xref: /qemu/hw/char/sclpconsole-lm.c (revision 2abf0da2) 
1 /*
2  * SCLP event types
3  *    Operations Command - Line Mode input
4  *    Message            - Line Mode output
5  *
6  * Copyright IBM, Corp. 2013
7  *
8  * Authors:
9  *  Heinz Graalfs <graalfs@linux.vnet.ibm.com>
10  *
11  * This work is licensed under the terms of the GNU GPL, version 2 or (at your
12  * option) any later version.  See the COPYING file in the top-level directory.
13  *
14  */
15 
16 #include "qemu/osdep.h"
17 #include "qemu/thread.h"
18 #include "qemu/error-report.h"
19 #include "qemu/module.h"
20 #include "chardev/char-fe.h"
21 
22 #include "hw/s390x/sclp.h"
23 #include "migration/vmstate.h"
24 #include "hw/s390x/event-facility.h"
25 #include "hw/qdev-properties.h"
26 #include "hw/qdev-properties-system.h"
27 #include "hw/s390x/ebcdic.h"
28 #include "qom/object.h"
29 
30 #define SIZE_BUFFER 4096
31 #define NEWLINE     "\n"
32 
33 typedef struct OprtnsCommand {
34     EventBufferHeader header;
35     MDMSU message_unit;
36     char data[];
37 } QEMU_PACKED OprtnsCommand;
38 
39 /* max size for line-mode data in 4K SCCB page */
40 #define SIZE_CONSOLE_BUFFER (SCCB_DATA_LEN - sizeof(OprtnsCommand))
41 
42 struct SCLPConsoleLM {
43     SCLPEvent event;
44     CharBackend chr;
45     bool echo;                  /* immediate echo of input if true        */
46     uint32_t write_errors;      /* errors writing to char layer           */
47     uint32_t length;            /* length of byte stream in buffer        */
48     uint8_t buf[SIZE_CONSOLE_BUFFER];
49 };
50 typedef struct SCLPConsoleLM SCLPConsoleLM;
51 
52 #define TYPE_SCLPLM_CONSOLE "sclplmconsole"
53 DECLARE_INSTANCE_CHECKER(SCLPConsoleLM, SCLPLM_CONSOLE,
54                          TYPE_SCLPLM_CONSOLE)
55 
56 /*
57 *  Character layer call-back functions
58  *
59  * Allow 1 character at a time
60  *
61  * Accumulate bytes from character layer in console buffer,
62  * event_pending is set when a newline character is encountered
63  *
64  * The maximum command line length is limited by the maximum
65  * space available in an SCCB. Line mode console input is sent
66  * truncated to the guest in case it doesn't fit into the SCCB.
67  */
68 
69 static int chr_can_read(void *opaque)
70 {
71     SCLPConsoleLM *scon = opaque;
72 
73     if (scon->event.event_pending) {
74         return 0;
75     }
76     return 1;
77 }
78 
79 static void chr_read(void *opaque, const uint8_t *buf, int size)
80 {
81     SCLPConsoleLM *scon = opaque;
82 
83     assert(size == 1);
84 
85     if (*buf == '\r' || *buf == '\n') {
86         scon->event.event_pending = true;
87         sclp_service_interrupt(0);
88         return;
89     }
90     if (scon->length == SIZE_CONSOLE_BUFFER) {
91         /* Eat the character, but still process CR and LF.  */
92         return;
93     }
94     scon->buf[scon->length] = *buf;
95     scon->length += 1;
96     if (scon->echo) {
97         /* XXX this blocks entire thread. Rewrite to use
98          * qemu_chr_fe_write and background I/O callbacks */
99         qemu_chr_fe_write_all(&scon->chr, buf, size);
100     }
101 }
102 
103 /* functions to be called by event facility */
104 
105 static bool can_handle_event(uint8_t type)
106 {
107     return type == SCLP_EVENT_MESSAGE || type == SCLP_EVENT_PMSGCMD;
108 }
109 
110 static sccb_mask_t send_mask(void)
111 {
112     return SCLP_EVENT_MASK_OP_CMD | SCLP_EVENT_MASK_PMSGCMD;
113 }
114 
115 static sccb_mask_t receive_mask(void)
116 {
117     return SCLP_EVENT_MASK_MSG | SCLP_EVENT_MASK_PMSGCMD;
118 }
119 
120 /*
121  * Triggered by SCLP's read_event_data
122  * - convert ASCII byte stream to EBCDIC and
123  * - copy converted data into provided (SCLP) buffer
124  */
125 static int get_console_data(SCLPEvent *event, uint8_t *buf, size_t *size,
126                             int avail)
127 {
128     int len;
129 
130     SCLPConsoleLM *cons = SCLPLM_CONSOLE(event);
131 
132     len = cons->length;
133     /* data need to fit into provided SCLP buffer */
134     if (len > avail) {
135         return 1;
136     }
137 
138     ebcdic_put(buf, (char *)&cons->buf, len);
139     *size = len;
140     cons->length = 0;
141     /* data provided and no more data pending */
142     event->event_pending = false;
143     qemu_notify_event();
144     return 0;
145 }
146 
147 static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
148                            int *slen)
149 {
150     int avail, rc;
151     size_t src_len;
152     uint8_t *to;
153     OprtnsCommand *oc = (OprtnsCommand *) evt_buf_hdr;
154 
155     if (!event->event_pending) {
156         /* no data pending */
157         return 0;
158     }
159 
160     to = (uint8_t *)&oc->data;
161     avail = *slen - sizeof(OprtnsCommand);
162     rc = get_console_data(event, to, &src_len, avail);
163     if (rc) {
164         /* data didn't fit, try next SCCB */
165         return 1;
166     }
167 
168     oc->message_unit.mdmsu.gds_id = GDS_ID_MDSMU;
169     oc->message_unit.mdmsu.length = cpu_to_be16(sizeof(struct MDMSU));
170 
171     oc->message_unit.cpmsu.gds_id = GDS_ID_CPMSU;
172     oc->message_unit.cpmsu.length =
173         cpu_to_be16(sizeof(struct MDMSU) - sizeof(GdsVector));
174 
175     oc->message_unit.text_command.gds_id = GDS_ID_TEXTCMD;
176     oc->message_unit.text_command.length =
177         cpu_to_be16(sizeof(struct MDMSU) - (2 * sizeof(GdsVector)));
178 
179     oc->message_unit.self_def_text_message.key = GDS_KEY_SELFDEFTEXTMSG;
180     oc->message_unit.self_def_text_message.length =
181         cpu_to_be16(sizeof(struct MDMSU) - (3 * sizeof(GdsVector)));
182 
183     oc->message_unit.text_message.key = GDS_KEY_TEXTMSG;
184     oc->message_unit.text_message.length =
185         cpu_to_be16(sizeof(GdsSubvector) + src_len);
186 
187     oc->header.length = cpu_to_be16(sizeof(OprtnsCommand) + src_len);
188     oc->header.type = SCLP_EVENT_OPRTNS_COMMAND;
189     *slen = avail - src_len;
190 
191     return 1;
192 }
193 
194 /*
195  * Triggered by SCLP's write_event_data
196  *  - write console data to character layer
197  *  returns < 0 if an error occurred
198  */
199 static int write_console_data(SCLPEvent *event, const uint8_t *buf, int len)
200 {
201     SCLPConsoleLM *scon = SCLPLM_CONSOLE(event);
202 
203     if (!qemu_chr_fe_backend_connected(&scon->chr)) {
204         /* If there's no backend, we can just say we consumed all data. */
205         return len;
206     }
207 
208     /* XXX this blocks entire thread. Rewrite to use
209      * qemu_chr_fe_write and background I/O callbacks */
210     return qemu_chr_fe_write_all(&scon->chr, buf, len);
211 }
212 
213 static int process_mdb(SCLPEvent *event, MDBO *mdbo)
214 {
215     int rc;
216     int len;
217     uint8_t buffer[SIZE_BUFFER];
218 
219     len = be16_to_cpu(mdbo->length);
220     len -= sizeof(mdbo->length) + sizeof(mdbo->type)
221             + sizeof(mdbo->mto.line_type_flags)
222             + sizeof(mdbo->mto.alarm_control)
223             + sizeof(mdbo->mto._reserved);
224 
225     assert(len <= SIZE_BUFFER);
226 
227     /* convert EBCDIC SCLP contents to ASCII console message */
228     ascii_put(buffer, mdbo->mto.message, len);
229     rc = write_console_data(event, (uint8_t *)NEWLINE, 1);
230     if (rc < 0) {
231         return rc;
232     }
233     return write_console_data(event, buffer, len);
234 }
235 
236 static int write_event_data(SCLPEvent *event, EventBufferHeader *ebh)
237 {
238     int len;
239     int written;
240     int errors = 0;
241     MDBO *mdbo;
242     SclpMsg *data = (SclpMsg *) ebh;
243     SCLPConsoleLM *scon = SCLPLM_CONSOLE(event);
244 
245     len = be16_to_cpu(data->mdb.header.length);
246     if (len < sizeof(data->mdb.header)) {
247         return SCLP_RC_INCONSISTENT_LENGTHS;
248     }
249     len -= sizeof(data->mdb.header);
250 
251     /* first check message buffers */
252     mdbo = data->mdb.mdbo;
253     while (len > 0) {
254         if (be16_to_cpu(mdbo->length) > len
255                 || be16_to_cpu(mdbo->length) == 0) {
256             return SCLP_RC_INCONSISTENT_LENGTHS;
257         }
258         len -= be16_to_cpu(mdbo->length);
259         mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
260     }
261 
262     /* then execute */
263     len = be16_to_cpu(data->mdb.header.length) - sizeof(data->mdb.header);
264     mdbo = data->mdb.mdbo;
265     while (len > 0) {
266         switch (be16_to_cpu(mdbo->type)) {
267         case MESSAGE_TEXT:
268             /* message text object */
269             written = process_mdb(event, mdbo);
270             if (written < 0) {
271                 /* character layer error */
272                 errors++;
273             }
274             break;
275         default: /* ignore */
276             break;
277         }
278         len -= be16_to_cpu(mdbo->length);
279         mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
280     }
281     if (errors) {
282         scon->write_errors += errors;
283     }
284     data->header.flags = SCLP_EVENT_BUFFER_ACCEPTED;
285 
286     return SCLP_RC_NORMAL_COMPLETION;
287 }
288 
289 /* functions for live migration */
290 
291 static const VMStateDescription vmstate_sclplmconsole = {
292     .name = "sclplmconsole",
293     .version_id = 0,
294     .minimum_version_id = 0,
295     .fields = (const VMStateField[]) {
296         VMSTATE_BOOL(event.event_pending, SCLPConsoleLM),
297         VMSTATE_UINT32(write_errors, SCLPConsoleLM),
298         VMSTATE_UINT32(length, SCLPConsoleLM),
299         VMSTATE_UINT8_ARRAY(buf, SCLPConsoleLM, SIZE_CONSOLE_BUFFER),
300         VMSTATE_END_OF_LIST()
301      }
302 };
303 
304 /* qemu object creation and initialization functions */
305 
306 /* tell character layer our call-back functions */
307 
308 static int console_init(SCLPEvent *event)
309 {
310     static bool console_available;
311 
312     SCLPConsoleLM *scon = SCLPLM_CONSOLE(event);
313 
314     if (console_available) {
315         error_report("Multiple line-mode operator consoles are not supported");
316         return -1;
317     }
318     console_available = true;
319 
320     qemu_chr_fe_set_handlers(&scon->chr, chr_can_read,
321                              chr_read, NULL, NULL, scon, NULL, true);
322 
323     return 0;
324 }
325 
326 static void console_reset(DeviceState *dev)
327 {
328    SCLPEvent *event = SCLP_EVENT(dev);
329    SCLPConsoleLM *scon = SCLPLM_CONSOLE(event);
330 
331    event->event_pending = false;
332    scon->length = 0;
333    scon->write_errors = 0;
334 }
335 
336 static Property console_properties[] = {
337     DEFINE_PROP_CHR("chardev", SCLPConsoleLM, chr),
338     DEFINE_PROP_UINT32("write_errors", SCLPConsoleLM, write_errors, 0),
339     DEFINE_PROP_BOOL("echo", SCLPConsoleLM, echo, true),
340     DEFINE_PROP_END_OF_LIST(),
341 };
342 
343 static void console_class_init(ObjectClass *klass, void *data)
344 {
345     DeviceClass *dc = DEVICE_CLASS(klass);
346     SCLPEventClass *ec = SCLP_EVENT_CLASS(klass);
347 
348     device_class_set_props(dc, console_properties);
349     dc->reset = console_reset;
350     dc->vmsd = &vmstate_sclplmconsole;
351     ec->init = console_init;
352     ec->get_send_mask = send_mask;
353     ec->get_receive_mask = receive_mask;
354     ec->can_handle_event = can_handle_event;
355     ec->read_event_data = read_event_data;
356     ec->write_event_data = write_event_data;
357     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
358 }
359 
360 static const TypeInfo sclp_console_info = {
361     .name          = TYPE_SCLPLM_CONSOLE,
362     .parent        = TYPE_SCLP_EVENT,
363     .instance_size = sizeof(SCLPConsoleLM),
364     .class_init    = console_class_init,
365     .class_size    = sizeof(SCLPEventClass),
366 };
367 
368 static void register_types(void)
369 {
370     type_register_static(&sclp_console_info);
371 }
372 
373 type_init(register_types)
374