xref: /qemu/hw/s390x/event-facility.c (revision 2ce68e4c) 
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 "sysemu/sysemu.h"
19 
20 #include "hw/s390x/sclp.h"
21 #include "hw/s390x/event-facility.h"
22 
23 typedef struct SCLPEventsBus {
24     BusState qbus;
25 } SCLPEventsBus;
26 
27 struct SCLPEventFacility {
28     SysBusDevice parent_obj;
29     SCLPEventsBus sbus;
30     /* guest' receive mask */
31     unsigned int receive_mask;
32 };
33 
34 /* return true if any child has event pending set */
35 static bool event_pending(SCLPEventFacility *ef)
36 {
37     BusChild *kid;
38     SCLPEvent *event;
39     SCLPEventClass *event_class;
40 
41     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
42         DeviceState *qdev = kid->child;
43         event = DO_UPCAST(SCLPEvent, qdev, qdev);
44         event_class = SCLP_EVENT_GET_CLASS(event);
45         if (event->event_pending &&
46             event_class->get_send_mask() & ef->receive_mask) {
47             return true;
48         }
49     }
50     return false;
51 }
52 
53 static unsigned int get_host_send_mask(SCLPEventFacility *ef)
54 {
55     unsigned int mask;
56     BusChild *kid;
57     SCLPEventClass *child;
58 
59     mask = 0;
60 
61     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
62         DeviceState *qdev = kid->child;
63         child = SCLP_EVENT_GET_CLASS((SCLPEvent *) qdev);
64         mask |= child->get_send_mask();
65     }
66     return mask;
67 }
68 
69 static unsigned int get_host_receive_mask(SCLPEventFacility *ef)
70 {
71     unsigned int mask;
72     BusChild *kid;
73     SCLPEventClass *child;
74 
75     mask = 0;
76 
77     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
78         DeviceState *qdev = kid->child;
79         child = SCLP_EVENT_GET_CLASS((SCLPEvent *) qdev);
80         mask |= child->get_receive_mask();
81     }
82     return mask;
83 }
84 
85 static uint16_t write_event_length_check(SCCB *sccb)
86 {
87     int slen;
88     unsigned elen = 0;
89     EventBufferHeader *event;
90     WriteEventData *wed = (WriteEventData *) sccb;
91 
92     event = (EventBufferHeader *) &wed->ebh;
93     for (slen = sccb_data_len(sccb); slen > 0; slen -= elen) {
94         elen = be16_to_cpu(event->length);
95         if (elen < sizeof(*event) || elen > slen) {
96             return SCLP_RC_EVENT_BUFFER_SYNTAX_ERROR;
97         }
98         event = (void *) event + elen;
99     }
100     if (slen) {
101         return SCLP_RC_INCONSISTENT_LENGTHS;
102     }
103     return SCLP_RC_NORMAL_COMPLETION;
104 }
105 
106 static uint16_t handle_write_event_buf(SCLPEventFacility *ef,
107                                        EventBufferHeader *event_buf, SCCB *sccb)
108 {
109     uint16_t rc;
110     BusChild *kid;
111     SCLPEvent *event;
112     SCLPEventClass *ec;
113 
114     rc = SCLP_RC_INVALID_FUNCTION;
115 
116     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
117         DeviceState *qdev = kid->child;
118         event = (SCLPEvent *) qdev;
119         ec = SCLP_EVENT_GET_CLASS(event);
120 
121         if (ec->write_event_data &&
122             ec->can_handle_event(event_buf->type)) {
123             rc = ec->write_event_data(event, event_buf);
124             break;
125         }
126     }
127     return rc;
128 }
129 
130 static uint16_t handle_sccb_write_events(SCLPEventFacility *ef, SCCB *sccb)
131 {
132     uint16_t rc;
133     int slen;
134     unsigned elen = 0;
135     EventBufferHeader *event_buf;
136     WriteEventData *wed = (WriteEventData *) sccb;
137 
138     event_buf = &wed->ebh;
139     rc = SCLP_RC_NORMAL_COMPLETION;
140 
141     /* loop over all contained event buffers */
142     for (slen = sccb_data_len(sccb); slen > 0; slen -= elen) {
143         elen = be16_to_cpu(event_buf->length);
144 
145         /* in case of a previous error mark all trailing buffers
146          * as not accepted */
147         if (rc != SCLP_RC_NORMAL_COMPLETION) {
148             event_buf->flags &= ~(SCLP_EVENT_BUFFER_ACCEPTED);
149         } else {
150             rc = handle_write_event_buf(ef, event_buf, sccb);
151         }
152         event_buf = (void *) event_buf + elen;
153     }
154     return rc;
155 }
156 
157 static void write_event_data(SCLPEventFacility *ef, SCCB *sccb)
158 {
159     if (sccb->h.function_code != SCLP_FC_NORMAL_WRITE) {
160         sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_FUNCTION);
161         goto out;
162     }
163     if (be16_to_cpu(sccb->h.length) < 8) {
164         sccb->h.response_code = cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
165         goto out;
166     }
167     /* first do a sanity check of the write events */
168     sccb->h.response_code = cpu_to_be16(write_event_length_check(sccb));
169 
170     /* if no early error, then execute */
171     if (sccb->h.response_code == be16_to_cpu(SCLP_RC_NORMAL_COMPLETION)) {
172         sccb->h.response_code =
173                 cpu_to_be16(handle_sccb_write_events(ef, sccb));
174     }
175 
176 out:
177     return;
178 }
179 
180 static uint16_t handle_sccb_read_events(SCLPEventFacility *ef, SCCB *sccb,
181                                         unsigned int mask)
182 {
183     uint16_t rc;
184     int slen;
185     unsigned elen;
186     BusChild *kid;
187     SCLPEvent *event;
188     SCLPEventClass *ec;
189     EventBufferHeader *event_buf;
190     ReadEventData *red = (ReadEventData *) sccb;
191 
192     event_buf = &red->ebh;
193     event_buf->length = 0;
194     slen = sizeof(sccb->data);
195 
196     rc = SCLP_RC_NO_EVENT_BUFFERS_STORED;
197 
198     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
199         DeviceState *qdev = kid->child;
200         event = (SCLPEvent *) qdev;
201         ec = SCLP_EVENT_GET_CLASS(event);
202 
203         if (mask & ec->get_send_mask()) {
204             if (ec->read_event_data(event, event_buf, &slen)) {
205                 elen = be16_to_cpu(event_buf->length);
206                 event_buf = (EventBufferHeader *) ((char *)event_buf + elen);
207                 rc = SCLP_RC_NORMAL_COMPLETION;
208             }
209         }
210     }
211 
212     if (sccb->h.control_mask[2] & SCLP_VARIABLE_LENGTH_RESPONSE) {
213         /* architecture suggests to reset variable-length-response bit */
214         sccb->h.control_mask[2] &= ~SCLP_VARIABLE_LENGTH_RESPONSE;
215         /* with a new length value */
216         sccb->h.length = cpu_to_be16(SCCB_SIZE - slen);
217     }
218     return rc;
219 }
220 
221 static void read_event_data(SCLPEventFacility *ef, SCCB *sccb)
222 {
223     unsigned int sclp_active_selection_mask;
224     unsigned int sclp_cp_receive_mask;
225 
226     ReadEventData *red = (ReadEventData *) sccb;
227 
228     if (be16_to_cpu(sccb->h.length) != SCCB_SIZE) {
229         sccb->h.response_code = cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
230         goto out;
231     }
232 
233     sclp_cp_receive_mask = ef->receive_mask;
234 
235     /* get active selection mask */
236     switch (sccb->h.function_code) {
237     case SCLP_UNCONDITIONAL_READ:
238         sclp_active_selection_mask = sclp_cp_receive_mask;
239         break;
240     case SCLP_SELECTIVE_READ:
241         sclp_active_selection_mask = be32_to_cpu(red->mask);
242         if (!sclp_cp_receive_mask ||
243             (sclp_active_selection_mask & ~sclp_cp_receive_mask)) {
244             sccb->h.response_code =
245                     cpu_to_be16(SCLP_RC_INVALID_SELECTION_MASK);
246             goto out;
247         }
248         break;
249     default:
250         sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_FUNCTION);
251         goto out;
252     }
253     sccb->h.response_code = cpu_to_be16(
254             handle_sccb_read_events(ef, sccb, sclp_active_selection_mask));
255 
256 out:
257     return;
258 }
259 
260 static void write_event_mask(SCLPEventFacility *ef, SCCB *sccb)
261 {
262     WriteEventMask *we_mask = (WriteEventMask *) sccb;
263 
264     /* Attention: We assume that Linux uses 4-byte masks, what it actually
265        does. Architecture allows for masks of variable size, though */
266     if (be16_to_cpu(we_mask->mask_length) != 4) {
267         sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_MASK_LENGTH);
268         goto out;
269     }
270 
271     /* keep track of the guest's capability masks */
272     ef->receive_mask = be32_to_cpu(we_mask->cp_receive_mask);
273 
274     /* return the SCLP's capability masks to the guest */
275     we_mask->send_mask = cpu_to_be32(get_host_send_mask(ef));
276     we_mask->receive_mask = cpu_to_be32(get_host_receive_mask(ef));
277 
278     sccb->h.response_code = cpu_to_be16(SCLP_RC_NORMAL_COMPLETION);
279 
280 out:
281     return;
282 }
283 
284 /* qemu object creation and initialization functions */
285 
286 #define TYPE_SCLP_EVENTS_BUS "s390-sclp-events-bus"
287 
288 static void sclp_events_bus_realize(BusState *bus, Error **errp)
289 {
290     BusChild *kid;
291 
292     /* TODO: recursive realization has to be done in common code */
293     QTAILQ_FOREACH(kid, &bus->children, sibling) {
294         DeviceState *dev = kid->child;
295 
296         object_property_set_bool(OBJECT(dev), true, "realized", errp);
297         if (*errp) {
298             return;
299         }
300     }
301 }
302 
303 static void sclp_events_bus_class_init(ObjectClass *klass, void *data)
304 {
305     BusClass *bc = BUS_CLASS(klass);
306 
307     bc->realize = sclp_events_bus_realize;
308 }
309 
310 static const TypeInfo sclp_events_bus_info = {
311     .name = TYPE_SCLP_EVENTS_BUS,
312     .parent = TYPE_BUS,
313     .class_init = sclp_events_bus_class_init,
314 };
315 
316 static void command_handler(SCLPEventFacility *ef, SCCB *sccb, uint64_t code)
317 {
318     switch (code & SCLP_CMD_CODE_MASK) {
319     case SCLP_CMD_READ_EVENT_DATA:
320         read_event_data(ef, sccb);
321         break;
322     case SCLP_CMD_WRITE_EVENT_DATA:
323         write_event_data(ef, sccb);
324         break;
325     case SCLP_CMD_WRITE_EVENT_MASK:
326         write_event_mask(ef, sccb);
327         break;
328     default:
329         sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_SCLP_COMMAND);
330         break;
331     }
332 }
333 
334 static const VMStateDescription vmstate_event_facility = {
335     .name = "vmstate-event-facility",
336     .version_id = 0,
337     .minimum_version_id = 0,
338     .fields = (VMStateField[]) {
339         VMSTATE_UINT32(receive_mask, SCLPEventFacility),
340         VMSTATE_END_OF_LIST()
341      }
342 };
343 
344 static void init_event_facility(Object *obj)
345 {
346     SCLPEventFacility *event_facility = EVENT_FACILITY(obj);
347     DeviceState *sdev = DEVICE(obj);
348     Object *new;
349 
350     /* Spawn a new bus for SCLP events */
351     qbus_create_inplace(&event_facility->sbus, sizeof(event_facility->sbus),
352                         TYPE_SCLP_EVENTS_BUS, sdev, NULL);
353 
354     new = object_new(TYPE_SCLP_QUIESCE);
355     object_property_add_child(obj, TYPE_SCLP_QUIESCE, new, NULL);
356     object_unref(new);
357     qdev_set_parent_bus(DEVICE(new), &event_facility->sbus.qbus);
358 
359     new = object_new(TYPE_SCLP_CPU_HOTPLUG);
360     object_property_add_child(obj, TYPE_SCLP_CPU_HOTPLUG, new, NULL);
361     object_unref(new);
362     qdev_set_parent_bus(DEVICE(new), &event_facility->sbus.qbus);
363     /* the facility will automatically realize the devices via the bus */
364 }
365 
366 static void reset_event_facility(DeviceState *dev)
367 {
368     SCLPEventFacility *sdev = EVENT_FACILITY(dev);
369 
370     sdev->receive_mask = 0;
371 }
372 
373 static void init_event_facility_class(ObjectClass *klass, void *data)
374 {
375     SysBusDeviceClass *sbdc = SYS_BUS_DEVICE_CLASS(klass);
376     DeviceClass *dc = DEVICE_CLASS(sbdc);
377     SCLPEventFacilityClass *k = EVENT_FACILITY_CLASS(dc);
378 
379     dc->reset = reset_event_facility;
380     dc->vmsd = &vmstate_event_facility;
381     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
382     k->command_handler = command_handler;
383     k->event_pending = event_pending;
384 }
385 
386 static const TypeInfo sclp_event_facility_info = {
387     .name          = TYPE_SCLP_EVENT_FACILITY,
388     .parent        = TYPE_SYS_BUS_DEVICE,
389     .instance_init = init_event_facility,
390     .instance_size = sizeof(SCLPEventFacility),
391     .class_init    = init_event_facility_class,
392     .class_size    = sizeof(SCLPEventFacilityClass),
393 };
394 
395 static void event_realize(DeviceState *qdev, Error **errp)
396 {
397     SCLPEvent *event = SCLP_EVENT(qdev);
398     SCLPEventClass *child = SCLP_EVENT_GET_CLASS(event);
399 
400     if (child->init) {
401         int rc = child->init(event);
402         if (rc < 0) {
403             error_setg(errp, "SCLP event initialization failed.");
404             return;
405         }
406     }
407 }
408 
409 static void event_unrealize(DeviceState *qdev, Error **errp)
410 {
411     SCLPEvent *event = SCLP_EVENT(qdev);
412     SCLPEventClass *child = SCLP_EVENT_GET_CLASS(event);
413     if (child->exit) {
414         int rc = child->exit(event);
415         if (rc < 0) {
416             error_setg(errp, "SCLP event exit failed.");
417             return;
418         }
419     }
420 }
421 
422 static void event_class_init(ObjectClass *klass, void *data)
423 {
424     DeviceClass *dc = DEVICE_CLASS(klass);
425 
426     dc->bus_type = TYPE_SCLP_EVENTS_BUS;
427     dc->realize = event_realize;
428     dc->unrealize = event_unrealize;
429 }
430 
431 static const TypeInfo sclp_event_type_info = {
432     .name = TYPE_SCLP_EVENT,
433     .parent = TYPE_DEVICE,
434     .instance_size = sizeof(SCLPEvent),
435     .class_init = event_class_init,
436     .class_size = sizeof(SCLPEventClass),
437     .abstract = true,
438 };
439 
440 static void register_types(void)
441 {
442     type_register_static(&sclp_events_bus_info);
443     type_register_static(&sclp_event_facility_info);
444     type_register_static(&sclp_event_type_info);
445 }
446 
447 type_init(register_types)
448