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     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
  90     waiocb->common.cb(waiocb->common.opaque, ret);
  91     qemu_aio_unref(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 const AIOCBInfo win32_aiocb_info = {
 110     .aiocb_size         = sizeof(QEMUWin32AIOCB),
 111 };
 112
 113 BlockAIOCB *win32_aio_submit(BlockDriverState *bs,
 114         QEMUWin32AIOState *aio, HANDLE hfile,
 115         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 116         BlockCompletionFunc *cb, void *opaque, int type)
 117 {
 118     struct QEMUWin32AIOCB *waiocb;
 119     uint64_t offset = sector_num * 512;
 120     DWORD rc;
 121
 122     waiocb = qemu_aio_get(&win32_aiocb_info, bs, cb, opaque);
 123     waiocb->nbytes = nb_sectors * 512;
 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);
 178     aio->is_aio_context_attached = false;
 179 }
 180
 181 void win32_aio_attach_aio_context(QEMUWin32AIOState *aio,
 182                                   AioContext *new_context)
 183 {
 184     aio->is_aio_context_attached = true;
 185     aio_set_event_notifier(new_context, &aio->e, win32_aio_completion_cb);
 186 }
 187
 188 QEMUWin32AIOState *win32_aio_init(void)
 189 {
 190     QEMUWin32AIOState *s;
 191
 192     s = g_malloc0(sizeof(*s));
 193     if (event_notifier_init(&s->e, false) < 0) {
 194         goto out_free_state;
 195     }
 196
 197     s->hIOCP = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, 0, 0);
 198     if (s->hIOCP == NULL) {
 199         goto out_close_efd;
 200     }
 201
 202     return s;
 203
 204 out_close_efd:
 205     event_notifier_cleanup(&s->e);
 206 out_free_state:
 207     g_free(s);
 208     return NULL;
 209 }
 210
 211 void win32_aio_cleanup(QEMUWin32AIOState *aio)
 212 {
 213     assert(!aio->is_aio_context_attached);
 214     CloseHandle(aio->hIOCP);
 215     event_notifier_cleanup(&aio->e);
 216     g_free(aio);
 217 }