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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
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 CharBackend 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_pv_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_pv_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 (qemu_chr_fe_backend_connected(&con->chr)) {
153 len = qemu_chr_fe_write(&con->chr,
154 con->buffer.data + con->buffer.consumed,
155 size);
156 } else {
157 len = size;
158 }
159 if (len < 1) {
160 if (!con->backlog) {
161 con->backlog = 1;
162 xen_pv_printf(&con->xendev, 1,
163 "backlog piling up, nobody listening?\n");
164 }
165 } else {
166 buffer_advance(&con->buffer, len);
167 if (con->backlog && len == size) {
168 con->backlog = 0;
169 xen_pv_printf(&con->xendev, 1, "backlog is gone\n");
170 }
171 }
172}
173
174
175
176static int con_init(struct XenDevice *xendev)
177{
178 struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
179 char *type, *dom, label[32];
180 int ret = 0;
181 const char *output;
182
183
184 dom = xs_get_domain_path(xenstore, con->xendev.dom);
185 if (!xendev->dev) {
186 snprintf(con->console, sizeof(con->console), "%s/console", dom);
187 } else {
188 snprintf(con->console, sizeof(con->console), "%s/device/console/%d", dom, xendev->dev);
189 }
190 free(dom);
191
192 type = xenstore_read_str(con->console, "type");
193 if (!type || strcmp(type, "ioemu") != 0) {
194 xen_pv_printf(xendev, 1, "not for me (type=%s)\n", type);
195 ret = -1;
196 goto out;
197 }
198
199 output = xenstore_read_str(con->console, "output");
200
201
202 if (output == NULL) {
203 if (con->xendev.dev) {
204 qemu_chr_fe_init(&con->chr, serial_hds[con->xendev.dev],
205 &error_abort);
206 }
207 } else {
208 snprintf(label, sizeof(label), "xencons%d", con->xendev.dev);
209 qemu_chr_fe_init(&con->chr,
210 qemu_chr_new(label, output), &error_abort);
211 }
212
213 xenstore_store_pv_console_info(con->xendev.dev,
214 qemu_chr_fe_get_driver(&con->chr));
215
216out:
217 g_free(type);
218 return ret;
219}
220
221static int con_initialise(struct XenDevice *xendev)
222{
223 struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
224 int limit;
225
226 if (xenstore_read_int(con->console, "ring-ref", &con->ring_ref) == -1)
227 return -1;
228 if (xenstore_read_int(con->console, "port", &con->xendev.remote_port) == -1)
229 return -1;
230 if (xenstore_read_int(con->console, "limit", &limit) == 0)
231 con->buffer.max_capacity = limit;
232
233 if (!xendev->dev) {
234 xen_pfn_t mfn = con->ring_ref;
235 con->sring = xenforeignmemory_map(xen_fmem, con->xendev.dom,
236 PROT_READ|PROT_WRITE,
237 1, &mfn, NULL);
238 } else {
239 con->sring = xengnttab_map_grant_ref(xendev->gnttabdev, con->xendev.dom,
240 con->ring_ref,
241 PROT_READ|PROT_WRITE);
242 }
243 if (!con->sring)
244 return -1;
245
246 xen_be_bind_evtchn(&con->xendev);
247 qemu_chr_fe_set_handlers(&con->chr, xencons_can_receive,
248 xencons_receive, NULL, NULL, con, NULL, true);
249
250 xen_pv_printf(xendev, 1,
251 "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 qemu_chr_fe_deinit(&con->chr, false);
264 xen_pv_unbind_evtchn(&con->xendev);
265
266 if (con->sring) {
267 if (!xendev->dev) {
268 xenforeignmemory_unmap(xen_fmem, con->sring, 1);
269 } else {
270 xengnttab_unmap(xendev->gnttabdev, con->sring, 1);
271 }
272 con->sring = NULL;
273 }
274}
275
276static void con_event(struct XenDevice *xendev)
277{
278 struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
279
280 buffer_append(con);
281 if (con->buffer.size - con->buffer.consumed)
282 xencons_send(con);
283}
284
285
286
287struct XenDevOps xen_console_ops = {
288 .size = sizeof(struct XenConsole),
289 .flags = DEVOPS_FLAG_IGNORE_STATE|DEVOPS_FLAG_NEED_GNTDEV,
290 .init = con_init,
291 .initialise = con_initialise,
292 .event = con_event,
293 .disconnect = con_disconnect,
294};
295
