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 "qemu/memalign.h"
  33 #include <windows.h>
  34 #include <winioctl.h>
  35
  36 #define FTYPE_FILE 0
  37 #define FTYPE_CD     1
  38 #define FTYPE_HARDDISK 2
  39
  40 struct QEMUWin32AIOState {
  41     HANDLE hIOCP;
  42     EventNotifier e;
  43     int count;
  44     AioContext *aio_ctx;
  45 };
  46
  47 typedef struct QEMUWin32AIOCB {
  48     BlockAIOCB common;
  49     struct QEMUWin32AIOState *ctx;
  50     int nbytes;
  51     OVERLAPPED ov;
  52     QEMUIOVector *qiov;
  53     void *buf;
  54     bool is_read;
  55     bool is_linear;
  56 } QEMUWin32AIOCB;
  57
  58 /*
  59  * Completes an AIO request (calls the callback and frees the ACB).
  60  */
  61 static void win32_aio_process_completion(QEMUWin32AIOState *s,
  62     QEMUWin32AIOCB *waiocb, DWORD count)
  63 {
  64     int ret;
  65     s->count--;
  66
  67     if (waiocb->ov.Internal != 0) {
  68         ret = -EIO;
  69     } else {
  70         ret = 0;
  71         if (count < waiocb->nbytes) {
  72             /* Short reads mean EOF, pad with zeros. */
  73             if (waiocb->is_read) {
  74                 qemu_iovec_memset(waiocb->qiov, count, 0,
  75                     waiocb->qiov->size - count);
  76             } else {
  77                 ret = -EINVAL;
  78             }
  79        }
  80     }
  81
  82     if (!waiocb->is_linear) {
  83         if (ret == 0 && waiocb->is_read) {
  84             QEMUIOVector *qiov = waiocb->qiov;
  85             iov_from_buf(qiov->iov, qiov->niov, 0, waiocb->buf, qiov->size);
  86         }
  87         qemu_vfree(waiocb->buf);
  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         uint64_t offset, uint64_t bytes, QEMUIOVector *qiov,
 116         BlockCompletionFunc *cb, void *opaque, int type)
 117 {
 118     struct QEMUWin32AIOCB *waiocb;
 119     DWORD rc;
 120
 121     waiocb = qemu_aio_get(&win32_aiocb_info, bs, cb, opaque);
 122     waiocb->nbytes = bytes;
 123     waiocb->qiov = qiov;
 124     waiocb->is_read = (type == QEMU_AIO_READ);
 125
 126     if (qiov->niov > 1) {
 127         waiocb->buf = qemu_try_blockalign(bs, qiov->size);
 128         if (waiocb->buf == NULL) {
 129             goto out;
 130         }
 131         if (type & QEMU_AIO_WRITE) {
 132             iov_to_buf(qiov->iov, qiov->niov, 0, waiocb->buf, qiov->size);
 133         }
 134         waiocb->is_linear = false;
 135     } else {
 136         waiocb->buf = qiov->iov[0].iov_base;
 137         waiocb->is_linear = true;
 138     }
 139
 140     memset(&waiocb->ov, 0, sizeof(waiocb->ov));
 141     waiocb->ov.Offset = (DWORD)offset;
 142     waiocb->ov.OffsetHigh = (DWORD)(offset >> 32);
 143     waiocb->ov.hEvent = event_notifier_get_handle(&aio->e);
 144
 145     aio->count++;
 146
 147     if (type & QEMU_AIO_READ) {
 148         rc = ReadFile(hfile, waiocb->buf, waiocb->nbytes, NULL, &waiocb->ov);
 149     } else {
 150         rc = WriteFile(hfile, waiocb->buf, waiocb->nbytes, NULL, &waiocb->ov);
 151     }
 152     if(rc == 0 && GetLastError() != ERROR_IO_PENDING) {
 153         goto out_dec_count;
 154     }
 155     return &waiocb->common;
 156
 157 out_dec_count:
 158     aio->count--;
 159 out:
 160     qemu_aio_unref(waiocb);
 161     return NULL;
 162 }
 163
 164 int win32_aio_attach(QEMUWin32AIOState *aio, HANDLE hfile)
 165 {
 166     if (CreateIoCompletionPort(hfile, aio->hIOCP, (ULONG_PTR) 0, 0) == NULL) {
 167         return -EINVAL;
 168     } else {
 169         return 0;
 170     }
 171 }
 172
 173 void win32_aio_detach_aio_context(QEMUWin32AIOState *aio,
 174                                   AioContext *old_context)
 175 {
 176     aio_set_event_notifier(old_context, &aio->e, false, NULL, NULL, NULL);
 177     aio->aio_ctx = NULL;
 178 }
 179
 180 void win32_aio_attach_aio_context(QEMUWin32AIOState *aio,
 181                                   AioContext *new_context)
 182 {
 183     aio->aio_ctx = new_context;
 184     aio_set_event_notifier(new_context, &aio->e, false,
 185                            win32_aio_completion_cb, NULL, NULL);
 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->aio_ctx);
 214     CloseHandle(aio->hIOCP);
 215     event_notifier_cleanup(&aio->e);
 216     g_free(aio);
 217 }