Re: [dpdk-dev] [PATCH 1/4] net/virtio: fix interrupt unregistering for listening socket

[Maxime Coquelin <maxime.coquelin@redhat.com>]

On 3/17/21 9:25 PM, Ilya Maximets wrote:
> virtio_user_dev_server_reconnect() is typically called from the
> interrupt context while checking the link state:
> 
>   vhost_user_update_link_state()
>   --> virtio_user_dev_server_reconnect()
> 
> Under this conditions callback unregistering always fails.  This means
> that listenfd is never unregistered and continue to trigger interrupts.
> For example, if second client will try to connect to the same socket,
> the server will receive interrupts infinitely because it will not
> accept them while listen fd is readable and generates epoll events.
> 
> Fix that by moving reconfiguration of interrupts out of the
> interrupt context to alarm handler.
> 
> 'virtio_user_dev_delayed_handler' renamed to
> 'virtio_user_dev_delayed_disconnect_handler' to better reflect its
> purpose.
> 
> Additionally improved error logging around interrupt management.
> 
> Fixes: bd8f50a45d0f ("net/virtio-user: support server mode")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
> ---
> 
> CC: Zhiyong Yang <zhiyong.yang@intel.com>
> 
>  drivers/net/virtio/virtio_user/vhost_user.c   |  4 +-
>  .../net/virtio/virtio_user/virtio_user_dev.c  | 70 ++++++++++++++-----
>  .../net/virtio/virtio_user/virtio_user_dev.h  |  2 +-
>  3 files changed, 57 insertions(+), 19 deletions(-)
> 

Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

Thanks,
Maxime