xref: /openbmc/qemu/block/qed-table.c (revision 41bd3603)
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