1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22#include "qemu/osdep.h"
23#include <sys/select.h>
24#include <termios.h>
25#include <sys/mman.h>
26
27#include "hw/hw.h"
28#include "sysemu/char.h"
29#include "hw/xen/xen_backend.h"
30
31#include <xen/io/console.h>
32
33struct buffer {
34 uint8_t *data;
35 size_t consumed;
36 size_t size;
37 size_t capacity;
38 size_t max_capacity;
39};
40
41struct XenConsole {
42 struct XenDevice xendev;
43 struct buffer buffer;
44 char console[XEN_BUFSIZE];
45 int ring_ref;
46 void *sring;
47 CharDriverState *chr;
48 int backlog;
49};
50
51static void buffer_append(struct XenConsole *con)
52{
53 struct buffer *buffer = &con->buffer;
54 XENCONS_RING_IDX cons, prod, size;
55 struct xencons_interface *intf = con->sring;
56
57 cons = intf->out_cons;
58 prod = intf->out_prod;
59 xen_mb();
60
61 size = prod - cons;
62 if ((size == 0) || (size > sizeof(intf->out)))
63 return;
64
65 if ((buffer->capacity - buffer->size) < size) {
66 buffer->capacity += (size + 1024);
67 buffer->data = g_realloc(buffer->data, buffer->capacity);
68 }
69
70 while (cons != prod)
71 buffer->data[buffer->size++] = intf->out[
72 MASK_XENCONS_IDX(cons++, intf->out)];
73
74 xen_mb();
75 intf->out_cons = cons;
76 xen_be_send_notify(&con->xendev);
77
78 if (buffer->max_capacity &&
79 buffer->size > buffer->max_capacity) {
80
81
82 size_t over = buffer->size - buffer->max_capacity;
83 uint8_t *maxpos = buffer->data + buffer->max_capacity;
84
85 memmove(maxpos - over, maxpos, over);
86 buffer->data = g_realloc(buffer->data, buffer->max_capacity);
87 buffer->size = buffer->capacity = buffer->max_capacity;
88
89 if (buffer->consumed > buffer->max_capacity - over)
90 buffer->consumed = buffer->max_capacity - over;
91 }
92}
93
94static void buffer_advance(struct buffer *buffer, size_t len)
95{
96 buffer->consumed += len;
97 if (buffer->consumed == buffer->size) {
98 buffer->consumed = 0;
99 buffer->size = 0;
100 }
101}
102
103static int ring_free_bytes(struct XenConsole *con)
104{
105 struct xencons_interface *intf = con->sring;
106 XENCONS_RING_IDX cons, prod, space;
107
108 cons = intf->in_cons;
109 prod = intf->in_prod;
110 xen_mb();
111
112 space = prod - cons;
113 if (space > sizeof(intf->in))
114 return 0;
115
116 return (sizeof(intf->in) - space);
117}
118
119static int xencons_can_receive(void *opaque)
120{
121 struct XenConsole *con = opaque;
122 return ring_free_bytes(con);
123}
124
125static void xencons_receive(void *opaque, const uint8_t *buf, int len)
126{
127 struct XenConsole *con = opaque;
128 struct xencons_interface *intf = con->sring;
129 XENCONS_RING_IDX prod;
130 int i, max;
131
132 max = ring_free_bytes(con);
133
134 if (max < len)
135 len = max;
136
137 prod = intf->in_prod;
138 for (i = 0; i < len; i++) {
139 intf->in[MASK_XENCONS_IDX(prod++, intf->in)] =
140 buf[i];
141 }
142 xen_wmb();
143 intf->in_prod = prod;
144 xen_be_send_notify(&con->xendev);
145}
146
147static void xencons_send(struct XenConsole *con)
148{
149 ssize_t len, size;
150
151 size = con->buffer.size - con->buffer.consumed;
152 if (con->chr)
153 len = qemu_chr_fe_write(con->chr, con->buffer.data + con->buffer.consumed,
154 size);
155 else
156 len = size;
157 if (len < 1) {
158 if (!con->backlog) {
159 con->backlog = 1;
160 xen_be_printf(&con->xendev, 1, "backlog piling up, nobody listening?\n");
161 }
162 } else {
163 buffer_advance(&con->buffer, len);
164 if (con->backlog && len == size) {
165 con->backlog = 0;
166 xen_be_printf(&con->xendev, 1, "backlog is gone\n");
167 }
168 }
169}
170
171
172
173static int con_init(struct XenDevice *xendev)
174{
175 struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
176 char *type, *dom, label[32];
177 int ret = 0;
178 const char *output;
179
180
181 dom = xs_get_domain_path(xenstore, con->xendev.dom);
182 if (!xendev->dev) {
183 snprintf(con->console, sizeof(con->console), "%s/console", dom);
184 } else {
185 snprintf(con->console, sizeof(con->console), "%s/device/console/%d", dom, xendev->dev);
186 }
187 free(dom);
188
189 type = xenstore_read_str(con->console, "type");
190 if (!type || strcmp(type, "ioemu") != 0) {
191 xen_be_printf(xendev, 1, "not for me (type=%s)\n", type);
192 ret = -1;
193 goto out;
194 }
195
196 output = xenstore_read_str(con->console, "output");
197
198
199 if (output == NULL) {
200 con->chr = serial_hds[con->xendev.dev];
201 } else {
202 snprintf(label, sizeof(label), "xencons%d", con->xendev.dev);
203 con->chr = qemu_chr_new(label, output, NULL);
204 }
205
206 xenstore_store_pv_console_info(con->xendev.dev, con->chr);
207
208out:
209 g_free(type);
210 return ret;
211}
212
213static int con_initialise(struct XenDevice *xendev)
214{
215 struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
216 int limit;
217
218 if (xenstore_read_int(con->console, "ring-ref", &con->ring_ref) == -1)
219 return -1;
220 if (xenstore_read_int(con->console, "port", &con->xendev.remote_port) == -1)
221 return -1;
222 if (xenstore_read_int(con->console, "limit", &limit) == 0)
223 con->buffer.max_capacity = limit;
224
225 if (!xendev->dev) {
226 xen_pfn_t mfn = con->ring_ref;
227 con->sring = xenforeignmemory_map(xen_fmem, con->xendev.dom,
228 PROT_READ|PROT_WRITE,
229 1, &mfn, NULL);
230 } else {
231 con->sring = xengnttab_map_grant_ref(xendev->gnttabdev, con->xendev.dom,
232 con->ring_ref,
233 PROT_READ|PROT_WRITE);
234 }
235 if (!con->sring)
236 return -1;
237
238 xen_be_bind_evtchn(&con->xendev);
239 if (con->chr) {
240 if (qemu_chr_fe_claim(con->chr) == 0) {
241 qemu_chr_add_handlers(con->chr, xencons_can_receive,
242 xencons_receive, NULL, con);
243 } else {
244 xen_be_printf(xendev, 0,
245 "xen_console_init error chardev %s already used\n",
246 con->chr->label);
247 con->chr = NULL;
248 }
249 }
250
251 xen_be_printf(xendev, 1, "ring mfn %d, remote port %d, local port %d, limit %zd\n",
252 con->ring_ref,
253 con->xendev.remote_port,
254 con->xendev.local_port,
255 con->buffer.max_capacity);
256 return 0;
257}
258
259static void con_disconnect(struct XenDevice *xendev)
260{
261 struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
262
263 if (con->chr) {
264 qemu_chr_add_handlers(con->chr, NULL, NULL, NULL, NULL);
265 qemu_chr_fe_release(con->chr);
266 }
267 xen_be_unbind_evtchn(&con->xendev);
268
269 if (con->sring) {
270 if (!xendev->dev) {
271 xenforeignmemory_unmap(xen_fmem, con->sring, 1);
272 } else {
273 xengnttab_unmap(xendev->gnttabdev, con->sring, 1);
274 }
275 con->sring = NULL;
276 }
277}
278
279static void con_event(struct XenDevice *xendev)
280{
281 struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
282
283 buffer_append(con);
284 if (con->buffer.size - con->buffer.consumed)
285 xencons_send(con);
286}
287
288
289
290struct XenDevOps xen_console_ops = {
291 .size = sizeof(struct XenConsole),
292 .flags = DEVOPS_FLAG_IGNORE_STATE|DEVOPS_FLAG_NEED_GNTDEV,
293 .init = con_init,
294 .initialise = con_initialise,
295 .event = con_event,
296 .disconnect = con_disconnect,
297};
298
