mirror of
https://github.com/qemu/qemu.git
synced 2024-12-18 17:53:40 +08:00
f5022a135e
Commit ed2aec4867f0d5f5de496bb765347b5d0cfe113d changed the return value of aio_ctx_prepare from false to true when only idle bottom halves are available. This broke PC old-style DMA, which uses them. Fix this by making aio_ctx_prepare return true only when non-idle bottom halves are scheduled to run. Reported-by: malc <av1474@comtv.ru> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: malc <av1474@comtv.ru>
223 lines
5.0 KiB
C
223 lines
5.0 KiB
C
/*
|
|
* QEMU System Emulator
|
|
*
|
|
* Copyright (c) 2003-2008 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-aio.h"
|
|
#include "main-loop.h"
|
|
|
|
/***********************************************************/
|
|
/* bottom halves (can be seen as timers which expire ASAP) */
|
|
|
|
struct QEMUBH {
|
|
AioContext *ctx;
|
|
QEMUBHFunc *cb;
|
|
void *opaque;
|
|
QEMUBH *next;
|
|
bool scheduled;
|
|
bool idle;
|
|
bool deleted;
|
|
};
|
|
|
|
QEMUBH *aio_bh_new(AioContext *ctx, QEMUBHFunc *cb, void *opaque)
|
|
{
|
|
QEMUBH *bh;
|
|
bh = g_malloc0(sizeof(QEMUBH));
|
|
bh->ctx = ctx;
|
|
bh->cb = cb;
|
|
bh->opaque = opaque;
|
|
bh->next = ctx->first_bh;
|
|
ctx->first_bh = bh;
|
|
return bh;
|
|
}
|
|
|
|
int aio_bh_poll(AioContext *ctx)
|
|
{
|
|
QEMUBH *bh, **bhp, *next;
|
|
int ret;
|
|
|
|
ctx->walking_bh++;
|
|
|
|
ret = 0;
|
|
for (bh = ctx->first_bh; bh; bh = next) {
|
|
next = bh->next;
|
|
if (!bh->deleted && bh->scheduled) {
|
|
bh->scheduled = 0;
|
|
if (!bh->idle)
|
|
ret = 1;
|
|
bh->idle = 0;
|
|
bh->cb(bh->opaque);
|
|
}
|
|
}
|
|
|
|
ctx->walking_bh--;
|
|
|
|
/* remove deleted bhs */
|
|
if (!ctx->walking_bh) {
|
|
bhp = &ctx->first_bh;
|
|
while (*bhp) {
|
|
bh = *bhp;
|
|
if (bh->deleted) {
|
|
*bhp = bh->next;
|
|
g_free(bh);
|
|
} else {
|
|
bhp = &bh->next;
|
|
}
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
void qemu_bh_schedule_idle(QEMUBH *bh)
|
|
{
|
|
if (bh->scheduled)
|
|
return;
|
|
bh->scheduled = 1;
|
|
bh->idle = 1;
|
|
}
|
|
|
|
void qemu_bh_schedule(QEMUBH *bh)
|
|
{
|
|
if (bh->scheduled)
|
|
return;
|
|
bh->scheduled = 1;
|
|
bh->idle = 0;
|
|
aio_notify(bh->ctx);
|
|
}
|
|
|
|
void qemu_bh_cancel(QEMUBH *bh)
|
|
{
|
|
bh->scheduled = 0;
|
|
}
|
|
|
|
void qemu_bh_delete(QEMUBH *bh)
|
|
{
|
|
bh->scheduled = 0;
|
|
bh->deleted = 1;
|
|
}
|
|
|
|
static gboolean
|
|
aio_ctx_prepare(GSource *source, gint *timeout)
|
|
{
|
|
AioContext *ctx = (AioContext *) source;
|
|
QEMUBH *bh;
|
|
|
|
for (bh = ctx->first_bh; bh; bh = bh->next) {
|
|
if (!bh->deleted && bh->scheduled) {
|
|
if (bh->idle) {
|
|
/* idle bottom halves will be polled at least
|
|
* every 10ms */
|
|
*timeout = 10;
|
|
} else {
|
|
/* non-idle bottom halves will be executed
|
|
* immediately */
|
|
*timeout = 0;
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static gboolean
|
|
aio_ctx_check(GSource *source)
|
|
{
|
|
AioContext *ctx = (AioContext *) source;
|
|
QEMUBH *bh;
|
|
|
|
for (bh = ctx->first_bh; bh; bh = bh->next) {
|
|
if (!bh->deleted && bh->scheduled) {
|
|
return true;
|
|
}
|
|
}
|
|
return aio_pending(ctx);
|
|
}
|
|
|
|
static gboolean
|
|
aio_ctx_dispatch(GSource *source,
|
|
GSourceFunc callback,
|
|
gpointer user_data)
|
|
{
|
|
AioContext *ctx = (AioContext *) source;
|
|
|
|
assert(callback == NULL);
|
|
aio_poll(ctx, false);
|
|
return true;
|
|
}
|
|
|
|
static void
|
|
aio_ctx_finalize(GSource *source)
|
|
{
|
|
AioContext *ctx = (AioContext *) source;
|
|
|
|
aio_set_event_notifier(ctx, &ctx->notifier, NULL, NULL);
|
|
event_notifier_cleanup(&ctx->notifier);
|
|
}
|
|
|
|
static GSourceFuncs aio_source_funcs = {
|
|
aio_ctx_prepare,
|
|
aio_ctx_check,
|
|
aio_ctx_dispatch,
|
|
aio_ctx_finalize
|
|
};
|
|
|
|
GSource *aio_get_g_source(AioContext *ctx)
|
|
{
|
|
g_source_ref(&ctx->source);
|
|
return &ctx->source;
|
|
}
|
|
|
|
void aio_notify(AioContext *ctx)
|
|
{
|
|
event_notifier_set(&ctx->notifier);
|
|
}
|
|
|
|
AioContext *aio_context_new(void)
|
|
{
|
|
AioContext *ctx;
|
|
ctx = (AioContext *) g_source_new(&aio_source_funcs, sizeof(AioContext));
|
|
event_notifier_init(&ctx->notifier, false);
|
|
aio_set_event_notifier(ctx, &ctx->notifier,
|
|
(EventNotifierHandler *)
|
|
event_notifier_test_and_clear, NULL);
|
|
|
|
return ctx;
|
|
}
|
|
|
|
void aio_context_ref(AioContext *ctx)
|
|
{
|
|
g_source_ref(&ctx->source);
|
|
}
|
|
|
|
void aio_context_unref(AioContext *ctx)
|
|
{
|
|
g_source_unref(&ctx->source);
|
|
}
|
|
|
|
void aio_flush(AioContext *ctx)
|
|
{
|
|
while (aio_poll(ctx, true));
|
|
}
|