Re: [dpdk-dev] [PATCH v7 1/7] ethdev: add set ptype function

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

>On 10/2/19 4:37 PM, Andrew Rybchenko wrote:
>> Hi,
>>
>> looks good, just few comments below.
>>
>> Many thanks for working on it,
>> Andrew.
>>

Thank you for your patience.

Pavan.

>> On 10/2/19 6:47 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>
>>
>> [snip]
>>
>>> diff --git a/lib/librte_ethdev/rte_ethdev.c
>>> b/lib/librte_ethdev/rte_ethdev.c
>>> index 17d183e1f..b1588fe7a 100644
>>> --- a/lib/librte_ethdev/rte_ethdev.c
>>> +++ b/lib/librte_ethdev/rte_ethdev.c
>>> @@ -2602,6 +2602,56 @@
>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, unsigned int num)
>>> +{
>>> +    unsigned 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);
>>
>> When 0 is returned above, we should set set_ptypes. So, below
>> check num vs set_types should be done before callbacks check and
>> I think it is OK to do
>>       set_ptypes[0] = RTE_PTYPE_UNKNOWN;
>
>of course if num > 0
>
>> just after the check. It will allow to simplify code below and will
>> make it set correctly even if 0 returned because of no callbacks.

Ack, will roll v8.

>>
>>> +
>>> +    if (num > 0 && set_ptypes == NULL)
>>> +        return -EINVAL;
>>> +
>>> +    if (ptype_mask == 0) {
>>> +        if (num > 0)
>>> +            set_ptypes[0] = RTE_PTYPE_UNKNOWN;
>>> +
>>> +        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;
>>> +
>>> +        return 0;
>>> +    }
>>> +
>>> +    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;
>>
>> I'd like to repeat my question about insufficient space to return
>> set_ptypes. Do we need to signal it somehow? If no, it should be
>> explained why in the comments here.

I actually documented it above set_supported_ptypes fn
"
+ *
+ * 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.
"

I will comment the code too. Just in case.

>>
>>> +        }
>>> +    }
>>> +
>>> +    if (set_ptypes != NULL)
>>> +        set_ptypes[j] = RTE_PTYPE_UNKNOWN;
>>> +
>>> +    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..c577a9172 100644
>>> --- a/lib/librte_ethdev/rte_ethdev.h
>>> +++ b/lib/librte_ethdev/rte_ethdev.h
>>> @@ -2431,6 +2431,42 @@ 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 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.
>>> + *
>>> + * 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.
>>> + * @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
>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_supported_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 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. */
>>> +
>>
>> Please, take a look at promiscuous mode callback and let's put
>> more verbose description here which better document interface
>> to drivers. I think ptyep_mask description should refer to
>corresponding
>> defines to be used.

Ack. More description never hurts.

>>
>> [snip]
>>