Re: [PATCH v7 03/10] virtio: decouple virtqueue from set notifier fd handler

[Jason Wang]

在 2021/6/2 上午11:47, Cindy Lu 写道:
> To support config interrupt.we need to decouple virtqueue number


s/we/ We/


> from virtio_queue_set_guest_notifier_fd_handler,
>
> Signed-off-by: Cindy Lu <lulu@redhat.com>
> ---
>   hw/s390x/virtio-ccw.c      |  6 +++---
>   hw/virtio/virtio-mmio.c    |  4 ++--
>   hw/virtio/virtio-pci.c     |  4 ++--
>   hw/virtio/virtio.c         | 17 +++++++++++------
>   include/hw/virtio/virtio.h |  2 +-
>   5 files changed, 19 insertions(+), 14 deletions(-)
>
> diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
> index 8195f3546e..58bb5232fd 100644
> --- a/hw/s390x/virtio-ccw.c
> +++ b/hw/s390x/virtio-ccw.c
> @@ -1028,11 +1028,11 @@ static int 
> virtio_ccw_set_guest_notifier(VirtioCcwDevice *dev, int n,
>           if (r < 0) {
>               return r;
>           }
> -        virtio_queue_set_guest_notifier_fd_handler(vq, true, with_irqfd);
> +        virtio_set_notifier_fd_handler(vdev, n, true, with_irqfd);
>           if (with_irqfd) {
>               r = virtio_ccw_add_irqfd(dev, n);
>               if (r) {
> -                virtio_queue_set_guest_notifier_fd_handler(vq, false,
> +                virtio_set_notifier_fd_handler(vdev, n, false,
>                                                              with_irqfd);
>                   return r;
>               }
> @@ -1056,7 +1056,7 @@ static int virtio_ccw_set_guest_notifier(VirtioCcwDevice 
> *dev, int n,
>           if (with_irqfd) {
>               virtio_ccw_remove_irqfd(dev, n);
>           }
> -        virtio_queue_set_guest_notifier_fd_handler(vq, false, with_irqfd);
> +        virtio_set_notifier_fd_handler(vdev, n, false, with_irqfd);
>           event_notifier_cleanup(notifier);
>       }
>       return 0;
> diff --git a/hw/virtio/virtio-mmio.c b/hw/virtio/virtio-mmio.c
> index 342c918ea7..13772d52bb 100644
> --- a/hw/virtio/virtio-mmio.c
> +++ b/hw/virtio/virtio-mmio.c
> @@ -658,9 +658,9 @@ static int virtio_mmio_set_guest_notifier(DeviceState *d, 
> int n, bool assign,
>           if (r < 0) {
>               return r;
>           }
> -        virtio_queue_set_guest_notifier_fd_handler(vq, true, with_irqfd);
> +        virtio_set_notifier_fd_handler(vdev, n, true, with_irqfd);
>       } else {
> -        virtio_queue_set_guest_notifier_fd_handler(vq, false, with_irqfd);
> +        virtio_set_notifier_fd_handler(vdev, n, false, with_irqfd);
>           event_notifier_cleanup(notifier);
>       }
>   
> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> index c5c080ec94..6a4ef413a4 100644
> --- a/hw/virtio/virtio-pci.c
> +++ b/hw/virtio/virtio-pci.c
> @@ -958,9 +958,9 @@ static int virtio_pci_set_guest_notifier(DeviceState *d, 
> int n, bool assign,
>           if (r < 0) {
>               return r;
>           }
> -        virtio_queue_set_guest_notifier_fd_handler(vq, true, with_irqfd);
> +        virtio_set_notifier_fd_handler(vdev, n, true, with_irqfd);
>       } else {
> -        virtio_queue_set_guest_notifier_fd_handler(vq, false, with_irqfd);
> +        virtio_set_notifier_fd_handler(vdev, n, false, with_irqfd);
>           event_notifier_cleanup(notifier);
>       }
>   
> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> index 07f4e60b30..c5d786bb5e 100644
> --- a/hw/virtio/virtio.c
> +++ b/hw/virtio/virtio.c
> @@ -3505,19 +3505,24 @@ static void 
> virtio_queue_guest_notifier_read(EventNotifier *n)
>       }
>   }
>   
> -void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign,
> -                                                bool with_irqfd)
> +
> +void virtio_set_notifier_fd_handler(VirtIODevice *vdev, int queue_no,
> +                               bool assign, bool with_irqfd)


Let's use "virtio_set_guest_notifier_fd_handler()".


>   {
> +    EventNotifier *e ;
> +    EventNotifierHandler *handler;
> +    VirtQueue *vq = virtio_get_queue(vdev, queue_no);
> +    e = &vq->guest_notifier;


So you still depends on the vq implicitly.

How about keep virtio_queue_set_guest_notifier_fd_handler() and factor 
its core logic to

virtio_set_guest_notifier_fd_handler() by passing the EventNotifier to 
this new helper?


> +    handler = virtio_queue_guest_notifier_read;
>       if (assign && !with_irqfd) {
> -        event_notifier_set_handler(&vq->guest_notifier,
> -                                   virtio_queue_guest_notifier_read);
> +        event_notifier_set_handler(e, handler);
>       } else {
> -        event_notifier_set_handler(&vq->guest_notifier, NULL);
> +        event_notifier_set_handler(e, NULL);
>       }
>       if (!assign) {
>           /* Test and clear notifier before closing it,
>            * in case poll callback didn't have time to run. */
> -        virtio_queue_guest_notifier_read(&vq->guest_notifier);
> +        handler(e);


Any reason for this change?

Thanks


>       }
>   }
>   
> diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
> index 63cb9455ed..447899dea5 100644
> --- a/include/hw/virtio/virtio.h
> +++ b/include/hw/virtio/virtio.h
> @@ -310,7 +310,7 @@ void virtio_queue_update_used_idx(VirtIODevice *vdev, int 
> n);
>   VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n);
>   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,
> +void virtio_set_notifier_fd_handler(VirtIODevice *vdev, int n, bool assign,
>                                                   bool with_irqfd);
>   int virtio_device_start_ioeventfd(VirtIODevice *vdev);
>   int virtio_device_grab_ioeventfd(VirtIODevice *vdev);