static void test_acquire(void)
{
QemuThread thread;
EventNotifier notifier;
AcquireTestData data;
/* Dummy event notifier ensures aio_poll() will block */
event_notifier_init(¬ifier, false);
aio_set_event_notifier(ctx, ¬ifier, dummy_notifier_read);
g_assert(!aio_poll(ctx, false)); /* consume aio_notify() */
qemu_mutex_init(&data.start_lock);
qemu_mutex_lock(&data.start_lock);
data.thread_acquired = false;
qemu_thread_create(&thread, "test_acquire_thread",
test_acquire_thread,
&data, QEMU_THREAD_JOINABLE);
/* Block in aio_poll(), let other thread kick us and acquire context */
aio_context_acquire(ctx);
qemu_mutex_unlock(&data.start_lock); /* let the thread run */
g_assert(!aio_poll(ctx, true));
aio_context_release(ctx);
qemu_thread_join(&thread);
aio_set_event_notifier(ctx, ¬ifier, NULL);
event_notifier_cleanup(¬ifier);
g_assert(data.thread_acquired);
}
void laio_attach_aio_context(void *s_, AioContext *new_context)
{
struct qemu_laio_state *s = s_;
s->completion_bh = aio_bh_new(new_context, qemu_laio_completion_bh, s);
aio_set_event_notifier(new_context, &s->e, qemu_laio_completion_cb);
}
void laio_detach_aio_context(void *s_, AioContext *old_context)
{
struct qemu_laio_state *s = s_;
aio_set_event_notifier(old_context, &s->e, NULL);
qemu_bh_delete(s->completion_bh);
}
void win32_aio_attach_aio_context(QEMUWin32AIOState *aio,
AioContext *new_context)
{
aio->is_aio_context_attached = true;
aio_set_event_notifier(new_context, &aio->e, false,
win32_aio_completion_cb);
}
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);
}
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;
}
static void
aio_ctx_finalize(GSource *source)
{
AioContext *ctx = (AioContext *) source;
thread_pool_free(ctx->thread_pool);
aio_set_event_notifier(ctx, &ctx->notifier, NULL, NULL);
event_notifier_cleanup(&ctx->notifier);
qemu_mutex_destroy(&ctx->bh_lock);
g_array_free(ctx->pollfds, TRUE);
}
AioContext *aio_context_new(void)
{
AioContext *ctx;
ctx = (AioContext *) g_source_new(&aio_source_funcs, sizeof(AioContext));
ctx->pollfds = g_array_new(FALSE, FALSE, sizeof(GPollFD));
ctx->thread_pool = NULL;
qemu_mutex_init(&ctx->bh_lock);
event_notifier_init(&ctx->notifier, false);
aio_set_event_notifier(ctx, &ctx->notifier,
(EventNotifierHandler *)
event_notifier_test_and_clear, NULL);
return ctx;
}
/* Context: QEMU global mutex held */
void virtio_blk_data_plane_stop(VirtIOBlockDataPlane *s)
{
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s->vdev)));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
VirtIOBlock *vblk = VIRTIO_BLK(s->vdev);
/* Better luck next time. */
if (s->disabled) {
s->disabled = false;
return;
}
if (!s->started || s->stopping) {
return;
}
s->stopping = true;
vblk->complete_request = s->saved_complete_request;
trace_virtio_blk_data_plane_stop(s);
aio_context_acquire(s->ctx);
/* Stop notifications for new requests from guest */
aio_set_event_notifier(s->ctx, &s->host_notifier, true, NULL);
/* Drain and switch bs back to the QEMU main loop */
blk_set_aio_context(s->conf->conf.blk, qemu_get_aio_context());
aio_context_release(s->ctx);
/* Sync vring state back to virtqueue so that non-dataplane request
* processing can continue when we disable the host notifier below.
*/
vring_teardown(&s->vring, s->vdev, 0);
k->set_host_notifier(qbus->parent, 0, false);
/* Clean up guest notifier (irq) */
k->set_guest_notifiers(qbus->parent, 1, false);
s->started = false;
s->stopping = false;
}
AioContext *aio_context_new(Error **errp)
{
int ret;
AioContext *ctx;
ctx = (AioContext *) g_source_new(&aio_source_funcs, sizeof(AioContext));
ret = event_notifier_init(&ctx->notifier, false);
if (ret < 0) {
g_source_destroy(&ctx->source);
error_setg_errno(errp, -ret, "Failed to initialize event notifier");
return NULL;
}
aio_set_event_notifier(ctx, &ctx->notifier,
(EventNotifierHandler *)
event_notifier_test_and_clear);
ctx->pollfds = g_array_new(FALSE, FALSE, sizeof(GPollFD));
ctx->thread_pool = NULL;
qemu_mutex_init(&ctx->bh_lock);
rfifolock_init(&ctx->lock, aio_rfifolock_cb, ctx);
timerlistgroup_init(&ctx->tlg, aio_timerlist_notify, ctx);
return ctx;
}
void qemu_aio_set_event_notifier(EventNotifier *notifier,
EventNotifierHandler *io_read,
AioFlushEventNotifierHandler *io_flush)
{
aio_set_event_notifier(qemu_aio_context, notifier, io_read, io_flush);
}
static void set_event_notifier(AioContext *ctx, EventNotifier *notifier,
EventNotifierHandler *handler)
{
aio_set_event_notifier(ctx, notifier, false, handler);
}
void qemu_aio_set_event_notifier(EventNotifier *notifier,
EventNotifierHandler *io_read)
{
aio_set_event_notifier(qemu_aio_context, notifier, io_read);
}
/* Context: QEMU global mutex held */
void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s)
{
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s->vdev)));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
VirtIOBlock *vblk = VIRTIO_BLK(s->vdev);
VirtQueue *vq;
int r;
if (s->started || s->disabled) {
return;
}
if (s->starting) {
return;
}
s->starting = true;
vq = virtio_get_queue(s->vdev, 0);
if (!vring_setup(&s->vring, s->vdev, 0)) {
goto fail_vring;
}
/* Set up guest notifier (irq) */
r = k->set_guest_notifiers(qbus->parent, 1, true);
if (r != 0) {
fprintf(stderr, "virtio-blk failed to set guest notifier (%d), "
"ensure -enable-kvm is set\n", r);
goto fail_guest_notifiers;
}
s->guest_notifier = virtio_queue_get_guest_notifier(vq);
/* Set up virtqueue notify */
r = k->set_host_notifier(qbus->parent, 0, true);
if (r != 0) {
fprintf(stderr, "virtio-blk failed to set host notifier (%d)\n", r);
goto fail_host_notifier;
}
s->host_notifier = *virtio_queue_get_host_notifier(vq);
s->saved_complete_request = vblk->complete_request;
vblk->complete_request = complete_request_vring;
s->starting = false;
s->started = true;
trace_virtio_blk_data_plane_start(s);
blk_set_aio_context(s->conf->conf.blk, s->ctx);
/* Kick right away to begin processing requests already in vring */
event_notifier_set(virtio_queue_get_host_notifier(vq));
/* Get this show started by hooking up our callbacks */
aio_context_acquire(s->ctx);
aio_set_event_notifier(s->ctx, &s->host_notifier, true,
handle_notify);
aio_context_release(s->ctx);
return;
fail_host_notifier:
k->set_guest_notifiers(qbus->parent, 1, false);
fail_guest_notifiers:
vring_teardown(&s->vring, s->vdev, 0);
s->disabled = true;
fail_vring:
s->starting = false;
}
void win32_aio_detach_aio_context(QEMUWin32AIOState *aio,
AioContext *old_context)
{
aio_set_event_notifier(old_context, &aio->e, NULL);
aio->is_aio_context_attached = false;
}
