Re: [PATCH v4] virtio-network: Clarify VLAN filter table configuration

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Jan 04, 2023 at 06:02:05AM +0200, Parav Pandit wrote:
> The filtering behavior of the VLAN filter commands is not very clear as
> discussed in thread [1].
> 
> Hence, add the command description and device requirements for it.
> 
> [1] https://www.mail-archive.com/qemu-devel@nongnu.org/msg912392.html
> Fixes: https://github.com/oasis-tcs/virtio-spec/issues/147
> Suggested-by: Si-Wei Liu <si-wei.liu@oracle.com>
> Signed-off-by: Parav Pandit <parav@nvidia.com>

Looks like we are going back to issues that we had in v1.
what happened here?

> ---
> changelog:
> v3->v4:
> - added description for accepting vlan tagged packets when vlan
>   filter is not negotiated
> v2->v3:
> - corrected grammar
> - simplified description for untagged packets
> v1->v2:
> - adapt to new file path
> v0->v1:
> - added missing conformance section link
> ---
>  .../virtio-network/device-conformance.tex     |  1 +
>  device-types/virtio-network/device.tex        | 22 +++++++++++++++++++
>  2 files changed, 23 insertions(+)
> 
> diff --git a/device-types/virtio-network/device-conformance.tex b/device-types/virtio-network/device-conformance.tex
> index c686377..54f6783 100644
> --- a/device-types/virtio-network/device-conformance.tex
> +++ b/device-types/virtio-network/device-conformance.tex
> @@ -9,6 +9,7 @@
>  \item \ref{devicenormative:Device Types / Network Device / Device Operation / Processing of Incoming Packets}
>  \item \ref{devicenormative:Device Types / Network Device / Device Operation / Control Virtqueue / Packet Receive Filtering}
>  \item \ref{devicenormative:Device Types / Network Device / Device Operation / Control Virtqueue / Setting MAC Address Filtering}
> +\item \ref{devicenormative:Device Types / Network Device / Device Operation / Control Virtqueue / VLAN Filtering}
>  \item \ref{devicenormative:Device Types / Network Device / Device Operation / Control Virtqueue / Gratuitous Packet Sending}
>  \item \ref{devicenormative:Device Types / Network Device / Device Operation / Control Virtqueue / Automatic receive steering in multiqueue mode}
>  \item \ref{devicenormative:Device Types / Network Device / Device Operation / Control Virtqueue / Receive-side scaling (RSS) / RSS processing}
> diff --git a/device-types/virtio-network/device.tex b/device-types/virtio-network/device.tex
> index e7cdd6f..0e6d872 100644
> --- a/device-types/virtio-network/device.tex
> +++ b/device-types/virtio-network/device.tex
> @@ -1210,6 +1210,28 @@ \subsubsection{Control Virtqueue}\label{sec:Device Types / Network Device / Devi
>  Both the VIRTIO_NET_CTRL_VLAN_ADD and VIRTIO_NET_CTRL_VLAN_DEL
>  command take a little-endian 16-bit VLAN id as the command-specific-data.
>  
> +VIRTIO_NET_CTRL_VLAN_ADD command adds the specified VLAN to the VLAN
> +filtering table.
> +
> +VIRTIO_NET_CTRL_VLAN_DEL command removes specified VLAN from the VLAN

the specified

> +filtering table which was previously added using
> +VIRTIO_NET_CTRL_VLAN_ADD command.

bad ordering so it's unclear what was added. it's vlan not the
table. So:
	removes the specified VLAN - which was previously added using
	VIRTIO_NET_CTRL_VLAN_ADD command - from the VLAN filtering table.

> +
> +\devicenormative{\subparagraph}{VLAN Filtering}{Device Types / Network Device / Device Operation / Control Virtqueue / VLAN Filtering}
> +
> +When VIRTIO_NET_F_CTRL_VLAN is not negotiated, the device accepts
> +all VLAN tagged packets that matches the device's filter
> +configuration.

bad grammar here and it's not a match.


> +
> +When VIRTIO_NET_F_CTRL_VLAN is negotiated, the device starts with
> +an empty VLAN filtering table.
> +
> +When VIRTIO_NET_F_CTRL_VLAN is negotiated, the device accepts all
> +VLAN tagged packets whose VLAN tag is found in the VLAN filtering
> +table; the device should drop all VLAN tagged packets whose VLAN tag
> +is not found in the VLAN filtering table. The VLAN filtering table
> +applies only to the VLAN tagged packets.
> +
>  \subparagraph{Legacy Interface: VLAN Filtering}\label{sec:Device Types / Network Device / Device Operation / Control Virtqueue / VLAN Filtering / Legacy Interface: VLAN Filtering}
>  When using the legacy interface, transitional devices and drivers
>  MUST format the VLAN id
> -- 
> 2.26.2