xref: /openbmc/qemu/hw/ipmi/ipmi_bmc_extern.c (revision 4f7689f0)
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     return;
146 }
147 
148 static void extern_timeout(void *opaque)
149 {
150     IPMIBmcExtern *ibe = opaque;
151     IPMIInterface *s = ibe->parent.intf;
152 
153     if (ibe->connected) {
154         if (ibe->waiting_rsp && (ibe->outlen == 0)) {
155             IPMIInterfaceClass *k = IPMI_INTERFACE_GET_CLASS(s);
156             /* The message response timed out, return an error. */
157             ibe->waiting_rsp = false;
158             ibe->inbuf[1] = ibe->outbuf[1] | 0x04;
159             ibe->inbuf[2] = ibe->outbuf[2];
160             ibe->inbuf[3] = IPMI_CC_TIMEOUT;
161             k->handle_rsp(s, ibe->outbuf[0], ibe->inbuf + 1, 3);
162         } else {
163             continue_send(ibe);
164         }
165     }
166 }
167 
168 static void addchar(IPMIBmcExtern *ibe, unsigned char ch)
169 {
170     switch (ch) {
171     case VM_MSG_CHAR:
172     case VM_CMD_CHAR:
173     case VM_ESCAPE_CHAR:
174         ibe->outbuf[ibe->outlen] = VM_ESCAPE_CHAR;
175         ibe->outlen++;
176         ch |= 0x10;
177         /* fall through */
178     default:
179         ibe->outbuf[ibe->outlen] = ch;
180         ibe->outlen++;
181     }
182 }
183 
184 static void ipmi_bmc_extern_handle_command(IPMIBmc *b,
185                                        uint8_t *cmd, unsigned int cmd_len,
186                                        unsigned int max_cmd_len,
187                                        uint8_t msg_id)
188 {
189     IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(b);
190     IPMIInterface *s = ibe->parent.intf;
191     uint8_t err = 0, csum;
192     unsigned int i;
193 
194     if (ibe->outlen) {
195         /* We already have a command queued.  Shouldn't ever happen. */
196         error_report("IPMI KCS: Got command when not finished with the"
197                      " previous command");
198         abort();
199     }
200 
201     /* If it's too short or it was truncated, return an error. */
202     if (cmd_len < 2) {
203         err = IPMI_CC_REQUEST_DATA_LENGTH_INVALID;
204     } else if ((cmd_len > max_cmd_len) || (cmd_len > MAX_IPMI_MSG_SIZE)) {
205         err = IPMI_CC_REQUEST_DATA_TRUNCATED;
206     } else if (!ibe->connected) {
207         err = IPMI_CC_BMC_INIT_IN_PROGRESS;
208     }
209     if (err) {
210         IPMIInterfaceClass *k = IPMI_INTERFACE_GET_CLASS(s);
211         unsigned char rsp[3];
212         rsp[0] = cmd[0] | 0x04;
213         rsp[1] = cmd[1];
214         rsp[2] = err;
215         ibe->waiting_rsp = false;
216         k->handle_rsp(s, msg_id, rsp, 3);
217         goto out;
218     }
219 
220     addchar(ibe, msg_id);
221     for (i = 0; i < cmd_len; i++) {
222         addchar(ibe, cmd[i]);
223     }
224     csum = ipmb_checksum(&msg_id, 1, 0);
225     addchar(ibe, -ipmb_checksum(cmd, cmd_len, csum));
226 
227     ibe->outbuf[ibe->outlen] = VM_MSG_CHAR;
228     ibe->outlen++;
229 
230     /* Start the transmit */
231     continue_send(ibe);
232 
233  out:
234     return;
235 }
236 
237 static void handle_hw_op(IPMIBmcExtern *ibe, unsigned char hw_op)
238 {
239     IPMIInterface *s = ibe->parent.intf;
240     IPMIInterfaceClass *k = IPMI_INTERFACE_GET_CLASS(s);
241 
242     switch (hw_op) {
243     case VM_CMD_VERSION:
244         /* We only support one version at this time. */
245         break;
246 
247     case VM_CMD_NOATTN:
248         k->set_atn(s, 0, 0);
249         break;
250 
251     case VM_CMD_ATTN:
252         k->set_atn(s, 1, 0);
253         break;
254 
255     case VM_CMD_ATTN_IRQ:
256         k->set_atn(s, 1, 1);
257         break;
258 
259     case VM_CMD_POWEROFF:
260         k->do_hw_op(s, IPMI_POWEROFF_CHASSIS, 0);
261         break;
262 
263     case VM_CMD_RESET:
264         k->do_hw_op(s, IPMI_RESET_CHASSIS, 0);
265         break;
266 
267     case VM_CMD_ENABLE_IRQ:
268         k->set_irq_enable(s, 1);
269         break;
270 
271     case VM_CMD_DISABLE_IRQ:
272         k->set_irq_enable(s, 0);
273         break;
274 
275     case VM_CMD_SEND_NMI:
276         k->do_hw_op(s, IPMI_SEND_NMI, 0);
277         break;
278 
279     case VM_CMD_GRACEFUL_SHUTDOWN:
280         k->do_hw_op(s, IPMI_SHUTDOWN_VIA_ACPI_OVERTEMP, 0);
281         break;
282     }
283 }
284 
285 static void handle_msg(IPMIBmcExtern *ibe)
286 {
287     IPMIInterfaceClass *k = IPMI_INTERFACE_GET_CLASS(ibe->parent.intf);
288 
289     if (ibe->in_escape) {
290         ipmi_debug("msg escape not ended\n");
291         return;
292     }
293     if (ibe->inpos < 5) {
294         ipmi_debug("msg too short\n");
295         return;
296     }
297     if (ibe->in_too_many) {
298         ibe->inbuf[3] = IPMI_CC_REQUEST_DATA_TRUNCATED;
299         ibe->inpos = 4;
300     } else if (ipmb_checksum(ibe->inbuf, ibe->inpos, 0) != 0) {
301         ipmi_debug("msg checksum failure\n");
302         return;
303     } else {
304         ibe->inpos--; /* Remove checksum */
305     }
306 
307     timer_del(ibe->extern_timer);
308     ibe->waiting_rsp = false;
309     k->handle_rsp(ibe->parent.intf, ibe->inbuf[0], ibe->inbuf + 1, ibe->inpos - 1);
310 }
311 
312 static int can_receive(void *opaque)
313 {
314     return 1;
315 }
316 
317 static void receive(void *opaque, const uint8_t *buf, int size)
318 {
319     IPMIBmcExtern *ibe = opaque;
320     int i;
321     unsigned char hw_op;
322 
323     for (i = 0; i < size; i++) {
324         unsigned char ch = buf[i];
325 
326         switch (ch) {
327         case VM_MSG_CHAR:
328             handle_msg(ibe);
329             ibe->in_too_many = false;
330             ibe->inpos = 0;
331             break;
332 
333         case VM_CMD_CHAR:
334             if (ibe->in_too_many) {
335                 ipmi_debug("cmd in too many\n");
336                 ibe->in_too_many = false;
337                 ibe->inpos = 0;
338                 break;
339             }
340             if (ibe->in_escape) {
341                 ipmi_debug("cmd in escape\n");
342                 ibe->in_too_many = false;
343                 ibe->inpos = 0;
344                 ibe->in_escape = false;
345                 break;
346             }
347             ibe->in_too_many = false;
348             if (ibe->inpos < 1) {
349                 break;
350             }
351             hw_op = ibe->inbuf[0];
352             ibe->inpos = 0;
353             goto out_hw_op;
354             break;
355 
356         case VM_ESCAPE_CHAR:
357             ibe->in_escape = true;
358             break;
359 
360         default:
361             if (ibe->in_escape) {
362                 ch &= ~0x10;
363                 ibe->in_escape = false;
364             }
365             if (ibe->in_too_many) {
366                 break;
367             }
368             if (ibe->inpos >= sizeof(ibe->inbuf)) {
369                 ibe->in_too_many = true;
370                 break;
371             }
372             ibe->inbuf[ibe->inpos] = ch;
373             ibe->inpos++;
374             break;
375         }
376     }
377     return;
378 
379  out_hw_op:
380     handle_hw_op(ibe, hw_op);
381 }
382 
383 static void chr_event(void *opaque, QEMUChrEvent event)
384 {
385     IPMIBmcExtern *ibe = opaque;
386     IPMIInterface *s = ibe->parent.intf;
387     IPMIInterfaceClass *k = IPMI_INTERFACE_GET_CLASS(s);
388     unsigned char v;
389 
390     switch (event) {
391     case CHR_EVENT_OPENED:
392         ibe->connected = true;
393         ibe->outpos = 0;
394         ibe->outlen = 0;
395         addchar(ibe, VM_CMD_VERSION);
396         addchar(ibe, VM_PROTOCOL_VERSION);
397         ibe->outbuf[ibe->outlen] = VM_CMD_CHAR;
398         ibe->outlen++;
399         addchar(ibe, VM_CMD_CAPABILITIES);
400         v = VM_CAPABILITIES_IRQ | VM_CAPABILITIES_ATTN;
401         if (k->do_hw_op(ibe->parent.intf, IPMI_POWEROFF_CHASSIS, 1) == 0) {
402             v |= VM_CAPABILITIES_POWER;
403         }
404         if (k->do_hw_op(ibe->parent.intf, IPMI_SHUTDOWN_VIA_ACPI_OVERTEMP, 1)
405             == 0) {
406             v |= VM_CAPABILITIES_GRACEFUL_SHUTDOWN;
407         }
408         if (k->do_hw_op(ibe->parent.intf, IPMI_RESET_CHASSIS, 1) == 0) {
409             v |= VM_CAPABILITIES_RESET;
410         }
411         if (k->do_hw_op(ibe->parent.intf, IPMI_SEND_NMI, 1) == 0) {
412             v |= VM_CAPABILITIES_NMI;
413         }
414         addchar(ibe, v);
415         ibe->outbuf[ibe->outlen] = VM_CMD_CHAR;
416         ibe->outlen++;
417         ibe->sending_cmd = false;
418         continue_send(ibe);
419         break;
420 
421     case CHR_EVENT_CLOSED:
422         if (!ibe->connected) {
423             return;
424         }
425         ibe->connected = false;
426         /*
427          * Don't hang the OS trying to handle the ATN bit, other end will
428          * resend on a reconnect.
429          */
430         k->set_atn(s, 0, 0);
431         if (ibe->waiting_rsp) {
432             ibe->waiting_rsp = false;
433             ibe->inbuf[1] = ibe->outbuf[1] | 0x04;
434             ibe->inbuf[2] = ibe->outbuf[2];
435             ibe->inbuf[3] = IPMI_CC_BMC_INIT_IN_PROGRESS;
436             k->handle_rsp(s, ibe->outbuf[0], ibe->inbuf + 1, 3);
437         }
438         break;
439 
440     case CHR_EVENT_BREAK:
441     case CHR_EVENT_MUX_IN:
442     case CHR_EVENT_MUX_OUT:
443         /* Ignore */
444         break;
445     }
446 }
447 
448 static void ipmi_bmc_extern_handle_reset(IPMIBmc *b)
449 {
450     IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(b);
451 
452     ibe->send_reset = true;
453     continue_send(ibe);
454 }
455 
456 static void ipmi_bmc_extern_realize(DeviceState *dev, Error **errp)
457 {
458     IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(dev);
459 
460     if (!qemu_chr_fe_backend_connected(&ibe->chr)) {
461         error_setg(errp, "IPMI external bmc requires chardev attribute");
462         return;
463     }
464 
465     qemu_chr_fe_set_handlers(&ibe->chr, can_receive, receive,
466                              chr_event, NULL, ibe, NULL, true);
467 }
468 
469 static int ipmi_bmc_extern_post_migrate(void *opaque, int version_id)
470 {
471     IPMIBmcExtern *ibe = opaque;
472 
473     /*
474      * We don't directly restore waiting_rsp, Instead, we return an
475      * error on the interface if a response was being waited for.
476      */
477     if (ibe->waiting_rsp) {
478         IPMIInterface *ii = ibe->parent.intf;
479         IPMIInterfaceClass *iic = IPMI_INTERFACE_GET_CLASS(ii);
480 
481         ibe->waiting_rsp = false;
482         ibe->inbuf[1] = ibe->outbuf[1] | 0x04;
483         ibe->inbuf[2] = ibe->outbuf[2];
484         ibe->inbuf[3] = IPMI_CC_BMC_INIT_IN_PROGRESS;
485         iic->handle_rsp(ii, ibe->outbuf[0], ibe->inbuf + 1, 3);
486     }
487     return 0;
488 }
489 
490 static const VMStateDescription vmstate_ipmi_bmc_extern = {
491     .name = TYPE_IPMI_BMC_EXTERN,
492     .version_id = 1,
493     .minimum_version_id = 1,
494     .post_load = ipmi_bmc_extern_post_migrate,
495     .fields      = (VMStateField[]) {
496         VMSTATE_BOOL(send_reset, IPMIBmcExtern),
497         VMSTATE_BOOL(waiting_rsp, IPMIBmcExtern),
498         VMSTATE_END_OF_LIST()
499     }
500 };
501 
502 static void ipmi_bmc_extern_init(Object *obj)
503 {
504     IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(obj);
505 
506     ibe->extern_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, extern_timeout, ibe);
507     vmstate_register(NULL, 0, &vmstate_ipmi_bmc_extern, ibe);
508 }
509 
510 static void ipmi_bmc_extern_finalize(Object *obj)
511 {
512     IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(obj);
513 
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     device_class_set_props(dc, 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