Re: [dpdk-dev] [PATCH v4 1/7] ethdev: add set ptype function

[Pavan Nikhilesh Bhagavatula <pbhagavatula@marvell.com>]

>-----Original Message-----
>From: Andrew Rybchenko <arybchenko@solarflare.com>
>Sent: Tuesday, October 1, 2019 12:34 PM
>To: Pavan Nikhilesh Bhagavatula <pbhagavatula@marvell.com>; Jerin
>Jacob Kollanukkaran <jerinj@marvell.com>; John McNamara
><john.mcnamara@intel.com>; Marko Kovacevic
><marko.kovacevic@intel.com>; Thomas Monjalon
><thomas@monjalon.net>; Ferruh Yigit <ferruh.yigit@intel.com>
>Cc: dev@dpdk.org
>Subject: [EXT] Re: [dpdk-dev] [PATCH v4 1/7] ethdev: add set ptype
>function
>On 10/1/19 9:34 AM, pbhagavatula@marvell.com wrote:
>> From: Pavan Nikhilesh <pbhagavatula@marvell.com>
>>
>> Add `rte_eth_dev_set_supported_ptypes` function that will allow the
>> application to inform the PMD the packet types it is interested in.
>> 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_supported_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_supported_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_supported_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>
>
>
>
>> diff --git a/doc/guides/rel_notes/release_19_11.rst
>b/doc/guides/rel_notes/release_19_11.rst
>> index 27cfbd9e3..7e31b9401 100644
>> --- a/doc/guides/rel_notes/release_19_11.rst
>> +++ b/doc/guides/rel_notes/release_19_11.rst
>> @@ -56,6 +56,13 @@ New Features
>>        Also, make sure to start the actual text at the margin.
>>
>======================================================
>===
>>
>> +* **Added ethdev API to set supported packet types**
>> +
>> +  *  Added new API ``rte_eth_dev_set_supported_ptypes`` that
>allows an
>> +     application to inform PMD about packet types classification the
>application
>> +     is interested in
>> +  *  This scheme will allow PMDs to avoid lookup to internal ptype
>table on Rx
>> +     and thereby improve Rx performance if application wishes do so.
>
>Extra empty line is required here in accordance with documentation
>guidelines.
>

Ack, will fix in v6.

>>   Removed Items
>>   -------------
>> diff --git a/lib/librte_ethdev/rte_ethdev.c
>b/lib/librte_ethdev/rte_ethdev.c
>> index 17d183e1f..061de7ac5 100644
>> --- a/lib/librte_ethdev/rte_ethdev.c
>> +++ b/lib/librte_ethdev/rte_ethdev.c
>> @@ -2602,6 +2602,44 @@
>rte_eth_dev_get_supported_ptypes(uint16_t port_id, uint32_t
>ptype_mask,
>>   	return j;
>>   }
>>
>> +int
>> +rte_eth_dev_set_supported_ptypes(uint16_t port_id, uint32_t
>ptype_mask,
>> +				 uint32_t *set_ptypes, int num)
>
>May be num should be unsigned int?

Ack, unsigned it makes sense.

>
>> +{
>> +	int i, j;
>> +	struct rte_eth_dev *dev;
>> +	const uint32_t *all_ptypes;
>> +
>> +	RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV);
>> +	dev = &rte_eth_devices[port_id];
>> +	RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops-
>>dev_supported_ptypes_get, 0);
>> +	RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops-
>>dev_supported_ptypes_set, 0);
>
>if (num > 0 && set_ptypes == NULL)
>     return -EINVAL;
>

Ack, will fix in v6.

>> +
>> +	if (ptype_mask == 0)
>
>if (num > 0)
>      set_ptypes[0] = RTE_PTYPE_UNKNOWN;
>

Ack, will fix in v6.

>> +		return (*dev->dev_ops-
>>dev_supported_ptypes_set)(dev,
>> +				ptype_mask);
>> +
>> +	all_ptypes = (*dev->dev_ops-
>>dev_supported_ptypes_get)(dev);
>> +	if (all_ptypes == NULL)
>
>if (num > 0)
>      set_ptypes[0] = RTE_PTYPE_UNKNOWN;
>

Ack, will fix in v6.

>> +		return 0;
>> +
>> +	for (i = 0, j = 0; set_ptypes && (all_ptypes[i] !=
>RTE_PTYPE_UNKNOWN);
>
>set_ptypes != NULL in accordance with coding guidelines
>
>> +
>	++i) {
>
>Please, consider to put condition check and increment in its own lines.
>IMHO, above it a bit hard to read.
>

Ack, will make it more readable.

>> +		if (ptype_mask & all_ptypes[i]) {
>
>Should it be done if all_ptypes[i] have some bits out of ptype_mask?
>Should set_ptypes have bits out of ptype_mask when set below?
>

Isn't all_ptypes[i] enum?. It makes sense if it's a bit mask. 
Get ptypes has a similar logic. 

>> +			if (j < num - 1) {
>> +				set_ptypes[j] = all_ptypes[i];
>> +				j++;
>> +				continue;
>> +			}
>> +			break;
>
>Do we need an indication if provided set_ptype is not enough
>to return all ptypes? I think it should be explained/highlighted
>in the function description with explanation why.
>
>> +		}
>> +	}
>> +
>> +	set_ptypes[j] = RTE_PTYPE_UNKNOWN;
>
>I think we should allow set_ptypes == NULL if num == 0.
>So, it should be set here if not NULL only.

Ack, will add a check here.

>
>> +
>> +	return (*dev->dev_ops->dev_supported_ptypes_set)(dev,
>ptype_mask);
>> +}
>> +
>>   void
>>   rte_eth_macaddr_get(uint16_t port_id, struct rte_ether_addr
>*mac_addr)
>>   {
>> diff --git a/lib/librte_ethdev/rte_ethdev.h
>b/lib/librte_ethdev/rte_ethdev.h
>> index d9871782e..6c5fd789a 100644
>> --- a/lib/librte_ethdev/rte_ethdev.h
>> +++ b/lib/librte_ethdev/rte_ethdev.h
>> @@ -2431,6 +2431,35 @@ 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 of the packet types classification in which
>> + * the recipient is interested.
>> + *
>> + * 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.
>> + *
>> + * @param port_id
>> + *   The port identifier of the Ethernet device.
>> + * @param ptype_mask
>> + *   The ptype family that application is interested in.
>> + * @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.
>> + * @param num
>> + *   Size of the array pointed by param ptypes.
>> + *   Should be rte_eth_dev_get_supported_ptypes() + 1 to
>accomodate the
>> + *   set ptypes.
>> + * @return
>> + *   - (0) if Success.
>> + *   - (-ENODEV) if *port_id* invalid.
>> + *   - (-EINVAL) if *ptype_mask* is invalid.
>
>or set_ptype is NULL when num is greater than zero.
>
>> + */
>> +__rte_experimental
>> +int rte_eth_dev_set_supported_ptypes(uint16_t port_id, uint32_t
>ptype_mask,
>> +				     uint32_t *set_ptypes, 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 2922d5b7c..93bc34480 100644
>> --- a/lib/librte_ethdev/rte_ethdev_core.h
>> +++ b/lib/librte_ethdev/rte_ethdev_core.h
>> @@ -110,6 +110,10 @@ typedef void (*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. */
>>
>> +typedef uint32_t (*eth_dev_supported_ptypes_set_t)(struct
>rte_eth_dev *dev,
>> +					      uint32_t ptype_mask);
>> +/**< @internal Inform device about packet types in which the
>recipient is interested. */
>> +
>>   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. */
>> @@ -421,6 +425,8 @@ 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_supported_ptypes_set_t
>dev_supported_ptypes_set;
>> +	/**< Inform device about packet types in which the recipient is
>interested. */
>>
>>   	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 6df42a47b..e14745b9c 100644
>> --- a/lib/librte_ethdev/rte_ethdev_version.map
>> +++ b/lib/librte_ethdev/rte_ethdev_version.map
>> @@ -283,4 +283,7 @@ EXPERIMENTAL {
>>
>>   	# added in 19.08
>>   	rte_eth_read_clock;
>> +
>> +	# added in 19.11
>> +	rte_eth_dev_set_supported_ptypes;
>>   };