1 /*
2 * SCLP
3 * Event Facility
4 * handles SCLP event types
5 * - Signal Quiesce - system power down
6 * - ASCII Console Data - VT220 read and write
7 *
8 * Copyright IBM, Corp. 2012
9 *
10 * Authors:
11 * Heinz Graalfs <graalfs@de.ibm.com>
12 *
13 * This work is licensed under the terms of the GNU GPL, version 2 or (at your
14 * option) any later version. See the COPYING file in the top-level directory.
15 *
16 */
17
18 #include "qemu/osdep.h"
19 #include "qapi/error.h"
20 #include "qemu/module.h"
21
22 #include "hw/s390x/sclp.h"
23 #include "migration/vmstate.h"
24 #include "hw/s390x/event-facility.h"
25
26 typedef struct SCLPEventsBus {
27 BusState qbus;
28 } SCLPEventsBus;
29
30 /* we need to save 32 bit chunks for compatibility */
31 #if HOST_BIG_ENDIAN
32 #define RECV_MASK_LOWER 1
33 #define RECV_MASK_UPPER 0
34 #else /* little endian host */
35 #define RECV_MASK_LOWER 0
36 #define RECV_MASK_UPPER 1
37 #endif
38
39 struct SCLPEventFacility {
40 SysBusDevice parent_obj;
41 SCLPEventsBus sbus;
42 SCLPEvent quiesce, cpu_hotplug;
43 /* guest's receive mask */
44 union {
45 uint32_t receive_mask_pieces[2];
46 sccb_mask_t receive_mask;
47 };
48 /*
49 * when false, we keep the same broken, backwards compatible behaviour as
50 * before, allowing only masks of size exactly 4; when true, we implement
51 * the architecture correctly, allowing all valid mask sizes. Needed for
52 * migration toward older versions.
53 */
54 bool allow_all_mask_sizes;
55 /* length of the receive mask */
56 uint16_t mask_length;
57 };
58
59 /* return true if any child has event pending set */
event_pending(SCLPEventFacility * ef)60 static bool event_pending(SCLPEventFacility *ef)
61 {
62 BusChild *kid;
63 SCLPEvent *event;
64 SCLPEventClass *event_class;
65
66 QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
67 event = SCLP_EVENT(kid->child);
68 event_class = SCLP_EVENT_GET_CLASS(event);
69 if (event->event_pending &&
70 event_class->get_send_mask() & ef->receive_mask) {
71 return true;
72 }
73 }
74 return false;
75 }
76
get_host_send_mask(SCLPEventFacility * ef)77 static sccb_mask_t get_host_send_mask(SCLPEventFacility *ef)
78 {
79 sccb_mask_t mask;
80 BusChild *kid;
81 SCLPEventClass *child;
82
83 mask = 0;
84
85 QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
86 DeviceState *qdev = kid->child;
87 child = SCLP_EVENT_GET_CLASS((SCLPEvent *) qdev);
88 mask |= child->get_send_mask();
89 }
90 return mask;
91 }
92
get_host_receive_mask(SCLPEventFacility * ef)93 static sccb_mask_t get_host_receive_mask(SCLPEventFacility *ef)
94 {
95 sccb_mask_t mask;
96 BusChild *kid;
97 SCLPEventClass *child;
98
99 mask = 0;
100
101 QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
102 DeviceState *qdev = kid->child;
103 child = SCLP_EVENT_GET_CLASS((SCLPEvent *) qdev);
104 mask |= child->get_receive_mask();
105 }
106 return mask;
107 }
108
write_event_length_check(SCCB * sccb)109 static uint16_t write_event_length_check(SCCB *sccb)
110 {
111 int slen;
112 unsigned elen = 0;
113 EventBufferHeader *event;
114 WriteEventData *wed = (WriteEventData *) sccb;
115
116 event = (EventBufferHeader *) &wed->ebh;
117 for (slen = sccb_data_len(sccb); slen > 0; slen -= elen) {
118 elen = be16_to_cpu(event->length);
119 if (elen < sizeof(*event) || elen > slen) {
120 return SCLP_RC_EVENT_BUFFER_SYNTAX_ERROR;
121 }
122 event = (void *) event + elen;
123 }
124 if (slen) {
125 return SCLP_RC_INCONSISTENT_LENGTHS;
126 }
127 return SCLP_RC_NORMAL_COMPLETION;
128 }
129
handle_write_event_buf(SCLPEventFacility * ef,EventBufferHeader * event_buf,SCCB * sccb)130 static uint16_t handle_write_event_buf(SCLPEventFacility *ef,
131 EventBufferHeader *event_buf, SCCB *sccb)
132 {
133 uint16_t rc;
134 BusChild *kid;
135 SCLPEvent *event;
136 SCLPEventClass *ec;
137
138 rc = SCLP_RC_INVALID_FUNCTION;
139
140 QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
141 DeviceState *qdev = kid->child;
142 event = (SCLPEvent *) qdev;
143 ec = SCLP_EVENT_GET_CLASS(event);
144
145 if (ec->write_event_data &&
146 ec->can_handle_event(event_buf->type)) {
147 rc = ec->write_event_data(event, event_buf);
148 break;
149 }
150 }
151 return rc;
152 }
153
handle_sccb_write_events(SCLPEventFacility * ef,SCCB * sccb)154 static uint16_t handle_sccb_write_events(SCLPEventFacility *ef, SCCB *sccb)
155 {
156 uint16_t rc;
157 int slen;
158 unsigned elen = 0;
159 EventBufferHeader *event_buf;
160 WriteEventData *wed = (WriteEventData *) sccb;
161
162 event_buf = &wed->ebh;
163 rc = SCLP_RC_NORMAL_COMPLETION;
164
165 /* loop over all contained event buffers */
166 for (slen = sccb_data_len(sccb); slen > 0; slen -= elen) {
167 elen = be16_to_cpu(event_buf->length);
168
169 /* in case of a previous error mark all trailing buffers
170 * as not accepted */
171 if (rc != SCLP_RC_NORMAL_COMPLETION) {
172 event_buf->flags &= ~(SCLP_EVENT_BUFFER_ACCEPTED);
173 } else {
174 rc = handle_write_event_buf(ef, event_buf, sccb);
175 }
176 event_buf = (void *) event_buf + elen;
177 }
178 return rc;
179 }
180
write_event_data(SCLPEventFacility * ef,SCCB * sccb)181 static void write_event_data(SCLPEventFacility *ef, SCCB *sccb)
182 {
183 if (sccb->h.function_code != SCLP_FC_NORMAL_WRITE) {
184 sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_FUNCTION);
185 return;
186 }
187 if (be16_to_cpu(sccb->h.length) < 8) {
188 sccb->h.response_code = cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
189 return;
190 }
191 /* first do a sanity check of the write events */
192 sccb->h.response_code = cpu_to_be16(write_event_length_check(sccb));
193
194 /* if no early error, then execute */
195 if (sccb->h.response_code == be16_to_cpu(SCLP_RC_NORMAL_COMPLETION)) {
196 sccb->h.response_code =
197 cpu_to_be16(handle_sccb_write_events(ef, sccb));
198 }
199 }
200
handle_sccb_read_events(SCLPEventFacility * ef,SCCB * sccb,sccb_mask_t mask)201 static uint16_t handle_sccb_read_events(SCLPEventFacility *ef, SCCB *sccb,
202 sccb_mask_t mask)
203 {
204 uint16_t rc;
205 int slen;
206 unsigned elen;
207 BusChild *kid;
208 SCLPEvent *event;
209 SCLPEventClass *ec;
210 EventBufferHeader *event_buf;
211 ReadEventData *red = (ReadEventData *) sccb;
212
213 event_buf = &red->ebh;
214 event_buf->length = 0;
215 slen = sccb_data_len(sccb);
216
217 rc = SCLP_RC_NO_EVENT_BUFFERS_STORED;
218
219 QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
220 DeviceState *qdev = kid->child;
221 event = (SCLPEvent *) qdev;
222 ec = SCLP_EVENT_GET_CLASS(event);
223
224 if (mask & ec->get_send_mask()) {
225 if (ec->read_event_data(event, event_buf, &slen)) {
226 elen = be16_to_cpu(event_buf->length);
227 event_buf = (EventBufferHeader *) ((char *)event_buf + elen);
228 rc = SCLP_RC_NORMAL_COMPLETION;
229 }
230 }
231 }
232
233 if (sccb->h.control_mask[2] & SCLP_VARIABLE_LENGTH_RESPONSE) {
234 /* architecture suggests to reset variable-length-response bit */
235 sccb->h.control_mask[2] &= ~SCLP_VARIABLE_LENGTH_RESPONSE;
236 /* with a new length value */
237 sccb->h.length = cpu_to_be16(SCCB_SIZE - slen);
238 }
239 return rc;
240 }
241
242 /* copy up to src_len bytes and fill the rest of dst with zeroes */
copy_mask(uint8_t * dst,uint8_t * src,uint16_t dst_len,uint16_t src_len)243 static void copy_mask(uint8_t *dst, uint8_t *src, uint16_t dst_len,
244 uint16_t src_len)
245 {
246 int i;
247
248 for (i = 0; i < dst_len; i++) {
249 dst[i] = i < src_len ? src[i] : 0;
250 }
251 }
252
read_event_data(SCLPEventFacility * ef,SCCB * sccb)253 static void read_event_data(SCLPEventFacility *ef, SCCB *sccb)
254 {
255 sccb_mask_t sclp_active_selection_mask;
256 sccb_mask_t sclp_cp_receive_mask;
257
258 ReadEventData *red = (ReadEventData *) sccb;
259
260 if (be16_to_cpu(sccb->h.length) != SCCB_SIZE) {
261 sccb->h.response_code = cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
262 return;
263 }
264
265 switch (sccb->h.function_code) {
266 case SCLP_UNCONDITIONAL_READ:
267 sccb->h.response_code = cpu_to_be16(
268 handle_sccb_read_events(ef, sccb, ef->receive_mask));
269 break;
270 case SCLP_SELECTIVE_READ:
271 /* get active selection mask */
272 sclp_cp_receive_mask = ef->receive_mask;
273
274 copy_mask((uint8_t *)&sclp_active_selection_mask, (uint8_t *)&red->mask,
275 sizeof(sclp_active_selection_mask), ef->mask_length);
276 sclp_active_selection_mask = be64_to_cpu(sclp_active_selection_mask);
277 if (!sclp_cp_receive_mask ||
278 (sclp_active_selection_mask & ~sclp_cp_receive_mask)) {
279 sccb->h.response_code =
280 cpu_to_be16(SCLP_RC_INVALID_SELECTION_MASK);
281 } else {
282 sccb->h.response_code = cpu_to_be16(
283 handle_sccb_read_events(ef, sccb, sclp_active_selection_mask));
284 }
285 break;
286 default:
287 sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_FUNCTION);
288 }
289 }
290
write_event_mask(SCLPEventFacility * ef,SCCB * sccb)291 static void write_event_mask(SCLPEventFacility *ef, SCCB *sccb)
292 {
293 WriteEventMask *we_mask = (WriteEventMask *) sccb;
294 uint16_t mask_length = be16_to_cpu(we_mask->mask_length);
295 sccb_mask_t tmp_mask;
296
297 if (!mask_length || (mask_length > SCLP_EVENT_MASK_LEN_MAX) ||
298 ((mask_length != 4) && !ef->allow_all_mask_sizes)) {
299 sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_MASK_LENGTH);
300 return;
301 }
302
303 /*
304 * Note: We currently only support masks up to 8 byte length;
305 * the remainder is filled up with zeroes. Older Linux
306 * kernels use a 4 byte mask length, newer ones can use both
307 * 8 or 4 depending on what is available on the host.
308 */
309
310 /* keep track of the guest's capability masks */
311 copy_mask((uint8_t *)&tmp_mask, WEM_CP_RECEIVE_MASK(we_mask, mask_length),
312 sizeof(tmp_mask), mask_length);
313 ef->receive_mask = be64_to_cpu(tmp_mask);
314
315 /* return the SCLP's capability masks to the guest */
316 tmp_mask = cpu_to_be64(get_host_receive_mask(ef));
317 copy_mask(WEM_RECEIVE_MASK(we_mask, mask_length), (uint8_t *)&tmp_mask,
318 mask_length, sizeof(tmp_mask));
319 tmp_mask = cpu_to_be64(get_host_send_mask(ef));
320 copy_mask(WEM_SEND_MASK(we_mask, mask_length), (uint8_t *)&tmp_mask,
321 mask_length, sizeof(tmp_mask));
322
323 sccb->h.response_code = cpu_to_be16(SCLP_RC_NORMAL_COMPLETION);
324 ef->mask_length = mask_length;
325 }
326
327 /* qemu object creation and initialization functions */
328
329 #define TYPE_SCLP_EVENTS_BUS "s390-sclp-events-bus"
330
331 static const TypeInfo sclp_events_bus_info = {
332 .name = TYPE_SCLP_EVENTS_BUS,
333 .parent = TYPE_BUS,
334 };
335
command_handler(SCLPEventFacility * ef,SCCB * sccb,uint64_t code)336 static void command_handler(SCLPEventFacility *ef, SCCB *sccb, uint64_t code)
337 {
338 switch (code & SCLP_CMD_CODE_MASK) {
339 case SCLP_CMD_READ_EVENT_DATA:
340 read_event_data(ef, sccb);
341 break;
342 case SCLP_CMD_WRITE_EVENT_DATA:
343 write_event_data(ef, sccb);
344 break;
345 case SCLP_CMD_WRITE_EVENT_MASK:
346 write_event_mask(ef, sccb);
347 break;
348 }
349 }
350
vmstate_event_facility_mask64_needed(void * opaque)351 static bool vmstate_event_facility_mask64_needed(void *opaque)
352 {
353 SCLPEventFacility *ef = opaque;
354
355 return (ef->receive_mask & 0xFFFFFFFF) != 0;
356 }
357
vmstate_event_facility_mask_length_needed(void * opaque)358 static bool vmstate_event_facility_mask_length_needed(void *opaque)
359 {
360 SCLPEventFacility *ef = opaque;
361
362 return ef->allow_all_mask_sizes;
363 }
364
365 static const VMStateDescription vmstate_event_facility_mask64 = {
366 .name = "vmstate-event-facility/mask64",
367 .version_id = 0,
368 .minimum_version_id = 0,
369 .needed = vmstate_event_facility_mask64_needed,
370 .fields = (const VMStateField[]) {
371 VMSTATE_UINT32(receive_mask_pieces[RECV_MASK_LOWER], SCLPEventFacility),
372 VMSTATE_END_OF_LIST()
373 }
374 };
375
376 static const VMStateDescription vmstate_event_facility_mask_length = {
377 .name = "vmstate-event-facility/mask_length",
378 .version_id = 0,
379 .minimum_version_id = 0,
380 .needed = vmstate_event_facility_mask_length_needed,
381 .fields = (const VMStateField[]) {
382 VMSTATE_UINT16(mask_length, SCLPEventFacility),
383 VMSTATE_END_OF_LIST()
384 }
385 };
386
387 static const VMStateDescription vmstate_event_facility = {
388 .name = "vmstate-event-facility",
389 .version_id = 0,
390 .minimum_version_id = 0,
391 .fields = (const VMStateField[]) {
392 VMSTATE_UINT32(receive_mask_pieces[RECV_MASK_UPPER], SCLPEventFacility),
393 VMSTATE_END_OF_LIST()
394 },
395 .subsections = (const VMStateDescription * const []) {
396 &vmstate_event_facility_mask64,
397 &vmstate_event_facility_mask_length,
398 NULL
399 }
400 };
401
sclp_event_set_allow_all_mask_sizes(Object * obj,bool value,Error ** errp)402 static void sclp_event_set_allow_all_mask_sizes(Object *obj, bool value,
403 Error **errp)
404 {
405 SCLPEventFacility *ef = (SCLPEventFacility *)obj;
406
407 ef->allow_all_mask_sizes = value;
408 }
409
sclp_event_get_allow_all_mask_sizes(Object * obj,Error ** errp)410 static bool sclp_event_get_allow_all_mask_sizes(Object *obj, Error **errp)
411 {
412 SCLPEventFacility *ef = (SCLPEventFacility *)obj;
413
414 return ef->allow_all_mask_sizes;
415 }
416
init_event_facility(Object * obj)417 static void init_event_facility(Object *obj)
418 {
419 SCLPEventFacility *event_facility = EVENT_FACILITY(obj);
420 DeviceState *sdev = DEVICE(obj);
421
422 event_facility->mask_length = 4;
423 event_facility->allow_all_mask_sizes = true;
424 object_property_add_bool(obj, "allow_all_mask_sizes",
425 sclp_event_get_allow_all_mask_sizes,
426 sclp_event_set_allow_all_mask_sizes);
427
428 /* Spawn a new bus for SCLP events */
429 qbus_init(&event_facility->sbus, sizeof(event_facility->sbus),
430 TYPE_SCLP_EVENTS_BUS, sdev, NULL);
431
432 object_initialize_child(obj, TYPE_SCLP_QUIESCE,
433 &event_facility->quiesce,
434 TYPE_SCLP_QUIESCE);
435
436 object_initialize_child(obj, TYPE_SCLP_CPU_HOTPLUG,
437 &event_facility->cpu_hotplug,
438 TYPE_SCLP_CPU_HOTPLUG);
439 }
440
realize_event_facility(DeviceState * dev,Error ** errp)441 static void realize_event_facility(DeviceState *dev, Error **errp)
442 {
443 SCLPEventFacility *event_facility = EVENT_FACILITY(dev);
444
445 if (!qdev_realize(DEVICE(&event_facility->quiesce),
446 BUS(&event_facility->sbus), errp)) {
447 return;
448 }
449 if (!qdev_realize(DEVICE(&event_facility->cpu_hotplug),
450 BUS(&event_facility->sbus), errp)) {
451 qdev_unrealize(DEVICE(&event_facility->quiesce));
452 return;
453 }
454 }
455
reset_event_facility(DeviceState * dev)456 static void reset_event_facility(DeviceState *dev)
457 {
458 SCLPEventFacility *sdev = EVENT_FACILITY(dev);
459
460 sdev->receive_mask = 0;
461 }
462
init_event_facility_class(ObjectClass * klass,void * data)463 static void init_event_facility_class(ObjectClass *klass, void *data)
464 {
465 SysBusDeviceClass *sbdc = SYS_BUS_DEVICE_CLASS(klass);
466 DeviceClass *dc = DEVICE_CLASS(sbdc);
467 SCLPEventFacilityClass *k = EVENT_FACILITY_CLASS(dc);
468
469 dc->realize = realize_event_facility;
470 dc->reset = reset_event_facility;
471 dc->vmsd = &vmstate_event_facility;
472 set_bit(DEVICE_CATEGORY_MISC, dc->categories);
473 k->command_handler = command_handler;
474 k->event_pending = event_pending;
475 }
476
477 static const TypeInfo sclp_event_facility_info = {
478 .name = TYPE_SCLP_EVENT_FACILITY,
479 .parent = TYPE_SYS_BUS_DEVICE,
480 .instance_init = init_event_facility,
481 .instance_size = sizeof(SCLPEventFacility),
482 .class_init = init_event_facility_class,
483 .class_size = sizeof(SCLPEventFacilityClass),
484 };
485
event_realize(DeviceState * qdev,Error ** errp)486 static void event_realize(DeviceState *qdev, Error **errp)
487 {
488 SCLPEvent *event = SCLP_EVENT(qdev);
489 SCLPEventClass *child = SCLP_EVENT_GET_CLASS(event);
490
491 if (child->init) {
492 int rc = child->init(event);
493 if (rc < 0) {
494 error_setg(errp, "SCLP event initialization failed.");
495 return;
496 }
497 }
498 }
499
event_class_init(ObjectClass * klass,void * data)500 static void event_class_init(ObjectClass *klass, void *data)
501 {
502 DeviceClass *dc = DEVICE_CLASS(klass);
503
504 dc->bus_type = TYPE_SCLP_EVENTS_BUS;
505 dc->realize = event_realize;
506 }
507
508 static const TypeInfo sclp_event_type_info = {
509 .name = TYPE_SCLP_EVENT,
510 .parent = TYPE_DEVICE,
511 .instance_size = sizeof(SCLPEvent),
512 .class_init = event_class_init,
513 .class_size = sizeof(SCLPEventClass),
514 .abstract = true,
515 };
516
register_types(void)517 static void register_types(void)
518 {
519 type_register_static(&sclp_events_bus_info);
520 type_register_static(&sclp_event_facility_info);
521 type_register_static(&sclp_event_type_info);
522 }
523
type_init(register_types)524 type_init(register_types)
525
526 BusState *sclp_get_event_facility_bus(SCLPEventFacility *ef)
527 {
528 return BUS(&ef->sbus);
529 }
530