[dpdk-dev] [PATCH v2 07/20] net/mlx5: add flow VLAN item

[Nélio Laranjeiro]

On Tue, Jul 03, 2018 at 04:56:21PM -0700, Yongseok Koh wrote:
> On Wed, Jun 27, 2018 at 05:07:39PM +0200, Nelio Laranjeiro wrote:
> > Signed-off-by: Nelio Laranjeiro <nelio.laranjeiro at 6wind.com>
> > ---
> >  drivers/net/mlx5/mlx5_flow.c | 123 +++++++++++++++++++++++++++++++++++
> >  1 file changed, 123 insertions(+)
> > 
> > diff --git a/drivers/net/mlx5/mlx5_flow.c b/drivers/net/mlx5/mlx5_flow.c
> > index 6593eafa0..6a576ddd9 100644
> > --- a/drivers/net/mlx5/mlx5_flow.c
> > +++ b/drivers/net/mlx5/mlx5_flow.c
> > @@ -420,6 +420,126 @@ mlx5_flow_item_eth(const struct rte_flow_item *item, struct rte_flow *flow,
> >  	return size;
> >  }
> >  
> > +/**
> > + * Update the VLAN tag in the Ethernet spec.
> > + *
> > + * @param attr[in, out]
> > + *   Pointer to Verbs attributes structure.
> > + * @param eth[in]
> > + *   Verbs structure containing the VLAN information to copy.
> > + */
> > +static void
> > +mlx5_flow_item_vlan_update(struct ibv_flow_attr *attr,
> > +			   struct ibv_flow_spec_eth *eth)
> > +{
> > +	unsigned int i;
> > +	enum ibv_flow_spec_type search = IBV_FLOW_SPEC_ETH;
> > +	struct ibv_spec_header *hdr = (struct ibv_spec_header *)
> > +		((uint8_t *)attr + sizeof(struct ibv_flow_attr));
> > +
> > +	for (i = 0; i != attr->num_of_specs; ++i) {
> > +		if (hdr->type == search) {
> > +			struct ibv_flow_spec_eth *e =
> > +				(struct ibv_flow_spec_eth *)hdr;
> > +
> > +			e->val.vlan_tag = eth->val.vlan_tag;
> > +			e->mask.vlan_tag = eth->mask.vlan_tag;
> 
> You'll have to overwrite ether_type as well, otherwise the e->ether_type would
> have TPID.

Right,

> > +			break;
> > +		}
> > +		hdr = (struct ibv_spec_header *)((uint8_t *)hdr + hdr->size);
> > +	}
> > +}
> > +
> > +/**
> > + * Validate VLAN layer and possibly create/modify the Verbs specification.
> > + *
> > + * @param item[in]
> > + *   Item specification.
> > + * @param flow[in, out]
> > + *   Pointer to flow structure.
> > + * @param flow_size[in]
> > + *   Size of the buffer to store the specification.
> > + * @param error
> > + *   Pointer to error structure.
> > + *
> > + * @return
> > + *   size in bytes necessary for the conversion, a negative errno value
> > + *   otherwise and rte_errno is set.
> > + */
> > +static int
> > +mlx5_flow_item_vlan(const struct rte_flow_item *item, struct rte_flow *flow,
> > +		    const size_t flow_size, struct rte_flow_error *error)
> > +{
> > +	const struct rte_flow_item_vlan *spec = item->spec;
> > +	const struct rte_flow_item_vlan *mask = item->mask;
> > +	const struct rte_flow_item_vlan nic_mask = {
> > +		.tci = RTE_BE16(0x0fff),
> > +	};
> > +	unsigned int size = sizeof(struct ibv_flow_spec_eth);
> > +	struct ibv_flow_spec_eth eth = {
> > +		.type = IBV_FLOW_SPEC_ETH,
> > +		.size = size,
> > +	};
> > +	int ret;
> > +	const uint32_t lm = MLX5_FLOW_LAYER_OUTER_L3 |
> > +			MLX5_FLOW_LAYER_OUTER_L4;
> 
> What does 'lm' stand for? Better to use l34m?

l34m seems better,

> > +	const uint32_t vlanm = MLX5_FLOW_LAYER_OUTER_VLAN;
> > +	const uint32_t l2m = MLX5_FLOW_LAYER_OUTER_L2;
> > +
> > +	if (flow->layers & vlanm)
> > +		return rte_flow_error_set(error, ENOTSUP,
> > +					  RTE_FLOW_ERROR_TYPE_ITEM,
> > +					  item,
> > +					  "L2 layers already configured");
> 
> L2? Not VLAN?

Indeed it is VLAN.

> > +	else if ((flow->layers & lm) != 0)
> > +		return rte_flow_error_set(error, ENOTSUP,
> > +					  RTE_FLOW_ERROR_TYPE_ITEM,
> > +					  item,
> > +					  "L2 layer cannot follow L3/L4 layer");
> > +	if (!mask)
> > +		mask = &rte_flow_item_vlan_mask;
> > +	ret = mlx5_flow_item_validate(item, (const uint8_t *)mask,
> > +				      (const uint8_t *)&nic_mask,
> > +				      sizeof(struct rte_flow_item_vlan), error);
> > +	if (ret)
> > +		return ret;
> > +	if (spec) {
> > +		eth.val.vlan_tag = spec->tci;
> > +		eth.mask.vlan_tag = mask->tci;
> > +		eth.val.vlan_tag &= eth.mask.vlan_tag;
> > +		eth.val.ether_type = spec->inner_type;
> > +		eth.mask.ether_type = mask->inner_type;
> > +		eth.val.ether_type &= eth.mask.ether_type;
> > +	}
> > +	/*
> > +	 * From verbs perspective an empty VLAN is equivalent
> > +	 * to a packet without VLAN layer.
> > +	 */
> > +	if (!eth.mask.vlan_tag)
> > +		return rte_flow_error_set(error, EINVAL,
> > +					  RTE_FLOW_ERROR_TYPE_ITEM_SPEC,
> > +					  item->spec,
> > +					  "VLAN cannot be empty");
> > +	/* Outer TPID cannot be matched. */
> > +	if (eth.mask.ether_type)
> > +		return rte_flow_error_set(error, ENOTSUP,
> > +					  RTE_FLOW_ERROR_TYPE_ITEM_SPEC,
> > +					  item->spec,
> > +					  "VLAN TPID matching is not"
> > +					  " supported");
> 
> Not sure 100% but I don't think ether_type means TPID but the inner packet type
> coming after the VLAN ID. E.g.
> 
> 	/dmac/smac/0x8100/TCI/0x0800/ipv4...
>                                  ^
>                                  |

I remember to have faced such issue several months ago, from what I
understood it is configurable but there is no way in Verbs to make it.
Currently (after testing) it matches the above logic, I will remove this
check.

> > +	if (!(flow->layers & l2m)) {
> > +		if (size <= flow_size)
> > +			mlx5_flow_spec_verbs_add(flow, &eth, size);
> > +	} else {
> > +		if (flow->verbs.attr)
> > +			mlx5_flow_item_vlan_update(flow->verbs.attr, &eth);
> > +		size = 0; /**< Only an update is done in eth specification. */
> 
> Any specific reason to use doxygen style comment only here?

No reason, I'll remove it.

Thanks,

-- 
Nélio Laranjeiro
6WIND