Re: [dpdk-dev] [RFC] ethdev: add VLAN attributes to ETH item

[Matan Azrad <matan@mellanox.com>]

But if the user want to force only one vlan and don't care about others?


> -----Original Message-----
> From: Dekel Peled <dekelp@mellanox.com>
> Sent: Wednesday, August 5, 2020 9:54 AM
> To: Eli Britstein <elibr@mellanox.com>; ferruh.yigit@intel.com;
> arybchenko@solarflare.com; Ori Kam <orika@mellanox.com>; Thomas
> Monjalon <thomas@monjalon.net>
> Cc: Asaf Penso <asafp@mellanox.com>; Matan Azrad
> <matan@mellanox.com>; dev@dpdk.org
> Subject: RE: [RFC] ethdev: add VLAN attributes to ETH item
> 
> Thanks, PSB.
> 
> > -----Original Message-----
> > From: Eli Britstein <elibr@mellanox.com>
> > Sent: Tuesday, August 4, 2020 6:47 PM
> > To: Dekel Peled <dekelp@mellanox.com>; ferruh.yigit@intel.com;
> > arybchenko@solarflare.com; Ori Kam <orika@mellanox.com>; Thomas
> > Monjalon <thomas@monjalon.net>
> > Cc: Asaf Penso <asafp@mellanox.com>; Matan Azrad
> <matan@mellanox.com>;
> > dev@dpdk.org
> > Subject: Re: [RFC] ethdev: add VLAN attributes to ETH item
> >
> >
> > On 8/4/2020 6:36 PM, Dekel Peled wrote:
> > > In existing code the match on tagged/untagged packets is not explicit.
> > > Recent documentation update [1] describes the different patterns and
> > > clarifies the intended use of different patterns.
> > >
> > > This patch proposes an update to ETH item struct, to clearly define
> > > the required characteristic of a packet, and enable precise match criteria.
> > >
> > > [1] http://mails.dpdk.org/archives/dev/2020-May/166257.html
> > >
> > > Signed-off-by: Dekel Peled <dekelp@mellanox.com>
> > > ---
> > >   lib/librte_ethdev/rte_flow.h | 9 +++++++++
> > >   1 file changed, 9 insertions(+)
> > >
> > > diff --git a/lib/librte_ethdev/rte_flow.h
> > > b/lib/librte_ethdev/rte_flow.h index cf0eccb..345feb5 100644
> > > --- a/lib/librte_ethdev/rte_flow.h
> > > +++ b/lib/librte_ethdev/rte_flow.h
> > > @@ -726,11 +726,20 @@ struct rte_flow_item_raw {
> > >    * If the @p ETH item is the only item in the pattern, and the @p type
> field
> > >    * is not specified, then both tagged and untagged packets will match
> the
> > >    * pattern.
> > > + * The fields @p cvlan_exist and @p svlan_exist can be used to
> > > + match specific
> > > + * packet types, instead of using the @p type field. This can be
> > > + used to match
> > > + * on packets that do/don't contain either cvlan, svlan, or both.
> > > + * The field @p num_of_vlans can be used to match packets by the
> > > + exact number
> > > + * of VLANs in header.
> > >    */
> > >   struct rte_flow_item_eth {
> > >   	struct rte_ether_addr dst; /**< Destination MAC. */
> > >   	struct rte_ether_addr src; /**< Source MAC. */
> > >   	rte_be16_t type; /**< EtherType or TPID. */
> > > +	uint32_t cvlan_exist:1; /**< C-tag VLAN exist in header. */
> > > +	uint32_t svlan_exist:1; /**< S-tag VLAN exist in header. */
> > > +	uint32_t reserved:14; /**< Reserved, must be zero. */
> > > +	uint32_t num_of_vlans:16; /**< Number of VLANs in header. */
> > We can deduct from num_of_vlans the values of cvlan_exist/svlan_exist,
> > so those are redundant fields. Keeping them introduce a conflicting
> > match. For example num_of_vlans=0 and cvlan_exist=1.
> 
> Such conflict is simple to validate and reject.
> Even if num_of_vlans is removed, we can still get conflict svlan_exist=1,
> cvlan_exist=0.
> The different fields are proposed to allow flexible match on different VLAN
> attributes.
> Every PMD can choose to support any or none of them.
> 
> > >   };
> > >
> > >   /** Default mask for RTE_FLOW_ITEM_TYPE_ETH. */