qemu

win32-aio.c (6056B)

---

 /*
  * Block driver for RAW files (win32)
  *
  * Copyright (c) 2006 Fabrice Bellard
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
 
 #include "qemu/osdep.h"
 #include "qemu/timer.h"
 #include "block/block_int.h"
 #include "block/aio.h"
 #include "block/raw-aio.h"
 #include "qemu/event_notifier.h"
 #include "qemu/iov.h"
 #include "qemu/memalign.h"
 #include <windows.h>
 #include <winioctl.h>
 
 #define FTYPE_FILE 0
 #define FTYPE_CD     1
 #define FTYPE_HARDDISK 2
 
 struct QEMUWin32AIOState {
     HANDLE hIOCP;
     EventNotifier e;
     int count;
     AioContext *aio_ctx;
 };
 
 typedef struct QEMUWin32AIOCB {
     BlockAIOCB common;
     struct QEMUWin32AIOState *ctx;
     int nbytes;
     OVERLAPPED ov;
     QEMUIOVector *qiov;
     void *buf;
     bool is_read;
     bool is_linear;
 } QEMUWin32AIOCB;
 
 /*
  * Completes an AIO request (calls the callback and frees the ACB).
  */
 static void win32_aio_process_completion(QEMUWin32AIOState *s,
     QEMUWin32AIOCB *waiocb, DWORD count)
 {
     int ret;
     s->count--;
 
     if (waiocb->ov.Internal != 0) {
         ret = -EIO;
     } else {
         ret = 0;
         if (count < waiocb->nbytes) {
             /* Short reads mean EOF, pad with zeros. */
             if (waiocb->is_read) {
                 qemu_iovec_memset(waiocb->qiov, count, 0,
                     waiocb->qiov->size - count);
             } else {
                 ret = -EINVAL;
             }
        }
     }
 
     if (!waiocb->is_linear) {
         if (ret == 0 && waiocb->is_read) {
             QEMUIOVector *qiov = waiocb->qiov;
             iov_from_buf(qiov->iov, qiov->niov, 0, waiocb->buf, qiov->size);
         }
         qemu_vfree(waiocb->buf);
     }
 
     waiocb->common.cb(waiocb->common.opaque, ret);
     qemu_aio_unref(waiocb);
 }
 
 static void win32_aio_completion_cb(EventNotifier *e)
 {
     QEMUWin32AIOState *s = container_of(e, QEMUWin32AIOState, e);
     DWORD count;
     ULONG_PTR key;
     OVERLAPPED *ov;
 
     event_notifier_test_and_clear(&s->e);
     while (GetQueuedCompletionStatus(s->hIOCP, &count, &key, &ov, 0)) {
         QEMUWin32AIOCB *waiocb = container_of(ov, QEMUWin32AIOCB, ov);
 
         win32_aio_process_completion(s, waiocb, count);
     }
 }
 
 static const AIOCBInfo win32_aiocb_info = {
     .aiocb_size         = sizeof(QEMUWin32AIOCB),
 };
 
 BlockAIOCB *win32_aio_submit(BlockDriverState *bs,
         QEMUWin32AIOState *aio, HANDLE hfile,
         uint64_t offset, uint64_t bytes, QEMUIOVector *qiov,
         BlockCompletionFunc *cb, void *opaque, int type)
 {
     struct QEMUWin32AIOCB *waiocb;
     DWORD rc;
 
     waiocb = qemu_aio_get(&win32_aiocb_info, bs, cb, opaque);
     waiocb->nbytes = bytes;
     waiocb->qiov = qiov;
     waiocb->is_read = (type == QEMU_AIO_READ);
 
     if (qiov->niov > 1) {
         waiocb->buf = qemu_try_blockalign(bs, qiov->size);
         if (waiocb->buf == NULL) {
             goto out;
         }
         if (type & QEMU_AIO_WRITE) {
             iov_to_buf(qiov->iov, qiov->niov, 0, waiocb->buf, qiov->size);
         }
         waiocb->is_linear = false;
     } else {
         waiocb->buf = qiov->iov[0].iov_base;
         waiocb->is_linear = true;
     }
 
     memset(&waiocb->ov, 0, sizeof(waiocb->ov));
     waiocb->ov.Offset = (DWORD)offset;
     waiocb->ov.OffsetHigh = (DWORD)(offset >> 32);
     waiocb->ov.hEvent = event_notifier_get_handle(&aio->e);
 
     aio->count++;
 
     if (type & QEMU_AIO_READ) {
         rc = ReadFile(hfile, waiocb->buf, waiocb->nbytes, NULL, &waiocb->ov);
     } else {
         rc = WriteFile(hfile, waiocb->buf, waiocb->nbytes, NULL, &waiocb->ov);
     }
     if(rc == 0 && GetLastError() != ERROR_IO_PENDING) {
         goto out_dec_count;
     }
     return &waiocb->common;
 
 out_dec_count:
     aio->count--;
 out:
     qemu_aio_unref(waiocb);
     return NULL;
 }
 
 int win32_aio_attach(QEMUWin32AIOState *aio, HANDLE hfile)
 {
     if (CreateIoCompletionPort(hfile, aio->hIOCP, (ULONG_PTR) 0, 0) == NULL) {
         return -EINVAL;
     } else {
         return 0;
     }
 }
 
 void win32_aio_detach_aio_context(QEMUWin32AIOState *aio,
                                   AioContext *old_context)
 {
     aio_set_event_notifier(old_context, &aio->e, false, NULL, NULL, NULL);
     aio->aio_ctx = NULL;
 }
 
 void win32_aio_attach_aio_context(QEMUWin32AIOState *aio,
                                   AioContext *new_context)
 {
     aio->aio_ctx = new_context;
     aio_set_event_notifier(new_context, &aio->e, false,
                            win32_aio_completion_cb, NULL, NULL);
 }
 
 QEMUWin32AIOState *win32_aio_init(void)
 {
     QEMUWin32AIOState *s;
 
     s = g_malloc0(sizeof(*s));
     if (event_notifier_init(&s->e, false) < 0) {
         goto out_free_state;
     }
 
     s->hIOCP = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, 0, 0);
     if (s->hIOCP == NULL) {
         goto out_close_efd;
     }
 
     return s;
 
 out_close_efd:
     event_notifier_cleanup(&s->e);
 out_free_state:
     g_free(s);
     return NULL;
 }
 
 void win32_aio_cleanup(QEMUWin32AIOState *aio)
 {
     assert(!aio->aio_ctx);
     CloseHandle(aio->hIOCP);
     event_notifier_cleanup(&aio->e);
     g_free(aio);
 }