Commit 4fe6d78b authored by Gal Hammer's avatar Gal Hammer Committed by Michael S. Tsirkin
Browse files

virtio: postpone the execution of event_notifier_cleanup function 



Use the EventNotifier's cleanup callback function to execute the
event_notifier_cleanup function after kvm unregistered the eventfd.

This change supports running the virtio_bus_set_host_notifier
function inside a memory region transaction. Otherwise, a closed
fd is sent to kvm, which results in a failure.

Signed-off-by: default avatarGal Hammer <ghammer@redhat.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent f87d72f5

accel/kvm/kvm-all.c

+4 −0
Original line number Diff line number Diff line
@@ -812,6 +812,10 @@ static void kvm_mem_ioeventfd_del(MemoryListener *listener, 
    if (r < 0) {

        abort();

    }



    if (e->cleanup) {

        e->cleanup(e);

    }

}



static void kvm_io_ioeventfd_add(MemoryListener *listener,

hw/virtio/virtio-bus.c

+11 −8
Original line number Diff line number Diff line
@@ -256,6 +256,15 @@ bool virtio_bus_ioeventfd_enabled(VirtioBusState *bus) 
    return k->ioeventfd_assign && k->ioeventfd_enabled(proxy);

}



static void virtio_bus_cleanup_event_notifier(EventNotifier *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);

}



/*

 * This function switches ioeventfd on/off in the device.

 * The caller must set or clear the handlers for the EventNotifier.
@@ -283,19 +292,13 @@ int virtio_bus_set_host_notifier(VirtioBusState *bus, int n, bool assign) 
        r = k->ioeventfd_assign(proxy, notifier, n, true);

        if (r < 0) {

            error_report("%s: unable to assign ioeventfd: %d", __func__, r);

            goto cleanup_event_notifier;

            virtio_bus_cleanup_event_notifier(notifier);

        }

        return 0;

    } else {

        notifier->cleanup = virtio_bus_cleanup_event_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;

}