Re: [dpdk-dev] [PATCH v16 1/8] ethdev: add set ptype function

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 11/6/2019 7:17 PM, pbhagavatula@marvell.com wrote:
> From: Pavan Nikhilesh <pbhagavatula@marvell.com>
> 
> Add `rte_eth_dev_set_ptypes` function that will allow the application
> to inform the PMD about reduced range of packet types to handle.
> Based on the ptypes set PMDs can optimize their Rx path.
> 
> -If application doesn’t want any ptype information it can call
> `rte_eth_dev_set_ptypes(ethdev_id, RTE_PTYPE_UNKNOWN, NULL, 0)`
> and PMD may skip packet type processing and set rte_mbuf::packet_type to
> RTE_PTYPE_UNKNOWN.
> 
> -If application doesn’t call `rte_eth_dev_set_ptypes` PMD can return
> `rte_mbuf::packet_type` with `rte_eth_dev_get_supported_ptypes`.
> 
> -If application is interested only in L2/L3 layer, it can inform the PMD
> to update `rte_mbuf::packet_type` with L2/L3 ptype by calling
> `rte_eth_dev_set_ptypes(ethdev_id,
> 		RTE_PTYPE_L2_MASK | RTE_PTYPE_L3_MASK, NULL, 0)`.
> 
> Suggested-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
> Signed-off-by: Pavan Nikhilesh <pbhagavatula@marvell.com>
> Reviewed-by: Andrew Rybchenko <arybchenko@solarflare.com>
> ---
>  doc/guides/nics/features.rst             |  7 +-
>  doc/guides/rel_notes/release_19_11.rst   |  8 +++
>  lib/librte_ethdev/rte_ethdev.c           | 87 +++++++++++++++++++++++-
>  lib/librte_ethdev/rte_ethdev.h           | 36 ++++++++++
>  lib/librte_ethdev/rte_ethdev_core.h      | 18 +++++
>  lib/librte_ethdev/rte_ethdev_version.map |  1 +
>  6 files changed, 154 insertions(+), 3 deletions(-)
> 
> diff --git a/doc/guides/nics/features.rst b/doc/guides/nics/features.rst
> index 7a31cf7c8..f33e8e6d4 100644
> --- a/doc/guides/nics/features.rst
> +++ b/doc/guides/nics/features.rst
> @@ -583,9 +583,12 @@ Packet type parsing
>  -------------------
>  
>  Supports packet type parsing and returns a list of supported types.
> +Allows application to set ptypes it is interested in.
>  
> -* **[implements] eth_dev_ops**: ``dev_supported_ptypes_get``.
> -* **[related]    API**: ``rte_eth_dev_get_supported_ptypes()``.
> +* **[implements] eth_dev_ops**: ``dev_supported_ptypes_get``,
> +* **[related]    API**: ``rte_eth_dev_get_supported_ptypes()``,
> +  ``rte_eth_dev_set_ptypes()``, ``dev_ptypes_set``.
> +* **[provides]   mbuf**: ``mbuf.packet_type``.
>  
>  
>  .. _nic_features_timesync:
> diff --git a/doc/guides/rel_notes/release_19_11.rst b/doc/guides/rel_notes/release_19_11.rst
> index 23182d187..2fa54aadc 100644
> --- a/doc/guides/rel_notes/release_19_11.rst
> +++ b/doc/guides/rel_notes/release_19_11.rst
> @@ -86,6 +86,13 @@ New Features
>    SET_TAG action and TAG item have been added to support transient flow
>    tag.
>  
> +* **Added ethdev API to set supported packet types**
> +
> +  * Added new API ``rte_eth_dev_set_ptypes`` that allows an application to
> +    inform PMD about about reduced range of packet types to handle.
> +  * This scheme will allow PMDs to avoid lookup to internal ptype table on Rx
> +    and thereby improve Rx performance if application wishes do so.
> +
>  * **Updated the enic driver.**
>  
>    * Added support for Geneve with options offload.
> @@ -258,6 +265,7 @@ New Features
>    * Rx metadata is delivered to host via a dynamic field of ``rte_mbuf`` with
>      PKT_RX_DYNF_METADATA.
>  
> +
>  Removed Items
>  -------------
>  
> diff --git a/lib/librte_ethdev/rte_ethdev.c b/lib/librte_ethdev/rte_ethdev.c
> index 652c369e5..13e6daaf4 100644
> --- a/lib/librte_ethdev/rte_ethdev.c
> +++ b/lib/librte_ethdev/rte_ethdev.c
> @@ -2879,6 +2879,92 @@ rte_eth_dev_get_supported_ptypes(uint16_t port_id, uint32_t ptype_mask,
>  	return j;
>  }
>  
> +int
> +rte_eth_dev_set_ptypes(uint16_t port_id, uint32_t ptype_mask,
> +				 uint32_t *set_ptypes, unsigned int num)
> +{
> +	const uint32_t valid_ptype_masks[] = {
> +		RTE_PTYPE_L2_MASK,
> +		RTE_PTYPE_L3_MASK,
> +		RTE_PTYPE_L4_MASK,
> +		RTE_PTYPE_TUNNEL_MASK,
> +		RTE_PTYPE_INNER_L2_MASK,
> +		RTE_PTYPE_INNER_L3_MASK,
> +		RTE_PTYPE_INNER_L4_MASK,
> +	};
> +	const uint32_t *all_ptypes;
> +	struct rte_eth_dev *dev;
> +	uint32_t unused_mask;
> +	unsigned int i, j;
> +	int ret;
> +
> +	RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV);
> +	dev = &rte_eth_devices[port_id];
> +
> +	if (num > 0 && set_ptypes == NULL)
> +		return -EINVAL;
> +
> +	if (*dev->dev_ops->dev_supported_ptypes_get == NULL ||
> +			*dev->dev_ops->dev_ptypes_set == NULL) {
> +		ret = 0;
> +		goto ptype_unknown;
> +	}

Hi Pavan, Andrew,

Why API is not returning "-ENOTSUP" id dev_ops is not provided as done it other
APIs?

> +
> +	if (ptype_mask == 0) {
> +		ret = (*dev->dev_ops->dev_ptypes_set)(dev,
> +				ptype_mask);
> +		goto ptype_unknown;
> +	}
> +
> +	unused_mask = ptype_mask;
> +	for (i = 0; i < RTE_DIM(valid_ptype_masks); i++) {
> +		uint32_t mask = ptype_mask & valid_ptype_masks[i];
> +		if (mask && mask != valid_ptype_masks[i]) {
> +			ret = -EINVAL;
> +			goto ptype_unknown;
> +		}
> +		unused_mask &= ~valid_ptype_masks[i];
> +	}

What does above block does?
Does it mean 'ptype_mask' only can be combination of 'valid_ptype_masks' items?
Let's say can't I set only 'RTE_PTYPE_L2_ETHER' as requested ptype?
Why this limitation and is it documented anywhere, like the API documentation?

> +
> +	if (unused_mask) {
> +		ret = -EINVAL;
> +		goto ptype_unknown;
> +	}
> +
> +	all_ptypes = (*dev->dev_ops->dev_supported_ptypes_get)(dev);
> +	if (all_ptypes == NULL) {
> +		ret = 0;
> +		goto ptype_unknown;
> +	}
> +
> +	/*
> +	 * Accodommodate as many set_ptypes as possible. If the supplied

s/Accodommodate/Accommodate

> +	 * set_ptypes array is insufficient fill it partially.
> +	 */
> +	for (i = 0, j = 0; set_ptypes != NULL &&
> +				(all_ptypes[i] != RTE_PTYPE_UNKNOWN); ++i) {
> +		if (ptype_mask & all_ptypes[i]) {
> +			if (j < num - 1) {
> +				set_ptypes[j] = all_ptypes[i];
> +				j++;
> +				continue;
> +			}
> +			break;
> +		}
> +	}
> +
> +	if (set_ptypes != NULL && j < num)
> +		set_ptypes[j] = RTE_PTYPE_UNKNOWN;
> +
> +	return (*dev->dev_ops->dev_ptypes_set)(dev, ptype_mask);

Only a question, at this stage API knows the supported ptypes by device, does it
make sense to check if 'ptype_mask' has anything unsupported instead of passing
it to the driver and expect driver to check it?

> +
> +ptype_unknown:
> +	if (num > 0)
> +		set_ptypes[0] = RTE_PTYPE_UNKNOWN;
> +
> +	return ret;
> +}
> +
>  int
>  rte_eth_macaddr_get(uint16_t port_id, struct rte_ether_addr *mac_addr)
>  {
> @@ -2891,7 +2977,6 @@ rte_eth_macaddr_get(uint16_t port_id, struct rte_ether_addr *mac_addr)
>  	return 0;
>  }
>  
> -
>  int
>  rte_eth_dev_get_mtu(uint16_t port_id, uint16_t *mtu)
>  {
> diff --git a/lib/librte_ethdev/rte_ethdev.h b/lib/librte_ethdev/rte_ethdev.h
> index 44d77b332..a7872819d 100644
> --- a/lib/librte_ethdev/rte_ethdev.h
> +++ b/lib/librte_ethdev/rte_ethdev.h
> @@ -2604,6 +2604,42 @@ int rte_eth_dev_fw_version_get(uint16_t port_id,
>   */
>  int rte_eth_dev_get_supported_ptypes(uint16_t port_id, uint32_t ptype_mask,
>  				     uint32_t *ptypes, int num);
> +/**
> + * @warning
> + * @b EXPERIMENTAL: this API may change without prior notice.
> + *
> + * Inform Ethernet device about reduced range of packet types to handle.
> + *
> + * Application can use this function to set only specific ptypes that it's
> + * interested. This information can be used by the PMD to optimize Rx path.
> + *
> + * The function accepts an array `set_ptypes` allocated by the caller to
> + * store the packet types set by the driver, the last element of the array
> + * is set to RTE_PTYPE_UNKNOWN. The size of the `set_ptype` array should be
> + * `rte_eth_dev_get_supported_ptypes() + 1` else it might only be filled
> + * partially.
> + *
> + * @param port_id
> + *   The port identifier of the Ethernet device.
> + * @param ptype_mask
> + *   The ptype family that application is interested in should be bitwise OR of
> + *   RTE_PTYPE_*_MASK or 0.

No strong opinion but is it really a mask? it doesn't used to mask any value,
but it is list of ptypes that application requests, in a bitwise ORed form, so I
this it can be ptypes.

> + * @param set_ptypes
> + *   An array pointer to store set packet types, allocated by caller. The
> + *   function marks the end of array with RTE_PTYPE_UNKNOWN.

Not for this patch, but is an API also required to get current supported ptypes
from the driver? Even application keeps this list, something can reset in the
device/driver, supported pytpe list can be changed and it can differ with what
application knows.

> + * @param num
> + *   Size of the array pointed by param ptypes.
> + *   Should be rte_eth_dev_get_supported_ptypes() + 1 to accommodate the
> + *   set ptypes.
> + * @return
> + *   - (0) if Success.
> + *   - (-ENODEV) if *port_id* invalid.
> + *   - (-EINVAL) if *ptype_mask* is invalid (or) set_ptypes is NULL and
> + *     num > 0.
> + */
> +__rte_experimental
> +int rte_eth_dev_set_ptypes(uint16_t port_id, uint32_t ptype_mask,
> +			   uint32_t *set_ptypes, unsigned int num);
>  
>  /**
>   * Retrieve the MTU of an Ethernet device.
> diff --git a/lib/librte_ethdev/rte_ethdev_core.h b/lib/librte_ethdev/rte_ethdev_core.h
> index f215af7c9..657c39b56 100644
> --- a/lib/librte_ethdev/rte_ethdev_core.h
> +++ b/lib/librte_ethdev/rte_ethdev_core.h
> @@ -234,6 +234,22 @@ typedef int (*eth_dev_infos_get_t)(struct rte_eth_dev *dev,
>  typedef const uint32_t *(*eth_dev_supported_ptypes_get_t)(struct rte_eth_dev *dev);
>  /**< @internal Get supported ptypes of an Ethernet device. */
>  
> +/**
> + * @internal
> + * Inform Ethernet device about reduced range of packet types to handle.
> + *
> + * @param dev
> + *   The Ethernet device identifier.
> + * @param ptype_mask
> + *   The ptype family that application is interested in should be bitwise OR of
> + *   RTE_PTYPE_*_MASK or 0.
> + * @return
> + *   - (0) if Success.
> + *   - (-EINVAL) if *ptype_mask* is invalid.
> + */
> +typedef int (*eth_dev_ptypes_set_t)(struct rte_eth_dev *dev,
> +				     uint32_t ptype_mask);
> +
>  typedef int (*eth_queue_start_t)(struct rte_eth_dev *dev,
>  				    uint16_t queue_id);
>  /**< @internal Start rx and tx of a queue of an Ethernet device. */
> @@ -630,6 +646,8 @@ struct eth_dev_ops {
>  	eth_fw_version_get_t       fw_version_get; /**< Get firmware version. */
>  	eth_dev_supported_ptypes_get_t dev_supported_ptypes_get;
>  	/**< Get packet types supported and identified by device. */
> +	eth_dev_ptypes_set_t dev_ptypes_set;
> +	/**< Inform Ethernet device about reduced range of packet types to handle. */
>  
>  	vlan_filter_set_t          vlan_filter_set; /**< Filter VLAN Setup. */
>  	vlan_tpid_set_t            vlan_tpid_set; /**< Outer/Inner VLAN TPID Setup. */
> diff --git a/lib/librte_ethdev/rte_ethdev_version.map b/lib/librte_ethdev/rte_ethdev_version.map
> index ee289ef13..ccfbeae23 100644
> --- a/lib/librte_ethdev/rte_ethdev_version.map
> +++ b/lib/librte_ethdev/rte_ethdev_version.map
> @@ -292,4 +292,5 @@ EXPERIMENTAL {
>  	rte_flow_dynf_metadata_offs;
>  	rte_flow_dynf_metadata_mask;
>  	rte_flow_dynf_metadata_register;
> +	rte_eth_dev_set_ptypes;
>  };
>