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raw-win32: implement native asynchronous I/O

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With the new support for EventNotifiers in the AIO event loop, we
can hook a completion port to every opened file and use asynchronous
I/O on them.

Wine's support is extremely inefficient, also because it really does
the I/O synchronously on regular files. (!)  But it works, and it is
good to keep the Win32 and POSIX ports as similar as possible.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2012-10-26 11:43:58 +02:00
parent 10fb6e0682
commit a27365265c
4 changed files with 274 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
block/Makefile.objs
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@ -3,7 +3,7 @@ block-obj-y += qcow2.o qcow2-refcount.o qcow2-cluster.o qcow2-snapshot.o qcow2-c
block-obj-y += qed.o qed-gencb.o qed-l2-cache.o qed-table.o qed-cluster.o
block-obj-y += qed-check.o
block-obj-y += parallels.o blkdebug.o blkverify.o
block-obj-$(CONFIG_WIN32) += raw-win32.o
block-obj-$(CONFIG_WIN32) += raw-win32.o win32-aio.o
block-obj-$(CONFIG_POSIX) += raw-posix.o
block-obj-$(CONFIG_LINUX_AIO) += linux-aio.o

10
block/raw-aio.h
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@ -35,4 +35,14 @@ BlockDriverAIOCB *laio_submit(BlockDriverState *bs, void *aio_ctx, int fd,
BlockDriverCompletionFunc *cb, void *opaque, int type);
#endif
#ifdef _WIN32
typedef struct QEMUWin32AIOState QEMUWin32AIOState;
QEMUWin32AIOState *win32_aio_init(void);
int win32_aio_attach(QEMUWin32AIOState *aio, HANDLE hfile);
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);
#endif
#endif /* QEMU_RAW_AIO_H */

42
block/raw-win32.c
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@ -36,6 +36,8 @@
#define FTYPE_CD 1
#define FTYPE_HARDDISK 2
static QEMUWin32AIOState *aio;
typedef struct RawWin32AIOData {
BlockDriverState *bs;
HANDLE hfile;
@ -50,6 +52,7 @@ typedef struct BDRVRawState {
HANDLE hfile;
int type;
char drive_path[16]; /* format: "d:\" */
QEMUWin32AIOState *aio;
} BDRVRawState;
/*
@ -208,6 +211,9 @@ static void raw_parse_flags(int flags, int *access_flags, DWORD *overlapped)
}
*overlapped = FILE_ATTRIBUTE_NORMAL;
if (flags & BDRV_O_NATIVE_AIO) {
*overlapped |= FILE_FLAG_OVERLAPPED;
}
if (flags & BDRV_O_NOCACHE) {
*overlapped |= FILE_FLAG_NO_BUFFERING;
}
@ -222,6 +228,13 @@ static int raw_open(BlockDriverState *bs, const char *filename, int flags)
s->type = FTYPE_FILE;
raw_parse_flags(flags, &access_flags, &overlapped);
if ((flags & BDRV_O_NATIVE_AIO) && aio == NULL) {
aio = win32_aio_init();
if (aio == NULL) {
return -EINVAL;
}
}
s->hfile = CreateFile(filename, access_flags,
FILE_SHARE_READ, NULL,
@ -231,7 +244,16 @@ static int raw_open(BlockDriverState *bs, const char *filename, int flags)
if (err == ERROR_ACCESS_DENIED)
return -EACCES;
return -1;
return -EINVAL;
}
if (flags & BDRV_O_NATIVE_AIO) {
int ret = win32_aio_attach(aio, s->hfile);
if (ret < 0) {
CloseHandle(s->hfile);
return ret;
}
s->aio = aio;
}
return 0;
}
@ -241,8 +263,13 @@ static BlockDriverAIOCB *raw_aio_readv(BlockDriverState *bs,
BlockDriverCompletionFunc *cb, void *opaque)
{
BDRVRawState *s = bs->opaque;
return paio_submit(bs, s->hfile, sector_num, qiov, nb_sectors,
cb, opaque, QEMU_AIO_READ);
if (s->aio) {
return win32_aio_submit(bs, s->aio, s->hfile, sector_num, qiov,
nb_sectors, cb, opaque, QEMU_AIO_READ);
} else {
return paio_submit(bs, s->hfile, sector_num, qiov, nb_sectors,
cb, opaque, QEMU_AIO_READ);
}
}
static BlockDriverAIOCB *raw_aio_writev(BlockDriverState *bs,
@ -250,8 +277,13 @@ static BlockDriverAIOCB *raw_aio_writev(BlockDriverState *bs,
BlockDriverCompletionFunc *cb, void *opaque)
{
BDRVRawState *s = bs->opaque;
return paio_submit(bs, s->hfile, sector_num, qiov, nb_sectors,
cb, opaque, QEMU_AIO_WRITE);
if (s->aio) {
return win32_aio_submit(bs, s->aio, s->hfile, sector_num, qiov,
nb_sectors, cb, opaque, QEMU_AIO_WRITE);
} else {
return paio_submit(bs, s->hfile, sector_num, qiov, nb_sectors,
cb, opaque, QEMU_AIO_WRITE);
}
}
static BlockDriverAIOCB *raw_aio_flush(BlockDriverState *bs,

226
block/win32-aio.c Normal file
View File

@ -0,0 +1,226 @@
/*
* 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_int.h"
#include "module.h"
#include "qemu-common.h"
#include "qemu-aio.h"
#include "raw-aio.h"
#include "event_notifier.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;
char *p = waiocb->buf;
int i;
for (i = 0; i < qiov->niov; ++i) {
memcpy(p, qiov->iov[i].iov_base, qiov->iov[i].iov_len);
p += qiov->iov[i].iov_len;
}
g_free(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 AIOPool win32_aio_pool = {
.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_aio_pool, 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) {
char *p = waiocb->buf;
int i;
for (i = 0; i < qiov->niov; ++i) {
memcpy(p, qiov->iov[i].iov_base, qiov->iov[i].iov_len);
p += qiov->iov[i].iov_len;
}
}
waiocb->is_linear = false;
} else {
waiocb->buf = qiov->iov[0].iov_base;
waiocb->is_linear = true;
}
waiocb->ov = (OVERLAPPED) {
.Offset = (DWORD) offset,
.OffsetHigh = (DWORD) (offset >> 32),
.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;
}