xref: /openbmc/qemu/hw/ipmi/ipmi_bmc_extern.c (revision 59a3a1c0)
1 /*
2  * IPMI BMC external connection
3  *
4  * Copyright (c) 2015 Corey Minyard, MontaVista Software, LLC
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 
25 /*
26  * This is designed to connect with OpenIPMI's lanserv serial interface
27  * using the "VM" connection type.  See that for details.
28  */
29 
30 #include "qemu/osdep.h"
31 #include "qemu/error-report.h"
32 #include "qemu/module.h"
33 #include "qapi/error.h"
34 #include "qemu/timer.h"
35 #include "chardev/char-fe.h"
36 #include "hw/ipmi/ipmi.h"
37 #include "hw/qdev-properties.h"
38 #include "migration/vmstate.h"
39 
40 #define VM_MSG_CHAR        0xA0 /* Marks end of message */
41 #define VM_CMD_CHAR        0xA1 /* Marks end of a command */
42 #define VM_ESCAPE_CHAR     0xAA /* Set bit 4 from the next byte to 0 */
43 
44 #define VM_PROTOCOL_VERSION        1
45 #define VM_CMD_VERSION             0xff /* A version number byte follows */
46 #define VM_CMD_NOATTN              0x00
47 #define VM_CMD_ATTN                0x01
48 #define VM_CMD_ATTN_IRQ            0x02
49 #define VM_CMD_POWEROFF            0x03
50 #define VM_CMD_RESET               0x04
51 #define VM_CMD_ENABLE_IRQ          0x05 /* Enable/disable the messaging irq */
52 #define VM_CMD_DISABLE_IRQ         0x06
53 #define VM_CMD_SEND_NMI            0x07
54 #define VM_CMD_CAPABILITIES        0x08
55 #define   VM_CAPABILITIES_POWER    0x01
56 #define   VM_CAPABILITIES_RESET    0x02
57 #define   VM_CAPABILITIES_IRQ      0x04
58 #define   VM_CAPABILITIES_NMI      0x08
59 #define   VM_CAPABILITIES_ATTN     0x10
60 #define   VM_CAPABILITIES_GRACEFUL_SHUTDOWN 0x20
61 #define VM_CMD_GRACEFUL_SHUTDOWN   0x09
62 
63 #define TYPE_IPMI_BMC_EXTERN "ipmi-bmc-extern"
64 #define IPMI_BMC_EXTERN(obj) OBJECT_CHECK(IPMIBmcExtern, (obj), \
65                                         TYPE_IPMI_BMC_EXTERN)
66 typedef struct IPMIBmcExtern {
67     IPMIBmc parent;
68 
69     CharBackend chr;
70 
71     bool connected;
72 
73     unsigned char inbuf[MAX_IPMI_MSG_SIZE + 2];
74     unsigned int inpos;
75     bool in_escape;
76     bool in_too_many;
77     bool waiting_rsp;
78     bool sending_cmd;
79 
80     unsigned char outbuf[(MAX_IPMI_MSG_SIZE + 2) * 2 + 1];
81     unsigned int outpos;
82     unsigned int outlen;
83 
84     struct QEMUTimer *extern_timer;
85 
86     /* A reset event is pending to be sent upstream. */
87     bool send_reset;
88 } IPMIBmcExtern;
89 
90 static int can_receive(void *opaque);
91 static void receive(void *opaque, const uint8_t *buf, int size);
92 static void chr_event(void *opaque, int event);
93 
94 static unsigned char
95 ipmb_checksum(const unsigned char *data, int size, unsigned char start)
96 {
97         unsigned char csum = start;
98 
99         for (; size > 0; size--, data++) {
100                 csum += *data;
101         }
102         return csum;
103 }
104 
105 static void continue_send(IPMIBmcExtern *ibe)
106 {
107     int ret;
108     if (ibe->outlen == 0) {
109         goto check_reset;
110     }
111  send:
112     ret = qemu_chr_fe_write(&ibe->chr, ibe->outbuf + ibe->outpos,
113                             ibe->outlen - ibe->outpos);
114     if (ret > 0) {
115         ibe->outpos += ret;
116     }
117     if (ibe->outpos < ibe->outlen) {
118         /* Not fully transmitted, try again in a 10ms */
119         timer_mod_ns(ibe->extern_timer,
120                      qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + 10000000);
121     } else {
122         /* Sent */
123         ibe->outlen = 0;
124         ibe->outpos = 0;
125         if (!ibe->sending_cmd) {
126             ibe->waiting_rsp = true;
127         } else {
128             ibe->sending_cmd = false;
129         }
130     check_reset:
131         if (ibe->connected && ibe->send_reset) {
132             /* Send the reset */
133             ibe->outbuf[0] = VM_CMD_RESET;
134             ibe->outbuf[1] = VM_CMD_CHAR;
135             ibe->outlen = 2;
136             ibe->outpos = 0;
137             ibe->send_reset = false;
138             ibe->sending_cmd = true;
139             goto send;
140         }
141 
142         if (ibe->waiting_rsp) {
143             /* Make sure we get a response within 4 seconds. */
144             timer_mod_ns(ibe->extern_timer,
145                          qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + 4000000000ULL);
146         }
147     }
148     return;
149 }
150 
151 static void extern_timeout(void *opaque)
152 {
153     IPMIBmcExtern *ibe = opaque;
154     IPMIInterface *s = ibe->parent.intf;
155 
156     if (ibe->connected) {
157         if (ibe->waiting_rsp && (ibe->outlen == 0)) {
158             IPMIInterfaceClass *k = IPMI_INTERFACE_GET_CLASS(s);
159             /* The message response timed out, return an error. */
160             ibe->waiting_rsp = false;
161             ibe->inbuf[1] = ibe->outbuf[1] | 0x04;
162             ibe->inbuf[2] = ibe->outbuf[2];
163             ibe->inbuf[3] = IPMI_CC_TIMEOUT;
164             k->handle_rsp(s, ibe->outbuf[0], ibe->inbuf + 1, 3);
165         } else {
166             continue_send(ibe);
167         }
168     }
169 }
170 
171 static void addchar(IPMIBmcExtern *ibe, unsigned char ch)
172 {
173     switch (ch) {
174     case VM_MSG_CHAR:
175     case VM_CMD_CHAR:
176     case VM_ESCAPE_CHAR:
177         ibe->outbuf[ibe->outlen] = VM_ESCAPE_CHAR;
178         ibe->outlen++;
179         ch |= 0x10;
180         /* No break */
181 
182     default:
183         ibe->outbuf[ibe->outlen] = ch;
184         ibe->outlen++;
185     }
186 }
187 
188 static void ipmi_bmc_extern_handle_command(IPMIBmc *b,
189                                        uint8_t *cmd, unsigned int cmd_len,
190                                        unsigned int max_cmd_len,
191                                        uint8_t msg_id)
192 {
193     IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(b);
194     IPMIInterface *s = ibe->parent.intf;
195     uint8_t err = 0, csum;
196     unsigned int i;
197 
198     if (ibe->outlen) {
199         /* We already have a command queued.  Shouldn't ever happen. */
200         error_report("IPMI KCS: Got command when not finished with the"
201                      " previous command");
202         abort();
203     }
204 
205     /* If it's too short or it was truncated, return an error. */
206     if (cmd_len < 2) {
207         err = IPMI_CC_REQUEST_DATA_LENGTH_INVALID;
208     } else if ((cmd_len > max_cmd_len) || (cmd_len > MAX_IPMI_MSG_SIZE)) {
209         err = IPMI_CC_REQUEST_DATA_TRUNCATED;
210     } else if (!ibe->connected) {
211         err = IPMI_CC_BMC_INIT_IN_PROGRESS;
212     }
213     if (err) {
214         IPMIInterfaceClass *k = IPMI_INTERFACE_GET_CLASS(s);
215         unsigned char rsp[3];
216         rsp[0] = cmd[0] | 0x04;
217         rsp[1] = cmd[1];
218         rsp[2] = err;
219         ibe->waiting_rsp = false;
220         k->handle_rsp(s, msg_id, rsp, 3);
221         goto out;
222     }
223 
224     addchar(ibe, msg_id);
225     for (i = 0; i < cmd_len; i++) {
226         addchar(ibe, cmd[i]);
227     }
228     csum = ipmb_checksum(&msg_id, 1, 0);
229     addchar(ibe, -ipmb_checksum(cmd, cmd_len, csum));
230 
231     ibe->outbuf[ibe->outlen] = VM_MSG_CHAR;
232     ibe->outlen++;
233 
234     /* Start the transmit */
235     continue_send(ibe);
236 
237  out:
238     return;
239 }
240 
241 static void handle_hw_op(IPMIBmcExtern *ibe, unsigned char hw_op)
242 {
243     IPMIInterface *s = ibe->parent.intf;
244     IPMIInterfaceClass *k = IPMI_INTERFACE_GET_CLASS(s);
245 
246     switch (hw_op) {
247     case VM_CMD_VERSION:
248         /* We only support one version at this time. */
249         break;
250 
251     case VM_CMD_NOATTN:
252         k->set_atn(s, 0, 0);
253         break;
254 
255     case VM_CMD_ATTN:
256         k->set_atn(s, 1, 0);
257         break;
258 
259     case VM_CMD_ATTN_IRQ:
260         k->set_atn(s, 1, 1);
261         break;
262 
263     case VM_CMD_POWEROFF:
264         k->do_hw_op(s, IPMI_POWEROFF_CHASSIS, 0);
265         break;
266 
267     case VM_CMD_RESET:
268         k->do_hw_op(s, IPMI_RESET_CHASSIS, 0);
269         break;
270 
271     case VM_CMD_ENABLE_IRQ:
272         k->set_irq_enable(s, 1);
273         break;
274 
275     case VM_CMD_DISABLE_IRQ:
276         k->set_irq_enable(s, 0);
277         break;
278 
279     case VM_CMD_SEND_NMI:
280         k->do_hw_op(s, IPMI_SEND_NMI, 0);
281         break;
282 
283     case VM_CMD_GRACEFUL_SHUTDOWN:
284         k->do_hw_op(s, IPMI_SHUTDOWN_VIA_ACPI_OVERTEMP, 0);
285         break;
286     }
287 }
288 
289 static void handle_msg(IPMIBmcExtern *ibe)
290 {
291     IPMIInterfaceClass *k = IPMI_INTERFACE_GET_CLASS(ibe->parent.intf);
292 
293     if (ibe->in_escape) {
294         ipmi_debug("msg escape not ended\n");
295         return;
296     }
297     if (ibe->inpos < 5) {
298         ipmi_debug("msg too short\n");
299         return;
300     }
301     if (ibe->in_too_many) {
302         ibe->inbuf[3] = IPMI_CC_REQUEST_DATA_TRUNCATED;
303         ibe->inpos = 4;
304     } else if (ipmb_checksum(ibe->inbuf, ibe->inpos, 0) != 0) {
305         ipmi_debug("msg checksum failure\n");
306         return;
307     } else {
308         ibe->inpos--; /* Remove checkum */
309     }
310 
311     timer_del(ibe->extern_timer);
312     ibe->waiting_rsp = false;
313     k->handle_rsp(ibe->parent.intf, ibe->inbuf[0], ibe->inbuf + 1, ibe->inpos - 1);
314 }
315 
316 static int can_receive(void *opaque)
317 {
318     return 1;
319 }
320 
321 static void receive(void *opaque, const uint8_t *buf, int size)
322 {
323     IPMIBmcExtern *ibe = opaque;
324     int i;
325     unsigned char hw_op;
326 
327     for (i = 0; i < size; i++) {
328         unsigned char ch = buf[i];
329 
330         switch (ch) {
331         case VM_MSG_CHAR:
332             handle_msg(ibe);
333             ibe->in_too_many = false;
334             ibe->inpos = 0;
335             break;
336 
337         case VM_CMD_CHAR:
338             if (ibe->in_too_many) {
339                 ipmi_debug("cmd in too many\n");
340                 ibe->in_too_many = false;
341                 ibe->inpos = 0;
342                 break;
343             }
344             if (ibe->in_escape) {
345                 ipmi_debug("cmd in escape\n");
346                 ibe->in_too_many = false;
347                 ibe->inpos = 0;
348                 ibe->in_escape = false;
349                 break;
350             }
351             ibe->in_too_many = false;
352             if (ibe->inpos < 1) {
353                 break;
354             }
355             hw_op = ibe->inbuf[0];
356             ibe->inpos = 0;
357             goto out_hw_op;
358             break;
359 
360         case VM_ESCAPE_CHAR:
361             ibe->in_escape = true;
362             break;
363 
364         default:
365             if (ibe->in_escape) {
366                 ch &= ~0x10;
367                 ibe->in_escape = false;
368             }
369             if (ibe->in_too_many) {
370                 break;
371             }
372             if (ibe->inpos >= sizeof(ibe->inbuf)) {
373                 ibe->in_too_many = true;
374                 break;
375             }
376             ibe->inbuf[ibe->inpos] = ch;
377             ibe->inpos++;
378             break;
379         }
380     }
381     return;
382 
383  out_hw_op:
384     handle_hw_op(ibe, hw_op);
385 }
386 
387 static void chr_event(void *opaque, int event)
388 {
389     IPMIBmcExtern *ibe = opaque;
390     IPMIInterface *s = ibe->parent.intf;
391     IPMIInterfaceClass *k = IPMI_INTERFACE_GET_CLASS(s);
392     unsigned char v;
393 
394     switch (event) {
395     case CHR_EVENT_OPENED:
396         ibe->connected = true;
397         ibe->outpos = 0;
398         ibe->outlen = 0;
399         addchar(ibe, VM_CMD_VERSION);
400         addchar(ibe, VM_PROTOCOL_VERSION);
401         ibe->outbuf[ibe->outlen] = VM_CMD_CHAR;
402         ibe->outlen++;
403         addchar(ibe, VM_CMD_CAPABILITIES);
404         v = VM_CAPABILITIES_IRQ | VM_CAPABILITIES_ATTN;
405         if (k->do_hw_op(ibe->parent.intf, IPMI_POWEROFF_CHASSIS, 1) == 0) {
406             v |= VM_CAPABILITIES_POWER;
407         }
408         if (k->do_hw_op(ibe->parent.intf, IPMI_SHUTDOWN_VIA_ACPI_OVERTEMP, 1)
409             == 0) {
410             v |= VM_CAPABILITIES_GRACEFUL_SHUTDOWN;
411         }
412         if (k->do_hw_op(ibe->parent.intf, IPMI_RESET_CHASSIS, 1) == 0) {
413             v |= VM_CAPABILITIES_RESET;
414         }
415         if (k->do_hw_op(ibe->parent.intf, IPMI_SEND_NMI, 1) == 0) {
416             v |= VM_CAPABILITIES_NMI;
417         }
418         addchar(ibe, v);
419         ibe->outbuf[ibe->outlen] = VM_CMD_CHAR;
420         ibe->outlen++;
421         ibe->sending_cmd = false;
422         continue_send(ibe);
423         break;
424 
425     case CHR_EVENT_CLOSED:
426         if (!ibe->connected) {
427             return;
428         }
429         ibe->connected = false;
430         /*
431          * Don't hang the OS trying to handle the ATN bit, other end will
432          * resend on a reconnect.
433          */
434         k->set_atn(s, 0, 0);
435         if (ibe->waiting_rsp) {
436             ibe->waiting_rsp = false;
437             ibe->inbuf[1] = ibe->outbuf[1] | 0x04;
438             ibe->inbuf[2] = ibe->outbuf[2];
439             ibe->inbuf[3] = IPMI_CC_BMC_INIT_IN_PROGRESS;
440             k->handle_rsp(s, ibe->outbuf[0], ibe->inbuf + 1, 3);
441         }
442         break;
443     }
444 }
445 
446 static void ipmi_bmc_extern_handle_reset(IPMIBmc *b)
447 {
448     IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(b);
449 
450     ibe->send_reset = true;
451     continue_send(ibe);
452 }
453 
454 static void ipmi_bmc_extern_realize(DeviceState *dev, Error **errp)
455 {
456     IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(dev);
457 
458     if (!qemu_chr_fe_backend_connected(&ibe->chr)) {
459         error_setg(errp, "IPMI external bmc requires chardev attribute");
460         return;
461     }
462 
463     qemu_chr_fe_set_handlers(&ibe->chr, can_receive, receive,
464                              chr_event, NULL, ibe, NULL, true);
465 }
466 
467 static int ipmi_bmc_extern_post_migrate(void *opaque, int version_id)
468 {
469     IPMIBmcExtern *ibe = opaque;
470 
471     /*
472      * We don't directly restore waiting_rsp, Instead, we return an
473      * error on the interface if a response was being waited for.
474      */
475     if (ibe->waiting_rsp) {
476         IPMIInterface *ii = ibe->parent.intf;
477         IPMIInterfaceClass *iic = IPMI_INTERFACE_GET_CLASS(ii);
478 
479         ibe->waiting_rsp = false;
480         ibe->inbuf[1] = ibe->outbuf[1] | 0x04;
481         ibe->inbuf[2] = ibe->outbuf[2];
482         ibe->inbuf[3] = IPMI_CC_BMC_INIT_IN_PROGRESS;
483         iic->handle_rsp(ii, ibe->outbuf[0], ibe->inbuf + 1, 3);
484     }
485     return 0;
486 }
487 
488 static const VMStateDescription vmstate_ipmi_bmc_extern = {
489     .name = TYPE_IPMI_BMC_EXTERN,
490     .version_id = 1,
491     .minimum_version_id = 1,
492     .post_load = ipmi_bmc_extern_post_migrate,
493     .fields      = (VMStateField[]) {
494         VMSTATE_BOOL(send_reset, IPMIBmcExtern),
495         VMSTATE_BOOL(waiting_rsp, IPMIBmcExtern),
496         VMSTATE_END_OF_LIST()
497     }
498 };
499 
500 static void ipmi_bmc_extern_init(Object *obj)
501 {
502     IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(obj);
503 
504     ibe->extern_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, extern_timeout, ibe);
505     vmstate_register(NULL, 0, &vmstate_ipmi_bmc_extern, ibe);
506 }
507 
508 static void ipmi_bmc_extern_finalize(Object *obj)
509 {
510     IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(obj);
511 
512     timer_del(ibe->extern_timer);
513     timer_free(ibe->extern_timer);
514 }
515 
516 static Property ipmi_bmc_extern_properties[] = {
517     DEFINE_PROP_CHR("chardev", IPMIBmcExtern, chr),
518     DEFINE_PROP_END_OF_LIST(),
519 };
520 
521 static void ipmi_bmc_extern_class_init(ObjectClass *oc, void *data)
522 {
523     DeviceClass *dc = DEVICE_CLASS(oc);
524     IPMIBmcClass *bk = IPMI_BMC_CLASS(oc);
525 
526     bk->handle_command = ipmi_bmc_extern_handle_command;
527     bk->handle_reset = ipmi_bmc_extern_handle_reset;
528     dc->hotpluggable = false;
529     dc->realize = ipmi_bmc_extern_realize;
530     dc->props = ipmi_bmc_extern_properties;
531 }
532 
533 static const TypeInfo ipmi_bmc_extern_type = {
534     .name          = TYPE_IPMI_BMC_EXTERN,
535     .parent        = TYPE_IPMI_BMC,
536     .instance_size = sizeof(IPMIBmcExtern),
537     .instance_init = ipmi_bmc_extern_init,
538     .instance_finalize = ipmi_bmc_extern_finalize,
539     .class_init    = ipmi_bmc_extern_class_init,
540  };
541 
542 static void ipmi_bmc_extern_register_types(void)
543 {
544     type_register_static(&ipmi_bmc_extern_type);
545 }
546 
547 type_init(ipmi_bmc_extern_register_types)
548