PPC: e500: msync is 440 only, e500 has real sync
[qemu.git] / hw / xen_console.c
1 /*
2 * Copyright (C) International Business Machines Corp., 2005
3 * Author(s): Anthony Liguori <aliguori@us.ibm.com>
4 *
5 * Copyright (C) Red Hat 2007
6 *
7 * Xen Console
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; under version 2 of the License.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, see <http://www.gnu.org/licenses/>.
20 */
21
22 #include <stdlib.h>
23 #include <errno.h>
24 #include <string.h>
25 #include <sys/select.h>
26 #include <fcntl.h>
27 #include <unistd.h>
28 #include <termios.h>
29 #include <stdarg.h>
30 #include <sys/mman.h>
31 #include <xs.h>
32 #include <xen/io/console.h>
33 #include <xenctrl.h>
34
35 #include "hw.h"
36 #include "qemu-char.h"
37 #include "xen_backend.h"
38
39 struct buffer {
40 uint8_t *data;
41 size_t consumed;
42 size_t size;
43 size_t capacity;
44 size_t max_capacity;
45 };
46
47 struct XenConsole {
48 struct XenDevice xendev; /* must be first */
49 struct buffer buffer;
50 char console[XEN_BUFSIZE];
51 int ring_ref;
52 void *sring;
53 CharDriverState *chr;
54 int backlog;
55 };
56
57 static void buffer_append(struct XenConsole *con)
58 {
59 struct buffer *buffer = &con->buffer;
60 XENCONS_RING_IDX cons, prod, size;
61 struct xencons_interface *intf = con->sring;
62
63 cons = intf->out_cons;
64 prod = intf->out_prod;
65 xen_mb();
66
67 size = prod - cons;
68 if ((size == 0) || (size > sizeof(intf->out)))
69 return;
70
71 if ((buffer->capacity - buffer->size) < size) {
72 buffer->capacity += (size + 1024);
73 buffer->data = g_realloc(buffer->data, buffer->capacity);
74 }
75
76 while (cons != prod)
77 buffer->data[buffer->size++] = intf->out[
78 MASK_XENCONS_IDX(cons++, intf->out)];
79
80 xen_mb();
81 intf->out_cons = cons;
82 xen_be_send_notify(&con->xendev);
83
84 if (buffer->max_capacity &&
85 buffer->size > buffer->max_capacity) {
86 /* Discard the middle of the data. */
87
88 size_t over = buffer->size - buffer->max_capacity;
89 uint8_t *maxpos = buffer->data + buffer->max_capacity;
90
91 memmove(maxpos - over, maxpos, over);
92 buffer->data = g_realloc(buffer->data, buffer->max_capacity);
93 buffer->size = buffer->capacity = buffer->max_capacity;
94
95 if (buffer->consumed > buffer->max_capacity - over)
96 buffer->consumed = buffer->max_capacity - over;
97 }
98 }
99
100 static void buffer_advance(struct buffer *buffer, size_t len)
101 {
102 buffer->consumed += len;
103 if (buffer->consumed == buffer->size) {
104 buffer->consumed = 0;
105 buffer->size = 0;
106 }
107 }
108
109 static int ring_free_bytes(struct XenConsole *con)
110 {
111 struct xencons_interface *intf = con->sring;
112 XENCONS_RING_IDX cons, prod, space;
113
114 cons = intf->in_cons;
115 prod = intf->in_prod;
116 xen_mb();
117
118 space = prod - cons;
119 if (space > sizeof(intf->in))
120 return 0; /* ring is screwed: ignore it */
121
122 return (sizeof(intf->in) - space);
123 }
124
125 static int xencons_can_receive(void *opaque)
126 {
127 struct XenConsole *con = opaque;
128 return ring_free_bytes(con);
129 }
130
131 static void xencons_receive(void *opaque, const uint8_t *buf, int len)
132 {
133 struct XenConsole *con = opaque;
134 struct xencons_interface *intf = con->sring;
135 XENCONS_RING_IDX prod;
136 int i, max;
137
138 max = ring_free_bytes(con);
139 /* The can_receive() func limits this, but check again anyway */
140 if (max < len)
141 len = max;
142
143 prod = intf->in_prod;
144 for (i = 0; i < len; i++) {
145 intf->in[MASK_XENCONS_IDX(prod++, intf->in)] =
146 buf[i];
147 }
148 xen_wmb();
149 intf->in_prod = prod;
150 xen_be_send_notify(&con->xendev);
151 }
152
153 static void xencons_send(struct XenConsole *con)
154 {
155 ssize_t len, size;
156
157 size = con->buffer.size - con->buffer.consumed;
158 if (con->chr)
159 len = qemu_chr_fe_write(con->chr, con->buffer.data + con->buffer.consumed,
160 size);
161 else
162 len = size;
163 if (len < 1) {
164 if (!con->backlog) {
165 con->backlog = 1;
166 xen_be_printf(&con->xendev, 1, "backlog piling up, nobody listening?\n");
167 }
168 } else {
169 buffer_advance(&con->buffer, len);
170 if (con->backlog && len == size) {
171 con->backlog = 0;
172 xen_be_printf(&con->xendev, 1, "backlog is gone\n");
173 }
174 }
175 }
176
177 /* -------------------------------------------------------------------- */
178
179 static int con_init(struct XenDevice *xendev)
180 {
181 struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
182 char *type, *dom, label[32];
183 int ret = 0;
184 const char *output;
185
186 /* setup */
187 dom = xs_get_domain_path(xenstore, con->xendev.dom);
188 snprintf(con->console, sizeof(con->console), "%s/console", dom);
189 free(dom);
190
191 type = xenstore_read_str(con->console, "type");
192 if (!type || strcmp(type, "ioemu") != 0) {
193 xen_be_printf(xendev, 1, "not for me (type=%s)\n", type);
194 ret = -1;
195 goto out;
196 }
197
198 output = xenstore_read_str(con->console, "output");
199
200 /* no Xen override, use qemu output device */
201 if (output == NULL) {
202 con->chr = serial_hds[con->xendev.dev];
203 } else {
204 snprintf(label, sizeof(label), "xencons%d", con->xendev.dev);
205 con->chr = qemu_chr_new(label, output, NULL);
206 }
207
208 xenstore_store_pv_console_info(con->xendev.dev, con->chr);
209
210 out:
211 g_free(type);
212 return ret;
213 }
214
215 static int con_initialise(struct XenDevice *xendev)
216 {
217 struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
218 int limit;
219
220 if (xenstore_read_int(con->console, "ring-ref", &con->ring_ref) == -1)
221 return -1;
222 if (xenstore_read_int(con->console, "port", &con->xendev.remote_port) == -1)
223 return -1;
224 if (xenstore_read_int(con->console, "limit", &limit) == 0)
225 con->buffer.max_capacity = limit;
226
227 con->sring = xc_map_foreign_range(xen_xc, con->xendev.dom,
228 XC_PAGE_SIZE,
229 PROT_READ|PROT_WRITE,
230 con->ring_ref);
231 if (!con->sring)
232 return -1;
233
234 xen_be_bind_evtchn(&con->xendev);
235 if (con->chr)
236 qemu_chr_add_handlers(con->chr, xencons_can_receive, xencons_receive,
237 NULL, con);
238
239 xen_be_printf(xendev, 1, "ring mfn %d, remote port %d, local port %d, limit %zd\n",
240 con->ring_ref,
241 con->xendev.remote_port,
242 con->xendev.local_port,
243 con->buffer.max_capacity);
244 return 0;
245 }
246
247 static void con_disconnect(struct XenDevice *xendev)
248 {
249 struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
250
251 if (con->chr)
252 qemu_chr_add_handlers(con->chr, NULL, NULL, NULL, NULL);
253 xen_be_unbind_evtchn(&con->xendev);
254
255 if (con->sring) {
256 munmap(con->sring, XC_PAGE_SIZE);
257 con->sring = NULL;
258 }
259 }
260
261 static void con_event(struct XenDevice *xendev)
262 {
263 struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
264
265 buffer_append(con);
266 if (con->buffer.size - con->buffer.consumed)
267 xencons_send(con);
268 }
269
270 /* -------------------------------------------------------------------- */
271
272 struct XenDevOps xen_console_ops = {
273 .size = sizeof(struct XenConsole),
274 .flags = DEVOPS_FLAG_IGNORE_STATE,
275 .init = con_init,
276 .initialise = con_initialise,
277 .event = con_event,
278 .disconnect = con_disconnect,
279 };