block/win32-aio.c

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