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 };
  44
  45 typedef struct QEMUWin32AIOCB {
  46     BlockDriverAIOCB common;
  47     struct QEMUWin32AIOState *ctx;
  48     int nbytes;
  49     OVERLAPPED ov;
  50     QEMUIOVector *qiov;
  51     void *buf;
  52     bool is_read;
  53     bool is_linear;
  54 } QEMUWin32AIOCB;
  55
  56 /*
  57  * Completes an AIO request (calls the callback and frees the ACB).
  58  */
  59 static void win32_aio_process_completion(QEMUWin32AIOState *s,
  60     QEMUWin32AIOCB *waiocb, DWORD count)
  61 {
  62     int ret;
  63     s->count--;
  64
  65     if (waiocb->ov.Internal != 0) {
  66         ret = -EIO;
  67     } else {
  68         ret = 0;
  69         if (count < waiocb->nbytes) {
  70             /* Short reads mean EOF, pad with zeros. */
  71             if (waiocb->is_read) {
  72                 qemu_iovec_memset(waiocb->qiov, count, 0,
  73                     waiocb->qiov->size - count);
  74             } else {
  75                 ret = -EINVAL;
  76             }
  77        }
  78     }
  79
  80     if (!waiocb->is_linear) {
  81         if (ret == 0 && waiocb->is_read) {
  82             QEMUIOVector *qiov = waiocb->qiov;
  83             iov_from_buf(qiov->iov, qiov->niov, 0, waiocb->buf, qiov->size);
  84         }
  85         qemu_vfree(waiocb->buf);
  86     }
  87
  88
  89     waiocb->common.cb(waiocb->common.opaque, ret);
  90     qemu_aio_release(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 int win32_aio_flush_cb(EventNotifier *e)
 109 {
 110     QEMUWin32AIOState *s = container_of(e, QEMUWin32AIOState, e);
 111
 112     return (s->count > 0) ? 1 : 0;
 113 }
 114
 115 static void win32_aio_cancel(BlockDriverAIOCB *blockacb)
 116 {
 117     QEMUWin32AIOCB *waiocb = (QEMUWin32AIOCB *)blockacb;
 118
 119     /*
 120      * CancelIoEx is only supported in Vista and newer.  For now, just
 121      * wait for completion.
 122      */
 123     while (!HasOverlappedIoCompleted(&waiocb->ov)) {
 124         qemu_aio_wait();
 125     }
 126 }
 127
 128 static const AIOCBInfo win32_aiocb_info = {
 129     .aiocb_size         = sizeof(QEMUWin32AIOCB),
 130     .cancel             = win32_aio_cancel,
 131 };
 132
 133 BlockDriverAIOCB *win32_aio_submit(BlockDriverState *bs,
 134         QEMUWin32AIOState *aio, HANDLE hfile,
 135         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 136         BlockDriverCompletionFunc *cb, void *opaque, int type)
 137 {
 138     struct QEMUWin32AIOCB *waiocb;
 139     uint64_t offset = sector_num * 512;
 140     DWORD rc;
 141
 142     waiocb = qemu_aio_get(&win32_aiocb_info, bs, cb, opaque);
 143     waiocb->nbytes = nb_sectors * 512;
 144     waiocb->qiov = qiov;
 145     waiocb->is_read = (type == QEMU_AIO_READ);
 146
 147     if (qiov->niov > 1) {
 148         waiocb->buf = qemu_blockalign(bs, qiov->size);
 149         if (type & QEMU_AIO_WRITE) {
 150             iov_to_buf(qiov->iov, qiov->niov, 0, waiocb->buf, qiov->size);
 151         }
 152         waiocb->is_linear = false;
 153     } else {
 154         waiocb->buf = qiov->iov[0].iov_base;
 155         waiocb->is_linear = true;
 156     }
 157
 158     memset(&waiocb->ov, 0, sizeof(waiocb->ov));
 159     waiocb->ov.Offset = (DWORD)offset;
 160     waiocb->ov.OffsetHigh = (DWORD)(offset >> 32);
 161     waiocb->ov.hEvent = event_notifier_get_handle(&aio->e);
 162
 163     aio->count++;
 164
 165     if (type & QEMU_AIO_READ) {
 166         rc = ReadFile(hfile, waiocb->buf, waiocb->nbytes, NULL, &waiocb->ov);
 167     } else {
 168         rc = WriteFile(hfile, waiocb->buf, waiocb->nbytes, NULL, &waiocb->ov);
 169     }
 170     if(rc == 0 && GetLastError() != ERROR_IO_PENDING) {
 171         goto out_dec_count;
 172     }
 173     return &waiocb->common;
 174
 175 out_dec_count:
 176     aio->count--;
 177     qemu_aio_release(waiocb);
 178     return NULL;
 179 }
 180
 181 int win32_aio_attach(QEMUWin32AIOState *aio, HANDLE hfile)
 182 {
 183     if (CreateIoCompletionPort(hfile, aio->hIOCP, (ULONG_PTR) 0, 0) == NULL) {
 184         return -EINVAL;
 185     } else {
 186         return 0;
 187     }
 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     qemu_aio_set_event_notifier(&s->e, win32_aio_completion_cb,
 205                                 win32_aio_flush_cb);
 206
 207     return s;
 208
 209 out_close_efd:
 210     event_notifier_cleanup(&s->e);
 211 out_free_state:
 212     g_free(s);
 213     return NULL;
 214 }