xref: /openbmc/qemu/block/qed-table.c (revision 1f32989d)
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 }
107 
108 /**
109  * Write out an updated part or all of a table
110  *
111  * @s:          QED state
112  * @offset:     Offset of table in image file, in bytes
113  * @table:      Table
114  * @index:      Index of first element
115  * @n:          Number of elements
116  * @flush:      Whether or not to sync to disk
117  * @cb:         Completion function
118  * @opaque:     Argument for completion function
119  */
120 static void qed_write_table(BDRVQEDState *s, uint64_t offset, QEDTable *table,
121                             unsigned int index, unsigned int n, bool flush,
122                             BlockDriverCompletionFunc *cb, void *opaque)
123 {
124     QEDWriteTableCB *write_table_cb;
125     unsigned int sector_mask = BDRV_SECTOR_SIZE / sizeof(uint64_t) - 1;
126     unsigned int start, end, i;
127     size_t len_bytes;
128 
129     trace_qed_write_table(s, offset, table, index, n);
130 
131     /* Calculate indices of the first and one after last elements */
132     start = index & ~sector_mask;
133     end = (index + n + sector_mask) & ~sector_mask;
134 
135     len_bytes = (end - start) * sizeof(uint64_t);
136 
137     write_table_cb = gencb_alloc(sizeof(*write_table_cb), cb, opaque);
138     write_table_cb->s = s;
139     write_table_cb->orig_table = table;
140     write_table_cb->flush = flush;
141     write_table_cb->table = qemu_blockalign(s->bs, len_bytes);
142     write_table_cb->iov.iov_base = write_table_cb->table->offsets;
143     write_table_cb->iov.iov_len = len_bytes;
144     qemu_iovec_init_external(&write_table_cb->qiov, &write_table_cb->iov, 1);
145 
146     /* Byteswap table */
147     for (i = start; i < end; i++) {
148         uint64_t le_offset = cpu_to_le64(table->offsets[i]);
149         write_table_cb->table->offsets[i - start] = le_offset;
150     }
151 
152     /* Adjust for offset into table */
153     offset += start * sizeof(uint64_t);
154 
155     bdrv_aio_writev(s->bs->file, offset / BDRV_SECTOR_SIZE,
156                     &write_table_cb->qiov,
157                     write_table_cb->qiov.size / BDRV_SECTOR_SIZE,
158                     qed_write_table_cb, write_table_cb);
159 }
160 
161 /**
162  * Propagate return value from async callback
163  */
164 static void qed_sync_cb(void *opaque, int ret)
165 {
166     *(int *)opaque = ret;
167 }
168 
169 int qed_read_l1_table_sync(BDRVQEDState *s)
170 {
171     int ret = -EINPROGRESS;
172 
173     qed_read_table(s, s->header.l1_table_offset,
174                    s->l1_table, qed_sync_cb, &ret);
175     while (ret == -EINPROGRESS) {
176         qemu_aio_wait();
177     }
178 
179     return ret;
180 }
181 
182 void qed_write_l1_table(BDRVQEDState *s, unsigned int index, unsigned int n,
183                         BlockDriverCompletionFunc *cb, void *opaque)
184 {
185     BLKDBG_EVENT(s->bs->file, BLKDBG_L1_UPDATE);
186     qed_write_table(s, s->header.l1_table_offset,
187                     s->l1_table, index, n, false, cb, opaque);
188 }
189 
190 int qed_write_l1_table_sync(BDRVQEDState *s, unsigned int index,
191                             unsigned int n)
192 {
193     int ret = -EINPROGRESS;
194 
195     qed_write_l1_table(s, index, n, qed_sync_cb, &ret);
196     while (ret == -EINPROGRESS) {
197         qemu_aio_wait();
198     }
199 
200     return ret;
201 }
202 
203 typedef struct {
204     GenericCB gencb;
205     BDRVQEDState *s;
206     uint64_t l2_offset;
207     QEDRequest *request;
208 } QEDReadL2TableCB;
209 
210 static void qed_read_l2_table_cb(void *opaque, int ret)
211 {
212     QEDReadL2TableCB *read_l2_table_cb = opaque;
213     QEDRequest *request = read_l2_table_cb->request;
214     BDRVQEDState *s = read_l2_table_cb->s;
215     CachedL2Table *l2_table = request->l2_table;
216     uint64_t l2_offset = read_l2_table_cb->l2_offset;
217 
218     if (ret) {
219         /* can't trust loaded L2 table anymore */
220         qed_unref_l2_cache_entry(l2_table);
221         request->l2_table = NULL;
222     } else {
223         l2_table->offset = l2_offset;
224 
225         qed_commit_l2_cache_entry(&s->l2_cache, l2_table);
226 
227         /* This is guaranteed to succeed because we just committed the entry
228          * to the cache.
229          */
230         request->l2_table = qed_find_l2_cache_entry(&s->l2_cache, l2_offset);
231         assert(request->l2_table != NULL);
232     }
233 
234     gencb_complete(&read_l2_table_cb->gencb, ret);
235 }
236 
237 void qed_read_l2_table(BDRVQEDState *s, QEDRequest *request, uint64_t offset,
238                        BlockDriverCompletionFunc *cb, void *opaque)
239 {
240     QEDReadL2TableCB *read_l2_table_cb;
241 
242     qed_unref_l2_cache_entry(request->l2_table);
243 
244     /* Check for cached L2 entry */
245     request->l2_table = qed_find_l2_cache_entry(&s->l2_cache, offset);
246     if (request->l2_table) {
247         cb(opaque, 0);
248         return;
249     }
250 
251     request->l2_table = qed_alloc_l2_cache_entry(&s->l2_cache);
252     request->l2_table->table = qed_alloc_table(s);
253 
254     read_l2_table_cb = gencb_alloc(sizeof(*read_l2_table_cb), cb, opaque);
255     read_l2_table_cb->s = s;
256     read_l2_table_cb->l2_offset = offset;
257     read_l2_table_cb->request = request;
258 
259     BLKDBG_EVENT(s->bs->file, BLKDBG_L2_LOAD);
260     qed_read_table(s, offset, request->l2_table->table,
261                    qed_read_l2_table_cb, read_l2_table_cb);
262 }
263 
264 int qed_read_l2_table_sync(BDRVQEDState *s, QEDRequest *request, uint64_t offset)
265 {
266     int ret = -EINPROGRESS;
267 
268     qed_read_l2_table(s, request, offset, qed_sync_cb, &ret);
269     while (ret == -EINPROGRESS) {
270         qemu_aio_wait();
271     }
272 
273     return ret;
274 }
275 
276 void qed_write_l2_table(BDRVQEDState *s, QEDRequest *request,
277                         unsigned int index, unsigned int n, bool flush,
278                         BlockDriverCompletionFunc *cb, void *opaque)
279 {
280     BLKDBG_EVENT(s->bs->file, BLKDBG_L2_UPDATE);
281     qed_write_table(s, request->l2_table->offset,
282                     request->l2_table->table, index, n, flush, cb, opaque);
283 }
284 
285 int qed_write_l2_table_sync(BDRVQEDState *s, QEDRequest *request,
286                             unsigned int index, unsigned int n, bool flush)
287 {
288     int ret = -EINPROGRESS;
289 
290     qed_write_l2_table(s, request, index, n, flush, qed_sync_cb, &ret);
291     while (ret == -EINPROGRESS) {
292         qemu_aio_wait();
293     }
294 
295     return ret;
296 }
297