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virtio: inline virtio_queue_set_host_notifier_fd_handler

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Of the three possible parameter combinations for
virtio_queue_set_host_notifier_fd_handler:

- assign=true/set_handler=true is only called from
  virtio_device_start_ioeventfd

- assign=false/set_handler=false is called from
  set_host_notifier_internal but it only does something when
  reached from virtio_device_stop_ioeventfd_impl; otherwise
  there is no EventNotifier set on qemu_get_aio_context().

- assign=true/set_handler=false is called from
  set_host_notifier_internal, but it is not doing anything:
  with the new start_ioeventfd and stop_ioeventfd methods,
  there is never an EventNotifier set on qemu_get_aio_context()
  at this point.  This is enforced by the assertion in
  virtio_bus_set_host_notifier.

Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Paolo Bonzini 2016-10-21 22:48:15 +02:00 committed by Michael S. Tsirkin
parent ed08a2a0ba
commit fa283a4a8b
3 changed files with 21 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
hw/virtio/virtio-bus.c
View File

@ -163,19 +163,22 @@ static int set_host_notifier_internal(DeviceState *proxy, VirtioBusState *bus,
__func__, strerror(-r), r);
return r;
}
virtio_queue_set_host_notifier_fd_handler(vq, true, false);
r = k->ioeventfd_assign(proxy, notifier, n, assign);
r = k->ioeventfd_assign(proxy, notifier, n, true);
if (r < 0) {
error_report("%s: unable to assign ioeventfd: %d", __func__, r);
virtio_queue_set_host_notifier_fd_handler(vq, false, false);
event_notifier_cleanup(notifier);
return r;
goto cleanup_event_notifier;
}
return 0;
} else {
k->ioeventfd_assign(proxy, notifier, n, assign);
virtio_queue_set_host_notifier_fd_handler(vq, false, false);
event_notifier_cleanup(notifier);
k->ioeventfd_assign(proxy, notifier, n, false);
}
cleanup_event_notifier:
/* Test and clear notifier after disabling event,
* in case poll callback didn't have time to run.
*/
virtio_queue_host_notifier_read(notifier);
event_notifier_cleanup(notifier);
return r;
}

27
hw/virtio/virtio.c
View File

@ -2042,7 +2042,7 @@ void virtio_queue_aio_set_host_notifier_handler(VirtQueue *vq, AioContext *ctx,
}
}
static void virtio_queue_host_notifier_read(EventNotifier *n)
void virtio_queue_host_notifier_read(EventNotifier *n)
{
VirtQueue *vq = container_of(n, VirtQueue, host_notifier);
if (event_notifier_test_and_clear(n)) {
@ -2050,22 +2050,6 @@ static void virtio_queue_host_notifier_read(EventNotifier *n)
}
}
void virtio_queue_set_host_notifier_fd_handler(VirtQueue *vq, bool assign,
bool set_handler)
{
if (assign && set_handler) {
event_notifier_set_handler(&vq->host_notifier, true,
virtio_queue_host_notifier_read);
} else {
event_notifier_set_handler(&vq->host_notifier, true, NULL);
}
if (!assign) {
/* Test and clear notifier before after disabling event,
* in case poll callback didn't have time to run. */
virtio_queue_host_notifier_read(&vq->host_notifier);
}
}
EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq)
{
return &vq->host_notifier;
@ -2148,6 +2132,7 @@ static int virtio_device_start_ioeventfd_impl(VirtIODevice *vdev)
int n, r, err;
for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
VirtQueue *vq = &vdev->vq[n];
if (!virtio_queue_get_num(vdev, n)) {
continue;
}
@ -2156,7 +2141,8 @@ static int virtio_device_start_ioeventfd_impl(VirtIODevice *vdev)
err = r;
goto assign_error;
}
virtio_queue_set_host_notifier_fd_handler(&vdev->vq[n], true, true);
event_notifier_set_handler(&vq->host_notifier, true,
virtio_queue_host_notifier_read);
}
for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
@ -2171,10 +2157,12 @@ static int virtio_device_start_ioeventfd_impl(VirtIODevice *vdev)
assign_error:
while (--n >= 0) {
VirtQueue *vq = &vdev->vq[n];
if (!virtio_queue_get_num(vdev, n)) {
continue;
}
event_notifier_set_handler(&vq->host_notifier, true, NULL);
r = virtio_bus_set_host_notifier(qbus, n, false);
assert(r >= 0);
}
@ -2195,9 +2183,12 @@ static void virtio_device_stop_ioeventfd_impl(VirtIODevice *vdev)
int n, r;
for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
VirtQueue *vq = &vdev->vq[n];
if (!virtio_queue_get_num(vdev, n)) {
continue;
}
event_notifier_set_handler(&vq->host_notifier, true, NULL);
r = virtio_bus_set_host_notifier(qbus, n, false);
assert(r >= 0);
}

3
include/hw/virtio/virtio.h
View File

@ -272,8 +272,7 @@ int virtio_device_start_ioeventfd(VirtIODevice *vdev);
void virtio_device_stop_ioeventfd(VirtIODevice *vdev);
bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev);
EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq);
void virtio_queue_set_host_notifier_fd_handler(VirtQueue *vq, bool assign,
bool set_handler);
void virtio_queue_host_notifier_read(EventNotifier *n);
void virtio_queue_aio_set_host_notifier_handler(VirtQueue *vq, AioContext *ctx,
void (*fn)(VirtIODevice *,
VirtQueue *));