 0);
983 
984         if (r < 0) {
985             return r;
986         }
987         virtio_queue_set_guest_notifier_fd_handler(vq, true, with_irqfd);
988         if (with_irqfd) {
989             r = virtio_ccw_add_irqfd(dev, n);
990             if (r) {
991                 virtio_queue_set_guest_notifier_fd_handler(vq, false,
992                                                            with_irqfd);
993                 return r;
994             }
995         }
996         /*
997          * We do not support individual masking for channel devices, so we
998          * need to manually trigger any guest masking callbacks here.
999          */
1000         if (k->guest_notifier_mask && vdev->use_guest_notifier_mask) {
1001             k->guest_notifier_mask(vdev, n, false);
1002         }
1003         /* get lost events and re-inject */
1004         if (k->guest_notifier_pending &&
1005             k->guest_notifier_pending(vdev, n)) {
1006             event_notifier_set(notifier);
1007         }
1008     } else {
1009         if (k->guest_notifier_mask && vdev->use_guest_notifier_mask) {
1010             k->guest_notifier_mask(vdev, n, true);
1011         }
1012         if (with_irqfd) {
1013             virtio_ccw_remove_irqfd(dev, n);
1014         }
1015         virtio_queue_set_guest_notifier_fd_handler(vq, false, with_irqfd);
1016         event_notifier_cleanup(notifier);
1017     }
1018     return 0;
1019 }
1020 
1021 static int virtio_ccw_set_guest_notifiers(DeviceState *d, int nvqs,
1022                                           bool assigned)
1023 {
1024     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
1025     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
1026     CcwDevice *ccw_dev = CCW_DEVICE(d);
1027     bool with_irqfd = ccw_dev->sch->thinint_active && kvm_irqfds_enabled();
1028     int r, n;
1029 
1030     if (with_irqfd && assigned) {
1031         /* irq routes need to be set up before assigning irqfds */
1032         r = virtio_ccw_setup_irqroutes(dev, nvqs);
1033         if (r < 0) {
1034             goto irqroute_error;
1035         }
1036     }
1037     for (n = 0; n < nvqs; n++) {
1038         if (!virtio_queue_get_num(vdev, n)) {
1039             break;
1040         }
1041         r = virtio_ccw_set_guest_notifier(dev, n, assigned, with_irqfd);
1042         if (r < 0) {
1043             goto assign_error;
1044         }
1045     }
1046     if (with_irqfd && !assigned) {
1047         /* release irq routes after irqfds have been released */
1048         virtio_ccw_release_irqroutes(dev, nvqs);
1049     }
1050     return 0;
1051 
1052 assign_error:
1053     while (--n >= 0) {
1054         virtio_ccw_set_guest_notifier(dev, n, !assigned, false);
1055     }
1056 irqroute_error:
1057     if (with_irqfd && assigned) {
1058         virtio_ccw_release_irqroutes(dev, nvqs);
1059     }
1060     return r;
1061 }
1062 
1063 static void virtio_ccw_save_queue(DeviceState *d, int n, QEMUFile *f)
1064 {
1065     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
1066     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
1067 
1068     qemu_put_be16(f, virtio_queue_vector(vdev, n));
1069 }
1070 
1071 static int virtio_ccw_load_queue(DeviceState *d, int n, QEMUFile *f)
1072 {
1073     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
1074     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
1075     uint16_t vector;
1076 
1077     qemu_get_be16s(f, &vector);
1078     virtio_queue_set_vector(vdev, n , vector);
1079 
1080     return 0;
1081 }
1082 
1083 static void virtio_ccw_save_config(DeviceState *d, QEMUFile *f)
1084 {
1085     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
1086     vmstate_save_state(f, &vmstate_virtio_ccw_dev, dev, NULL);
1087 }
1088 
1089 static int virtio_ccw_load_config(DeviceState *d, QEMUFile *f)
1090 {
1091     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
1092     return vmstate_load_state(f, &vmstate_virtio_ccw_dev, dev, 1);
1093 }
1094 
1095 static void virtio_ccw_pre_plugged(DeviceState *d, Error **errp)
1096 {
1097    VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
1098    VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
1099 
1100     if (dev->max_rev >= 1) {
1101         virtio_add_feature(&vdev->host_features, VIRTIO_F_VERSION_1);
1102     }
1103 }
1104 
1105 /* This is called by virtio-bus just after the device is plugged. */
1106 static void virtio_ccw_device_plugged(DeviceState *d, Error **errp)
1107 {
1108     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
1109     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
1110     CcwDevice *ccw_dev = CCW_DEVICE(d);
1111     SubchDev *sch = ccw_dev->sch;
1112     int n = virtio_get_num_queues(vdev);
1113     S390FLICState *flic = s390_get_flic();
1114 
1115     if (!virtio_has_feature(vdev->host_features, VIRTIO_F_VERSION_1)) {
1116         dev->max_rev = 0;
1117     }
1118 
1119     if (virtio_get_num_queues(vdev) > VIRTIO_QUEUE_MAX) {
1120         error_setg(errp, "The number of virtqueues %d "
1121                    "exceeds virtio limit %d", n,
1122                    VIRTIO_QUEUE_MAX);
1123         return;
1124     }
1125     if (virtio_get_num_queues(vdev) > flic->adapter_routes_max_batch) {
1126         error_setg(errp, "The number of virtqueues %d "
1127                    "exceeds flic adapter route limit %d", n,
1128                    flic->adapter_routes_max_batch);
1129         return;
1130     }
1131 
1132     sch->id.cu_model = virtio_bus_get_vdev_id(&dev->bus);
1133 
1134 
1135     css_generate_sch_crws(sch->cssid, sch->ssid, sch->schid,
1136                           d->hotplugged, 1);
1137 }
1138 
1139 static void virtio_ccw_device_unplugged(DeviceState *d)
1140 {
1141     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
1142 
1143     virtio_ccw_stop_ioeventfd(dev);
1144 }
1145 /**************** Virtio-ccw Bus Device Descriptions *******************/
1146 
1147 static void virtio_ccw_busdev_realize(DeviceState *dev, Error **errp)
1148 {
1149     VirtioCcwDevice *_dev = (VirtioCcwDevice *)dev;
1150 
1151     virtio_ccw_bus_new(&_dev->bus, sizeof(_dev->bus), _dev);
1152     virtio_ccw_device_realize(_dev, errp);
1153 }
1154 
1155 static void virtio_ccw_busdev_unrealize(DeviceState *dev, Error **errp)
1156 {
1157     VirtioCcwDevice *_dev = (VirtioCcwDevice *)dev;
1158 
1159     virtio_ccw_device_unrealize(_dev, errp);
1160 }
1161 
1162 static void virtio_ccw_busdev_unplug(HotplugHandler *hotplug_dev,
1163                                      DeviceState *dev, Error **errp)
1164 {
1165     VirtioCcwDevice *_dev = to_virtio_ccw_dev_fast(dev);
1166 
1167     virtio_ccw_stop_ioeventfd(_dev);
1168 }
1169 
1170 static void virtio_ccw_device_class_init(ObjectClass *klass, void *data)
1171 {
1172     DeviceClass *dc = DEVICE_CLASS(klass);
1173     CCWDeviceClass *k = CCW_DEVICE_CLASS(dc);
1174     VirtIOCCWDeviceClass *vdc = VIRTIO_CCW_DEVICE_CLASS(klass);
1175 
1176     k->unplug = virtio_ccw_busdev_unplug;
1177     dc->realize = virtio_ccw_busdev_realize;
1178     dc->unrealize = virtio_ccw_busdev_unrealize;
1179     dc->bus_type = TYPE_VIRTUAL_CSS_BUS;
1180     device_class_set_parent_reset(dc, virtio_ccw_reset, &vdc->parent_reset);
1181 }
1182 
1183 static const TypeInfo virtio_ccw_device_info = {
1184     .name = TYPE_VIRTIO_CCW_DEVICE,
1185     .parent = TYPE_CCW_DEVICE,
1186     .instance_size = sizeof(VirtioCcwDevice),
1187     .class_init = virtio_ccw_device_class_init,
1188     .class_size = sizeof(VirtIOCCWDeviceClass),
1189     .abstract = true,
1190 };
1191 
1192 /* virtio-ccw-bus */
1193 
1194 static void virtio_ccw_bus_new(VirtioBusState *bus, size_t bus_size,
1195                                VirtioCcwDevice *dev)
1196 {
1197     DeviceState *qdev = DEVICE(dev);
1198     char virtio_bus_name[] = "virtio-bus";
1199 
1200     qbus_create_inplace(bus, bus_size, TYPE_VIRTIO_CCW_BUS,
1201                         qdev, virtio_bus_name);
1202 }
1203 
1204 static void virtio_ccw_bus_class_init(ObjectClass *klass, void *data)
1205 {
1206     VirtioBusClass *k = VIRTIO_BUS_CLASS(klass);
1207     BusClass *bus_class = BUS_CLASS(klass);
1208 
1209     bus_class->max_dev = 1;
1210     k->notify = virtio_ccw_notify;
1211     k->vmstate_change = virtio_ccw_vmstate_change;
1212     k->query_guest_notifiers = virtio_ccw_query_guest_notifiers;
1213     k->set_guest_notifiers = virtio_ccw_set_guest_notifiers;
1214     k->save_queue = virtio_ccw_save_queue;
1215     k->load_queue = virtio_ccw_load_queue;
1216     k->save_config = virtio_ccw_save_config;
1217     k->load_config = virtio_ccw_load_config;
1218     k->pre_plugged = virtio_ccw_pre_plugged;
1219     k->device_plugged = virtio_ccw_device_plugged;
1220     k->device_unplugged = virtio_ccw_device_unplugged;
1221     k->ioeventfd_enabled = virtio_ccw_ioeventfd_enabled;
1222     k->ioeventfd_assign = virtio_ccw_ioeventfd_assign;
1223 }
1224 
1225 static const TypeInfo virtio_ccw_bus_info = {
1226     .name = TYPE_VIRTIO_CCW_BUS,
1227     .parent = TYPE_VIRTIO_BUS,
1228     .instance_size = sizeof(VirtioCcwBusState),
1229     .class_init = virtio_ccw_bus_class_init,
1230 };
1231 
1232 static void virtio_ccw_register(void)
1233 {
1234     type_register_static(&virtio_ccw_bus_info);
1235     type_register_static(&virtio_ccw_device_info);
1236 }
1237 
1238 type_init(virtio_ccw_register)
1239