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-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 }