Re: [PATCH v1 1/4] virtio:add support in configure interrupt

[Jason Wang <jasowang@redhat.com>]

On 2021/1/13 下午11:45, Cindy Lu wrote:
> Add configure notifier and virtio_set_config_notifier_fd_handler
> in virtio
>
> Signed-off-by: Cindy Lu <lulu@redhat.com>
> ---
>   hw/virtio/virtio.c         | 25 +++++++++++++++++++++++++
>   include/hw/virtio/virtio.h |  5 +++++
>   2 files changed, 30 insertions(+)
>
> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> index ceb58fda6c..66ed1daf95 100644
> --- a/hw/virtio/virtio.c
> +++ b/hw/virtio/virtio.c
> @@ -3502,6 +3502,15 @@ static void virtio_queue_guest_notifier_read(EventNotifier *n)
>       }
>   }
>   
> +static void virtio_queue_config_read(EventNotifier *n)
> +{


Note that the config interrupt belongs to the device. So it's better not 
name it as "queue" here.


> +    VirtIODevice *vdev = container_of(n, VirtIODevice, config_notifier);
> +
> +    if (event_notifier_test_and_clear(n)) {
> +
> +        virtio_notify_config(vdev);
> +    }
> +}
>   void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign,
>                                                   bool with_irqfd)
>   {
> @@ -3518,6 +3527,17 @@ void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign,
>       }
>   }
>   
> +void virtio_set_config_notifier_fd_handler(VirtIODevice *vdev, bool assign,
> +                                                bool with_irqfd)
> +{
> +    if (assign && !with_irqfd) {
> +        event_notifier_set_handler(&vdev->config_notifier,
> +                                   virtio_queue_config_read);
> +    } else {
> +       event_notifier_set_handler(&vdev->config_notifier, NULL);
> +    }
> +}


I wonder whether we can simply generalize 
virtio_queue_set_guest_notifier_fd_handler from

void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign,
                                                 bool with_irqfd)

to

void virtio_set_guest_notifier_fd_handler(EventNotifier *e, bool assign,
                                                 bool with_irqfd)


Since there's actually no virtqueue specific setup in this function, 
what its callee really want is a simple EventNotifier.

Thanks


> +
>   EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq)
>   {
>       return &vq->guest_notifier;
> @@ -3591,6 +3611,11 @@ EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq)
>       return &vq->host_notifier;
>   }
>   
> +EventNotifier *virtio_queue_get_config_notifier(VirtIODevice *vdev)
> +{
> +    return &vdev->config_notifier;
> +
> +}
>   void virtio_queue_set_host_notifier_enabled(VirtQueue *vq, bool enabled)
>   {
>       vq->host_notifier_enabled = enabled;
> diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
> index b7ece7a6a8..38bd28242e 100644
> --- a/include/hw/virtio/virtio.h
> +++ b/include/hw/virtio/virtio.h
> @@ -108,6 +108,7 @@ struct VirtIODevice
>       bool use_guest_notifier_mask;
>       AddressSpace *dma_as;
>       QLIST_HEAD(, VirtQueue) *vector_queues;
> +    EventNotifier config_notifier;
>   };
>   
>   struct VirtioDeviceClass {
> @@ -310,11 +311,15 @@ uint16_t virtio_get_queue_index(VirtQueue *vq);
>   EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq);
>   void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign,
>                                                   bool with_irqfd);
> +void virtio_set_config_notifier_fd_handler(VirtIODevice *vdev, bool assign,
> +                                                bool with_irqfd);
> +
>   int virtio_device_start_ioeventfd(VirtIODevice *vdev);
>   int virtio_device_grab_ioeventfd(VirtIODevice *vdev);
>   void virtio_device_release_ioeventfd(VirtIODevice *vdev);
>   bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev);
>   EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq);
> +EventNotifier *virtio_queue_get_config_notifier(VirtIODevice *vdev);
>   void virtio_queue_set_host_notifier_enabled(VirtQueue *vq, bool enabled);
>   void virtio_queue_host_notifier_read(EventNotifier *n);
>   void virtio_queue_aio_set_host_notifier_handler(VirtQueue *vq, AioContext *ctx,