On 6/26/2018 9:54 AM, Xueming Li wrote:
> Currently, rte_flow pattern only match packet header fields.
> This patch adds additional data to match the packet.
>
> For example, in egress direction, to do an action depending on the VM
> id, the application needs to configure rte_flow rule with the new
> metadata pattern:
> pattern meta data is {vm} / end action encap …
> Then the PMD will send VM id as metadata associated in mbuf to NIC,
> then egress flow on NIC match metadata as other regular packet headers,
> the appropriate encapsulation is done according to the VM id metadata.
>
> Metadata could be used on ingress as well to save useful info before
> flow modification (not defined yet) or decapsulation action. PMD is
> responsible to save metadata into mbuf field. The application must get
> metadata from the mbuf.
>
> Cc: Thomas Monjalon <tho...@monjalon.net>
> Cc: Olivier Matz <olivier.m...@6wind.com>
> Cc: Shahaf Shuler <shah...@mellanox.com>
> Signed-off-by: Xueming Li <xuemi...@mellanox.com>
> ---
> doc/guides/prog_guide/rte_flow.rst | 7 +++++++
> lib/librte_ethdev/rte_flow.c | 1 +
> lib/librte_ethdev/rte_flow.h | 28 ++++++++++++++++++++++++++++
> 3 files changed, 36 insertions(+)
>
> diff --git a/doc/guides/prog_guide/rte_flow.rst
> b/doc/guides/prog_guide/rte_flow.rst
> index b305a72a5..7989e5856 100644
> --- a/doc/guides/prog_guide/rte_flow.rst
> +++ b/doc/guides/prog_guide/rte_flow.rst
> @@ -1191,6 +1191,13 @@ Normally preceded by any of:
> - `Item: ICMP6_ND_NS`_
> - `Item: ICMP6_ND_OPT`_
>
> +Item: ``META``
> +^^^^^^^^^^^^^^
> +
> +Matches a metadata variable.
> +
> +- ``data``: 64 bit value.
> +
Isn't this "user data" more than metadata?
And there is only one userdata can be provided for a flow.
Can there be a need to provide multiple userdata? Should we support it?
For your example, on egress what if you want to do specific action on a flow for
both VM id and process id, you can only pass single user data?
What about passing a key-value pair?
