xref: /openbmc/qemu/hw/ipmi/ipmi_bmc_extern.c (revision ba632924)
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 "qapi/error.h"
33 #include "qemu/timer.h"
34 #include "chardev/char-fe.h"
35 #include "sysemu/sysemu.h"
36 #include "hw/ipmi/ipmi.h"
37 
38 #define VM_MSG_CHAR        0xA0 /* Marks end of message */
39 #define VM_CMD_CHAR        0xA1 /* Marks end of a command */
40 #define VM_ESCAPE_CHAR     0xAA /* Set bit 4 from the next byte to 0 */
41 
42 #define VM_PROTOCOL_VERSION        1
43 #define VM_CMD_VERSION             0xff /* A version number byte follows */
44 #define VM_CMD_NOATTN              0x00
45 #define VM_CMD_ATTN                0x01
46 #define VM_CMD_ATTN_IRQ            0x02
47 #define VM_CMD_POWEROFF            0x03
48 #define VM_CMD_RESET               0x04
49 #define VM_CMD_ENABLE_IRQ          0x05 /* Enable/disable the messaging irq */
50 #define VM_CMD_DISABLE_IRQ         0x06
51 #define VM_CMD_SEND_NMI            0x07
52 #define VM_CMD_CAPABILITIES        0x08
53 #define   VM_CAPABILITIES_POWER    0x01
54 #define   VM_CAPABILITIES_RESET    0x02
55 #define   VM_CAPABILITIES_IRQ      0x04
56 #define   VM_CAPABILITIES_NMI      0x08
57 #define   VM_CAPABILITIES_ATTN     0x10
58 #define   VM_CAPABILITIES_GRACEFUL_SHUTDOWN 0x20
59 #define VM_CMD_GRACEFUL_SHUTDOWN   0x09
60 
61 #define TYPE_IPMI_BMC_EXTERN "ipmi-bmc-extern"
62 #define IPMI_BMC_EXTERN(obj) OBJECT_CHECK(IPMIBmcExtern, (obj), \
63                                         TYPE_IPMI_BMC_EXTERN)
64 typedef struct IPMIBmcExtern {
65     IPMIBmc parent;
66 
67     CharBackend chr;
68 
69     bool connected;
70 
71     unsigned char inbuf[MAX_IPMI_MSG_SIZE + 2];
72     unsigned int inpos;
73     bool in_escape;
74     bool in_too_many;
75     bool waiting_rsp;
76     bool sending_cmd;
77 
78     unsigned char outbuf[(MAX_IPMI_MSG_SIZE + 2) * 2 + 1];
79     unsigned int outpos;
80     unsigned int outlen;
81 
82     struct QEMUTimer *extern_timer;
83 
84     /* A reset event is pending to be sent upstream. */
85     bool send_reset;
86 } IPMIBmcExtern;
87 
88 static int can_receive(void *opaque);
89 static void receive(void *opaque, const uint8_t *buf, int size);
90 static void chr_event(void *opaque, int event);
91 
92 static unsigned char
93 ipmb_checksum(const unsigned char *data, int size, unsigned char start)
94 {
95         unsigned char csum = start;
96 
97         for (; size > 0; size--, data++) {
98                 csum += *data;
99         }
100         return csum;
101 }
102 
103 static void continue_send(IPMIBmcExtern *ibe)
104 {
105     int ret;
106     if (ibe->outlen == 0) {
107         goto check_reset;
108     }
109  send:
110     ret = qemu_chr_fe_write(&ibe->chr, ibe->outbuf + ibe->outpos,
111                             ibe->outlen - ibe->outpos);
112     if (ret > 0) {
113         ibe->outpos += ret;
114     }
115     if (ibe->outpos < ibe->outlen) {
116         /* Not fully transmitted, try again in a 10ms */
117         timer_mod_ns(ibe->extern_timer,
118                      qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + 10000000);
119     } else {
120         /* Sent */
121         ibe->outlen = 0;
122         ibe->outpos = 0;
123         if (!ibe->sending_cmd) {
124             ibe->waiting_rsp = true;
125         } else {
126             ibe->sending_cmd = false;
127         }
128     check_reset:
129         if (ibe->connected && ibe->send_reset) {
130             /* Send the reset */
131             ibe->outbuf[0] = VM_CMD_RESET;
132             ibe->outbuf[1] = VM_CMD_CHAR;
133             ibe->outlen = 2;
134             ibe->outpos = 0;
135             ibe->send_reset = false;
136             ibe->sending_cmd = true;
137             goto send;
138         }
139 
140         if (ibe->waiting_rsp) {
141             /* Make sure we get a response within 4 seconds. */
142             timer_mod_ns(ibe->extern_timer,
143                          qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + 4000000000ULL);
144         }
145     }
146     return;
147 }
148 
149 static void extern_timeout(void *opaque)
150 {
151     IPMIBmcExtern *ibe = opaque;
152     IPMIInterface *s = ibe->parent.intf;
153 
154     if (ibe->connected) {
155         if (ibe->waiting_rsp && (ibe->outlen == 0)) {
156             IPMIInterfaceClass *k = IPMI_INTERFACE_GET_CLASS(s);
157             /* The message response timed out, return an error. */
158             ibe->waiting_rsp = false;
159             ibe->inbuf[1] = ibe->outbuf[1] | 0x04;
160             ibe->inbuf[2] = ibe->outbuf[2];
161             ibe->inbuf[3] = IPMI_CC_TIMEOUT;
162             k->handle_rsp(s, ibe->outbuf[0], ibe->inbuf + 1, 3);
163         } else {
164             continue_send(ibe);
165         }
166     }
167 }
168 
169 static void addchar(IPMIBmcExtern *ibe, unsigned char ch)
170 {
171     switch (ch) {
172     case VM_MSG_CHAR:
173     case VM_CMD_CHAR:
174     case VM_ESCAPE_CHAR:
175         ibe->outbuf[ibe->outlen] = VM_ESCAPE_CHAR;
176         ibe->outlen++;
177         ch |= 0x10;
178         /* No break */
179 
180     default:
181         ibe->outbuf[ibe->outlen] = ch;
182         ibe->outlen++;
183     }
184 }
185 
186 static void ipmi_bmc_extern_handle_command(IPMIBmc *b,
187                                        uint8_t *cmd, unsigned int cmd_len,
188                                        unsigned int max_cmd_len,
189                                        uint8_t msg_id)
190 {
191     IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(b);
192     IPMIInterface *s = ibe->parent.intf;
193     uint8_t err = 0, csum;
194     unsigned int i;
195 
196     if (ibe->outlen) {
197         /* We already have a command queued.  Shouldn't ever happen. */
198         error_report("IPMI KCS: Got command when not finished with the"
199                      " previous command");
200         abort();
201     }
202 
203     /* If it's too short or it was truncated, return an error. */
204     if (cmd_len < 2) {
205         err = IPMI_CC_REQUEST_DATA_LENGTH_INVALID;
206     } else if ((cmd_len > max_cmd_len) || (cmd_len > MAX_IPMI_MSG_SIZE)) {
207         err = IPMI_CC_REQUEST_DATA_TRUNCATED;
208     } else if (!ibe->connected) {
209         err = IPMI_CC_BMC_INIT_IN_PROGRESS;
210     }
211     if (err) {
212         IPMIInterfaceClass *k = IPMI_INTERFACE_GET_CLASS(s);
213         unsigned char rsp[3];
214         rsp[0] = cmd[0] | 0x04;
215         rsp[1] = cmd[1];
216         rsp[2] = err;
217         ibe->waiting_rsp = false;
218         k->handle_rsp(s, msg_id, rsp, 3);
219         goto out;
220     }
221 
222     addchar(ibe, msg_id);
223     for (i = 0; i < cmd_len; i++) {
224         addchar(ibe, cmd[i]);
225     }
226     csum = ipmb_checksum(&msg_id, 1, 0);
227     addchar(ibe, -ipmb_checksum(cmd, cmd_len, csum));
228 
229     ibe->outbuf[ibe->outlen] = VM_MSG_CHAR;
230     ibe->outlen++;
231 
232     /* Start the transmit */
233     continue_send(ibe);
234 
235  out:
236     return;
237 }
238 
239 static void handle_hw_op(IPMIBmcExtern *ibe, unsigned char hw_op)
240 {
241     IPMIInterface *s = ibe->parent.intf;
242     IPMIInterfaceClass *k = IPMI_INTERFACE_GET_CLASS(s);
243 
244     switch (hw_op) {
245     case VM_CMD_VERSION:
246         /* We only support one version at this time. */
247         break;
248 
249     case VM_CMD_NOATTN:
250         k->set_atn(s, 0, 0);
251         break;
252 
253     case VM_CMD_ATTN:
254         k->set_atn(s, 1, 0);
255         break;
256 
257     case VM_CMD_ATTN_IRQ:
258         k->set_atn(s, 1, 1);
259         break;
260 
261     case VM_CMD_POWEROFF:
262         k->do_hw_op(s, IPMI_POWEROFF_CHASSIS, 0);
263         break;
264 
265     case VM_CMD_RESET:
266         k->do_hw_op(s, IPMI_RESET_CHASSIS, 0);
267         break;
268 
269     case VM_CMD_ENABLE_IRQ:
270         k->set_irq_enable(s, 1);
271         break;
272 
273     case VM_CMD_DISABLE_IRQ:
274         k->set_irq_enable(s, 0);
275         break;
276 
277     case VM_CMD_SEND_NMI:
278         k->do_hw_op(s, IPMI_SEND_NMI, 0);
279         break;
280 
281     case VM_CMD_GRACEFUL_SHUTDOWN:
282         k->do_hw_op(s, IPMI_SHUTDOWN_VIA_ACPI_OVERTEMP, 0);
283         break;
284     }
285 }
286 
287 static void handle_msg(IPMIBmcExtern *ibe)
288 {
289     IPMIInterfaceClass *k = IPMI_INTERFACE_GET_CLASS(ibe->parent.intf);
290 
291     if (ibe->in_escape) {
292         ipmi_debug("msg escape not ended\n");
293         return;
294     }
295     if (ibe->inpos < 5) {
296         ipmi_debug("msg too short\n");
297         return;
298     }
299     if (ibe->in_too_many) {
300         ibe->inbuf[3] = IPMI_CC_REQUEST_DATA_TRUNCATED;
301         ibe->inpos = 4;
302     } else if (ipmb_checksum(ibe->inbuf, ibe->inpos, 0) != 0) {
303         ipmi_debug("msg checksum failure\n");
304         return;
305     } else {
306         ibe->inpos--; /* Remove checkum */
307     }
308 
309     timer_del(ibe->extern_timer);
310     ibe->waiting_rsp = false;
311     k->handle_rsp(ibe->parent.intf, ibe->inbuf[0], ibe->inbuf + 1, ibe->inpos - 1);
312 }
313 
314 static int can_receive(void *opaque)
315 {
316     return 1;
317 }
318 
319 static void receive(void *opaque, const uint8_t *buf, int size)
320 {
321     IPMIBmcExtern *ibe = opaque;
322     int i;
323     unsigned char hw_op;
324 
325     for (i = 0; i < size; i++) {
326         unsigned char ch = buf[i];
327 
328         switch (ch) {
329         case VM_MSG_CHAR:
330             handle_msg(ibe);
331             ibe->in_too_many = false;
332             ibe->inpos = 0;
333             break;
334 
335         case VM_CMD_CHAR:
336             if (ibe->in_too_many) {
337                 ipmi_debug("cmd in too many\n");
338                 ibe->in_too_many = false;
339                 ibe->inpos = 0;
340                 break;
341             }
342             if (ibe->in_escape) {
343                 ipmi_debug("cmd in escape\n");
344                 ibe->in_too_many = false;
345                 ibe->inpos = 0;
346                 ibe->in_escape = false;
347                 break;
348             }
349             ibe->in_too_many = false;
350             if (ibe->inpos < 1) {
351                 break;
352             }
353             hw_op = ibe->inbuf[0];
354             ibe->inpos = 0;
355             goto out_hw_op;
356             break;
357 
358         case VM_ESCAPE_CHAR:
359             ibe->in_escape = true;
360             break;
361 
362         default:
363             if (ibe->in_escape) {
364                 ch &= ~0x10;
365                 ibe->in_escape = false;
366             }
367             if (ibe->in_too_many) {
368                 break;
369             }
370             if (ibe->inpos >= sizeof(ibe->inbuf)) {
371                 ibe->in_too_many = true;
372                 break;
373             }
374             ibe->inbuf[ibe->inpos] = ch;
375             ibe->inpos++;
376             break;
377         }
378     }
379     return;
380 
381  out_hw_op:
382     handle_hw_op(ibe, hw_op);
383 }
384 
385 static void chr_event(void *opaque, int event)
386 {
387     IPMIBmcExtern *ibe = opaque;
388     IPMIInterface *s = ibe->parent.intf;
389     IPMIInterfaceClass *k = IPMI_INTERFACE_GET_CLASS(s);
390     unsigned char v;
391 
392     switch (event) {
393     case CHR_EVENT_OPENED:
394         ibe->connected = true;
395         ibe->outpos = 0;
396         ibe->outlen = 0;
397         addchar(ibe, VM_CMD_VERSION);
398         addchar(ibe, VM_PROTOCOL_VERSION);
399         ibe->outbuf[ibe->outlen] = VM_CMD_CHAR;
400         ibe->outlen++;
401         addchar(ibe, VM_CMD_CAPABILITIES);
402         v = VM_CAPABILITIES_IRQ | VM_CAPABILITIES_ATTN;
403         if (k->do_hw_op(ibe->parent.intf, IPMI_POWEROFF_CHASSIS, 1) == 0) {
404             v |= VM_CAPABILITIES_POWER;
405         }
406         if (k->do_hw_op(ibe->parent.intf, IPMI_SHUTDOWN_VIA_ACPI_OVERTEMP, 1)
407             == 0) {
408             v |= VM_CAPABILITIES_GRACEFUL_SHUTDOWN;
409         }
410         if (k->do_hw_op(ibe->parent.intf, IPMI_RESET_CHASSIS, 1) == 0) {
411             v |= VM_CAPABILITIES_RESET;
412         }
413         if (k->do_hw_op(ibe->parent.intf, IPMI_SEND_NMI, 1) == 0) {
414             v |= VM_CAPABILITIES_NMI;
415         }
416         addchar(ibe, v);
417         ibe->outbuf[ibe->outlen] = VM_CMD_CHAR;
418         ibe->outlen++;
419         ibe->sending_cmd = false;
420         continue_send(ibe);
421         break;
422 
423     case CHR_EVENT_CLOSED:
424         if (!ibe->connected) {
425             return;
426         }
427         ibe->connected = false;
428         /*
429          * Don't hang the OS trying to handle the ATN bit, other end will
430          * resend on a reconnect.
431          */
432         k->set_atn(s, 0, 0);
433         if (ibe->waiting_rsp) {
434             ibe->waiting_rsp = false;
435             ibe->inbuf[1] = ibe->outbuf[1] | 0x04;
436             ibe->inbuf[2] = ibe->outbuf[2];
437             ibe->inbuf[3] = IPMI_CC_BMC_INIT_IN_PROGRESS;
438             k->handle_rsp(s, ibe->outbuf[0], ibe->inbuf + 1, 3);
439         }
440         break;
441     }
442 }
443 
444 static void ipmi_bmc_extern_handle_reset(IPMIBmc *b)
445 {
446     IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(b);
447 
448     ibe->send_reset = true;
449     continue_send(ibe);
450 }
451 
452 static void ipmi_bmc_extern_realize(DeviceState *dev, Error **errp)
453 {
454     IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(dev);
455 
456     if (!qemu_chr_fe_backend_connected(&ibe->chr)) {
457         error_setg(errp, "IPMI external bmc requires chardev attribute");
458         return;
459     }
460 
461     qemu_chr_fe_set_handlers(&ibe->chr, can_receive, receive,
462                              chr_event, NULL, ibe, NULL, true);
463 }
464 
465 static int ipmi_bmc_extern_post_migrate(void *opaque, int version_id)
466 {
467     IPMIBmcExtern *ibe = opaque;
468 
469     /*
470      * We don't directly restore waiting_rsp, Instead, we return an
471      * error on the interface if a response was being waited for.
472      */
473     if (ibe->waiting_rsp) {
474         IPMIInterface *ii = ibe->parent.intf;
475         IPMIInterfaceClass *iic = IPMI_INTERFACE_GET_CLASS(ii);
476 
477         ibe->waiting_rsp = false;
478         ibe->inbuf[1] = ibe->outbuf[1] | 0x04;
479         ibe->inbuf[2] = ibe->outbuf[2];
480         ibe->inbuf[3] = IPMI_CC_BMC_INIT_IN_PROGRESS;
481         iic->handle_rsp(ii, ibe->outbuf[0], ibe->inbuf + 1, 3);
482     }
483     return 0;
484 }
485 
486 static const VMStateDescription vmstate_ipmi_bmc_extern = {
487     .name = TYPE_IPMI_BMC_EXTERN,
488     .version_id = 1,
489     .minimum_version_id = 1,
490     .post_load = ipmi_bmc_extern_post_migrate,
491     .fields      = (VMStateField[]) {
492         VMSTATE_BOOL(send_reset, IPMIBmcExtern),
493         VMSTATE_BOOL(waiting_rsp, IPMIBmcExtern),
494         VMSTATE_END_OF_LIST()
495     }
496 };
497 
498 static void ipmi_bmc_extern_init(Object *obj)
499 {
500     IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(obj);
501 
502     ibe->extern_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, extern_timeout, ibe);
503     vmstate_register(NULL, 0, &vmstate_ipmi_bmc_extern, ibe);
504 }
505 
506 static void ipmi_bmc_extern_finalize(Object *obj)
507 {
508     IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(obj);
509 
510     timer_del(ibe->extern_timer);
511     timer_free(ibe->extern_timer);
512 }
513 
514 static Property ipmi_bmc_extern_properties[] = {
515     DEFINE_PROP_CHR("chardev", IPMIBmcExtern, chr),
516     DEFINE_PROP_END_OF_LIST(),
517 };
518 
519 static void ipmi_bmc_extern_class_init(ObjectClass *oc, void *data)
520 {
521     DeviceClass *dc = DEVICE_CLASS(oc);
522     IPMIBmcClass *bk = IPMI_BMC_CLASS(oc);
523 
524     bk->handle_command = ipmi_bmc_extern_handle_command;
525     bk->handle_reset = ipmi_bmc_extern_handle_reset;
526     dc->hotpluggable = false;
527     dc->realize = ipmi_bmc_extern_realize;
528     dc->props = 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