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1 /*
2 * Copyright (c) 2021-2023 Oracle and/or its affiliates.
3 *
4 * This work is licensed under the terms of the GNU GPL, version 2 or later.
5 * See the COPYING file in the top-level directory.
6 */
7
8 #include "qemu/osdep.h"
9 #include "system/ramblock.h"
10 #include "qemu/cutils.h"
11 #include "qemu/error-report.h"
12 #include "qapi/error.h"
13 #include "channel.h"
14 #include "file.h"
15 #include "migration.h"
16 #include "io/channel-file.h"
17 #include "io/channel-socket.h"
18 #include "io/channel-util.h"
19 #include "options.h"
20 #include "trace.h"
21
22 #define OFFSET_OPTION ",offset="
23
24 static struct FileOutgoingArgs {
25 char *fname;
26 } outgoing_args;
27
28 /* Remove the offset option from @filespec and return it in @offsetp. */
29
30 int file_parse_offset(char *filespec, uint64_t *offsetp, Error **errp)
31 {
32 char *option = strstr(filespec, OFFSET_OPTION);
33 int ret;
34
35 if (option) {
36 *option = 0;
37 option += sizeof(OFFSET_OPTION) - 1;
38 ret = qemu_strtosz(option, NULL, offsetp);
39 if (ret) {
40 error_setg_errno(errp, -ret, "file URI has bad offset %s", option);
41 return -1;
42 }
43 }
44 return 0;
45 }
46
47 void file_cleanup_outgoing_migration(void)
48 {
49 g_free(outgoing_args.fname);
50 outgoing_args.fname = NULL;
51 }
52
53 static void file_enable_direct_io(int *flags)
54 {
55 #ifdef O_DIRECT
56 *flags |= O_DIRECT;
57 #else
58 /* it should have been rejected when setting the parameter */
59 g_assert_not_reached();
60 #endif
61 }
62
63 bool file_send_channel_create(gpointer opaque, Error **errp)
64 {
65 QIOChannelFile *ioc;
66 int flags = O_WRONLY;
67 bool ret = true;
68
69 if (migrate_direct_io()) {
70 /*
71 * Enable O_DIRECT for the secondary channels. These are used
72 * for sending ram pages and writes should be guaranteed to be
73 * aligned to at least page size.
74 */
75 file_enable_direct_io(&flags);
76 }
77
78 ioc = qio_channel_file_new_path(outgoing_args.fname, flags, 0, errp);
79 if (!ioc) {
80 ret = false;
81 goto out;
82 }
83
84 multifd_channel_connect(opaque, QIO_CHANNEL(ioc));
85
86 out:
87 /*
88 * File channel creation is synchronous. However posting this
89 * semaphore here is simpler than adding a special case.
90 */
91 multifd_send_channel_created();
92
93 return ret;
94 }
95
96 QIOChannel *file_connect_outgoing(MigrationState *s,
97 FileMigrationArgs *file_args, Error **errp)
98 {
99 QIOChannelFile *fioc = NULL;
100 g_autofree char *filename = g_strdup(file_args->filename);
101 uint64_t offset = file_args->offset;
102 QIOChannel *ioc = NULL;
103
104 trace_migration_file_outgoing(filename);
105
106 fioc = qio_channel_file_new_path(filename, O_CREAT | O_WRONLY, 0600, errp);
107 if (!fioc) {
108 goto out;
109 }
110
111 if (ftruncate(fioc->fd, offset)) {
112 error_setg_errno(errp, errno,
113 "failed to truncate migration file to offset %" PRIx64,
114 offset);
115 object_unref(OBJECT(fioc));
116 goto out;
117 }
118
119 outgoing_args.fname = g_strdup(filename);
120
121 ioc = QIO_CHANNEL(fioc);
122 if (offset && qio_channel_io_seek(ioc, offset, SEEK_SET, errp) < 0) {
123 object_unref(OBJECT(fioc));
124 ioc = NULL;
125 goto out;
126 }
127 qio_channel_set_name(ioc, "migration-file-outgoing");
128 out:
129 return ioc;
130 }
131
132 static gboolean file_accept_incoming_migration(QIOChannel *ioc,
133 GIOCondition condition,
134 gpointer opaque)
135 {
136 migration_channel_process_incoming(ioc);
137 object_unref(OBJECT(ioc));
138 return G_SOURCE_REMOVE;
139 }
140
141 static void file_create_incoming_channels(QIOChannel *ioc, char *filename,
142 Error **errp)
143 {
144 int i, channels = 1;
145 g_autofree QIOChannel **iocs = NULL;
146 int flags = O_RDONLY;
147
148 if (migrate_multifd()) {
149 channels += migrate_multifd_channels();
150 if (migrate_direct_io()) {
151 file_enable_direct_io(&flags);
152 }
153 }
154
155 iocs = g_new0(QIOChannel *, channels);
156 iocs[0] = ioc;
157
158 for (i = 1; i < channels; i++) {
159 QIOChannelFile *fioc = qio_channel_file_new_path(filename, flags, 0, errp);
160
161 if (!fioc) {
162 while (i) {
163 object_unref(iocs[--i]);
164 }
165 return;
166 }
167
168 iocs[i] = QIO_CHANNEL(fioc);
169 }
170
171 for (i = 0; i < channels; i++) {
172 qio_channel_set_name(iocs[i], "migration-file-incoming");
173 qio_channel_add_watch_full(iocs[i], G_IO_IN,
174 file_accept_incoming_migration,
175 NULL, NULL,
176 g_main_context_get_thread_default());
177 }
178 }
179
180 void file_connect_incoming(FileMigrationArgs *file_args, Error **errp)
181 {
182 g_autofree char *filename = g_strdup(file_args->filename);
183 QIOChannelFile *fioc = NULL;
184 uint64_t offset = file_args->offset;
185
186 trace_migration_file_incoming(filename);
187
188 fioc = qio_channel_file_new_path(filename, O_RDONLY, 0, errp);
189 if (!fioc) {
190 return;
191 }
192
193 if (offset &&
194 qio_channel_io_seek(QIO_CHANNEL(fioc), offset, SEEK_SET, errp) < 0) {
195 object_unref(OBJECT(fioc));
196 return;
197 }
198
199 file_create_incoming_channels(QIO_CHANNEL(fioc), filename, errp);
200 }
201
202 int file_write_ramblock_iov(QIOChannel *ioc, const struct iovec *iov,
203 int niov, MultiFDPages_t *pages, Error **errp)
204 {
205 int ret = 0;
206 int i, slice_idx, slice_num;
207 uintptr_t base, next, offset;
208 size_t len;
209 RAMBlock *block = pages->block;
210
211 slice_idx = 0;
212 slice_num = 1;
213
214 /*
215 * If the iov array doesn't have contiguous elements, we need to
216 * split it in slices because we only have one file offset for the
217 * whole iov. Do this here so callers don't need to break the iov
218 * array themselves.
219 */
220 for (i = 0; i < niov; i++, slice_num++) {
221 base = (uintptr_t) iov[i].iov_base;
222
223 if (i != niov - 1) {
224 len = iov[i].iov_len;
225 next = (uintptr_t) iov[i + 1].iov_base;
226
227 if (base + len == next) {
228 continue;
229 }
230 }
231
232 /*
233 * Use the offset of the first element of the segment that
234 * we're sending.
235 */
236 offset = (uintptr_t) iov[slice_idx].iov_base - (uintptr_t) block->host;
237 if (offset >= block->used_length) {
238 error_setg(errp, "offset %" PRIxPTR
239 "outside of ramblock %s range", offset, block->idstr);
240 ret = -1;
241 break;
242 }
243
244 ret = qio_channel_pwritev_all(ioc, &iov[slice_idx], slice_num,
245 block->pages_offset + offset, errp);
246 if (ret < 0) {
247 break;
248 }
249
250 slice_idx += slice_num;
251 slice_num = 0;
252 }
253
254 return ret;
255 }
256
257 int multifd_file_recv_data(MultiFDRecvParams *p, Error **errp)
258 {
259 ERRP_GUARD();
260 MultiFDRecvData *data = p->data;
261 int ret;
262
263 ret = qio_channel_pread_all(p->c, (char *) data->opaque,
264 data->size, data->file_offset, errp);
265 if (ret != 0) {
266 error_prepend(errp,
267 "multifd recv (%u): ",
268 p->id);
269 return -1;
270 }
271
272 return 0;
273 }