xref: /openbmc/qemu/block/win32-aio.c (revision 764a6ee9)
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 
25 #include "qemu/osdep.h"
26 #include "qemu/timer.h"
27 #include "block/block-io.h"
28 #include "block/block_int.h"
29 #include "block/aio.h"
30 #include "block/raw-aio.h"
31 #include "qemu/event_notifier.h"
32 #include "qemu/iov.h"
33 #include "qemu/memalign.h"
34 #include <windows.h>
35 #include <winioctl.h>
36 
37 #define FTYPE_FILE 0
38 #define FTYPE_CD     1
39 #define FTYPE_HARDDISK 2
40 
41 struct QEMUWin32AIOState {
42     HANDLE hIOCP;
43     EventNotifier e;
44     int count;
45     AioContext *aio_ctx;
46 };
47 
48 typedef struct QEMUWin32AIOCB {
49     BlockAIOCB common;
50     struct QEMUWin32AIOState *ctx;
51     int nbytes;
52     OVERLAPPED ov;
53     QEMUIOVector *qiov;
54     void *buf;
55     bool is_read;
56     bool is_linear;
57 } QEMUWin32AIOCB;
58 
59 /*
60  * Completes an AIO request (calls the callback and frees the ACB).
61  */
62 static void win32_aio_process_completion(QEMUWin32AIOState *s,
63     QEMUWin32AIOCB *waiocb, DWORD count)
64 {
65     int ret;
66     s->count--;
67 
68     if (waiocb->ov.Internal != 0) {
69         ret = -EIO;
70     } else {
71         ret = 0;
72         if (count < waiocb->nbytes) {
73             /* Short reads mean EOF, pad with zeros. */
74             if (waiocb->is_read) {
75                 qemu_iovec_memset(waiocb->qiov, count, 0,
76                     waiocb->qiov->size - count);
77             } else {
78                 ret = -EINVAL;
79             }
80        }
81     }
82 
83     if (!waiocb->is_linear) {
84         if (ret == 0 && waiocb->is_read) {
85             QEMUIOVector *qiov = waiocb->qiov;
86             iov_from_buf(qiov->iov, qiov->niov, 0, waiocb->buf, qiov->size);
87         }
88         qemu_vfree(waiocb->buf);
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         uint64_t offset, uint64_t bytes, QEMUIOVector *qiov,
117         BlockCompletionFunc *cb, void *opaque, int type)
118 {
119     struct QEMUWin32AIOCB *waiocb;
120     DWORD rc;
121 
122     waiocb = qemu_aio_get(&win32_aiocb_info, bs, cb, opaque);
123     waiocb->nbytes = bytes;
124     waiocb->qiov = qiov;
125     waiocb->is_read = (type == QEMU_AIO_READ);
126 
127     if (qiov->niov > 1) {
128         waiocb->buf = qemu_try_blockalign(bs, qiov->size);
129         if (waiocb->buf == NULL) {
130             goto out;
131         }
132         if (type & QEMU_AIO_WRITE) {
133             iov_to_buf(qiov->iov, qiov->niov, 0, waiocb->buf, qiov->size);
134         }
135         waiocb->is_linear = false;
136     } else {
137         waiocb->buf = qiov->iov[0].iov_base;
138         waiocb->is_linear = true;
139     }
140 
141     memset(&waiocb->ov, 0, sizeof(waiocb->ov));
142     waiocb->ov.Offset = (DWORD)offset;
143     waiocb->ov.OffsetHigh = (DWORD)(offset >> 32);
144     waiocb->ov.hEvent = event_notifier_get_handle(&aio->e);
145 
146     aio->count++;
147 
148     if (type & QEMU_AIO_READ) {
149         rc = ReadFile(hfile, waiocb->buf, waiocb->nbytes, NULL, &waiocb->ov);
150     } else {
151         rc = WriteFile(hfile, waiocb->buf, waiocb->nbytes, NULL, &waiocb->ov);
152     }
153     if(rc == 0 && GetLastError() != ERROR_IO_PENDING) {
154         goto out_dec_count;
155     }
156     return &waiocb->common;
157 
158 out_dec_count:
159     aio->count--;
160 out:
161     qemu_aio_unref(waiocb);
162     return NULL;
163 }
164 
165 int win32_aio_attach(QEMUWin32AIOState *aio, HANDLE hfile)
166 {
167     if (CreateIoCompletionPort(hfile, aio->hIOCP, (ULONG_PTR) 0, 0) == NULL) {
168         return -EINVAL;
169     } else {
170         return 0;
171     }
172 }
173 
174 void win32_aio_detach_aio_context(QEMUWin32AIOState *aio,
175                                   AioContext *old_context)
176 {
177     aio_set_event_notifier(old_context, &aio->e, NULL, NULL, NULL);
178     aio->aio_ctx = NULL;
179 }
180 
181 void win32_aio_attach_aio_context(QEMUWin32AIOState *aio,
182                                   AioContext *new_context)
183 {
184     aio->aio_ctx = new_context;
185     aio_set_event_notifier(new_context, &aio->e, win32_aio_completion_cb,
186                            NULL, NULL);
187 }
188 
189 QEMUWin32AIOState *win32_aio_init(void)
190 {
191     QEMUWin32AIOState *s;
192 
193     s = g_malloc0(sizeof(*s));
194     if (event_notifier_init(&s->e, false) < 0) {
195         goto out_free_state;
196     }
197 
198     s->hIOCP = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, 0, 0);
199     if (s->hIOCP == NULL) {
200         goto out_close_efd;
201     }
202 
203     return s;
204 
205 out_close_efd:
206     event_notifier_cleanup(&s->e);
207 out_free_state:
208     g_free(s);
209     return NULL;
210 }
211 
212 void win32_aio_cleanup(QEMUWin32AIOState *aio)
213 {
214     assert(!aio->aio_ctx);
215     CloseHandle(aio->hIOCP);
216     event_notifier_cleanup(&aio->e);
217     g_free(aio);
218 }
219