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