xref: /openbmc/qemu/hw/s390x/virtio-ccw.c (revision 7f623d08)
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 "hw/virtio/virtio-access.h"
25 #include "hw/virtio/virtio-bus.h"
26 #include "hw/s390x/adapter.h"
27 #include "hw/s390x/s390_flic.h"
28 
29 #include "hw/s390x/ioinst.h"
30 #include "hw/s390x/css.h"
31 #include "virtio-ccw.h"
32 #include "trace.h"
33 #include "hw/s390x/css-bridge.h"
34 #include "hw/s390x/s390-virtio-ccw.h"
35 
36 #define NR_CLASSIC_INDICATOR_BITS 64
37 
38 static int virtio_ccw_dev_post_load(void *opaque, int version_id)
39 {
40     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(opaque);
41     CcwDevice *ccw_dev = CCW_DEVICE(dev);
42     CCWDeviceClass *ck = CCW_DEVICE_GET_CLASS(ccw_dev);
43 
44     ccw_dev->sch->driver_data = dev;
45     if (ccw_dev->sch->thinint_active) {
46         dev->routes.adapter.adapter_id = css_get_adapter_id(
47                                          CSS_IO_ADAPTER_VIRTIO,
48                                          dev->thinint_isc);
49     }
50     /* Re-fill subch_id after loading the subchannel states.*/
51     if (ck->refill_ids) {
52         ck->refill_ids(ccw_dev);
53     }
54     return 0;
55 }
56 
57 typedef struct VirtioCcwDeviceTmp {
58     VirtioCcwDevice *parent;
59     uint16_t config_vector;
60 } VirtioCcwDeviceTmp;
61 
62 static int virtio_ccw_dev_tmp_pre_save(void *opaque)
63 {
64     VirtioCcwDeviceTmp *tmp = opaque;
65     VirtioCcwDevice *dev = tmp->parent;
66     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
67 
68     tmp->config_vector = vdev->config_vector;
69 
70     return 0;
71 }
72 
73 static int virtio_ccw_dev_tmp_post_load(void *opaque, int version_id)
74 {
75     VirtioCcwDeviceTmp *tmp = opaque;
76     VirtioCcwDevice *dev = tmp->parent;
77     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
78 
79     vdev->config_vector = tmp->config_vector;
80     return 0;
81 }
82 
83 const VMStateDescription vmstate_virtio_ccw_dev_tmp = {
84     .name = "s390_virtio_ccw_dev_tmp",
85     .pre_save = virtio_ccw_dev_tmp_pre_save,
86     .post_load = virtio_ccw_dev_tmp_post_load,
87     .fields = (VMStateField[]) {
88         VMSTATE_UINT16(config_vector, VirtioCcwDeviceTmp),
89         VMSTATE_END_OF_LIST()
90     }
91 };
92 
93 const VMStateDescription vmstate_virtio_ccw_dev = {
94     .name = "s390_virtio_ccw_dev",
95     .version_id = 1,
96     .minimum_version_id = 1,
97     .post_load = virtio_ccw_dev_post_load,
98     .fields = (VMStateField[]) {
99         VMSTATE_CCW_DEVICE(parent_obj, VirtioCcwDevice),
100         VMSTATE_PTR_TO_IND_ADDR(indicators, VirtioCcwDevice),
101         VMSTATE_PTR_TO_IND_ADDR(indicators2, VirtioCcwDevice),
102         VMSTATE_PTR_TO_IND_ADDR(summary_indicator, VirtioCcwDevice),
103         /*
104          * Ugly hack because VirtIODevice does not migrate itself.
105          * This also makes legacy via vmstate_save_state possible.
106          */
107         VMSTATE_WITH_TMP(VirtioCcwDevice, VirtioCcwDeviceTmp,
108                          vmstate_virtio_ccw_dev_tmp),
109         VMSTATE_STRUCT(routes, VirtioCcwDevice, 1, vmstate_adapter_routes,
110                        AdapterRoutes),
111         VMSTATE_UINT8(thinint_isc, VirtioCcwDevice),
112         VMSTATE_INT32(revision, VirtioCcwDevice),
113         VMSTATE_END_OF_LIST()
114     }
115 };
116 
117 static void virtio_ccw_bus_new(VirtioBusState *bus, size_t bus_size,
118                                VirtioCcwDevice *dev);
119 
120 VirtIODevice *virtio_ccw_get_vdev(SubchDev *sch)
121 {
122     VirtIODevice *vdev = NULL;
123     VirtioCcwDevice *dev = sch->driver_data;
124 
125     if (dev) {
126         vdev = virtio_bus_get_device(&dev->bus);
127     }
128     return vdev;
129 }
130 
131 static void virtio_ccw_start_ioeventfd(VirtioCcwDevice *dev)
132 {
133     virtio_bus_start_ioeventfd(&dev->bus);
134 }
135 
136 static void virtio_ccw_stop_ioeventfd(VirtioCcwDevice *dev)
137 {
138     virtio_bus_stop_ioeventfd(&dev->bus);
139 }
140 
141 static bool virtio_ccw_ioeventfd_enabled(DeviceState *d)
142 {
143     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
144 
145     return (dev->flags & VIRTIO_CCW_FLAG_USE_IOEVENTFD) != 0;
146 }
147 
148 static int virtio_ccw_ioeventfd_assign(DeviceState *d, EventNotifier *notifier,
149                                        int n, bool assign)
150 {
151     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
152     CcwDevice *ccw_dev = CCW_DEVICE(dev);
153     SubchDev *sch = ccw_dev->sch;
154     uint32_t sch_id = (css_build_subchannel_id(sch) << 16) | sch->schid;
155 
156     return s390_assign_subch_ioeventfd(notifier, sch_id, n, assign);
157 }
158 
159 /* Communication blocks used by several channel commands. */
160 typedef struct VqInfoBlockLegacy {
161     uint64_t queue;
162     uint32_t align;
163     uint16_t index;
164     uint16_t num;
165 } QEMU_PACKED VqInfoBlockLegacy;
166 
167 typedef struct VqInfoBlock {
168     uint64_t desc;
169     uint32_t res0;
170     uint16_t index;
171     uint16_t num;
172     uint64_t avail;
173     uint64_t used;
174 } QEMU_PACKED VqInfoBlock;
175 
176 typedef struct VqConfigBlock {
177     uint16_t index;
178     uint16_t num_max;
179 } QEMU_PACKED VqConfigBlock;
180 
181 typedef struct VirtioFeatDesc {
182     uint32_t features;
183     uint8_t index;
184 } QEMU_PACKED VirtioFeatDesc;
185 
186 typedef struct VirtioThinintInfo {
187     hwaddr summary_indicator;
188     hwaddr device_indicator;
189     uint64_t ind_bit;
190     uint8_t isc;
191 } QEMU_PACKED VirtioThinintInfo;
192 
193 typedef struct VirtioRevInfo {
194     uint16_t revision;
195     uint16_t length;
196     uint8_t data[0];
197 } QEMU_PACKED VirtioRevInfo;
198 
199 /* Specify where the virtqueues for the subchannel are in guest memory. */
200 static int virtio_ccw_set_vqs(SubchDev *sch, VqInfoBlock *info,
201                               VqInfoBlockLegacy *linfo)
202 {
203     VirtIODevice *vdev = virtio_ccw_get_vdev(sch);
204     uint16_t index = info ? info->index : linfo->index;
205     uint16_t num = info ? info->num : linfo->num;
206     uint64_t desc = info ? info->desc : linfo->queue;
207 
208     if (index >= VIRTIO_QUEUE_MAX) {
209         return -EINVAL;
210     }
211 
212     /* Current code in virtio.c relies on 4K alignment. */
213     if (linfo && desc && (linfo->align != 4096)) {
214         return -EINVAL;
215     }
216 
217     if (!vdev) {
218         return -EINVAL;
219     }
220 
221     if (info) {
222         virtio_queue_set_rings(vdev, index, desc, info->avail, info->used);
223     } else {
224         virtio_queue_set_addr(vdev, index, desc);
225     }
226     if (!desc) {
227         virtio_queue_set_vector(vdev, index, VIRTIO_NO_VECTOR);
228     } else {
229         if (info) {
230             /* virtio-1 allows changing the ring size. */
231             if (virtio_queue_get_max_num(vdev, index) < num) {
232                 /* Fail if we exceed the maximum number. */
233                 return -EINVAL;
234             }
235             virtio_queue_set_num(vdev, index, num);
236         } else if (virtio_queue_get_num(vdev, index) > num) {
237             /* Fail if we don't have a big enough queue. */
238             return -EINVAL;
239         }
240         /* We ignore possible increased num for legacy for compatibility. */
241         virtio_queue_set_vector(vdev, index, index);
242     }
243     /* tell notify handler in case of config change */
244     vdev->config_vector = VIRTIO_QUEUE_MAX;
245     return 0;
246 }
247 
248 static void virtio_ccw_reset_virtio(VirtioCcwDevice *dev, VirtIODevice *vdev)
249 {
250     CcwDevice *ccw_dev = CCW_DEVICE(dev);
251 
252     virtio_ccw_stop_ioeventfd(dev);
253     virtio_reset(vdev);
254     if (dev->indicators) {
255         release_indicator(&dev->routes.adapter, dev->indicators);
256         dev->indicators = NULL;
257     }
258     if (dev->indicators2) {
259         release_indicator(&dev->routes.adapter, dev->indicators2);
260         dev->indicators2 = NULL;
261     }
262     if (dev->summary_indicator) {
263         release_indicator(&dev->routes.adapter, dev->summary_indicator);
264         dev->summary_indicator = NULL;
265     }
266     ccw_dev->sch->thinint_active = false;
267 }
268 
269 static int virtio_ccw_handle_set_vq(SubchDev *sch, CCW1 ccw, bool check_len,
270                                     bool is_legacy)
271 {
272     int ret;
273     VqInfoBlock info;
274     VqInfoBlockLegacy linfo;
275     size_t info_len = is_legacy ? sizeof(linfo) : sizeof(info);
276 
277     if (check_len) {
278         if (ccw.count != info_len) {
279             return -EINVAL;
280         }
281     } else if (ccw.count < info_len) {
282         /* Can't execute command. */
283         return -EINVAL;
284     }
285     if (!ccw.cda) {
286         return -EFAULT;
287     }
288     if (is_legacy) {
289         ccw_dstream_read(&sch->cds, linfo);
290         be64_to_cpus(&linfo.queue);
291         be32_to_cpus(&linfo.align);
292         be16_to_cpus(&linfo.index);
293         be16_to_cpus(&linfo.num);
294         ret = virtio_ccw_set_vqs(sch, NULL, &linfo);
295     } else {
296         ccw_dstream_read(&sch->cds, info);
297         be64_to_cpus(&info.desc);
298         be16_to_cpus(&info.index);
299         be16_to_cpus(&info.num);
300         be64_to_cpus(&info.avail);
301         be64_to_cpus(&info.used);
302         ret = virtio_ccw_set_vqs(sch, &info, NULL);
303     }
304     sch->curr_status.scsw.count = 0;
305     return ret;
306 }
307 
308 static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
309 {
310     int ret;
311     VirtioRevInfo revinfo;
312     uint8_t status;
313     VirtioFeatDesc features;
314     hwaddr indicators;
315     VqConfigBlock vq_config;
316     VirtioCcwDevice *dev = sch->driver_data;
317     VirtIODevice *vdev = virtio_ccw_get_vdev(sch);
318     bool check_len;
319     int len;
320     VirtioThinintInfo thinint;
321 
322     if (!dev) {
323         return -EINVAL;
324     }
325 
326     trace_virtio_ccw_interpret_ccw(sch->cssid, sch->ssid, sch->schid,
327                                    ccw.cmd_code);
328     check_len = !((ccw.flags & CCW_FLAG_SLI) && !(ccw.flags & CCW_FLAG_DC));
329 
330     if (dev->force_revision_1 && dev->revision < 0 &&
331         ccw.cmd_code != CCW_CMD_SET_VIRTIO_REV) {
332         /*
333          * virtio-1 drivers must start with negotiating to a revision >= 1,
334          * so post a command reject for all other commands
335          */
336         return -ENOSYS;
337     }
338 
339     /* Look at the command. */
340     switch (ccw.cmd_code) {
341     case CCW_CMD_SET_VQ:
342         ret = virtio_ccw_handle_set_vq(sch, ccw, check_len, dev->revision < 1);
343         break;
344     case CCW_CMD_VDEV_RESET:
345         virtio_ccw_reset_virtio(dev, vdev);
346         ret = 0;
347         break;
348     case CCW_CMD_READ_FEAT:
349         if (check_len) {
350             if (ccw.count != sizeof(features)) {
351                 ret = -EINVAL;
352                 break;
353             }
354         } else if (ccw.count < sizeof(features)) {
355             /* Can't execute command. */
356             ret = -EINVAL;
357             break;
358         }
359         if (!ccw.cda) {
360             ret = -EFAULT;
361         } else {
362             VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
363 
364             ccw_dstream_advance(&sch->cds, sizeof(features.features));
365             ccw_dstream_read(&sch->cds, features.index);
366             if (features.index == 0) {
367                 if (dev->revision >= 1) {
368                     /* Don't offer legacy features for modern devices. */
369                     features.features = (uint32_t)
370                         (vdev->host_features & ~vdc->legacy_features);
371                 } else {
372                     features.features = (uint32_t)vdev->host_features;
373                 }
374             } else if ((features.index == 1) && (dev->revision >= 1)) {
375                 /*
376                  * Only offer feature bits beyond 31 if the guest has
377                  * negotiated at least revision 1.
378                  */
379                 features.features = (uint32_t)(vdev->host_features >> 32);
380             } else {
381                 /* Return zeroes if the guest supports more feature bits. */
382                 features.features = 0;
383             }
384             ccw_dstream_rewind(&sch->cds);
385             cpu_to_le32s(&features.features);
386             ccw_dstream_write(&sch->cds, features.features);
387             sch->curr_status.scsw.count = ccw.count - sizeof(features);
388             ret = 0;
389         }
390         break;
391     case CCW_CMD_WRITE_FEAT:
392         if (check_len) {
393             if (ccw.count != sizeof(features)) {
394                 ret = -EINVAL;
395                 break;
396             }
397         } else if (ccw.count < sizeof(features)) {
398             /* Can't execute command. */
399             ret = -EINVAL;
400             break;
401         }
402         if (!ccw.cda) {
403             ret = -EFAULT;
404         } else {
405             ccw_dstream_read(&sch->cds, features);
406             le32_to_cpus(&features.features);
407             if (features.index == 0) {
408                 virtio_set_features(vdev,
409                                     (vdev->guest_features & 0xffffffff00000000ULL) |
410                                     features.features);
411             } else if ((features.index == 1) && (dev->revision >= 1)) {
412                 /*
413                  * If the guest did not negotiate at least revision 1,
414                  * we did not offer it any feature bits beyond 31. Such a
415                  * guest passing us any bit here is therefore buggy.
416                  */
417                 virtio_set_features(vdev,
418                                     (vdev->guest_features & 0x00000000ffffffffULL) |
419                                     ((uint64_t)features.features << 32));
420             } else {
421                 /*
422                  * If the guest supports more feature bits, assert that it
423                  * passes us zeroes for those we don't support.
424                  */
425                 if (features.features) {
426                     qemu_log_mask(LOG_GUEST_ERROR,
427                                   "Guest bug: features[%i]=%x (expected 0)",
428                                   features.index, features.features);
429                     /* XXX: do a unit check here? */
430                 }
431             }
432             sch->curr_status.scsw.count = ccw.count - sizeof(features);
433             ret = 0;
434         }
435         break;
436     case CCW_CMD_READ_CONF:
437         if (check_len) {
438             if (ccw.count > vdev->config_len) {
439                 ret = -EINVAL;
440                 break;
441             }
442         }
443         len = MIN(ccw.count, vdev->config_len);
444         if (!ccw.cda) {
445             ret = -EFAULT;
446         } else {
447             virtio_bus_get_vdev_config(&dev->bus, vdev->config);
448             ccw_dstream_write_buf(&sch->cds, vdev->config, len);
449             sch->curr_status.scsw.count = ccw.count - len;
450             ret = 0;
451         }
452         break;
453     case CCW_CMD_WRITE_CONF:
454         if (check_len) {
455             if (ccw.count > vdev->config_len) {
456                 ret = -EINVAL;
457                 break;
458             }
459         }
460         len = MIN(ccw.count, vdev->config_len);
461         if (!ccw.cda) {
462             ret = -EFAULT;
463         } else {
464             ret = ccw_dstream_read_buf(&sch->cds, vdev->config, len);
465             if (!ret) {
466                 virtio_bus_set_vdev_config(&dev->bus, vdev->config);
467                 sch->curr_status.scsw.count = ccw.count - len;
468             }
469         }
470         break;
471     case CCW_CMD_READ_STATUS:
472         if (check_len) {
473             if (ccw.count != sizeof(status)) {
474                 ret = -EINVAL;
475                 break;
476             }
477         } else if (ccw.count < sizeof(status)) {
478             /* Can't execute command. */
479             ret = -EINVAL;
480             break;
481         }
482         if (!ccw.cda) {
483             ret = -EFAULT;
484         } else {
485             address_space_stb(&address_space_memory, ccw.cda, vdev->status,
486                                         MEMTXATTRS_UNSPECIFIED, NULL);
487             sch->curr_status.scsw.count = ccw.count - sizeof(vdev->status);
488             ret = 0;
489         }
490         break;
491     case CCW_CMD_WRITE_STATUS:
492         if (check_len) {
493             if (ccw.count != sizeof(status)) {
494                 ret = -EINVAL;
495                 break;
496             }
497         } else if (ccw.count < sizeof(status)) {
498             /* Can't execute command. */
499             ret = -EINVAL;
500             break;
501         }
502         if (!ccw.cda) {
503             ret = -EFAULT;
504         } else {
505             ccw_dstream_read(&sch->cds, status);
506             if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
507                 virtio_ccw_stop_ioeventfd(dev);
508             }
509             if (virtio_set_status(vdev, status) == 0) {
510                 if (vdev->status == 0) {
511                     virtio_ccw_reset_virtio(dev, vdev);
512                 }
513                 if (status & VIRTIO_CONFIG_S_DRIVER_OK) {
514                     virtio_ccw_start_ioeventfd(dev);
515                 }
516                 sch->curr_status.scsw.count = ccw.count - sizeof(status);
517                 ret = 0;
518             } else {
519                 /* Trigger a command reject. */
520                 ret = -ENOSYS;
521             }
522         }
523         break;
524     case CCW_CMD_SET_IND:
525         if (check_len) {
526             if (ccw.count != sizeof(indicators)) {
527                 ret = -EINVAL;
528                 break;
529             }
530         } else if (ccw.count < sizeof(indicators)) {
531             /* Can't execute command. */
532             ret = -EINVAL;
533             break;
534         }
535         if (sch->thinint_active) {
536             /* Trigger a command reject. */
537             ret = -ENOSYS;
538             break;
539         }
540         if (virtio_get_num_queues(vdev) > NR_CLASSIC_INDICATOR_BITS) {
541             /* More queues than indicator bits --> trigger a reject */
542             ret = -ENOSYS;
543             break;
544         }
545         if (!ccw.cda) {
546             ret = -EFAULT;
547         } else {
548             ccw_dstream_read(&sch->cds, indicators);
549             be64_to_cpus(&indicators);
550             dev->indicators = get_indicator(indicators, sizeof(uint64_t));
551             sch->curr_status.scsw.count = ccw.count - sizeof(indicators);
552             ret = 0;
553         }
554         break;
555     case CCW_CMD_SET_CONF_IND:
556         if (check_len) {
557             if (ccw.count != sizeof(indicators)) {
558                 ret = -EINVAL;
559                 break;
560             }
561         } else if (ccw.count < sizeof(indicators)) {
562             /* Can't execute command. */
563             ret = -EINVAL;
564             break;
565         }
566         if (!ccw.cda) {
567             ret = -EFAULT;
568         } else {
569             ccw_dstream_read(&sch->cds, indicators);
570             be64_to_cpus(&indicators);
571             dev->indicators2 = get_indicator(indicators, sizeof(uint64_t));
572             sch->curr_status.scsw.count = ccw.count - sizeof(indicators);
573             ret = 0;
574         }
575         break;
576     case CCW_CMD_READ_VQ_CONF:
577         if (check_len) {
578             if (ccw.count != sizeof(vq_config)) {
579                 ret = -EINVAL;
580                 break;
581             }
582         } else if (ccw.count < sizeof(vq_config)) {
583             /* Can't execute command. */
584             ret = -EINVAL;
585             break;
586         }
587         if (!ccw.cda) {
588             ret = -EFAULT;
589         } else {
590             ccw_dstream_read(&sch->cds, vq_config.index);
591             be16_to_cpus(&vq_config.index);
592             if (vq_config.index >= VIRTIO_QUEUE_MAX) {
593                 ret = -EINVAL;
594                 break;
595             }
596             vq_config.num_max = virtio_queue_get_num(vdev,
597                                                      vq_config.index);
598             cpu_to_be16s(&vq_config.num_max);
599             ccw_dstream_write(&sch->cds, vq_config.num_max);
600             sch->curr_status.scsw.count = ccw.count - sizeof(vq_config);
601             ret = 0;
602         }
603         break;
604     case CCW_CMD_SET_IND_ADAPTER:
605         if (check_len) {
606             if (ccw.count != sizeof(thinint)) {
607                 ret = -EINVAL;
608                 break;
609             }
610         } else if (ccw.count < sizeof(thinint)) {
611             /* Can't execute command. */
612             ret = -EINVAL;
613             break;
614         }
615         if (!ccw.cda) {
616             ret = -EFAULT;
617         } else if (dev->indicators && !sch->thinint_active) {
618             /* Trigger a command reject. */
619             ret = -ENOSYS;
620         } else {
621             if (ccw_dstream_read(&sch->cds, thinint)) {
622                 ret = -EFAULT;
623             } else {
624                 be64_to_cpus(&thinint.ind_bit);
625                 be64_to_cpus(&thinint.summary_indicator);
626                 be64_to_cpus(&thinint.device_indicator);
627 
628                 dev->summary_indicator =
629                     get_indicator(thinint.summary_indicator, sizeof(uint8_t));
630                 dev->indicators =
631                     get_indicator(thinint.device_indicator,
632                                   thinint.ind_bit / 8 + 1);
633                 dev->thinint_isc = thinint.isc;
634                 dev->routes.adapter.ind_offset = thinint.ind_bit;
635                 dev->routes.adapter.summary_offset = 7;
636                 dev->routes.adapter.adapter_id = css_get_adapter_id(
637                                                  CSS_IO_ADAPTER_VIRTIO,
638                                                  dev->thinint_isc);
639                 sch->thinint_active = ((dev->indicators != NULL) &&
640                                        (dev->summary_indicator != NULL));
641                 sch->curr_status.scsw.count = ccw.count - sizeof(thinint);
642                 ret = 0;
643             }
644         }
645         break;
646     case CCW_CMD_SET_VIRTIO_REV:
647         len = sizeof(revinfo);
648         if (ccw.count < len) {
649             ret = -EINVAL;
650             break;
651         }
652         if (!ccw.cda) {
653             ret = -EFAULT;
654             break;
655         }
656         ccw_dstream_read_buf(&sch->cds, &revinfo, 4);
657         be16_to_cpus(&revinfo.revision);
658         be16_to_cpus(&revinfo.length);
659         if (ccw.count < len + revinfo.length ||
660             (check_len && ccw.count > len + revinfo.length)) {
661             ret = -EINVAL;
662             break;
663         }
664         /*
665          * Once we start to support revisions with additional data, we'll
666          * need to fetch it here. Nothing to do for now, though.
667          */
668         if (dev->revision >= 0 ||
669             revinfo.revision > virtio_ccw_rev_max(dev) ||
670             (dev->force_revision_1 && !revinfo.revision)) {
671             ret = -ENOSYS;
672             break;
673         }
674         ret = 0;
675         dev->revision = revinfo.revision;
676         break;
677     default:
678         ret = -ENOSYS;
679         break;
680     }
681     return ret;
682 }
683 
684 static void virtio_sch_disable_cb(SubchDev *sch)
685 {
686     VirtioCcwDevice *dev = sch->driver_data;
687 
688     dev->revision = -1;
689 }
690 
691 static void virtio_ccw_device_realize(VirtioCcwDevice *dev, Error **errp)
692 {
693     VirtIOCCWDeviceClass *k = VIRTIO_CCW_DEVICE_GET_CLASS(dev);
694     CcwDevice *ccw_dev = CCW_DEVICE(dev);
695     CCWDeviceClass *ck = CCW_DEVICE_GET_CLASS(ccw_dev);
696     SubchDev *sch;
697     Error *err = NULL;
698 
699     sch = css_create_sch(ccw_dev->devno, errp);
700     if (!sch) {
701         return;
702     }
703     if (!virtio_ccw_rev_max(dev) && dev->force_revision_1) {
704         error_setg(&err, "Invalid value of property max_rev "
705                    "(is %d expected >= 1)", virtio_ccw_rev_max(dev));
706         goto out_err;
707     }
708 
709     sch->driver_data = dev;
710     sch->ccw_cb = virtio_ccw_cb;
711     sch->disable_cb = virtio_sch_disable_cb;
712     sch->id.reserved = 0xff;
713     sch->id.cu_type = VIRTIO_CCW_CU_TYPE;
714     sch->do_subchannel_work = do_subchannel_work_virtual;
715     ccw_dev->sch = sch;
716     dev->indicators = NULL;
717     dev->revision = -1;
718     css_sch_build_virtual_schib(sch, 0, VIRTIO_CCW_CHPID_TYPE);
719 
720     trace_virtio_ccw_new_device(
721         sch->cssid, sch->ssid, sch->schid, sch->devno,
722         ccw_dev->devno.valid ? "user-configured" : "auto-configured");
723 
724     if (kvm_enabled() && !kvm_eventfds_enabled()) {
725         dev->flags &= ~VIRTIO_CCW_FLAG_USE_IOEVENTFD;
726     }
727 
728     if (k->realize) {
729         k->realize(dev, &err);
730         if (err) {
731             goto out_err;
732         }
733     }
734 
735     ck->realize(ccw_dev, &err);
736     if (err) {
737         goto out_err;
738     }
739 
740     return;
741 
742 out_err:
743     error_propagate(errp, err);
744     css_subch_assign(sch->cssid, sch->ssid, sch->schid, sch->devno, NULL);
745     ccw_dev->sch = NULL;
746     g_free(sch);
747 }
748 
749 static void virtio_ccw_device_unrealize(VirtioCcwDevice *dev, Error **errp)
750 {
751     VirtIOCCWDeviceClass *dc = VIRTIO_CCW_DEVICE_GET_CLASS(dev);
752     CcwDevice *ccw_dev = CCW_DEVICE(dev);
753     SubchDev *sch = ccw_dev->sch;
754 
755     if (dc->unrealize) {
756         dc->unrealize(dev, errp);
757     }
758 
759     if (sch) {
760         css_subch_assign(sch->cssid, sch->ssid, sch->schid, sch->devno, NULL);
761         g_free(sch);
762         ccw_dev->sch = NULL;
763     }
764     if (dev->indicators) {
765         release_indicator(&dev->routes.adapter, dev->indicators);
766         dev->indicators = NULL;
767     }
768 }
769 
770 /* DeviceState to VirtioCcwDevice. Note: used on datapath,
771  * be careful and test performance if you change this.
772  */
773 static inline VirtioCcwDevice *to_virtio_ccw_dev_fast(DeviceState *d)
774 {
775     CcwDevice *ccw_dev = to_ccw_dev_fast(d);
776 
777     return container_of(ccw_dev, VirtioCcwDevice, parent_obj);
778 }
779 
780 static uint8_t virtio_set_ind_atomic(SubchDev *sch, uint64_t ind_loc,
781                                      uint8_t to_be_set)
782 {
783     uint8_t ind_old, ind_new;
784     hwaddr len = 1;
785     uint8_t *ind_addr;
786 
787     ind_addr = cpu_physical_memory_map(ind_loc, &len, 1);
788     if (!ind_addr) {
789         error_report("%s(%x.%x.%04x): unable to access indicator",
790                      __func__, sch->cssid, sch->ssid, sch->schid);
791         return -1;
792     }
793     do {
794         ind_old = *ind_addr;
795         ind_new = ind_old | to_be_set;
796     } while (atomic_cmpxchg(ind_addr, ind_old, ind_new) != ind_old);
797     trace_virtio_ccw_set_ind(ind_loc, ind_old, ind_new);
798     cpu_physical_memory_unmap(ind_addr, len, 1, len);
799 
800     return ind_old;
801 }
802 
803 static void virtio_ccw_notify(DeviceState *d, uint16_t vector)
804 {
805     VirtioCcwDevice *dev = to_virtio_ccw_dev_fast(d);
806     CcwDevice *ccw_dev = to_ccw_dev_fast(d);
807     SubchDev *sch = ccw_dev->sch;
808     uint64_t indicators;
809 
810     if (vector == VIRTIO_NO_VECTOR) {
811         return;
812     }
813     /*
814      * vector < VIRTIO_QUEUE_MAX: notification for a virtqueue
815      * vector == VIRTIO_QUEUE_MAX: configuration change notification
816      * bits beyond that are unused and should never be notified for
817      */
818     assert(vector <= VIRTIO_QUEUE_MAX);
819 
820     if (vector < VIRTIO_QUEUE_MAX) {
821         if (!dev->indicators) {
822             return;
823         }
824         if (sch->thinint_active) {
825             /*
826              * In the adapter interrupt case, indicators points to a
827              * memory area that may be (way) larger than 64 bit and
828              * ind_bit indicates the start of the indicators in a big
829              * endian notation.
830              */
831             uint64_t ind_bit = dev->routes.adapter.ind_offset;
832 
833             virtio_set_ind_atomic(sch, dev->indicators->addr +
834                                   (ind_bit + vector) / 8,
835                                   0x80 >> ((ind_bit + vector) % 8));
836             if (!virtio_set_ind_atomic(sch, dev->summary_indicator->addr,
837                                        0x01)) {
838                 css_adapter_interrupt(CSS_IO_ADAPTER_VIRTIO, dev->thinint_isc);
839             }
840         } else {
841             assert(vector < NR_CLASSIC_INDICATOR_BITS);
842             indicators = address_space_ldq(&address_space_memory,
843                                            dev->indicators->addr,
844                                            MEMTXATTRS_UNSPECIFIED,
845                                            NULL);
846             indicators |= 1ULL << vector;
847             address_space_stq(&address_space_memory, dev->indicators->addr,
848                               indicators, MEMTXATTRS_UNSPECIFIED, NULL);
849             css_conditional_io_interrupt(sch);
850         }
851     } else {
852         if (!dev->indicators2) {
853             return;
854         }
855         indicators = address_space_ldq(&address_space_memory,
856                                        dev->indicators2->addr,
857                                        MEMTXATTRS_UNSPECIFIED,
858                                        NULL);
859         indicators |= 1ULL;
860         address_space_stq(&address_space_memory, dev->indicators2->addr,
861                           indicators, MEMTXATTRS_UNSPECIFIED, NULL);
862         css_conditional_io_interrupt(sch);
863     }
864 }
865 
866 static void virtio_ccw_reset(DeviceState *d)
867 {
868     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
869     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
870     VirtIOCCWDeviceClass *vdc = VIRTIO_CCW_DEVICE_GET_CLASS(dev);
871 
872     virtio_ccw_reset_virtio(dev, vdev);
873     if (vdc->parent_reset) {
874         vdc->parent_reset(d);
875     }
876 }
877 
878 static void virtio_ccw_vmstate_change(DeviceState *d, bool running)
879 {
880     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
881 
882     if (running) {
883         virtio_ccw_start_ioeventfd(dev);
884     } else {
885         virtio_ccw_stop_ioeventfd(dev);
886     }
887 }
888 
889 static bool virtio_ccw_query_guest_notifiers(DeviceState *d)
890 {
891     CcwDevice *dev = CCW_DEVICE(d);
892 
893     return !!(dev->sch->curr_status.pmcw.flags & PMCW_FLAGS_MASK_ENA);
894 }
895 
896 static int virtio_ccw_get_mappings(VirtioCcwDevice *dev)
897 {
898     int r;
899     CcwDevice *ccw_dev = CCW_DEVICE(dev);
900 
901     if (!ccw_dev->sch->thinint_active) {
902         return -EINVAL;
903     }
904 
905     r = map_indicator(&dev->routes.adapter, dev->summary_indicator);
906     if (r) {
907         return r;
908     }
909     r = map_indicator(&dev->routes.adapter, dev->indicators);
910     if (r) {
911         return r;
912     }
913     dev->routes.adapter.summary_addr = dev->summary_indicator->map;
914     dev->routes.adapter.ind_addr = dev->indicators->map;
915 
916     return 0;
917 }
918 
919 static int virtio_ccw_setup_irqroutes(VirtioCcwDevice *dev, int nvqs)
920 {
921     int i;
922     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
923     int ret;
924     S390FLICState *fs = s390_get_flic();
925     S390FLICStateClass *fsc = s390_get_flic_class(fs);
926 
927     ret = virtio_ccw_get_mappings(dev);
928     if (ret) {
929         return ret;
930     }
931     for (i = 0; i < nvqs; i++) {
932         if (!virtio_queue_get_num(vdev, i)) {
933             break;
934         }
935     }
936     dev->routes.num_routes = i;
937     return fsc->add_adapter_routes(fs, &dev->routes);
938 }
939 
940 static void virtio_ccw_release_irqroutes(VirtioCcwDevice *dev, int nvqs)
941 {
942     S390FLICState *fs = s390_get_flic();
943     S390FLICStateClass *fsc = s390_get_flic_class(fs);
944 
945     fsc->release_adapter_routes(fs, &dev->routes);
946 }
947 
948 static int virtio_ccw_add_irqfd(VirtioCcwDevice *dev, int n)
949 {
950     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
951     VirtQueue *vq = virtio_get_queue(vdev, n);
952     EventNotifier *notifier = virtio_queue_get_guest_notifier(vq);
953 
954     return kvm_irqchip_add_irqfd_notifier_gsi(kvm_state, notifier, NULL,
955                                               dev->routes.gsi[n]);
956 }
957 
958 static void virtio_ccw_remove_irqfd(VirtioCcwDevice *dev, int n)
959 {
960     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
961     VirtQueue *vq = virtio_get_queue(vdev, n);
962     EventNotifier *notifier = virtio_queue_get_guest_notifier(vq);
963     int ret;
964 
965     ret = kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state, notifier,
966                                                 dev->routes.gsi[n]);
967     assert(ret == 0);
968 }
969 
970 static int virtio_ccw_set_guest_notifier(VirtioCcwDevice *dev, int n,
971                                          bool assign, bool with_irqfd)
972 {
973     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
974     VirtQueue *vq = virtio_get_queue(vdev, n);
975     EventNotifier *notifier = virtio_queue_get_guest_notifier(vq);
976     VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
977 
978     if (assign) {
979         int r = event_notifier_init(notifier, 0);
980 
981         if (r < 0) {
982             return r;
983         }
984         virtio_queue_set_guest_notifier_fd_handler(vq, true, with_irqfd);
985         if (with_irqfd) {
986             r = virtio_ccw_add_irqfd(dev, n);
987             if (r) {
988                 virtio_queue_set_guest_notifier_fd_handler(vq, false,
989                                                            with_irqfd);
990                 return r;
991             }
992         }
993         /*
994          * We do not support individual masking for channel devices, so we
995          * need to manually trigger any guest masking callbacks here.
996          */
997         if (k->guest_notifier_mask && vdev->use_guest_notifier_mask) {
998             k->guest_notifier_mask(vdev, n, false);
999         }
1000         /* get lost events and re-inject */
1001         if (k->guest_notifier_pending &&
1002             k->guest_notifier_pending(vdev, n)) {
1003             event_notifier_set(notifier);
1004         }
1005     } else {
1006         if (k->guest_notifier_mask && vdev->use_guest_notifier_mask) {
1007             k->guest_notifier_mask(vdev, n, true);
1008         }
1009         if (with_irqfd) {
1010             virtio_ccw_remove_irqfd(dev, n);
1011         }
1012         virtio_queue_set_guest_notifier_fd_handler(vq, false, with_irqfd);
1013         event_notifier_cleanup(notifier);
1014     }
1015     return 0;
1016 }
1017 
1018 static int virtio_ccw_set_guest_notifiers(DeviceState *d, int nvqs,
1019                                           bool assigned)
1020 {
1021     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
1022     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
1023     CcwDevice *ccw_dev = CCW_DEVICE(d);
1024     bool with_irqfd = ccw_dev->sch->thinint_active && kvm_irqfds_enabled();
1025     int r, n;
1026 
1027     if (with_irqfd && assigned) {
1028         /* irq routes need to be set up before assigning irqfds */
1029         r = virtio_ccw_setup_irqroutes(dev, nvqs);
1030         if (r < 0) {
1031             goto irqroute_error;
1032         }
1033     }
1034     for (n = 0; n < nvqs; n++) {
1035         if (!virtio_queue_get_num(vdev, n)) {
1036             break;
1037         }
1038         r = virtio_ccw_set_guest_notifier(dev, n, assigned, with_irqfd);
1039         if (r < 0) {
1040             goto assign_error;
1041         }
1042     }
1043     if (with_irqfd && !assigned) {
1044         /* release irq routes after irqfds have been released */
1045         virtio_ccw_release_irqroutes(dev, nvqs);
1046     }
1047     return 0;
1048 
1049 assign_error:
1050     while (--n >= 0) {
1051         virtio_ccw_set_guest_notifier(dev, n, !assigned, false);
1052     }
1053 irqroute_error:
1054     if (with_irqfd && assigned) {
1055         virtio_ccw_release_irqroutes(dev, nvqs);
1056     }
1057     return r;
1058 }
1059 
1060 static void virtio_ccw_save_queue(DeviceState *d, int n, QEMUFile *f)
1061 {
1062     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
1063     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
1064 
1065     qemu_put_be16(f, virtio_queue_vector(vdev, n));
1066 }
1067 
1068 static int virtio_ccw_load_queue(DeviceState *d, int n, QEMUFile *f)
1069 {
1070     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
1071     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
1072     uint16_t vector;
1073 
1074     qemu_get_be16s(f, &vector);
1075     virtio_queue_set_vector(vdev, n , vector);
1076 
1077     return 0;
1078 }
1079 
1080 static void virtio_ccw_save_config(DeviceState *d, QEMUFile *f)
1081 {
1082     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
1083     vmstate_save_state(f, &vmstate_virtio_ccw_dev, dev, NULL);
1084 }
1085 
1086 static int virtio_ccw_load_config(DeviceState *d, QEMUFile *f)
1087 {
1088     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
1089     return vmstate_load_state(f, &vmstate_virtio_ccw_dev, dev, 1);
1090 }
1091 
1092 static void virtio_ccw_pre_plugged(DeviceState *d, Error **errp)
1093 {
1094    VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
1095    VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
1096 
1097     if (dev->max_rev >= 1) {
1098         virtio_add_feature(&vdev->host_features, VIRTIO_F_VERSION_1);
1099     }
1100 }
1101 
1102 /* This is called by virtio-bus just after the device is plugged. */
1103 static void virtio_ccw_device_plugged(DeviceState *d, Error **errp)
1104 {
1105     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
1106     VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
1107     CcwDevice *ccw_dev = CCW_DEVICE(d);
1108     SubchDev *sch = ccw_dev->sch;
1109     int n = virtio_get_num_queues(vdev);
1110     S390FLICState *flic = s390_get_flic();
1111 
1112     if (!virtio_has_feature(vdev->host_features, VIRTIO_F_VERSION_1)) {
1113         dev->max_rev = 0;
1114     }
1115 
1116     if (virtio_get_num_queues(vdev) > VIRTIO_QUEUE_MAX) {
1117         error_setg(errp, "The number of virtqueues %d "
1118                    "exceeds virtio limit %d", n,
1119                    VIRTIO_QUEUE_MAX);
1120         return;
1121     }
1122     if (virtio_get_num_queues(vdev) > flic->adapter_routes_max_batch) {
1123         error_setg(errp, "The number of virtqueues %d "
1124                    "exceeds flic adapter route limit %d", n,
1125                    flic->adapter_routes_max_batch);
1126         return;
1127     }
1128 
1129     sch->id.cu_model = virtio_bus_get_vdev_id(&dev->bus);
1130 
1131 
1132     css_generate_sch_crws(sch->cssid, sch->ssid, sch->schid,
1133                           d->hotplugged, 1);
1134 }
1135 
1136 static void virtio_ccw_device_unplugged(DeviceState *d)
1137 {
1138     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
1139 
1140     virtio_ccw_stop_ioeventfd(dev);
1141 }
1142 /**************** Virtio-ccw Bus Device Descriptions *******************/
1143 
1144 static void virtio_ccw_busdev_realize(DeviceState *dev, Error **errp)
1145 {
1146     VirtioCcwDevice *_dev = (VirtioCcwDevice *)dev;
1147 
1148     virtio_ccw_bus_new(&_dev->bus, sizeof(_dev->bus), _dev);
1149     virtio_ccw_device_realize(_dev, errp);
1150 }
1151 
1152 static void virtio_ccw_busdev_unrealize(DeviceState *dev, Error **errp)
1153 {
1154     VirtioCcwDevice *_dev = (VirtioCcwDevice *)dev;
1155 
1156     virtio_ccw_device_unrealize(_dev, errp);
1157 }
1158 
1159 static void virtio_ccw_busdev_unplug(HotplugHandler *hotplug_dev,
1160                                      DeviceState *dev, Error **errp)
1161 {
1162     VirtioCcwDevice *_dev = to_virtio_ccw_dev_fast(dev);
1163 
1164     virtio_ccw_stop_ioeventfd(_dev);
1165 }
1166 
1167 static void virtio_ccw_device_class_init(ObjectClass *klass, void *data)
1168 {
1169     DeviceClass *dc = DEVICE_CLASS(klass);
1170     CCWDeviceClass *k = CCW_DEVICE_CLASS(dc);
1171     VirtIOCCWDeviceClass *vdc = VIRTIO_CCW_DEVICE_CLASS(klass);
1172 
1173     k->unplug = virtio_ccw_busdev_unplug;
1174     dc->realize = virtio_ccw_busdev_realize;
1175     dc->unrealize = virtio_ccw_busdev_unrealize;
1176     dc->bus_type = TYPE_VIRTUAL_CSS_BUS;
1177     device_class_set_parent_reset(dc, virtio_ccw_reset, &vdc->parent_reset);
1178 }
1179 
1180 static const TypeInfo virtio_ccw_device_info = {
1181     .name = TYPE_VIRTIO_CCW_DEVICE,
1182     .parent = TYPE_CCW_DEVICE,
1183     .instance_size = sizeof(VirtioCcwDevice),
1184     .class_init = virtio_ccw_device_class_init,
1185     .class_size = sizeof(VirtIOCCWDeviceClass),
1186     .abstract = true,
1187 };
1188 
1189 /* virtio-ccw-bus */
1190 
1191 static void virtio_ccw_bus_new(VirtioBusState *bus, size_t bus_size,
1192                                VirtioCcwDevice *dev)
1193 {
1194     DeviceState *qdev = DEVICE(dev);
1195     char virtio_bus_name[] = "virtio-bus";
1196 
1197     qbus_create_inplace(bus, bus_size, TYPE_VIRTIO_CCW_BUS,
1198                         qdev, virtio_bus_name);
1199 }
1200 
1201 static void virtio_ccw_bus_class_init(ObjectClass *klass, void *data)
1202 {
1203     VirtioBusClass *k = VIRTIO_BUS_CLASS(klass);
1204     BusClass *bus_class = BUS_CLASS(klass);
1205 
1206     bus_class->max_dev = 1;
1207     k->notify = virtio_ccw_notify;
1208     k->vmstate_change = virtio_ccw_vmstate_change;
1209     k->query_guest_notifiers = virtio_ccw_query_guest_notifiers;
1210     k->set_guest_notifiers = virtio_ccw_set_guest_notifiers;
1211     k->save_queue = virtio_ccw_save_queue;
1212     k->load_queue = virtio_ccw_load_queue;
1213     k->save_config = virtio_ccw_save_config;
1214     k->load_config = virtio_ccw_load_config;
1215     k->pre_plugged = virtio_ccw_pre_plugged;
1216     k->device_plugged = virtio_ccw_device_plugged;
1217     k->device_unplugged = virtio_ccw_device_unplugged;
1218     k->ioeventfd_enabled = virtio_ccw_ioeventfd_enabled;
1219     k->ioeventfd_assign = virtio_ccw_ioeventfd_assign;
1220 }
1221 
1222 static const TypeInfo virtio_ccw_bus_info = {
1223     .name = TYPE_VIRTIO_CCW_BUS,
1224     .parent = TYPE_VIRTIO_BUS,
1225     .instance_size = sizeof(VirtioCcwBusState),
1226     .class_init = virtio_ccw_bus_class_init,
1227 };
1228 
1229 static void virtio_ccw_register(void)
1230 {
1231     type_register_static(&virtio_ccw_bus_info);
1232     type_register_static(&virtio_ccw_device_info);
1233 }
1234 
1235 type_init(virtio_ccw_register)
1236