xref: /qemu/hw/char/sclpconsole-lm.c (revision e3a6e0da) 
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/s390x/ebcdic.h"
27 #include "qom/object.h"
28 
29 #define SIZE_BUFFER 4096
30 #define NEWLINE     "\n"
31 
32 typedef struct OprtnsCommand {
33     EventBufferHeader header;
34     MDMSU message_unit;
35     char data[];
36 } QEMU_PACKED OprtnsCommand;
37 
38 /* max size for line-mode data in 4K SCCB page */
39 #define SIZE_CONSOLE_BUFFER (SCCB_DATA_LEN - sizeof(OprtnsCommand))
40 
41 struct SCLPConsoleLM {
42     SCLPEvent event;
43     CharBackend chr;
44     bool echo;                  /* immediate echo of input if true        */
45     uint32_t write_errors;      /* errors writing to char layer           */
46     uint32_t length;            /* length of byte stream in buffer        */
47     uint8_t buf[SIZE_CONSOLE_BUFFER];
48 };
49 typedef struct SCLPConsoleLM SCLPConsoleLM;
50 
51 #define TYPE_SCLPLM_CONSOLE "sclplmconsole"
52 DECLARE_INSTANCE_CHECKER(SCLPConsoleLM, SCLPLM_CONSOLE,
53                          TYPE_SCLPLM_CONSOLE)
54 
55 /*
56 *  Character layer call-back functions
57  *
58  * Allow 1 character at a time
59  *
60  * Accumulate bytes from character layer in console buffer,
61  * event_pending is set when a newline character is encountered
62  *
63  * The maximum command line length is limited by the maximum
64  * space available in an SCCB. Line mode console input is sent
65  * truncated to the guest in case it doesn't fit into the SCCB.
66  */
67 
68 static int chr_can_read(void *opaque)
69 {
70     SCLPConsoleLM *scon = opaque;
71 
72     if (scon->event.event_pending) {
73         return 0;
74     }
75     return 1;
76 }
77 
78 static void chr_read(void *opaque, const uint8_t *buf, int size)
79 {
80     SCLPConsoleLM *scon = opaque;
81 
82     assert(size == 1);
83 
84     if (*buf == '\r' || *buf == '\n') {
85         scon->event.event_pending = true;
86         sclp_service_interrupt(0);
87         return;
88     }
89     if (scon->length == SIZE_CONSOLE_BUFFER) {
90         /* Eat the character, but still process CR and LF.  */
91         return;
92     }
93     scon->buf[scon->length] = *buf;
94     scon->length += 1;
95     if (scon->echo) {
96         /* XXX this blocks entire thread. Rewrite to use
97          * qemu_chr_fe_write and background I/O callbacks */
98         qemu_chr_fe_write_all(&scon->chr, buf, size);
99     }
100 }
101 
102 /* functions to be called by event facility */
103 
104 static bool can_handle_event(uint8_t type)
105 {
106     return type == SCLP_EVENT_MESSAGE || type == SCLP_EVENT_PMSGCMD;
107 }
108 
109 static sccb_mask_t send_mask(void)
110 {
111     return SCLP_EVENT_MASK_OP_CMD | SCLP_EVENT_MASK_PMSGCMD;
112 }
113 
114 static sccb_mask_t receive_mask(void)
115 {
116     return SCLP_EVENT_MASK_MSG | SCLP_EVENT_MASK_PMSGCMD;
117 }
118 
119 /*
120  * Triggered by SCLP's read_event_data
121  * - convert ASCII byte stream to EBCDIC and
122  * - copy converted data into provided (SCLP) buffer
123  */
124 static int get_console_data(SCLPEvent *event, uint8_t *buf, size_t *size,
125                             int avail)
126 {
127     int len;
128 
129     SCLPConsoleLM *cons = SCLPLM_CONSOLE(event);
130 
131     len = cons->length;
132     /* data need to fit into provided SCLP buffer */
133     if (len > avail) {
134         return 1;
135     }
136 
137     ebcdic_put(buf, (char *)&cons->buf, len);
138     *size = len;
139     cons->length = 0;
140     /* data provided and no more data pending */
141     event->event_pending = false;
142     qemu_notify_event();
143     return 0;
144 }
145 
146 static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
147                            int *slen)
148 {
149     int avail, rc;
150     size_t src_len;
151     uint8_t *to;
152     OprtnsCommand *oc = (OprtnsCommand *) evt_buf_hdr;
153 
154     if (!event->event_pending) {
155         /* no data pending */
156         return 0;
157     }
158 
159     to = (uint8_t *)&oc->data;
160     avail = *slen - sizeof(OprtnsCommand);
161     rc = get_console_data(event, to, &src_len, avail);
162     if (rc) {
163         /* data didn't fit, try next SCCB */
164         return 1;
165     }
166 
167     oc->message_unit.mdmsu.gds_id = GDS_ID_MDSMU;
168     oc->message_unit.mdmsu.length = cpu_to_be16(sizeof(struct MDMSU));
169 
170     oc->message_unit.cpmsu.gds_id = GDS_ID_CPMSU;
171     oc->message_unit.cpmsu.length =
172         cpu_to_be16(sizeof(struct MDMSU) - sizeof(GdsVector));
173 
174     oc->message_unit.text_command.gds_id = GDS_ID_TEXTCMD;
175     oc->message_unit.text_command.length =
176         cpu_to_be16(sizeof(struct MDMSU) - (2 * sizeof(GdsVector)));
177 
178     oc->message_unit.self_def_text_message.key = GDS_KEY_SELFDEFTEXTMSG;
179     oc->message_unit.self_def_text_message.length =
180         cpu_to_be16(sizeof(struct MDMSU) - (3 * sizeof(GdsVector)));
181 
182     oc->message_unit.text_message.key = GDS_KEY_TEXTMSG;
183     oc->message_unit.text_message.length =
184         cpu_to_be16(sizeof(GdsSubvector) + src_len);
185 
186     oc->header.length = cpu_to_be16(sizeof(OprtnsCommand) + src_len);
187     oc->header.type = SCLP_EVENT_OPRTNS_COMMAND;
188     *slen = avail - src_len;
189 
190     return 1;
191 }
192 
193 /*
194  * Triggered by SCLP's write_event_data
195  *  - write console data to character layer
196  *  returns < 0 if an error occurred
197  */
198 static int write_console_data(SCLPEvent *event, const uint8_t *buf, int len)
199 {
200     SCLPConsoleLM *scon = SCLPLM_CONSOLE(event);
201 
202     if (!qemu_chr_fe_backend_connected(&scon->chr)) {
203         /* If there's no backend, we can just say we consumed all data. */
204         return len;
205     }
206 
207     /* XXX this blocks entire thread. Rewrite to use
208      * qemu_chr_fe_write and background I/O callbacks */
209     return qemu_chr_fe_write_all(&scon->chr, buf, len);
210 }
211 
212 static int process_mdb(SCLPEvent *event, MDBO *mdbo)
213 {
214     int rc;
215     int len;
216     uint8_t buffer[SIZE_BUFFER];
217 
218     len = be16_to_cpu(mdbo->length);
219     len -= sizeof(mdbo->length) + sizeof(mdbo->type)
220             + sizeof(mdbo->mto.line_type_flags)
221             + sizeof(mdbo->mto.alarm_control)
222             + sizeof(mdbo->mto._reserved);
223 
224     assert(len <= SIZE_BUFFER);
225 
226     /* convert EBCDIC SCLP contents to ASCII console message */
227     ascii_put(buffer, mdbo->mto.message, len);
228     rc = write_console_data(event, (uint8_t *)NEWLINE, 1);
229     if (rc < 0) {
230         return rc;
231     }
232     return write_console_data(event, buffer, len);
233 }
234 
235 static int write_event_data(SCLPEvent *event, EventBufferHeader *ebh)
236 {
237     int len;
238     int written;
239     int errors = 0;
240     MDBO *mdbo;
241     SclpMsg *data = (SclpMsg *) ebh;
242     SCLPConsoleLM *scon = SCLPLM_CONSOLE(event);
243 
244     len = be16_to_cpu(data->mdb.header.length);
245     if (len < sizeof(data->mdb.header)) {
246         return SCLP_RC_INCONSISTENT_LENGTHS;
247     }
248     len -= sizeof(data->mdb.header);
249 
250     /* first check message buffers */
251     mdbo = data->mdb.mdbo;
252     while (len > 0) {
253         if (be16_to_cpu(mdbo->length) > len
254                 || be16_to_cpu(mdbo->length) == 0) {
255             return SCLP_RC_INCONSISTENT_LENGTHS;
256         }
257         len -= be16_to_cpu(mdbo->length);
258         mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
259     }
260 
261     /* then execute */
262     len = be16_to_cpu(data->mdb.header.length) - sizeof(data->mdb.header);
263     mdbo = data->mdb.mdbo;
264     while (len > 0) {
265         switch (be16_to_cpu(mdbo->type)) {
266         case MESSAGE_TEXT:
267             /* message text object */
268             written = process_mdb(event, mdbo);
269             if (written < 0) {
270                 /* character layer error */
271                 errors++;
272             }
273             break;
274         default: /* ignore */
275             break;
276         }
277         len -= be16_to_cpu(mdbo->length);
278         mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
279     }
280     if (errors) {
281         scon->write_errors += errors;
282     }
283     data->header.flags = SCLP_EVENT_BUFFER_ACCEPTED;
284 
285     return SCLP_RC_NORMAL_COMPLETION;
286 }
287 
288 /* functions for live migration */
289 
290 static const VMStateDescription vmstate_sclplmconsole = {
291     .name = "sclplmconsole",
292     .version_id = 0,
293     .minimum_version_id = 0,
294     .fields = (VMStateField[]) {
295         VMSTATE_BOOL(event.event_pending, SCLPConsoleLM),
296         VMSTATE_UINT32(write_errors, SCLPConsoleLM),
297         VMSTATE_UINT32(length, SCLPConsoleLM),
298         VMSTATE_UINT8_ARRAY(buf, SCLPConsoleLM, SIZE_CONSOLE_BUFFER),
299         VMSTATE_END_OF_LIST()
300      }
301 };
302 
303 /* qemu object creation and initialization functions */
304 
305 /* tell character layer our call-back functions */
306 
307 static int console_init(SCLPEvent *event)
308 {
309     static bool console_available;
310 
311     SCLPConsoleLM *scon = SCLPLM_CONSOLE(event);
312 
313     if (console_available) {
314         error_report("Multiple line-mode operator consoles are not supported");
315         return -1;
316     }
317     console_available = true;
318 
319     qemu_chr_fe_set_handlers(&scon->chr, chr_can_read,
320                              chr_read, NULL, NULL, scon, NULL, true);
321 
322     return 0;
323 }
324 
325 static void console_reset(DeviceState *dev)
326 {
327    SCLPEvent *event = SCLP_EVENT(dev);
328    SCLPConsoleLM *scon = SCLPLM_CONSOLE(event);
329 
330    event->event_pending = false;
331    scon->length = 0;
332    scon->write_errors = 0;
333 }
334 
335 static Property console_properties[] = {
336     DEFINE_PROP_CHR("chardev", SCLPConsoleLM, chr),
337     DEFINE_PROP_UINT32("write_errors", SCLPConsoleLM, write_errors, 0),
338     DEFINE_PROP_BOOL("echo", SCLPConsoleLM, echo, true),
339     DEFINE_PROP_END_OF_LIST(),
340 };
341 
342 static void console_class_init(ObjectClass *klass, void *data)
343 {
344     DeviceClass *dc = DEVICE_CLASS(klass);
345     SCLPEventClass *ec = SCLP_EVENT_CLASS(klass);
346 
347     device_class_set_props(dc, console_properties);
348     dc->reset = console_reset;
349     dc->vmsd = &vmstate_sclplmconsole;
350     ec->init = console_init;
351     ec->get_send_mask = send_mask;
352     ec->get_receive_mask = receive_mask;
353     ec->can_handle_event = can_handle_event;
354     ec->read_event_data = read_event_data;
355     ec->write_event_data = write_event_data;
356     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
357 }
358 
359 static const TypeInfo sclp_console_info = {
360     .name          = TYPE_SCLPLM_CONSOLE,
361     .parent        = TYPE_SCLP_EVENT,
362     .instance_size = sizeof(SCLPConsoleLM),
363     .class_init    = console_class_init,
364     .class_size    = sizeof(SCLPEventClass),
365 };
366 
367 static void register_types(void)
368 {
369     type_register_static(&sclp_console_info);
370 }
371 
372 type_init(register_types)
373