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