Re: [RFC PATCH v2 18/19] vdpa_sim: filter destination mac address

From: Eugenio Perez Martin <eperezma@redhat.com>
To: Gautam Dawar <gautam.dawar@xilinx.com>
Cc: Gautam Dawar <gdawar@xilinx.com>,
	Martin Petrus Hubertus Habets <martinh@xilinx.com>,
	Harpreet Singh Anand <hanand@xilinx.com>,
	Tanuj Murlidhar Kamde <tanujk@xilinx.com>,
	Jason Wang <jasowang@redhat.com>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	Zhu Lingshan <lingshan.zhu@intel.com>,
	Stefano Garzarella <sgarzare@redhat.com>,
	Xie Yongji <xieyongji@bytedance.com>, Eli Cohen <elic@nvidia.com>,
	Si-Wei Liu <si-wei.liu@oracle.com>,
	Parav Pandit <parav@nvidia.com>, Longpeng <longpeng2@huawei.com>,
	virtualization <virtualization@lists.linux-foundation.org>,
	linux-kernel@vger.kernel.org, kvm list <kvm@vger.kernel.org>,
	netdev@vger.kernel.org
Subject: Re: [RFC PATCH v2 18/19] vdpa_sim: filter destination mac address
Date: Thu, 10 Mar 2022 19:22:06 +0100	[thread overview]
Message-ID: <CAJaqyWeW87TqKxNWPEayyi81uBd_W+Jekdt4sq_d9adCkbwp2g@mail.gmail.com> (raw)
In-Reply-To: <20220224212314.1326-19-gdawar@xilinx.com>

On Thu, Feb 24, 2022 at 10:29 PM Gautam Dawar <gautam.dawar@xilinx.com> wrote:
>
> This patch implements a simple unicast filter for vDPA simulator.
>
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> Signed-off-by: Gautam Dawar <gdawar@xilinx.com>
> ---
>  drivers/vdpa/vdpa_sim/vdpa_sim_net.c | 49 ++++++++++++++++++----------
>  1 file changed, 31 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim_net.c b/drivers/vdpa/vdpa_sim/vdpa_sim_net.c
> index 05d552cb7f94..ed5ade4ae570 100644
> --- a/drivers/vdpa/vdpa_sim/vdpa_sim_net.c
> +++ b/drivers/vdpa/vdpa_sim/vdpa_sim_net.c
> @@ -47,13 +47,28 @@ static void vdpasim_net_complete(struct vdpasim_virtqueue *vq, size_t len)
>         local_bh_enable();
>  }
>
> +static bool receive_filter(struct vdpasim *vdpasim, size_t len)
> +{
> +       bool modern = vdpasim->features & (1ULL << VIRTIO_F_VERSION_1);
> +       size_t hdr_len = modern ? sizeof(struct virtio_net_hdr_v1) :
> +                                 sizeof(struct virtio_net_hdr);
> +
> +       if (len < ETH_ALEN + hdr_len)
> +               return false;
> +
> +       if (!strncmp(vdpasim->buffer + hdr_len,
> +                    vdpasim->config.mac, ETH_ALEN))
> +               return true;
> +
> +       return false;
> +}
> +
>  static void vdpasim_net_work(struct work_struct *work)
>  {
>         struct vdpasim *vdpasim = container_of(work, struct vdpasim, work);
>         struct vdpasim_virtqueue *txq = &vdpasim->vqs[1];
>         struct vdpasim_virtqueue *rxq = &vdpasim->vqs[0];
>         ssize_t read, write;
> -       size_t total_write;
>         int pkts = 0;
>         int err;
>
> @@ -66,36 +81,34 @@ static void vdpasim_net_work(struct work_struct *work)
>                 goto out;
>
>         while (true) {
> -               total_write = 0;
>                 err = vringh_getdesc_iotlb(&txq->vring, &txq->out_iov, NULL,
>                                            &txq->head, GFP_ATOMIC);
>                 if (err <= 0)
>                         break;
>
> +               read = vringh_iov_pull_iotlb(&txq->vring, &txq->out_iov,
> +                                            vdpasim->buffer,
> +                                            PAGE_SIZE);
> +
> +               if (!receive_filter(vdpasim, read)) {
> +                       vdpasim_complete(txq, 0);

vdpasim_net_complete?

Thanks!

> +                       continue;
> +               }
> +
>                 err = vringh_getdesc_iotlb(&rxq->vring, NULL, &rxq->in_iov,
>                                            &rxq->head, GFP_ATOMIC);
>                 if (err <= 0) {
> -                       vringh_complete_iotlb(&txq->vring, txq->head, 0);
> +                       vdpasim_net_complete(txq, 0);
>                         break;
>                 }
>
> -               while (true) {
> -                       read = vringh_iov_pull_iotlb(&txq->vring, &txq->out_iov,
> -                                                    vdpasim->buffer,
> -                                                    PAGE_SIZE);
> -                       if (read <= 0)
> -                               break;
> -
> -                       write = vringh_iov_push_iotlb(&rxq->vring, &rxq->in_iov,
> -                                                     vdpasim->buffer, read);
> -                       if (write <= 0)
> -                               break;
> -
> -                       total_write += write;
> -               }
> +               write = vringh_iov_push_iotlb(&rxq->vring, &rxq->in_iov,
> +                                             vdpasim->buffer, read);
> +               if (write <= 0)
> +                       break;
>
>                 vdpasim_net_complete(txq, 0);
> -               vdpasim_net_complete(rxq, total_write);
> +               vdpasim_net_complete(rxq, write);
>
>                 if (++pkts > 4) {
>                         schedule_work(&vdpasim->work);
> --
> 2.25.0
>