xref: /openbmc/qemu/hw/ipmi/ipmi_bmc_extern.c (revision 8a2b516ba2855c4530388051de2b8d17bc780ea8)
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 "hw/qdev-properties-system.h"
39 #include "migration/vmstate.h"
40 #include "qom/object.h"
41 
42 #define VM_MSG_CHAR        0xA0 /* Marks end of message */
43 #define VM_CMD_CHAR        0xA1 /* Marks end of a command */
44 #define VM_ESCAPE_CHAR     0xAA /* Set bit 4 from the next byte to 0 */
45 
46 #define VM_PROTOCOL_VERSION        1
47 #define VM_CMD_VERSION             0xff /* A version number byte follows */
48 #define VM_CMD_NOATTN              0x00
49 #define VM_CMD_ATTN                0x01
50 #define VM_CMD_ATTN_IRQ            0x02
51 #define VM_CMD_POWEROFF            0x03
52 #define VM_CMD_RESET               0x04
53 #define VM_CMD_ENABLE_IRQ          0x05 /* Enable/disable the messaging irq */
54 #define VM_CMD_DISABLE_IRQ         0x06
55 #define VM_CMD_SEND_NMI            0x07
56 #define VM_CMD_CAPABILITIES        0x08
57 #define   VM_CAPABILITIES_POWER    0x01
58 #define   VM_CAPABILITIES_RESET    0x02
59 #define   VM_CAPABILITIES_IRQ      0x04
60 #define   VM_CAPABILITIES_NMI      0x08
61 #define   VM_CAPABILITIES_ATTN     0x10
62 #define   VM_CAPABILITIES_GRACEFUL_SHUTDOWN 0x20
63 #define VM_CMD_GRACEFUL_SHUTDOWN   0x09
64 
65 #define TYPE_IPMI_BMC_EXTERN "ipmi-bmc-extern"
66 OBJECT_DECLARE_SIMPLE_TYPE(IPMIBmcExtern, IPMI_BMC_EXTERN)
67 struct IPMIBmcExtern {
68     IPMIBmc parent;
69 
70     CharBackend chr;
71 
72     bool connected;
73 
74     unsigned char inbuf[MAX_IPMI_MSG_SIZE + 2];
75     unsigned int inpos;
76     bool in_escape;
77     bool in_too_many;
78     bool waiting_rsp;
79     bool sending_cmd;
80 
81     unsigned char outbuf[(MAX_IPMI_MSG_SIZE + 2) * 2 + 1];
82     unsigned int outpos;
83     unsigned int outlen;
84 
85     struct QEMUTimer *extern_timer;
86 
87     /* A reset event is pending to be sent upstream. */
88     bool send_reset;
89 };
90 
91 static unsigned char
92 ipmb_checksum(const unsigned char *data, int size, unsigned char start)
93 {
94         unsigned char csum = start;
95 
96         for (; size > 0; size--, data++) {
97                 csum += *data;
98         }
99         return csum;
100 }
101 
102 static void continue_send(IPMIBmcExtern *ibe)
103 {
104     int ret;
105     if (ibe->outlen == 0) {
106         goto check_reset;
107     }
108  send:
109     ret = qemu_chr_fe_write(&ibe->chr, ibe->outbuf + ibe->outpos,
110                             ibe->outlen - ibe->outpos);
111     if (ret > 0) {
112         ibe->outpos += ret;
113     }
114     if (ibe->outpos < ibe->outlen) {
115         /* Not fully transmitted, try again in a 10ms */
116         timer_mod_ns(ibe->extern_timer,
117                      qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + 10000000);
118     } else {
119         /* Sent */
120         ibe->outlen = 0;
121         ibe->outpos = 0;
122         if (!ibe->sending_cmd) {
123             ibe->waiting_rsp = true;
124         } else {
125             ibe->sending_cmd = false;
126         }
127     check_reset:
128         if (ibe->connected && ibe->send_reset) {
129             /* Send the reset */
130             ibe->outbuf[0] = VM_CMD_RESET;
131             ibe->outbuf[1] = VM_CMD_CHAR;
132             ibe->outlen = 2;
133             ibe->outpos = 0;
134             ibe->send_reset = false;
135             ibe->sending_cmd = true;
136             goto send;
137         }
138 
139         if (ibe->waiting_rsp) {
140             /* Make sure we get a response within 4 seconds. */
141             timer_mod_ns(ibe->extern_timer,
142                          qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + 4000000000ULL);
143         }
144     }
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 }
234 
235 static void handle_hw_op(IPMIBmcExtern *ibe, unsigned char hw_op)
236 {
237     IPMIInterface *s = ibe->parent.intf;
238     IPMIInterfaceClass *k = IPMI_INTERFACE_GET_CLASS(s);
239 
240     switch (hw_op) {
241     case VM_CMD_VERSION:
242         /* We only support one version at this time. */
243         break;
244 
245     case VM_CMD_NOATTN:
246         k->set_atn(s, 0, 0);
247         break;
248 
249     case VM_CMD_ATTN:
250         k->set_atn(s, 1, 0);
251         break;
252 
253     case VM_CMD_ATTN_IRQ:
254         k->set_atn(s, 1, 1);
255         break;
256 
257     case VM_CMD_POWEROFF:
258         k->do_hw_op(s, IPMI_POWEROFF_CHASSIS, 0);
259         break;
260 
261     case VM_CMD_RESET:
262         k->do_hw_op(s, IPMI_RESET_CHASSIS, 0);
263         break;
264 
265     case VM_CMD_ENABLE_IRQ:
266         k->set_irq_enable(s, 1);
267         break;
268 
269     case VM_CMD_DISABLE_IRQ:
270         k->set_irq_enable(s, 0);
271         break;
272 
273     case VM_CMD_SEND_NMI:
274         k->do_hw_op(s, IPMI_SEND_NMI, 0);
275         break;
276 
277     case VM_CMD_GRACEFUL_SHUTDOWN:
278         k->do_hw_op(s, IPMI_SHUTDOWN_VIA_ACPI_OVERTEMP, 0);
279         break;
280     }
281 }
282 
283 static void handle_msg(IPMIBmcExtern *ibe)
284 {
285     IPMIInterfaceClass *k = IPMI_INTERFACE_GET_CLASS(ibe->parent.intf);
286 
287     if (ibe->in_escape) {
288         ipmi_debug("msg escape not ended\n");
289         return;
290     }
291     if (ibe->inpos < 5) {
292         ipmi_debug("msg too short\n");
293         return;
294     }
295     if (ibe->in_too_many) {
296         ibe->inbuf[3] = IPMI_CC_REQUEST_DATA_TRUNCATED;
297         ibe->inpos = 4;
298     } else if (ipmb_checksum(ibe->inbuf, ibe->inpos, 0) != 0) {
299         ipmi_debug("msg checksum failure\n");
300         return;
301     } else {
302         ibe->inpos--; /* Remove checksum */
303     }
304 
305     timer_del(ibe->extern_timer);
306     ibe->waiting_rsp = false;
307     k->handle_rsp(ibe->parent.intf, ibe->inbuf[0], ibe->inbuf + 1, ibe->inpos - 1);
308 }
309 
310 static int can_receive(void *opaque)
311 {
312     return 1;
313 }
314 
315 static void receive(void *opaque, const uint8_t *buf, int size)
316 {
317     IPMIBmcExtern *ibe = opaque;
318     int i;
319     unsigned char hw_op;
320 
321     for (i = 0; i < size; i++) {
322         unsigned char ch = buf[i];
323 
324         switch (ch) {
325         case VM_MSG_CHAR:
326             handle_msg(ibe);
327             ibe->in_too_many = false;
328             ibe->inpos = 0;
329             break;
330 
331         case VM_CMD_CHAR:
332             if (ibe->in_too_many) {
333                 ipmi_debug("cmd in too many\n");
334                 ibe->in_too_many = false;
335                 ibe->inpos = 0;
336                 break;
337             }
338             if (ibe->in_escape) {
339                 ipmi_debug("cmd in escape\n");
340                 ibe->in_too_many = false;
341                 ibe->inpos = 0;
342                 ibe->in_escape = false;
343                 break;
344             }
345             ibe->in_too_many = false;
346             if (ibe->inpos < 1) {
347                 break;
348             }
349             hw_op = ibe->inbuf[0];
350             ibe->inpos = 0;
351             goto out_hw_op;
352             break;
353 
354         case VM_ESCAPE_CHAR:
355             ibe->in_escape = true;
356             break;
357 
358         default:
359             if (ibe->in_escape) {
360                 ch &= ~0x10;
361                 ibe->in_escape = false;
362             }
363             if (ibe->in_too_many) {
364                 break;
365             }
366             if (ibe->inpos >= sizeof(ibe->inbuf)) {
367                 ibe->in_too_many = true;
368                 break;
369             }
370             ibe->inbuf[ibe->inpos] = ch;
371             ibe->inpos++;
372             break;
373         }
374     }
375     return;
376 
377  out_hw_op:
378     handle_hw_op(ibe, hw_op);
379 }
380 
381 static void chr_event(void *opaque, QEMUChrEvent event)
382 {
383     IPMIBmcExtern *ibe = opaque;
384     IPMIInterface *s = ibe->parent.intf;
385     IPMIInterfaceClass *k = IPMI_INTERFACE_GET_CLASS(s);
386     unsigned char v;
387 
388     switch (event) {
389     case CHR_EVENT_OPENED:
390         ibe->connected = true;
391         ibe->outpos = 0;
392         ibe->outlen = 0;
393         addchar(ibe, VM_CMD_VERSION);
394         addchar(ibe, VM_PROTOCOL_VERSION);
395         ibe->outbuf[ibe->outlen] = VM_CMD_CHAR;
396         ibe->outlen++;
397         addchar(ibe, VM_CMD_CAPABILITIES);
398         v = VM_CAPABILITIES_IRQ | VM_CAPABILITIES_ATTN;
399         if (k->do_hw_op(ibe->parent.intf, IPMI_POWEROFF_CHASSIS, 1) == 0) {
400             v |= VM_CAPABILITIES_POWER;
401         }
402         if (k->do_hw_op(ibe->parent.intf, IPMI_SHUTDOWN_VIA_ACPI_OVERTEMP, 1)
403             == 0) {
404             v |= VM_CAPABILITIES_GRACEFUL_SHUTDOWN;
405         }
406         if (k->do_hw_op(ibe->parent.intf, IPMI_RESET_CHASSIS, 1) == 0) {
407             v |= VM_CAPABILITIES_RESET;
408         }
409         if (k->do_hw_op(ibe->parent.intf, IPMI_SEND_NMI, 1) == 0) {
410             v |= VM_CAPABILITIES_NMI;
411         }
412         addchar(ibe, v);
413         ibe->outbuf[ibe->outlen] = VM_CMD_CHAR;
414         ibe->outlen++;
415         ibe->sending_cmd = false;
416         continue_send(ibe);
417         break;
418 
419     case CHR_EVENT_CLOSED:
420         if (!ibe->connected) {
421             return;
422         }
423         ibe->connected = false;
424         /*
425          * Don't hang the OS trying to handle the ATN bit, other end will
426          * resend on a reconnect.
427          */
428         k->set_atn(s, 0, 0);
429         if (ibe->waiting_rsp) {
430             ibe->waiting_rsp = false;
431             ibe->inbuf[1] = ibe->outbuf[1] | 0x04;
432             ibe->inbuf[2] = ibe->outbuf[2];
433             ibe->inbuf[3] = IPMI_CC_BMC_INIT_IN_PROGRESS;
434             k->handle_rsp(s, ibe->outbuf[0], ibe->inbuf + 1, 3);
435         }
436         break;
437 
438     case CHR_EVENT_BREAK:
439     case CHR_EVENT_MUX_IN:
440     case CHR_EVENT_MUX_OUT:
441         /* Ignore */
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 int ipmi_bmc_extern_post_migrate(void *opaque, int version_id)
455 {
456     IPMIBmcExtern *ibe = opaque;
457 
458     /*
459      * We don't directly restore waiting_rsp, Instead, we return an
460      * error on the interface if a response was being waited for.
461      */
462     if (ibe->waiting_rsp) {
463         IPMIInterface *ii = ibe->parent.intf;
464         IPMIInterfaceClass *iic = IPMI_INTERFACE_GET_CLASS(ii);
465 
466         ibe->waiting_rsp = false;
467         ibe->inbuf[1] = ibe->outbuf[1] | 0x04;
468         ibe->inbuf[2] = ibe->outbuf[2];
469         ibe->inbuf[3] = IPMI_CC_BMC_INIT_IN_PROGRESS;
470         iic->handle_rsp(ii, ibe->outbuf[0], ibe->inbuf + 1, 3);
471     }
472     return 0;
473 }
474 
475 static const VMStateDescription vmstate_ipmi_bmc_extern = {
476     .name = TYPE_IPMI_BMC_EXTERN,
477     .version_id = 1,
478     .minimum_version_id = 1,
479     .post_load = ipmi_bmc_extern_post_migrate,
480     .fields = (const VMStateField[]) {
481         VMSTATE_BOOL(send_reset, IPMIBmcExtern),
482         VMSTATE_BOOL(waiting_rsp, IPMIBmcExtern),
483         VMSTATE_END_OF_LIST()
484     }
485 };
486 
487 static void ipmi_bmc_extern_realize(DeviceState *dev, Error **errp)
488 {
489     IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(dev);
490 
491     if (!qemu_chr_fe_backend_connected(&ibe->chr)) {
492         error_setg(errp, "IPMI external bmc requires chardev attribute");
493         return;
494     }
495 
496     qemu_chr_fe_set_handlers(&ibe->chr, can_receive, receive,
497                              chr_event, NULL, ibe, NULL, true);
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 }
506 
507 static void ipmi_bmc_extern_finalize(Object *obj)
508 {
509     IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(obj);
510 
511     timer_free(ibe->extern_timer);
512 }
513 
514 static const Property ipmi_bmc_extern_properties[] = {
515     DEFINE_PROP_CHR("chardev", IPMIBmcExtern, chr),
516 };
517 
518 static void ipmi_bmc_extern_class_init(ObjectClass *oc, void *data)
519 {
520     DeviceClass *dc = DEVICE_CLASS(oc);
521     IPMIBmcClass *bk = IPMI_BMC_CLASS(oc);
522 
523     bk->handle_command = ipmi_bmc_extern_handle_command;
524     bk->handle_reset = ipmi_bmc_extern_handle_reset;
525     dc->hotpluggable = false;
526     dc->realize = ipmi_bmc_extern_realize;
527     dc->vmsd = &vmstate_ipmi_bmc_extern;
528     device_class_set_props(dc, ipmi_bmc_extern_properties);
529 }
530 
531 static const TypeInfo ipmi_bmc_extern_type = {
532     .name          = TYPE_IPMI_BMC_EXTERN,
533     .parent        = TYPE_IPMI_BMC,
534     .instance_size = sizeof(IPMIBmcExtern),
535     .instance_init = ipmi_bmc_extern_init,
536     .instance_finalize = ipmi_bmc_extern_finalize,
537     .class_init    = ipmi_bmc_extern_class_init,
538  };
539 
540 static void ipmi_bmc_extern_register_types(void)
541 {
542     type_register_static(&ipmi_bmc_extern_type);
543 }
544 
545 type_init(ipmi_bmc_extern_register_types)
546