[dpdk-dev] [PATCH 10/17] net/fm10k/base: improve VF's multi-bit VLAN update requests

[Ferruh Yigit]

On 3/3/2017 3:17 AM, Qi Zhang wrote:
> The VF uses a multi-bit update request to clear unused VLANs whenever it
> resets. However, an accident in a previous refector broke multi-bit

s/refector/refactor

> updates for VFs, due to misreading a comment in fm10k_vf.c and
> attempting to reduce code duplication. The problem occurs because
> a multi-bit request has a non-zero length, and the PF would simply drop
> any request with the upper 16 bits set. In addition, a multi-bit vlan
> update does not have a concept for "VLAN 0" as the single bit update
> does.
> 
> A previous revision of this patch resolved the issue by simply removing
> the upper 16 bit check and the iov_select_vid checks. However, this would
> remove the checks for default VID and for ensuring no other VLANs can be
> enabled except pf_vid when it has been set. To resolve that issue, this
> revision uses the iov_select_vid when we have a single-bit update, and
> denies any multi-bit update when the VLAN was administratively set by
> the PF. This should be ok since the PF properly updates VLAN_TABLE when
> it assigns the PF vid. This ensures that requests to add or "remove" the
> PF vid work as expected, but a rogue VF could not use the multi-bit
> update as a loophole to attempt receiving traffic on other VLANs.
> 
> Signed-off-by: Qi Zhang <qi.z.zhang at intel.com>

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