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
26typedef struct SCLPEventsBus {
27 BusState qbus;
28} SCLPEventsBus;
29
30/* we need to save 32 bit chunks for compatibility */
31#ifdef HOST_WORDS_BIGENDIAN
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
39struct SCLPEventFacility {
40 SysBusDevice parent_obj;
41 SCLPEventsBus sbus;
42 /* guest's receive mask */
43 union {
44 uint32_t receive_mask_pieces[2];
45 sccb_mask_t receive_mask;
46 };
47 /*
48 * when false, we keep the same broken, backwards compatible behaviour as
49 * before, allowing only masks of size exactly 4; when true, we implement
50 * the architecture correctly, allowing all valid mask sizes. Needed for
51 * migration toward older versions.
52 */
53 bool allow_all_mask_sizes;
54 /* length of the receive mask */
55 uint16_t mask_length;
56};
57
58/* return true if any child has event pending set */
59static bool event_pending(SCLPEventFacility *ef)
60{
61 BusChild *kid;
62 SCLPEvent *event;
63 SCLPEventClass *event_class;
64
65 QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
66 DeviceState *qdev = kid->child;
67 event = DO_UPCAST(SCLPEvent, qdev, qdev);
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
77static 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
93static 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
109static 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
130static 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
154static 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
181static 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 goto out;
186 }
187 if (be16_to_cpu(sccb->h.length) < 8) {
188 sccb->h.response_code = cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
189 goto out;
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
200out:
201 return;
202}
203
204static uint16_t handle_sccb_read_events(SCLPEventFacility *ef, SCCB *sccb,
205 sccb_mask_t mask)
206{
207 uint16_t rc;
208 int slen;
209 unsigned elen;
210 BusChild *kid;
211 SCLPEvent *event;
212 SCLPEventClass *ec;
213 EventBufferHeader *event_buf;
214 ReadEventData *red = (ReadEventData *) sccb;
215
216 event_buf = &red->ebh;
217 event_buf->length = 0;
218 slen = sizeof(sccb->data);
219
220 rc = SCLP_RC_NO_EVENT_BUFFERS_STORED;
221
222 QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
223 DeviceState *qdev = kid->child;
224 event = (SCLPEvent *) qdev;
225 ec = SCLP_EVENT_GET_CLASS(event);
226
227 if (mask & ec->get_send_mask()) {
228 if (ec->read_event_data(event, event_buf, &slen)) {
229 elen = be16_to_cpu(event_buf->length);
230 event_buf = (EventBufferHeader *) ((char *)event_buf + elen);
231 rc = SCLP_RC_NORMAL_COMPLETION;
232 }
233 }
234 }
235
236 if (sccb->h.control_mask[2] & SCLP_VARIABLE_LENGTH_RESPONSE) {
237 /* architecture suggests to reset variable-length-response bit */
238 sccb->h.control_mask[2] &= ~SCLP_VARIABLE_LENGTH_RESPONSE;
239 /* with a new length value */
240 sccb->h.length = cpu_to_be16(SCCB_SIZE - slen);
241 }
242 return rc;
243}
244
245/* copy up to src_len bytes and fill the rest of dst with zeroes */
246static void copy_mask(uint8_t *dst, uint8_t *src, uint16_t dst_len,
247 uint16_t src_len)
248{
249 int i;
250
251 for (i = 0; i < dst_len; i++) {
252 dst[i] = i < src_len ? src[i] : 0;
253 }
254}
255
256static void read_event_data(SCLPEventFacility *ef, SCCB *sccb)
257{
258 sccb_mask_t sclp_active_selection_mask;
259 sccb_mask_t sclp_cp_receive_mask;
260
261 ReadEventData *red = (ReadEventData *) sccb;
262
263 if (be16_to_cpu(sccb->h.length) != SCCB_SIZE) {
264 sccb->h.response_code = cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
265 goto out;
266 }
267
268 sclp_cp_receive_mask = ef->receive_mask;
269
270 /* get active selection mask */
271 switch (sccb->h.function_code) {
272 case SCLP_UNCONDITIONAL_READ:
273 sclp_active_selection_mask = sclp_cp_receive_mask;
274 break;
275 case SCLP_SELECTIVE_READ:
276 copy_mask((uint8_t *)&sclp_active_selection_mask, (uint8_t *)&red->mask,
277 sizeof(sclp_active_selection_mask), ef->mask_length);
278 sclp_active_selection_mask = be64_to_cpu(sclp_active_selection_mask);
279 if (!sclp_cp_receive_mask ||
280 (sclp_active_selection_mask & ~sclp_cp_receive_mask)) {
281 sccb->h.response_code =
282 cpu_to_be16(SCLP_RC_INVALID_SELECTION_MASK);
283 goto out;
284 }
285 break;
286 default:
287 sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_FUNCTION);
288 goto out;
289 }
290 sccb->h.response_code = cpu_to_be16(
291 handle_sccb_read_events(ef, sccb, sclp_active_selection_mask));
292
293out:
294 return;
295}
296
297static void write_event_mask(SCLPEventFacility *ef, SCCB *sccb)
298{
299 WriteEventMask *we_mask = (WriteEventMask *) sccb;
300 uint16_t mask_length = be16_to_cpu(we_mask->mask_length);
301 sccb_mask_t tmp_mask;
302
303 if (!mask_length || (mask_length > SCLP_EVENT_MASK_LEN_MAX) ||
304 ((mask_length != 4) && !ef->allow_all_mask_sizes)) {
305 sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_MASK_LENGTH);
306 goto out;
307 }
308
309 /*
310 * Note: We currently only support masks up to 8 byte length;
311 * the remainder is filled up with zeroes. Older Linux
312 * kernels use a 4 byte mask length, newer ones can use both
313 * 8 or 4 depending on what is available on the host.
314 */
315
316 /* keep track of the guest's capability masks */
317 copy_mask((uint8_t *)&tmp_mask, WEM_CP_RECEIVE_MASK(we_mask, mask_length),
318 sizeof(tmp_mask), mask_length);
319 ef->receive_mask = be64_to_cpu(tmp_mask);
320
321 /* return the SCLP's capability masks to the guest */
322 tmp_mask = cpu_to_be64(get_host_receive_mask(ef));
323 copy_mask(WEM_RECEIVE_MASK(we_mask, mask_length), (uint8_t *)&tmp_mask,
324 mask_length, sizeof(tmp_mask));
325 tmp_mask = cpu_to_be64(get_host_send_mask(ef));
326 copy_mask(WEM_SEND_MASK(we_mask, mask_length), (uint8_t *)&tmp_mask,
327 mask_length, sizeof(tmp_mask));
328
329 sccb->h.response_code = cpu_to_be16(SCLP_RC_NORMAL_COMPLETION);
330 ef->mask_length = mask_length;
331
332out:
333 return;
334}
335
336/* qemu object creation and initialization functions */
337
338#define TYPE_SCLP_EVENTS_BUS "s390-sclp-events-bus"
339
340static void sclp_events_bus_realize(BusState *bus, Error **errp)
341{
342 BusChild *kid;
343
344 /* TODO: recursive realization has to be done in common code */
345 QTAILQ_FOREACH(kid, &bus->children, sibling) {
346 DeviceState *dev = kid->child;
347
348 object_property_set_bool(OBJECT(dev), true, "realized", errp);
349 if (*errp) {
350 return;
351 }
352 }
353}
354
355static void sclp_events_bus_class_init(ObjectClass *klass, void *data)
356{
357 BusClass *bc = BUS_CLASS(klass);
358
359 bc->realize = sclp_events_bus_realize;
360}
361
362static const TypeInfo sclp_events_bus_info = {
363 .name = TYPE_SCLP_EVENTS_BUS,
364 .parent = TYPE_BUS,
365 .class_init = sclp_events_bus_class_init,
366};
367
368static void command_handler(SCLPEventFacility *ef, SCCB *sccb, uint64_t code)
369{
370 switch (code & SCLP_CMD_CODE_MASK) {
371 case SCLP_CMD_READ_EVENT_DATA:
372 read_event_data(ef, sccb);
373 break;
374 case SCLP_CMD_WRITE_EVENT_DATA:
375 write_event_data(ef, sccb);
376 break;
377 case SCLP_CMD_WRITE_EVENT_MASK:
378 write_event_mask(ef, sccb);
379 break;
380 default:
381 sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_SCLP_COMMAND);
382 break;
383 }
384}
385
386static bool vmstate_event_facility_mask64_needed(void *opaque)
387{
388 SCLPEventFacility *ef = opaque;
389
390 return (ef->receive_mask & 0xFFFFFFFF) != 0;
391}
392
393static bool vmstate_event_facility_mask_length_needed(void *opaque)
394{
395 SCLPEventFacility *ef = opaque;
396
397 return ef->allow_all_mask_sizes;
398}
399
400static const VMStateDescription vmstate_event_facility_mask64 = {
401 .name = "vmstate-event-facility/mask64",
402 .version_id = 0,
403 .minimum_version_id = 0,
404 .needed = vmstate_event_facility_mask64_needed,
405 .fields = (VMStateField[]) {
406 VMSTATE_UINT32(receive_mask_pieces[RECV_MASK_LOWER], SCLPEventFacility),
407 VMSTATE_END_OF_LIST()
408 }
409};
410
411static const VMStateDescription vmstate_event_facility_mask_length = {
412 .name = "vmstate-event-facility/mask_length",
413 .version_id = 0,
414 .minimum_version_id = 0,
415 .needed = vmstate_event_facility_mask_length_needed,
416 .fields = (VMStateField[]) {
417 VMSTATE_UINT16(mask_length, SCLPEventFacility),
418 VMSTATE_END_OF_LIST()
419 }
420};
421
422static const VMStateDescription vmstate_event_facility = {
423 .name = "vmstate-event-facility",
424 .version_id = 0,
425 .minimum_version_id = 0,
426 .fields = (VMStateField[]) {
427 VMSTATE_UINT32(receive_mask_pieces[RECV_MASK_UPPER], SCLPEventFacility),
428 VMSTATE_END_OF_LIST()
429 },
430 .subsections = (const VMStateDescription * []) {
431 &vmstate_event_facility_mask64,
432 &vmstate_event_facility_mask_length,
433 NULL
434 }
435};
436
437static void sclp_event_set_allow_all_mask_sizes(Object *obj, bool value,
438 Error **errp)
439{
440 SCLPEventFacility *ef = (SCLPEventFacility *)obj;
441
442 ef->allow_all_mask_sizes = value;
443}
444
445static bool sclp_event_get_allow_all_mask_sizes(Object *obj, Error **e)
446{
447 SCLPEventFacility *ef = (SCLPEventFacility *)obj;
448
449 return ef->allow_all_mask_sizes;
450}
451
452static void init_event_facility(Object *obj)
453{
454 SCLPEventFacility *event_facility = EVENT_FACILITY(obj);
455 DeviceState *sdev = DEVICE(obj);
456 Object *new;
457
458 event_facility->mask_length = 4;
459 event_facility->allow_all_mask_sizes = true;
460 object_property_add_bool(obj, "allow_all_mask_sizes",
461 sclp_event_get_allow_all_mask_sizes,
462 sclp_event_set_allow_all_mask_sizes, NULL);
463 /* Spawn a new bus for SCLP events */
464 qbus_create_inplace(&event_facility->sbus, sizeof(event_facility->sbus),
465 TYPE_SCLP_EVENTS_BUS, sdev, NULL);
466
467 new = object_new(TYPE_SCLP_QUIESCE);
468 object_property_add_child(obj, TYPE_SCLP_QUIESCE, new, NULL);
469 object_unref(new);
470 qdev_set_parent_bus(DEVICE(new), BUS(&event_facility->sbus));
471
472 new = object_new(TYPE_SCLP_CPU_HOTPLUG);
473 object_property_add_child(obj, TYPE_SCLP_CPU_HOTPLUG, new, NULL);
474 object_unref(new);
475 qdev_set_parent_bus(DEVICE(new), BUS(&event_facility->sbus));
476 /* the facility will automatically realize the devices via the bus */
477}
478
479static void reset_event_facility(DeviceState *dev)
480{
481 SCLPEventFacility *sdev = EVENT_FACILITY(dev);
482
483 sdev->receive_mask = 0;
484}
485
486static void init_event_facility_class(ObjectClass *klass, void *data)
487{
488 SysBusDeviceClass *sbdc = SYS_BUS_DEVICE_CLASS(klass);
489 DeviceClass *dc = DEVICE_CLASS(sbdc);
490 SCLPEventFacilityClass *k = EVENT_FACILITY_CLASS(dc);
491
492 dc->reset = reset_event_facility;
493 dc->vmsd = &vmstate_event_facility;
494 set_bit(DEVICE_CATEGORY_MISC, dc->categories);
495 k->command_handler = command_handler;
496 k->event_pending = event_pending;
497}
498
499static const TypeInfo sclp_event_facility_info = {
500 .name = TYPE_SCLP_EVENT_FACILITY,
501 .parent = TYPE_SYS_BUS_DEVICE,
502 .instance_init = init_event_facility,
503 .instance_size = sizeof(SCLPEventFacility),
504 .class_init = init_event_facility_class,
505 .class_size = sizeof(SCLPEventFacilityClass),
506};
507
508static void event_realize(DeviceState *qdev, Error **errp)
509{
510 SCLPEvent *event = SCLP_EVENT(qdev);
511 SCLPEventClass *child = SCLP_EVENT_GET_CLASS(event);
512
513 if (child->init) {
514 int rc = child->init(event);
515 if (rc < 0) {
516 error_setg(errp, "SCLP event initialization failed.");
517 return;
518 }
519 }
520}
521
522static void event_class_init(ObjectClass *klass, void *data)
523{
524 DeviceClass *dc = DEVICE_CLASS(klass);
525
526 dc->bus_type = TYPE_SCLP_EVENTS_BUS;
527 dc->realize = event_realize;
528}
529
530static const TypeInfo sclp_event_type_info = {
531 .name = TYPE_SCLP_EVENT,
532 .parent = TYPE_DEVICE,
533 .instance_size = sizeof(SCLPEvent),
534 .class_init = event_class_init,
535 .class_size = sizeof(SCLPEventClass),
536 .abstract = true,
537};
538
539static void register_types(void)
540{
541 type_register_static(&sclp_events_bus_info);
542 type_register_static(&sclp_event_facility_info);
543 type_register_static(&sclp_event_type_info);
544}
545
546type_init(register_types)
547
548BusState *sclp_get_event_facility_bus(void)
549{
550 Object *busobj;
551 SCLPEventsBus *sbus;
552
553 busobj = object_resolve_path_type("", TYPE_SCLP_EVENTS_BUS, NULL);
554 sbus = OBJECT_CHECK(SCLPEventsBus, busobj, TYPE_SCLP_EVENTS_BUS);
555 if (!sbus) {
556 return NULL;
557 }
558
559 return &sbus->qbus;
560}
561