xref: /openbmc/qemu/block/win32-aio.c (revision 9c4218e9)
1 /*
2  * Block driver for RAW files (win32)
3  *
4  * Copyright (c) 2006 Fabrice Bellard
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 #include "qemu/osdep.h"
25 #include "qemu-common.h"
26 #include "qemu/timer.h"
27 #include "block/block_int.h"
28 #include "qemu/module.h"
29 #include "block/aio.h"
30 #include "raw-aio.h"
31 #include "qemu/event_notifier.h"
32 #include "qemu/iov.h"
33 #include <windows.h>
34 #include <winioctl.h>
35 
36 #define FTYPE_FILE 0
37 #define FTYPE_CD     1
38 #define FTYPE_HARDDISK 2
39 
40 struct QEMUWin32AIOState {
41     HANDLE hIOCP;
42     EventNotifier e;
43     int count;
44     bool is_aio_context_attached;
45 };
46 
47 typedef struct QEMUWin32AIOCB {
48     BlockAIOCB common;
49     struct QEMUWin32AIOState *ctx;
50     int nbytes;
51     OVERLAPPED ov;
52     QEMUIOVector *qiov;
53     void *buf;
54     bool is_read;
55     bool is_linear;
56 } QEMUWin32AIOCB;
57 
58 /*
59  * Completes an AIO request (calls the callback and frees the ACB).
60  */
61 static void win32_aio_process_completion(QEMUWin32AIOState *s,
62     QEMUWin32AIOCB *waiocb, DWORD count)
63 {
64     int ret;
65     s->count--;
66 
67     if (waiocb->ov.Internal != 0) {
68         ret = -EIO;
69     } else {
70         ret = 0;
71         if (count < waiocb->nbytes) {
72             /* Short reads mean EOF, pad with zeros. */
73             if (waiocb->is_read) {
74                 qemu_iovec_memset(waiocb->qiov, count, 0,
75                     waiocb->qiov->size - count);
76             } else {
77                 ret = -EINVAL;
78             }
79        }
80     }
81 
82     if (!waiocb->is_linear) {
83         if (ret == 0 && waiocb->is_read) {
84             QEMUIOVector *qiov = waiocb->qiov;
85             iov_from_buf(qiov->iov, qiov->niov, 0, waiocb->buf, qiov->size);
86         }
87         qemu_vfree(waiocb->buf);
88     }
89 
90 
91     waiocb->common.cb(waiocb->common.opaque, ret);
92     qemu_aio_unref(waiocb);
93 }
94 
95 static void win32_aio_completion_cb(EventNotifier *e)
96 {
97     QEMUWin32AIOState *s = container_of(e, QEMUWin32AIOState, e);
98     DWORD count;
99     ULONG_PTR key;
100     OVERLAPPED *ov;
101 
102     event_notifier_test_and_clear(&s->e);
103     while (GetQueuedCompletionStatus(s->hIOCP, &count, &key, &ov, 0)) {
104         QEMUWin32AIOCB *waiocb = container_of(ov, QEMUWin32AIOCB, ov);
105 
106         win32_aio_process_completion(s, waiocb, count);
107     }
108 }
109 
110 static const AIOCBInfo win32_aiocb_info = {
111     .aiocb_size         = sizeof(QEMUWin32AIOCB),
112 };
113 
114 BlockAIOCB *win32_aio_submit(BlockDriverState *bs,
115         QEMUWin32AIOState *aio, HANDLE hfile,
116         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
117         BlockCompletionFunc *cb, void *opaque, int type)
118 {
119     struct QEMUWin32AIOCB *waiocb;
120     uint64_t offset = sector_num * 512;
121     DWORD rc;
122 
123     waiocb = qemu_aio_get(&win32_aiocb_info, bs, cb, opaque);
124     waiocb->nbytes = nb_sectors * 512;
125     waiocb->qiov = qiov;
126     waiocb->is_read = (type == QEMU_AIO_READ);
127 
128     if (qiov->niov > 1) {
129         waiocb->buf = qemu_try_blockalign(bs, qiov->size);
130         if (waiocb->buf == NULL) {
131             goto out;
132         }
133         if (type & QEMU_AIO_WRITE) {
134             iov_to_buf(qiov->iov, qiov->niov, 0, waiocb->buf, qiov->size);
135         }
136         waiocb->is_linear = false;
137     } else {
138         waiocb->buf = qiov->iov[0].iov_base;
139         waiocb->is_linear = true;
140     }
141 
142     memset(&waiocb->ov, 0, sizeof(waiocb->ov));
143     waiocb->ov.Offset = (DWORD)offset;
144     waiocb->ov.OffsetHigh = (DWORD)(offset >> 32);
145     waiocb->ov.hEvent = event_notifier_get_handle(&aio->e);
146 
147     aio->count++;
148 
149     if (type & QEMU_AIO_READ) {
150         rc = ReadFile(hfile, waiocb->buf, waiocb->nbytes, NULL, &waiocb->ov);
151     } else {
152         rc = WriteFile(hfile, waiocb->buf, waiocb->nbytes, NULL, &waiocb->ov);
153     }
154     if(rc == 0 && GetLastError() != ERROR_IO_PENDING) {
155         goto out_dec_count;
156     }
157     return &waiocb->common;
158 
159 out_dec_count:
160     aio->count--;
161 out:
162     qemu_aio_unref(waiocb);
163     return NULL;
164 }
165 
166 int win32_aio_attach(QEMUWin32AIOState *aio, HANDLE hfile)
167 {
168     if (CreateIoCompletionPort(hfile, aio->hIOCP, (ULONG_PTR) 0, 0) == NULL) {
169         return -EINVAL;
170     } else {
171         return 0;
172     }
173 }
174 
175 void win32_aio_detach_aio_context(QEMUWin32AIOState *aio,
176                                   AioContext *old_context)
177 {
178     aio_set_event_notifier(old_context, &aio->e, false, NULL);
179     aio->is_aio_context_attached = false;
180 }
181 
182 void win32_aio_attach_aio_context(QEMUWin32AIOState *aio,
183                                   AioContext *new_context)
184 {
185     aio->is_aio_context_attached = true;
186     aio_set_event_notifier(new_context, &aio->e, false,
187                            win32_aio_completion_cb);
188 }
189 
190 QEMUWin32AIOState *win32_aio_init(void)
191 {
192     QEMUWin32AIOState *s;
193 
194     s = g_malloc0(sizeof(*s));
195     if (event_notifier_init(&s->e, false) < 0) {
196         goto out_free_state;
197     }
198 
199     s->hIOCP = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, 0, 0);
200     if (s->hIOCP == NULL) {
201         goto out_close_efd;
202     }
203 
204     return s;
205 
206 out_close_efd:
207     event_notifier_cleanup(&s->e);
208 out_free_state:
209     g_free(s);
210     return NULL;
211 }
212 
213 void win32_aio_cleanup(QEMUWin32AIOState *aio)
214 {
215     assert(!aio->is_aio_context_attached);
216     CloseHandle(aio->hIOCP);
217     event_notifier_cleanup(&aio->e);
218     g_free(aio);
219 }
220