qemu/block/win32-aio.c

216 lines
5.9 KiB
C

/*
* 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-common.h"
#include "qemu/timer.h"
#include "block/block_int.h"
#include "qemu/module.h"
#include "qemu-common.h"
#include "block/aio.h"
#include "raw-aio.h"
#include "qemu/event_notifier.h"
#include "qemu/iov.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;
};
typedef struct QEMUWin32AIOCB {
BlockDriverAIOCB 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_release(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 int win32_aio_flush_cb(EventNotifier *e)
{
QEMUWin32AIOState *s = container_of(e, QEMUWin32AIOState, e);
return (s->count > 0) ? 1 : 0;
}
static void win32_aio_cancel(BlockDriverAIOCB *blockacb)
{
QEMUWin32AIOCB *waiocb = (QEMUWin32AIOCB *)blockacb;
/*
* CancelIoEx is only supported in Vista and newer. For now, just
* wait for completion.
*/
while (!HasOverlappedIoCompleted(&waiocb->ov)) {
qemu_aio_wait();
}
}
static const AIOCBInfo win32_aiocb_info = {
.aiocb_size = sizeof(QEMUWin32AIOCB),
.cancel = win32_aio_cancel,
};
BlockDriverAIOCB *win32_aio_submit(BlockDriverState *bs,
QEMUWin32AIOState *aio, HANDLE hfile,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque, int type)
{
struct QEMUWin32AIOCB *waiocb;
uint64_t offset = sector_num * 512;
DWORD rc;
waiocb = qemu_aio_get(&win32_aiocb_info, bs, cb, opaque);
waiocb->nbytes = nb_sectors * 512;
waiocb->qiov = qiov;
waiocb->is_read = (type == QEMU_AIO_READ);
if (qiov->niov > 1) {
waiocb->buf = qemu_blockalign(bs, qiov->size);
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--;
qemu_aio_release(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;
}
}
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;
}
qemu_aio_set_event_notifier(&s->e, win32_aio_completion_cb,
win32_aio_flush_cb);
return s;
out_close_efd:
event_notifier_cleanup(&s->e);
out_free_state:
g_free(s);
return NULL;
}