Merge remote-tracking branch 'remotes/dagrh/tags/pull-virtiofs-20211026' into staging
[qemu.git] / migration / qemu-file-channel.c
1 /*
2 * QEMUFile backend for QIOChannel objects
3 *
4 * Copyright (c) 2015-2016 Red Hat, Inc
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24
25 #include "qemu/osdep.h"
26 #include "qemu-file-channel.h"
27 #include "qemu-file.h"
28 #include "io/channel-socket.h"
29 #include "io/channel-tls.h"
30 #include "qemu/iov.h"
31 #include "qemu/yank.h"
32 #include "yank_functions.h"
33
34
35 static ssize_t channel_writev_buffer(void *opaque,
36 struct iovec *iov,
37 int iovcnt,
38 int64_t pos,
39 Error **errp)
40 {
41 QIOChannel *ioc = QIO_CHANNEL(opaque);
42 ssize_t done = 0;
43 struct iovec *local_iov = g_new(struct iovec, iovcnt);
44 struct iovec *local_iov_head = local_iov;
45 unsigned int nlocal_iov = iovcnt;
46
47 nlocal_iov = iov_copy(local_iov, nlocal_iov,
48 iov, iovcnt,
49 0, iov_size(iov, iovcnt));
50
51 while (nlocal_iov > 0) {
52 ssize_t len;
53 len = qio_channel_writev(ioc, local_iov, nlocal_iov, errp);
54 if (len == QIO_CHANNEL_ERR_BLOCK) {
55 if (qemu_in_coroutine()) {
56 qio_channel_yield(ioc, G_IO_OUT);
57 } else {
58 qio_channel_wait(ioc, G_IO_OUT);
59 }
60 continue;
61 }
62 if (len < 0) {
63 done = -EIO;
64 goto cleanup;
65 }
66
67 iov_discard_front(&local_iov, &nlocal_iov, len);
68 done += len;
69 }
70
71 cleanup:
72 g_free(local_iov_head);
73 return done;
74 }
75
76
77 static ssize_t channel_get_buffer(void *opaque,
78 uint8_t *buf,
79 int64_t pos,
80 size_t size,
81 Error **errp)
82 {
83 QIOChannel *ioc = QIO_CHANNEL(opaque);
84 ssize_t ret;
85
86 do {
87 ret = qio_channel_read(ioc, (char *)buf, size, errp);
88 if (ret < 0) {
89 if (ret == QIO_CHANNEL_ERR_BLOCK) {
90 if (qemu_in_coroutine()) {
91 qio_channel_yield(ioc, G_IO_IN);
92 } else {
93 qio_channel_wait(ioc, G_IO_IN);
94 }
95 } else {
96 return -EIO;
97 }
98 }
99 } while (ret == QIO_CHANNEL_ERR_BLOCK);
100
101 return ret;
102 }
103
104
105 static int channel_close(void *opaque, Error **errp)
106 {
107 int ret;
108 QIOChannel *ioc = QIO_CHANNEL(opaque);
109 ret = qio_channel_close(ioc, errp);
110 if ((object_dynamic_cast(OBJECT(ioc), TYPE_QIO_CHANNEL_SOCKET) ||
111 object_dynamic_cast(OBJECT(ioc), TYPE_QIO_CHANNEL_TLS))
112 && OBJECT(ioc)->ref == 1) {
113 yank_unregister_function(MIGRATION_YANK_INSTANCE,
114 migration_yank_iochannel,
115 QIO_CHANNEL(ioc));
116 }
117 object_unref(OBJECT(ioc));
118 return ret;
119 }
120
121
122 static int channel_shutdown(void *opaque,
123 bool rd,
124 bool wr,
125 Error **errp)
126 {
127 QIOChannel *ioc = QIO_CHANNEL(opaque);
128
129 if (qio_channel_has_feature(ioc,
130 QIO_CHANNEL_FEATURE_SHUTDOWN)) {
131 QIOChannelShutdown mode;
132 if (rd && wr) {
133 mode = QIO_CHANNEL_SHUTDOWN_BOTH;
134 } else if (rd) {
135 mode = QIO_CHANNEL_SHUTDOWN_READ;
136 } else {
137 mode = QIO_CHANNEL_SHUTDOWN_WRITE;
138 }
139 if (qio_channel_shutdown(ioc, mode, errp) < 0) {
140 return -EIO;
141 }
142 }
143 return 0;
144 }
145
146
147 static int channel_set_blocking(void *opaque,
148 bool enabled,
149 Error **errp)
150 {
151 QIOChannel *ioc = QIO_CHANNEL(opaque);
152
153 if (qio_channel_set_blocking(ioc, enabled, errp) < 0) {
154 return -1;
155 }
156 return 0;
157 }
158
159 static QEMUFile *channel_get_input_return_path(void *opaque)
160 {
161 QIOChannel *ioc = QIO_CHANNEL(opaque);
162
163 return qemu_fopen_channel_output(ioc);
164 }
165
166 static QEMUFile *channel_get_output_return_path(void *opaque)
167 {
168 QIOChannel *ioc = QIO_CHANNEL(opaque);
169
170 return qemu_fopen_channel_input(ioc);
171 }
172
173 static const QEMUFileOps channel_input_ops = {
174 .get_buffer = channel_get_buffer,
175 .close = channel_close,
176 .shut_down = channel_shutdown,
177 .set_blocking = channel_set_blocking,
178 .get_return_path = channel_get_input_return_path,
179 };
180
181
182 static const QEMUFileOps channel_output_ops = {
183 .writev_buffer = channel_writev_buffer,
184 .close = channel_close,
185 .shut_down = channel_shutdown,
186 .set_blocking = channel_set_blocking,
187 .get_return_path = channel_get_output_return_path,
188 };
189
190
191 QEMUFile *qemu_fopen_channel_input(QIOChannel *ioc)
192 {
193 object_ref(OBJECT(ioc));
194 return qemu_fopen_ops(ioc, &channel_input_ops);
195 }
196
197 QEMUFile *qemu_fopen_channel_output(QIOChannel *ioc)
198 {
199 object_ref(OBJECT(ioc));
200 return qemu_fopen_ops(ioc, &channel_output_ops);
201 }