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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, write to the Free Software Foundation, Inc., | |
20 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. | |
21 | */ | |
22 | ||
23 | #include <stdlib.h> | |
24 | #include <errno.h> | |
25 | #include <string.h> | |
26 | #include <sys/select.h> | |
27 | #include <fcntl.h> | |
28 | #include <unistd.h> | |
29 | #include <termios.h> | |
30 | #include <stdarg.h> | |
31 | #include <sys/mman.h> | |
32 | #include <xs.h> | |
33 | #include <xen/io/console.h> | |
34 | #include <xenctrl.h> | |
35 | ||
36 | #include "hw.h" | |
37 | #include "sysemu.h" | |
38 | #include "qemu-char.h" | |
39 | #include "xen_backend.h" | |
40 | ||
41 | struct buffer { | |
42 | uint8_t *data; | |
43 | size_t consumed; | |
44 | size_t size; | |
45 | size_t capacity; | |
46 | size_t max_capacity; | |
47 | }; | |
48 | ||
49 | struct XenConsole { | |
50 | struct XenDevice xendev; /* must be first */ | |
51 | struct buffer buffer; | |
52 | char console[XEN_BUFSIZE]; | |
53 | int ring_ref; | |
54 | void *sring; | |
55 | CharDriverState *chr; | |
56 | int backlog; | |
57 | }; | |
58 | ||
59 | static void buffer_append(struct XenConsole *con) | |
60 | { | |
61 | struct buffer *buffer = &con->buffer; | |
62 | XENCONS_RING_IDX cons, prod, size; | |
63 | struct xencons_interface *intf = con->sring; | |
64 | ||
65 | cons = intf->out_cons; | |
66 | prod = intf->out_prod; | |
67 | xen_mb(); | |
68 | ||
69 | size = prod - cons; | |
70 | if ((size == 0) || (size > sizeof(intf->out))) | |
71 | return; | |
72 | ||
73 | if ((buffer->capacity - buffer->size) < size) { | |
74 | buffer->capacity += (size + 1024); | |
75 | buffer->data = qemu_realloc(buffer->data, buffer->capacity); | |
76 | } | |
77 | ||
78 | while (cons != prod) | |
79 | buffer->data[buffer->size++] = intf->out[ | |
80 | MASK_XENCONS_IDX(cons++, intf->out)]; | |
81 | ||
82 | xen_mb(); | |
83 | intf->out_cons = cons; | |
84 | xen_be_send_notify(&con->xendev); | |
85 | ||
86 | if (buffer->max_capacity && | |
87 | buffer->size > buffer->max_capacity) { | |
88 | /* Discard the middle of the data. */ | |
89 | ||
90 | size_t over = buffer->size - buffer->max_capacity; | |
91 | uint8_t *maxpos = buffer->data + buffer->max_capacity; | |
92 | ||
93 | memmove(maxpos - over, maxpos, over); | |
94 | buffer->data = qemu_realloc(buffer->data, buffer->max_capacity); | |
95 | buffer->size = buffer->capacity = buffer->max_capacity; | |
96 | ||
97 | if (buffer->consumed > buffer->max_capacity - over) | |
98 | buffer->consumed = buffer->max_capacity - over; | |
99 | } | |
100 | } | |
101 | ||
102 | static void buffer_advance(struct buffer *buffer, size_t len) | |
103 | { | |
104 | buffer->consumed += len; | |
105 | if (buffer->consumed == buffer->size) { | |
106 | buffer->consumed = 0; | |
107 | buffer->size = 0; | |
108 | } | |
109 | } | |
110 | ||
111 | static int ring_free_bytes(struct XenConsole *con) | |
112 | { | |
113 | struct xencons_interface *intf = con->sring; | |
114 | XENCONS_RING_IDX cons, prod, space; | |
115 | ||
116 | cons = intf->in_cons; | |
117 | prod = intf->in_prod; | |
118 | xen_mb(); | |
119 | ||
120 | space = prod - cons; | |
121 | if (space > sizeof(intf->in)) | |
122 | return 0; /* ring is screwed: ignore it */ | |
123 | ||
124 | return (sizeof(intf->in) - space); | |
125 | } | |
126 | ||
127 | static int xencons_can_receive(void *opaque) | |
128 | { | |
129 | struct XenConsole *con = opaque; | |
130 | return ring_free_bytes(con); | |
131 | } | |
132 | ||
133 | static void xencons_receive(void *opaque, const uint8_t *buf, int len) | |
134 | { | |
135 | struct XenConsole *con = opaque; | |
136 | struct xencons_interface *intf = con->sring; | |
137 | XENCONS_RING_IDX prod; | |
138 | int i, max; | |
139 | ||
140 | max = ring_free_bytes(con); | |
141 | /* The can_receive() func limits this, but check again anyway */ | |
142 | if (max < len) | |
143 | len = max; | |
144 | ||
145 | prod = intf->in_prod; | |
146 | for (i = 0; i < len; i++) { | |
147 | intf->in[MASK_XENCONS_IDX(prod++, intf->in)] = | |
148 | buf[i]; | |
149 | } | |
150 | xen_wmb(); | |
151 | intf->in_prod = prod; | |
152 | xen_be_send_notify(&con->xendev); | |
153 | } | |
154 | ||
155 | static void xencons_send(struct XenConsole *con) | |
156 | { | |
157 | ssize_t len, size; | |
158 | ||
159 | size = con->buffer.size - con->buffer.consumed; | |
160 | if (con->chr) | |
161 | len = qemu_chr_write(con->chr, con->buffer.data + con->buffer.consumed, | |
162 | size); | |
163 | else | |
164 | len = size; | |
165 | if (len < 1) { | |
166 | if (!con->backlog) { | |
167 | con->backlog = 1; | |
168 | xen_be_printf(&con->xendev, 1, "backlog piling up, nobody listening?\n"); | |
169 | } | |
170 | } else { | |
171 | buffer_advance(&con->buffer, len); | |
172 | if (con->backlog && len == size) { | |
173 | con->backlog = 0; | |
174 | xen_be_printf(&con->xendev, 1, "backlog is gone\n"); | |
175 | } | |
176 | } | |
177 | } | |
178 | ||
179 | /* -------------------------------------------------------------------- */ | |
180 | ||
181 | static int con_init(struct XenDevice *xendev) | |
182 | { | |
183 | struct XenConsole *con = container_of(xendev, struct XenConsole, xendev); | |
184 | char *type, *dom; | |
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"); | |
96248fd8 | 192 | if (!type || strcmp(type, "ioemu") != 0) { |
e57dd20b AL |
193 | xen_be_printf(xendev, 1, "not for me (type=%s)\n", type); |
194 | return -1; | |
195 | } | |
196 | ||
197 | if (!serial_hds[con->xendev.dev]) | |
198 | xen_be_printf(xendev, 1, "WARNING: serial line %d not configured\n", | |
199 | con->xendev.dev); | |
200 | else | |
201 | con->chr = serial_hds[con->xendev.dev]; | |
202 | ||
203 | return 0; | |
204 | } | |
205 | ||
206 | static int con_connect(struct XenDevice *xendev) | |
207 | { | |
208 | struct XenConsole *con = container_of(xendev, struct XenConsole, xendev); | |
209 | int limit; | |
210 | ||
211 | if (xenstore_read_int(con->console, "ring-ref", &con->ring_ref) == -1) | |
212 | return -1; | |
213 | if (xenstore_read_int(con->console, "port", &con->xendev.remote_port) == -1) | |
214 | return -1; | |
215 | if (xenstore_read_int(con->console, "limit", &limit) == 0) | |
216 | con->buffer.max_capacity = limit; | |
217 | ||
218 | con->sring = xc_map_foreign_range(xen_xc, con->xendev.dom, | |
219 | XC_PAGE_SIZE, | |
220 | PROT_READ|PROT_WRITE, | |
221 | con->ring_ref); | |
222 | if (!con->sring) | |
223 | return -1; | |
224 | ||
225 | xen_be_bind_evtchn(&con->xendev); | |
226 | if (con->chr) | |
227 | qemu_chr_add_handlers(con->chr, xencons_can_receive, xencons_receive, | |
228 | NULL, con); | |
229 | ||
230 | xen_be_printf(xendev, 1, "ring mfn %d, remote port %d, local port %d, limit %zd\n", | |
231 | con->ring_ref, | |
232 | con->xendev.remote_port, | |
233 | con->xendev.local_port, | |
234 | con->buffer.max_capacity); | |
235 | return 0; | |
236 | } | |
237 | ||
238 | static void con_disconnect(struct XenDevice *xendev) | |
239 | { | |
240 | struct XenConsole *con = container_of(xendev, struct XenConsole, xendev); | |
241 | ||
242 | if (con->chr) | |
243 | qemu_chr_add_handlers(con->chr, NULL, NULL, NULL, NULL); | |
244 | xen_be_unbind_evtchn(&con->xendev); | |
245 | ||
246 | if (con->sring) { | |
247 | munmap(con->sring, XC_PAGE_SIZE); | |
248 | con->sring = NULL; | |
249 | } | |
250 | } | |
251 | ||
252 | static void con_event(struct XenDevice *xendev) | |
253 | { | |
254 | struct XenConsole *con = container_of(xendev, struct XenConsole, xendev); | |
255 | ||
256 | buffer_append(con); | |
257 | if (con->buffer.size - con->buffer.consumed) | |
258 | xencons_send(con); | |
259 | } | |
260 | ||
261 | /* -------------------------------------------------------------------- */ | |
262 | ||
263 | struct XenDevOps xen_console_ops = { | |
264 | .size = sizeof(struct XenConsole), | |
265 | .flags = DEVOPS_FLAG_IGNORE_STATE, | |
266 | .init = con_init, | |
267 | .connect = con_connect, | |
268 | .event = con_event, | |
269 | .disconnect = con_disconnect, | |
270 | }; |