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 #include "qemu-common.h"
  25 #include "qemu/timer.h"
  26 #include "block/block_int.h"
  27 #include "qemu/module.h"
  28 #include "block/aio.h"
  29 #include "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     bool is_aio_context_attached;
  44 };
  45
  46 typedef struct QEMUWin32AIOCB {
  47     BlockDriverAIOCB 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
  90     waiocb->common.cb(waiocb->common.opaque, ret);
  91     qemu_aio_release(waiocb);
  92 }
  93
  94 static void win32_aio_completion_cb(EventNotifier *e)
  95 {
  96     QEMUWin32AIOState *s = container_of(e, QEMUWin32AIOState, e);
  97     DWORD count;
  98     ULONG_PTR key;
  99     OVERLAPPED *ov;
 100
 101     event_notifier_test_and_clear(&s->e);
 102     while (GetQueuedCompletionStatus(s->hIOCP, &count, &key, &ov, 0)) {
 103         QEMUWin32AIOCB *waiocb = container_of(ov, QEMUWin32AIOCB, ov);
 104
 105         win32_aio_process_completion(s, waiocb, count);
 106     }
 107 }
 108
 109 static void win32_aio_cancel(BlockDriverAIOCB *blockacb)
 110 {
 111     QEMUWin32AIOCB *waiocb = (QEMUWin32AIOCB *)blockacb;
 112
 113     /*
 114      * CancelIoEx is only supported in Vista and newer.  For now, just
 115      * wait for completion.
 116      */
 117     while (!HasOverlappedIoCompleted(&waiocb->ov)) {
 118         aio_poll(bdrv_get_aio_context(blockacb->bs), true);
 119     }
 120 }
 121
 122 static const AIOCBInfo win32_aiocb_info = {
 123     .aiocb_size         = sizeof(QEMUWin32AIOCB),
 124     .cancel             = win32_aio_cancel,
 125 };
 126
 127 BlockDriverAIOCB *win32_aio_submit(BlockDriverState *bs,
 128         QEMUWin32AIOState *aio, HANDLE hfile,
 129         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 130         BlockDriverCompletionFunc *cb, void *opaque, int type)
 131 {
 132     struct QEMUWin32AIOCB *waiocb;
 133     uint64_t offset = sector_num * 512;
 134     DWORD rc;
 135
 136     waiocb = qemu_aio_get(&win32_aiocb_info, bs, cb, opaque);
 137     waiocb->nbytes = nb_sectors * 512;
 138     waiocb->qiov = qiov;
 139     waiocb->is_read = (type == QEMU_AIO_READ);
 140
 141     if (qiov->niov > 1) {
 142         waiocb->buf = qemu_blockalign(bs, qiov->size);
 143         if (type & QEMU_AIO_WRITE) {
 144             iov_to_buf(qiov->iov, qiov->niov, 0, waiocb->buf, qiov->size);
 145         }
 146         waiocb->is_linear = false;
 147     } else {
 148         waiocb->buf = qiov->iov[0].iov_base;
 149         waiocb->is_linear = true;
 150     }
 151
 152     memset(&waiocb->ov, 0, sizeof(waiocb->ov));
 153     waiocb->ov.Offset = (DWORD)offset;
 154     waiocb->ov.OffsetHigh = (DWORD)(offset >> 32);
 155     waiocb->ov.hEvent = event_notifier_get_handle(&aio->e);
 156
 157     aio->count++;
 158
 159     if (type & QEMU_AIO_READ) {
 160         rc = ReadFile(hfile, waiocb->buf, waiocb->nbytes, NULL, &waiocb->ov);
 161     } else {
 162         rc = WriteFile(hfile, waiocb->buf, waiocb->nbytes, NULL, &waiocb->ov);
 163     }
 164     if(rc == 0 && GetLastError() != ERROR_IO_PENDING) {
 165         goto out_dec_count;
 166     }
 167     return &waiocb->common;
 168
 169 out_dec_count:
 170     aio->count--;
 171     qemu_aio_release(waiocb);
 172     return NULL;
 173 }
 174
 175 int win32_aio_attach(QEMUWin32AIOState *aio, HANDLE hfile)
 176 {
 177     if (CreateIoCompletionPort(hfile, aio->hIOCP, (ULONG_PTR) 0, 0) == NULL) {
 178         return -EINVAL;
 179     } else {
 180         return 0;
 181     }
 182 }
 183
 184 void win32_aio_detach_aio_context(QEMUWin32AIOState *aio,
 185                                   AioContext *old_context)
 186 {
 187     aio_set_event_notifier(old_context, &aio->e, NULL);
 188     aio->is_aio_context_attached = false;
 189 }
 190
 191 void win32_aio_attach_aio_context(QEMUWin32AIOState *aio,
 192                                   AioContext *new_context)
 193 {
 194     aio->is_aio_context_attached = true;
 195     aio_set_event_notifier(new_context, &aio->e, win32_aio_completion_cb);
 196 }
 197
 198 QEMUWin32AIOState *win32_aio_init(void)
 199 {
 200     QEMUWin32AIOState *s;
 201
 202     s = g_malloc0(sizeof(*s));
 203     if (event_notifier_init(&s->e, false) < 0) {
 204         goto out_free_state;
 205     }
 206
 207     s->hIOCP = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, 0, 0);
 208     if (s->hIOCP == NULL) {
 209         goto out_close_efd;
 210     }
 211
 212     return s;
 213
 214 out_close_efd:
 215     event_notifier_cleanup(&s->e);
 216 out_free_state:
 217     g_free(s);
 218     return NULL;
 219 }
 220
 221 void win32_aio_cleanup(QEMUWin32AIOState *aio)
 222 {
 223     assert(!aio->is_aio_context_attached);
 224     CloseHandle(aio->hIOCP);
 225     event_notifier_cleanup(&aio->e);
 226     g_free(aio);
 227 }