xref: /openbmc/qemu/hw/ipmi/ipmi_bmc_extern.c (revision 75c5bb0b)
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 unsigned char
91 ipmb_checksum(const unsigned char *data, int size, unsigned char start)
92 {
93         unsigned char csum = start;
94 
95         for (; size > 0; size--, data++) {
96                 csum += *data;
97         }
98         return csum;
99 }
100 
101 static void continue_send(IPMIBmcExtern *ibe)
102 {
103     int ret;
104     if (ibe->outlen == 0) {
105         goto check_reset;
106     }
107  send:
108     ret = qemu_chr_fe_write(&ibe->chr, ibe->outbuf + ibe->outpos,
109                             ibe->outlen - ibe->outpos);
110     if (ret > 0) {
111         ibe->outpos += ret;
112     }
113     if (ibe->outpos < ibe->outlen) {
114         /* Not fully transmitted, try again in a 10ms */
115         timer_mod_ns(ibe->extern_timer,
116                      qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + 10000000);
117     } else {
118         /* Sent */
119         ibe->outlen = 0;
120         ibe->outpos = 0;
121         if (!ibe->sending_cmd) {
122             ibe->waiting_rsp = true;
123         } else {
124             ibe->sending_cmd = false;
125         }
126     check_reset:
127         if (ibe->connected && ibe->send_reset) {
128             /* Send the reset */
129             ibe->outbuf[0] = VM_CMD_RESET;
130             ibe->outbuf[1] = VM_CMD_CHAR;
131             ibe->outlen = 2;
132             ibe->outpos = 0;
133             ibe->send_reset = false;
134             ibe->sending_cmd = true;
135             goto send;
136         }
137 
138         if (ibe->waiting_rsp) {
139             /* Make sure we get a response within 4 seconds. */
140             timer_mod_ns(ibe->extern_timer,
141                          qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + 4000000000ULL);
142         }
143     }
144     return;
145 }
146 
147 static void extern_timeout(void *opaque)
148 {
149     IPMIBmcExtern *ibe = opaque;
150     IPMIInterface *s = ibe->parent.intf;
151 
152     if (ibe->connected) {
153         if (ibe->waiting_rsp && (ibe->outlen == 0)) {
154             IPMIInterfaceClass *k = IPMI_INTERFACE_GET_CLASS(s);
155             /* The message response timed out, return an error. */
156             ibe->waiting_rsp = false;
157             ibe->inbuf[1] = ibe->outbuf[1] | 0x04;
158             ibe->inbuf[2] = ibe->outbuf[2];
159             ibe->inbuf[3] = IPMI_CC_TIMEOUT;
160             k->handle_rsp(s, ibe->outbuf[0], ibe->inbuf + 1, 3);
161         } else {
162             continue_send(ibe);
163         }
164     }
165 }
166 
167 static void addchar(IPMIBmcExtern *ibe, unsigned char ch)
168 {
169     switch (ch) {
170     case VM_MSG_CHAR:
171     case VM_CMD_CHAR:
172     case VM_ESCAPE_CHAR:
173         ibe->outbuf[ibe->outlen] = VM_ESCAPE_CHAR;
174         ibe->outlen++;
175         ch |= 0x10;
176         /* fall through */
177     default:
178         ibe->outbuf[ibe->outlen] = ch;
179         ibe->outlen++;
180     }
181 }
182 
183 static void ipmi_bmc_extern_handle_command(IPMIBmc *b,
184                                        uint8_t *cmd, unsigned int cmd_len,
185                                        unsigned int max_cmd_len,
186                                        uint8_t msg_id)
187 {
188     IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(b);
189     IPMIInterface *s = ibe->parent.intf;
190     uint8_t err = 0, csum;
191     unsigned int i;
192 
193     if (ibe->outlen) {
194         /* We already have a command queued.  Shouldn't ever happen. */
195         error_report("IPMI KCS: Got command when not finished with the"
196                      " previous command");
197         abort();
198     }
199 
200     /* If it's too short or it was truncated, return an error. */
201     if (cmd_len < 2) {
202         err = IPMI_CC_REQUEST_DATA_LENGTH_INVALID;
203     } else if ((cmd_len > max_cmd_len) || (cmd_len > MAX_IPMI_MSG_SIZE)) {
204         err = IPMI_CC_REQUEST_DATA_TRUNCATED;
205     } else if (!ibe->connected) {
206         err = IPMI_CC_BMC_INIT_IN_PROGRESS;
207     }
208     if (err) {
209         IPMIInterfaceClass *k = IPMI_INTERFACE_GET_CLASS(s);
210         unsigned char rsp[3];
211         rsp[0] = cmd[0] | 0x04;
212         rsp[1] = cmd[1];
213         rsp[2] = err;
214         ibe->waiting_rsp = false;
215         k->handle_rsp(s, msg_id, rsp, 3);
216         goto out;
217     }
218 
219     addchar(ibe, msg_id);
220     for (i = 0; i < cmd_len; i++) {
221         addchar(ibe, cmd[i]);
222     }
223     csum = ipmb_checksum(&msg_id, 1, 0);
224     addchar(ibe, -ipmb_checksum(cmd, cmd_len, csum));
225 
226     ibe->outbuf[ibe->outlen] = VM_MSG_CHAR;
227     ibe->outlen++;
228 
229     /* Start the transmit */
230     continue_send(ibe);
231 
232  out:
233     return;
234 }
235 
236 static void handle_hw_op(IPMIBmcExtern *ibe, unsigned char hw_op)
237 {
238     IPMIInterface *s = ibe->parent.intf;
239     IPMIInterfaceClass *k = IPMI_INTERFACE_GET_CLASS(s);
240 
241     switch (hw_op) {
242     case VM_CMD_VERSION:
243         /* We only support one version at this time. */
244         break;
245 
246     case VM_CMD_NOATTN:
247         k->set_atn(s, 0, 0);
248         break;
249 
250     case VM_CMD_ATTN:
251         k->set_atn(s, 1, 0);
252         break;
253 
254     case VM_CMD_ATTN_IRQ:
255         k->set_atn(s, 1, 1);
256         break;
257 
258     case VM_CMD_POWEROFF:
259         k->do_hw_op(s, IPMI_POWEROFF_CHASSIS, 0);
260         break;
261 
262     case VM_CMD_RESET:
263         k->do_hw_op(s, IPMI_RESET_CHASSIS, 0);
264         break;
265 
266     case VM_CMD_ENABLE_IRQ:
267         k->set_irq_enable(s, 1);
268         break;
269 
270     case VM_CMD_DISABLE_IRQ:
271         k->set_irq_enable(s, 0);
272         break;
273 
274     case VM_CMD_SEND_NMI:
275         k->do_hw_op(s, IPMI_SEND_NMI, 0);
276         break;
277 
278     case VM_CMD_GRACEFUL_SHUTDOWN:
279         k->do_hw_op(s, IPMI_SHUTDOWN_VIA_ACPI_OVERTEMP, 0);
280         break;
281     }
282 }
283 
284 static void handle_msg(IPMIBmcExtern *ibe)
285 {
286     IPMIInterfaceClass *k = IPMI_INTERFACE_GET_CLASS(ibe->parent.intf);
287 
288     if (ibe->in_escape) {
289         ipmi_debug("msg escape not ended\n");
290         return;
291     }
292     if (ibe->inpos < 5) {
293         ipmi_debug("msg too short\n");
294         return;
295     }
296     if (ibe->in_too_many) {
297         ibe->inbuf[3] = IPMI_CC_REQUEST_DATA_TRUNCATED;
298         ibe->inpos = 4;
299     } else if (ipmb_checksum(ibe->inbuf, ibe->inpos, 0) != 0) {
300         ipmi_debug("msg checksum failure\n");
301         return;
302     } else {
303         ibe->inpos--; /* Remove checkum */
304     }
305 
306     timer_del(ibe->extern_timer);
307     ibe->waiting_rsp = false;
308     k->handle_rsp(ibe->parent.intf, ibe->inbuf[0], ibe->inbuf + 1, ibe->inpos - 1);
309 }
310 
311 static int can_receive(void *opaque)
312 {
313     return 1;
314 }
315 
316 static void receive(void *opaque, const uint8_t *buf, int size)
317 {
318     IPMIBmcExtern *ibe = opaque;
319     int i;
320     unsigned char hw_op;
321 
322     for (i = 0; i < size; i++) {
323         unsigned char ch = buf[i];
324 
325         switch (ch) {
326         case VM_MSG_CHAR:
327             handle_msg(ibe);
328             ibe->in_too_many = false;
329             ibe->inpos = 0;
330             break;
331 
332         case VM_CMD_CHAR:
333             if (ibe->in_too_many) {
334                 ipmi_debug("cmd in too many\n");
335                 ibe->in_too_many = false;
336                 ibe->inpos = 0;
337                 break;
338             }
339             if (ibe->in_escape) {
340                 ipmi_debug("cmd in escape\n");
341                 ibe->in_too_many = false;
342                 ibe->inpos = 0;
343                 ibe->in_escape = false;
344                 break;
345             }
346             ibe->in_too_many = false;
347             if (ibe->inpos < 1) {
348                 break;
349             }
350             hw_op = ibe->inbuf[0];
351             ibe->inpos = 0;
352             goto out_hw_op;
353             break;
354 
355         case VM_ESCAPE_CHAR:
356             ibe->in_escape = true;
357             break;
358 
359         default:
360             if (ibe->in_escape) {
361                 ch &= ~0x10;
362                 ibe->in_escape = false;
363             }
364             if (ibe->in_too_many) {
365                 break;
366             }
367             if (ibe->inpos >= sizeof(ibe->inbuf)) {
368                 ibe->in_too_many = true;
369                 break;
370             }
371             ibe->inbuf[ibe->inpos] = ch;
372             ibe->inpos++;
373             break;
374         }
375     }
376     return;
377 
378  out_hw_op:
379     handle_hw_op(ibe, hw_op);
380 }
381 
382 static void chr_event(void *opaque, int event)
383 {
384     IPMIBmcExtern *ibe = opaque;
385     IPMIInterface *s = ibe->parent.intf;
386     IPMIInterfaceClass *k = IPMI_INTERFACE_GET_CLASS(s);
387     unsigned char v;
388 
389     switch (event) {
390     case CHR_EVENT_OPENED:
391         ibe->connected = true;
392         ibe->outpos = 0;
393         ibe->outlen = 0;
394         addchar(ibe, VM_CMD_VERSION);
395         addchar(ibe, VM_PROTOCOL_VERSION);
396         ibe->outbuf[ibe->outlen] = VM_CMD_CHAR;
397         ibe->outlen++;
398         addchar(ibe, VM_CMD_CAPABILITIES);
399         v = VM_CAPABILITIES_IRQ | VM_CAPABILITIES_ATTN;
400         if (k->do_hw_op(ibe->parent.intf, IPMI_POWEROFF_CHASSIS, 1) == 0) {
401             v |= VM_CAPABILITIES_POWER;
402         }
403         if (k->do_hw_op(ibe->parent.intf, IPMI_SHUTDOWN_VIA_ACPI_OVERTEMP, 1)
404             == 0) {
405             v |= VM_CAPABILITIES_GRACEFUL_SHUTDOWN;
406         }
407         if (k->do_hw_op(ibe->parent.intf, IPMI_RESET_CHASSIS, 1) == 0) {
408             v |= VM_CAPABILITIES_RESET;
409         }
410         if (k->do_hw_op(ibe->parent.intf, IPMI_SEND_NMI, 1) == 0) {
411             v |= VM_CAPABILITIES_NMI;
412         }
413         addchar(ibe, v);
414         ibe->outbuf[ibe->outlen] = VM_CMD_CHAR;
415         ibe->outlen++;
416         ibe->sending_cmd = false;
417         continue_send(ibe);
418         break;
419 
420     case CHR_EVENT_CLOSED:
421         if (!ibe->connected) {
422             return;
423         }
424         ibe->connected = false;
425         /*
426          * Don't hang the OS trying to handle the ATN bit, other end will
427          * resend on a reconnect.
428          */
429         k->set_atn(s, 0, 0);
430         if (ibe->waiting_rsp) {
431             ibe->waiting_rsp = false;
432             ibe->inbuf[1] = ibe->outbuf[1] | 0x04;
433             ibe->inbuf[2] = ibe->outbuf[2];
434             ibe->inbuf[3] = IPMI_CC_BMC_INIT_IN_PROGRESS;
435             k->handle_rsp(s, ibe->outbuf[0], ibe->inbuf + 1, 3);
436         }
437         break;
438 
439     case CHR_EVENT_BREAK:
440     case CHR_EVENT_MUX_IN:
441     case CHR_EVENT_MUX_OUT:
442         /* Ignore */
443         break;
444     }
445 }
446 
447 static void ipmi_bmc_extern_handle_reset(IPMIBmc *b)
448 {
449     IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(b);
450 
451     ibe->send_reset = true;
452     continue_send(ibe);
453 }
454 
455 static void ipmi_bmc_extern_realize(DeviceState *dev, Error **errp)
456 {
457     IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(dev);
458 
459     if (!qemu_chr_fe_backend_connected(&ibe->chr)) {
460         error_setg(errp, "IPMI external bmc requires chardev attribute");
461         return;
462     }
463 
464     qemu_chr_fe_set_handlers(&ibe->chr, can_receive, receive,
465                              chr_event, NULL, ibe, NULL, true);
466 }
467 
468 static int ipmi_bmc_extern_post_migrate(void *opaque, int version_id)
469 {
470     IPMIBmcExtern *ibe = opaque;
471 
472     /*
473      * We don't directly restore waiting_rsp, Instead, we return an
474      * error on the interface if a response was being waited for.
475      */
476     if (ibe->waiting_rsp) {
477         IPMIInterface *ii = ibe->parent.intf;
478         IPMIInterfaceClass *iic = IPMI_INTERFACE_GET_CLASS(ii);
479 
480         ibe->waiting_rsp = false;
481         ibe->inbuf[1] = ibe->outbuf[1] | 0x04;
482         ibe->inbuf[2] = ibe->outbuf[2];
483         ibe->inbuf[3] = IPMI_CC_BMC_INIT_IN_PROGRESS;
484         iic->handle_rsp(ii, ibe->outbuf[0], ibe->inbuf + 1, 3);
485     }
486     return 0;
487 }
488 
489 static const VMStateDescription vmstate_ipmi_bmc_extern = {
490     .name = TYPE_IPMI_BMC_EXTERN,
491     .version_id = 1,
492     .minimum_version_id = 1,
493     .post_load = ipmi_bmc_extern_post_migrate,
494     .fields      = (VMStateField[]) {
495         VMSTATE_BOOL(send_reset, IPMIBmcExtern),
496         VMSTATE_BOOL(waiting_rsp, IPMIBmcExtern),
497         VMSTATE_END_OF_LIST()
498     }
499 };
500 
501 static void ipmi_bmc_extern_init(Object *obj)
502 {
503     IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(obj);
504 
505     ibe->extern_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, extern_timeout, ibe);
506     vmstate_register(NULL, 0, &vmstate_ipmi_bmc_extern, ibe);
507 }
508 
509 static void ipmi_bmc_extern_finalize(Object *obj)
510 {
511     IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(obj);
512 
513     timer_del(ibe->extern_timer);
514     timer_free(ibe->extern_timer);
515 }
516 
517 static Property ipmi_bmc_extern_properties[] = {
518     DEFINE_PROP_CHR("chardev", IPMIBmcExtern, chr),
519     DEFINE_PROP_END_OF_LIST(),
520 };
521 
522 static void ipmi_bmc_extern_class_init(ObjectClass *oc, void *data)
523 {
524     DeviceClass *dc = DEVICE_CLASS(oc);
525     IPMIBmcClass *bk = IPMI_BMC_CLASS(oc);
526 
527     bk->handle_command = ipmi_bmc_extern_handle_command;
528     bk->handle_reset = ipmi_bmc_extern_handle_reset;
529     dc->hotpluggable = false;
530     dc->realize = ipmi_bmc_extern_realize;
531     dc->props = ipmi_bmc_extern_properties;
532 }
533 
534 static const TypeInfo ipmi_bmc_extern_type = {
535     .name          = TYPE_IPMI_BMC_EXTERN,
536     .parent        = TYPE_IPMI_BMC,
537     .instance_size = sizeof(IPMIBmcExtern),
538     .instance_init = ipmi_bmc_extern_init,
539     .instance_finalize = ipmi_bmc_extern_finalize,
540     .class_init    = ipmi_bmc_extern_class_init,
541  };
542 
543 static void ipmi_bmc_extern_register_types(void)
544 {
545     type_register_static(&ipmi_bmc_extern_type);
546 }
547 
548 type_init(ipmi_bmc_extern_register_types)
549