xref: /openbmc/qemu/hw/ipmi/ipmi_bmc_extern.c (revision 8fa3b702)
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 #include "qom/object.h"
40 
41 #define VM_MSG_CHAR        0xA0 /* Marks end of message */
42 #define VM_CMD_CHAR        0xA1 /* Marks end of a command */
43 #define VM_ESCAPE_CHAR     0xAA /* Set bit 4 from the next byte to 0 */
44 
45 #define VM_PROTOCOL_VERSION        1
46 #define VM_CMD_VERSION             0xff /* A version number byte follows */
47 #define VM_CMD_NOATTN              0x00
48 #define VM_CMD_ATTN                0x01
49 #define VM_CMD_ATTN_IRQ            0x02
50 #define VM_CMD_POWEROFF            0x03
51 #define VM_CMD_RESET               0x04
52 #define VM_CMD_ENABLE_IRQ          0x05 /* Enable/disable the messaging irq */
53 #define VM_CMD_DISABLE_IRQ         0x06
54 #define VM_CMD_SEND_NMI            0x07
55 #define VM_CMD_CAPABILITIES        0x08
56 #define   VM_CAPABILITIES_POWER    0x01
57 #define   VM_CAPABILITIES_RESET    0x02
58 #define   VM_CAPABILITIES_IRQ      0x04
59 #define   VM_CAPABILITIES_NMI      0x08
60 #define   VM_CAPABILITIES_ATTN     0x10
61 #define   VM_CAPABILITIES_GRACEFUL_SHUTDOWN 0x20
62 #define VM_CMD_GRACEFUL_SHUTDOWN   0x09
63 
64 #define TYPE_IPMI_BMC_EXTERN "ipmi-bmc-extern"
65 typedef struct IPMIBmcExtern IPMIBmcExtern;
66 DECLARE_INSTANCE_CHECKER(IPMIBmcExtern, IPMI_BMC_EXTERN,
67                          TYPE_IPMI_BMC_EXTERN)
68 struct IPMIBmcExtern {
69     IPMIBmc parent;
70 
71     CharBackend chr;
72 
73     bool connected;
74 
75     unsigned char inbuf[MAX_IPMI_MSG_SIZE + 2];
76     unsigned int inpos;
77     bool in_escape;
78     bool in_too_many;
79     bool waiting_rsp;
80     bool sending_cmd;
81 
82     unsigned char outbuf[(MAX_IPMI_MSG_SIZE + 2) * 2 + 1];
83     unsigned int outpos;
84     unsigned int outlen;
85 
86     struct QEMUTimer *extern_timer;
87 
88     /* A reset event is pending to be sent upstream. */
89     bool send_reset;
90 };
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         /* fall through */
179     default:
180         ibe->outbuf[ibe->outlen] = ch;
181         ibe->outlen++;
182     }
183 }
184 
185 static void ipmi_bmc_extern_handle_command(IPMIBmc *b,
186                                        uint8_t *cmd, unsigned int cmd_len,
187                                        unsigned int max_cmd_len,
188                                        uint8_t msg_id)
189 {
190     IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(b);
191     IPMIInterface *s = ibe->parent.intf;
192     uint8_t err = 0, csum;
193     unsigned int i;
194 
195     if (ibe->outlen) {
196         /* We already have a command queued.  Shouldn't ever happen. */
197         error_report("IPMI KCS: Got command when not finished with the"
198                      " previous command");
199         abort();
200     }
201 
202     /* If it's too short or it was truncated, return an error. */
203     if (cmd_len < 2) {
204         err = IPMI_CC_REQUEST_DATA_LENGTH_INVALID;
205     } else if ((cmd_len > max_cmd_len) || (cmd_len > MAX_IPMI_MSG_SIZE)) {
206         err = IPMI_CC_REQUEST_DATA_TRUNCATED;
207     } else if (!ibe->connected) {
208         err = IPMI_CC_BMC_INIT_IN_PROGRESS;
209     }
210     if (err) {
211         IPMIInterfaceClass *k = IPMI_INTERFACE_GET_CLASS(s);
212         unsigned char rsp[3];
213         rsp[0] = cmd[0] | 0x04;
214         rsp[1] = cmd[1];
215         rsp[2] = err;
216         ibe->waiting_rsp = false;
217         k->handle_rsp(s, msg_id, rsp, 3);
218         goto out;
219     }
220 
221     addchar(ibe, msg_id);
222     for (i = 0; i < cmd_len; i++) {
223         addchar(ibe, cmd[i]);
224     }
225     csum = ipmb_checksum(&msg_id, 1, 0);
226     addchar(ibe, -ipmb_checksum(cmd, cmd_len, csum));
227 
228     ibe->outbuf[ibe->outlen] = VM_MSG_CHAR;
229     ibe->outlen++;
230 
231     /* Start the transmit */
232     continue_send(ibe);
233 
234  out:
235     return;
236 }
237 
238 static void handle_hw_op(IPMIBmcExtern *ibe, unsigned char hw_op)
239 {
240     IPMIInterface *s = ibe->parent.intf;
241     IPMIInterfaceClass *k = IPMI_INTERFACE_GET_CLASS(s);
242 
243     switch (hw_op) {
244     case VM_CMD_VERSION:
245         /* We only support one version at this time. */
246         break;
247 
248     case VM_CMD_NOATTN:
249         k->set_atn(s, 0, 0);
250         break;
251 
252     case VM_CMD_ATTN:
253         k->set_atn(s, 1, 0);
254         break;
255 
256     case VM_CMD_ATTN_IRQ:
257         k->set_atn(s, 1, 1);
258         break;
259 
260     case VM_CMD_POWEROFF:
261         k->do_hw_op(s, IPMI_POWEROFF_CHASSIS, 0);
262         break;
263 
264     case VM_CMD_RESET:
265         k->do_hw_op(s, IPMI_RESET_CHASSIS, 0);
266         break;
267 
268     case VM_CMD_ENABLE_IRQ:
269         k->set_irq_enable(s, 1);
270         break;
271 
272     case VM_CMD_DISABLE_IRQ:
273         k->set_irq_enable(s, 0);
274         break;
275 
276     case VM_CMD_SEND_NMI:
277         k->do_hw_op(s, IPMI_SEND_NMI, 0);
278         break;
279 
280     case VM_CMD_GRACEFUL_SHUTDOWN:
281         k->do_hw_op(s, IPMI_SHUTDOWN_VIA_ACPI_OVERTEMP, 0);
282         break;
283     }
284 }
285 
286 static void handle_msg(IPMIBmcExtern *ibe)
287 {
288     IPMIInterfaceClass *k = IPMI_INTERFACE_GET_CLASS(ibe->parent.intf);
289 
290     if (ibe->in_escape) {
291         ipmi_debug("msg escape not ended\n");
292         return;
293     }
294     if (ibe->inpos < 5) {
295         ipmi_debug("msg too short\n");
296         return;
297     }
298     if (ibe->in_too_many) {
299         ibe->inbuf[3] = IPMI_CC_REQUEST_DATA_TRUNCATED;
300         ibe->inpos = 4;
301     } else if (ipmb_checksum(ibe->inbuf, ibe->inpos, 0) != 0) {
302         ipmi_debug("msg checksum failure\n");
303         return;
304     } else {
305         ibe->inpos--; /* Remove checkum */
306     }
307 
308     timer_del(ibe->extern_timer);
309     ibe->waiting_rsp = false;
310     k->handle_rsp(ibe->parent.intf, ibe->inbuf[0], ibe->inbuf + 1, ibe->inpos - 1);
311 }
312 
313 static int can_receive(void *opaque)
314 {
315     return 1;
316 }
317 
318 static void receive(void *opaque, const uint8_t *buf, int size)
319 {
320     IPMIBmcExtern *ibe = opaque;
321     int i;
322     unsigned char hw_op;
323 
324     for (i = 0; i < size; i++) {
325         unsigned char ch = buf[i];
326 
327         switch (ch) {
328         case VM_MSG_CHAR:
329             handle_msg(ibe);
330             ibe->in_too_many = false;
331             ibe->inpos = 0;
332             break;
333 
334         case VM_CMD_CHAR:
335             if (ibe->in_too_many) {
336                 ipmi_debug("cmd in too many\n");
337                 ibe->in_too_many = false;
338                 ibe->inpos = 0;
339                 break;
340             }
341             if (ibe->in_escape) {
342                 ipmi_debug("cmd in escape\n");
343                 ibe->in_too_many = false;
344                 ibe->inpos = 0;
345                 ibe->in_escape = false;
346                 break;
347             }
348             ibe->in_too_many = false;
349             if (ibe->inpos < 1) {
350                 break;
351             }
352             hw_op = ibe->inbuf[0];
353             ibe->inpos = 0;
354             goto out_hw_op;
355             break;
356 
357         case VM_ESCAPE_CHAR:
358             ibe->in_escape = true;
359             break;
360 
361         default:
362             if (ibe->in_escape) {
363                 ch &= ~0x10;
364                 ibe->in_escape = false;
365             }
366             if (ibe->in_too_many) {
367                 break;
368             }
369             if (ibe->inpos >= sizeof(ibe->inbuf)) {
370                 ibe->in_too_many = true;
371                 break;
372             }
373             ibe->inbuf[ibe->inpos] = ch;
374             ibe->inpos++;
375             break;
376         }
377     }
378     return;
379 
380  out_hw_op:
381     handle_hw_op(ibe, hw_op);
382 }
383 
384 static void chr_event(void *opaque, QEMUChrEvent event)
385 {
386     IPMIBmcExtern *ibe = opaque;
387     IPMIInterface *s = ibe->parent.intf;
388     IPMIInterfaceClass *k = IPMI_INTERFACE_GET_CLASS(s);
389     unsigned char v;
390 
391     switch (event) {
392     case CHR_EVENT_OPENED:
393         ibe->connected = true;
394         ibe->outpos = 0;
395         ibe->outlen = 0;
396         addchar(ibe, VM_CMD_VERSION);
397         addchar(ibe, VM_PROTOCOL_VERSION);
398         ibe->outbuf[ibe->outlen] = VM_CMD_CHAR;
399         ibe->outlen++;
400         addchar(ibe, VM_CMD_CAPABILITIES);
401         v = VM_CAPABILITIES_IRQ | VM_CAPABILITIES_ATTN;
402         if (k->do_hw_op(ibe->parent.intf, IPMI_POWEROFF_CHASSIS, 1) == 0) {
403             v |= VM_CAPABILITIES_POWER;
404         }
405         if (k->do_hw_op(ibe->parent.intf, IPMI_SHUTDOWN_VIA_ACPI_OVERTEMP, 1)
406             == 0) {
407             v |= VM_CAPABILITIES_GRACEFUL_SHUTDOWN;
408         }
409         if (k->do_hw_op(ibe->parent.intf, IPMI_RESET_CHASSIS, 1) == 0) {
410             v |= VM_CAPABILITIES_RESET;
411         }
412         if (k->do_hw_op(ibe->parent.intf, IPMI_SEND_NMI, 1) == 0) {
413             v |= VM_CAPABILITIES_NMI;
414         }
415         addchar(ibe, v);
416         ibe->outbuf[ibe->outlen] = VM_CMD_CHAR;
417         ibe->outlen++;
418         ibe->sending_cmd = false;
419         continue_send(ibe);
420         break;
421 
422     case CHR_EVENT_CLOSED:
423         if (!ibe->connected) {
424             return;
425         }
426         ibe->connected = false;
427         /*
428          * Don't hang the OS trying to handle the ATN bit, other end will
429          * resend on a reconnect.
430          */
431         k->set_atn(s, 0, 0);
432         if (ibe->waiting_rsp) {
433             ibe->waiting_rsp = false;
434             ibe->inbuf[1] = ibe->outbuf[1] | 0x04;
435             ibe->inbuf[2] = ibe->outbuf[2];
436             ibe->inbuf[3] = IPMI_CC_BMC_INIT_IN_PROGRESS;
437             k->handle_rsp(s, ibe->outbuf[0], ibe->inbuf + 1, 3);
438         }
439         break;
440 
441     case CHR_EVENT_BREAK:
442     case CHR_EVENT_MUX_IN:
443     case CHR_EVENT_MUX_OUT:
444         /* Ignore */
445         break;
446     }
447 }
448 
449 static void ipmi_bmc_extern_handle_reset(IPMIBmc *b)
450 {
451     IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(b);
452 
453     ibe->send_reset = true;
454     continue_send(ibe);
455 }
456 
457 static void ipmi_bmc_extern_realize(DeviceState *dev, Error **errp)
458 {
459     IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(dev);
460 
461     if (!qemu_chr_fe_backend_connected(&ibe->chr)) {
462         error_setg(errp, "IPMI external bmc requires chardev attribute");
463         return;
464     }
465 
466     qemu_chr_fe_set_handlers(&ibe->chr, can_receive, receive,
467                              chr_event, NULL, ibe, NULL, true);
468 }
469 
470 static int ipmi_bmc_extern_post_migrate(void *opaque, int version_id)
471 {
472     IPMIBmcExtern *ibe = opaque;
473 
474     /*
475      * We don't directly restore waiting_rsp, Instead, we return an
476      * error on the interface if a response was being waited for.
477      */
478     if (ibe->waiting_rsp) {
479         IPMIInterface *ii = ibe->parent.intf;
480         IPMIInterfaceClass *iic = IPMI_INTERFACE_GET_CLASS(ii);
481 
482         ibe->waiting_rsp = false;
483         ibe->inbuf[1] = ibe->outbuf[1] | 0x04;
484         ibe->inbuf[2] = ibe->outbuf[2];
485         ibe->inbuf[3] = IPMI_CC_BMC_INIT_IN_PROGRESS;
486         iic->handle_rsp(ii, ibe->outbuf[0], ibe->inbuf + 1, 3);
487     }
488     return 0;
489 }
490 
491 static const VMStateDescription vmstate_ipmi_bmc_extern = {
492     .name = TYPE_IPMI_BMC_EXTERN,
493     .version_id = 1,
494     .minimum_version_id = 1,
495     .post_load = ipmi_bmc_extern_post_migrate,
496     .fields      = (VMStateField[]) {
497         VMSTATE_BOOL(send_reset, IPMIBmcExtern),
498         VMSTATE_BOOL(waiting_rsp, IPMIBmcExtern),
499         VMSTATE_END_OF_LIST()
500     }
501 };
502 
503 static void ipmi_bmc_extern_init(Object *obj)
504 {
505     IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(obj);
506 
507     ibe->extern_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, extern_timeout, ibe);
508     vmstate_register(NULL, 0, &vmstate_ipmi_bmc_extern, ibe);
509 }
510 
511 static void ipmi_bmc_extern_finalize(Object *obj)
512 {
513     IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(obj);
514 
515     timer_del(ibe->extern_timer);
516     timer_free(ibe->extern_timer);
517 }
518 
519 static Property ipmi_bmc_extern_properties[] = {
520     DEFINE_PROP_CHR("chardev", IPMIBmcExtern, chr),
521     DEFINE_PROP_END_OF_LIST(),
522 };
523 
524 static void ipmi_bmc_extern_class_init(ObjectClass *oc, void *data)
525 {
526     DeviceClass *dc = DEVICE_CLASS(oc);
527     IPMIBmcClass *bk = IPMI_BMC_CLASS(oc);
528 
529     bk->handle_command = ipmi_bmc_extern_handle_command;
530     bk->handle_reset = ipmi_bmc_extern_handle_reset;
531     dc->hotpluggable = false;
532     dc->realize = ipmi_bmc_extern_realize;
533     device_class_set_props(dc, ipmi_bmc_extern_properties);
534 }
535 
536 static const TypeInfo ipmi_bmc_extern_type = {
537     .name          = TYPE_IPMI_BMC_EXTERN,
538     .parent        = TYPE_IPMI_BMC,
539     .instance_size = sizeof(IPMIBmcExtern),
540     .instance_init = ipmi_bmc_extern_init,
541     .instance_finalize = ipmi_bmc_extern_finalize,
542     .class_init    = ipmi_bmc_extern_class_init,
543  };
544 
545 static void ipmi_bmc_extern_register_types(void)
546 {
547     type_register_static(&ipmi_bmc_extern_type);
548 }
549 
550 type_init(ipmi_bmc_extern_register_types)
551