1 /* 2 * QEMU Enhanced Disk Format Table I/O 3 * 4 * Copyright IBM, Corp. 2010 5 * 6 * Authors: 7 * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> 8 * Anthony Liguori <aliguori@us.ibm.com> 9 * 10 * This work is licensed under the terms of the GNU LGPL, version 2 or later. 11 * See the COPYING.LIB file in the top-level directory. 12 * 13 */ 14 15 #include "trace.h" 16 #include "qemu_socket.h" /* for EINPROGRESS on Windows */ 17 #include "qed.h" 18 19 typedef struct { 20 GenericCB gencb; 21 BDRVQEDState *s; 22 QEDTable *table; 23 24 struct iovec iov; 25 QEMUIOVector qiov; 26 } QEDReadTableCB; 27 28 static void qed_read_table_cb(void *opaque, int ret) 29 { 30 QEDReadTableCB *read_table_cb = opaque; 31 QEDTable *table = read_table_cb->table; 32 int noffsets = read_table_cb->qiov.size / sizeof(uint64_t); 33 int i; 34 35 /* Handle I/O error */ 36 if (ret) { 37 goto out; 38 } 39 40 /* Byteswap offsets */ 41 for (i = 0; i < noffsets; i++) { 42 table->offsets[i] = le64_to_cpu(table->offsets[i]); 43 } 44 45 out: 46 /* Completion */ 47 trace_qed_read_table_cb(read_table_cb->s, read_table_cb->table, ret); 48 gencb_complete(&read_table_cb->gencb, ret); 49 } 50 51 static void qed_read_table(BDRVQEDState *s, uint64_t offset, QEDTable *table, 52 BlockDriverCompletionFunc *cb, void *opaque) 53 { 54 QEDReadTableCB *read_table_cb = gencb_alloc(sizeof(*read_table_cb), 55 cb, opaque); 56 QEMUIOVector *qiov = &read_table_cb->qiov; 57 58 trace_qed_read_table(s, offset, table); 59 60 read_table_cb->s = s; 61 read_table_cb->table = table; 62 read_table_cb->iov.iov_base = table->offsets, 63 read_table_cb->iov.iov_len = s->header.cluster_size * s->header.table_size, 64 65 qemu_iovec_init_external(qiov, &read_table_cb->iov, 1); 66 bdrv_aio_readv(s->bs->file, offset / BDRV_SECTOR_SIZE, qiov, 67 qiov->size / BDRV_SECTOR_SIZE, 68 qed_read_table_cb, read_table_cb); 69 } 70 71 typedef struct { 72 GenericCB gencb; 73 BDRVQEDState *s; 74 QEDTable *orig_table; 75 QEDTable *table; 76 bool flush; /* flush after write? */ 77 78 struct iovec iov; 79 QEMUIOVector qiov; 80 } QEDWriteTableCB; 81 82 static void qed_write_table_cb(void *opaque, int ret) 83 { 84 QEDWriteTableCB *write_table_cb = opaque; 85 86 trace_qed_write_table_cb(write_table_cb->s, 87 write_table_cb->orig_table, 88 write_table_cb->flush, 89 ret); 90 91 if (ret) { 92 goto out; 93 } 94 95 if (write_table_cb->flush) { 96 /* We still need to flush first */ 97 write_table_cb->flush = false; 98 bdrv_aio_flush(write_table_cb->s->bs, qed_write_table_cb, 99 write_table_cb); 100 return; 101 } 102 103 out: 104 qemu_vfree(write_table_cb->table); 105 gencb_complete(&write_table_cb->gencb, ret); 106 return; 107 } 108 109 /** 110 * Write out an updated part or all of a table 111 * 112 * @s: QED state 113 * @offset: Offset of table in image file, in bytes 114 * @table: Table 115 * @index: Index of first element 116 * @n: Number of elements 117 * @flush: Whether or not to sync to disk 118 * @cb: Completion function 119 * @opaque: Argument for completion function 120 */ 121 static void qed_write_table(BDRVQEDState *s, uint64_t offset, QEDTable *table, 122 unsigned int index, unsigned int n, bool flush, 123 BlockDriverCompletionFunc *cb, void *opaque) 124 { 125 QEDWriteTableCB *write_table_cb; 126 unsigned int sector_mask = BDRV_SECTOR_SIZE / sizeof(uint64_t) - 1; 127 unsigned int start, end, i; 128 size_t len_bytes; 129 130 trace_qed_write_table(s, offset, table, index, n); 131 132 /* Calculate indices of the first and one after last elements */ 133 start = index & ~sector_mask; 134 end = (index + n + sector_mask) & ~sector_mask; 135 136 len_bytes = (end - start) * sizeof(uint64_t); 137 138 write_table_cb = gencb_alloc(sizeof(*write_table_cb), cb, opaque); 139 write_table_cb->s = s; 140 write_table_cb->orig_table = table; 141 write_table_cb->flush = flush; 142 write_table_cb->table = qemu_blockalign(s->bs, len_bytes); 143 write_table_cb->iov.iov_base = write_table_cb->table->offsets; 144 write_table_cb->iov.iov_len = len_bytes; 145 qemu_iovec_init_external(&write_table_cb->qiov, &write_table_cb->iov, 1); 146 147 /* Byteswap table */ 148 for (i = start; i < end; i++) { 149 uint64_t le_offset = cpu_to_le64(table->offsets[i]); 150 write_table_cb->table->offsets[i - start] = le_offset; 151 } 152 153 /* Adjust for offset into table */ 154 offset += start * sizeof(uint64_t); 155 156 bdrv_aio_writev(s->bs->file, offset / BDRV_SECTOR_SIZE, 157 &write_table_cb->qiov, 158 write_table_cb->qiov.size / BDRV_SECTOR_SIZE, 159 qed_write_table_cb, write_table_cb); 160 } 161 162 /** 163 * Propagate return value from async callback 164 */ 165 static void qed_sync_cb(void *opaque, int ret) 166 { 167 *(int *)opaque = ret; 168 } 169 170 int qed_read_l1_table_sync(BDRVQEDState *s) 171 { 172 int ret = -EINPROGRESS; 173 174 qed_read_table(s, s->header.l1_table_offset, 175 s->l1_table, qed_sync_cb, &ret); 176 while (ret == -EINPROGRESS) { 177 qemu_aio_wait(); 178 } 179 180 return ret; 181 } 182 183 void qed_write_l1_table(BDRVQEDState *s, unsigned int index, unsigned int n, 184 BlockDriverCompletionFunc *cb, void *opaque) 185 { 186 BLKDBG_EVENT(s->bs->file, BLKDBG_L1_UPDATE); 187 qed_write_table(s, s->header.l1_table_offset, 188 s->l1_table, index, n, false, cb, opaque); 189 } 190 191 int qed_write_l1_table_sync(BDRVQEDState *s, unsigned int index, 192 unsigned int n) 193 { 194 int ret = -EINPROGRESS; 195 196 qed_write_l1_table(s, index, n, qed_sync_cb, &ret); 197 while (ret == -EINPROGRESS) { 198 qemu_aio_wait(); 199 } 200 201 return ret; 202 } 203 204 typedef struct { 205 GenericCB gencb; 206 BDRVQEDState *s; 207 uint64_t l2_offset; 208 QEDRequest *request; 209 } QEDReadL2TableCB; 210 211 static void qed_read_l2_table_cb(void *opaque, int ret) 212 { 213 QEDReadL2TableCB *read_l2_table_cb = opaque; 214 QEDRequest *request = read_l2_table_cb->request; 215 BDRVQEDState *s = read_l2_table_cb->s; 216 CachedL2Table *l2_table = request->l2_table; 217 uint64_t l2_offset = read_l2_table_cb->l2_offset; 218 219 if (ret) { 220 /* can't trust loaded L2 table anymore */ 221 qed_unref_l2_cache_entry(l2_table); 222 request->l2_table = NULL; 223 } else { 224 l2_table->offset = l2_offset; 225 226 qed_commit_l2_cache_entry(&s->l2_cache, l2_table); 227 228 /* This is guaranteed to succeed because we just committed the entry 229 * to the cache. 230 */ 231 request->l2_table = qed_find_l2_cache_entry(&s->l2_cache, l2_offset); 232 assert(request->l2_table != NULL); 233 } 234 235 gencb_complete(&read_l2_table_cb->gencb, ret); 236 } 237 238 void qed_read_l2_table(BDRVQEDState *s, QEDRequest *request, uint64_t offset, 239 BlockDriverCompletionFunc *cb, void *opaque) 240 { 241 QEDReadL2TableCB *read_l2_table_cb; 242 243 qed_unref_l2_cache_entry(request->l2_table); 244 245 /* Check for cached L2 entry */ 246 request->l2_table = qed_find_l2_cache_entry(&s->l2_cache, offset); 247 if (request->l2_table) { 248 cb(opaque, 0); 249 return; 250 } 251 252 request->l2_table = qed_alloc_l2_cache_entry(&s->l2_cache); 253 request->l2_table->table = qed_alloc_table(s); 254 255 read_l2_table_cb = gencb_alloc(sizeof(*read_l2_table_cb), cb, opaque); 256 read_l2_table_cb->s = s; 257 read_l2_table_cb->l2_offset = offset; 258 read_l2_table_cb->request = request; 259 260 BLKDBG_EVENT(s->bs->file, BLKDBG_L2_LOAD); 261 qed_read_table(s, offset, request->l2_table->table, 262 qed_read_l2_table_cb, read_l2_table_cb); 263 } 264 265 int qed_read_l2_table_sync(BDRVQEDState *s, QEDRequest *request, uint64_t offset) 266 { 267 int ret = -EINPROGRESS; 268 269 qed_read_l2_table(s, request, offset, qed_sync_cb, &ret); 270 while (ret == -EINPROGRESS) { 271 qemu_aio_wait(); 272 } 273 274 return ret; 275 } 276 277 void qed_write_l2_table(BDRVQEDState *s, QEDRequest *request, 278 unsigned int index, unsigned int n, bool flush, 279 BlockDriverCompletionFunc *cb, void *opaque) 280 { 281 BLKDBG_EVENT(s->bs->file, BLKDBG_L2_UPDATE); 282 qed_write_table(s, request->l2_table->offset, 283 request->l2_table->table, index, n, flush, cb, opaque); 284 } 285 286 int qed_write_l2_table_sync(BDRVQEDState *s, QEDRequest *request, 287 unsigned int index, unsigned int n, bool flush) 288 { 289 int ret = -EINPROGRESS; 290 291 qed_write_l2_table(s, request, index, n, flush, qed_sync_cb, &ret); 292 while (ret == -EINPROGRESS) { 293 qemu_aio_wait(); 294 } 295 296 return ret; 297 } 298