[1/9] ethdev: overwrite some comment related to RSS

Message ID 20231027092836.445224-2-haijie1@huawei.com (mailing list archive)
State Superseded, archived
Delegated to: Ferruh Yigit
Headers
Series support setting and querying RSS algorithms |

Checks

Context Check Description
ci/checkpatch success coding style OK

Commit Message

Jie Hai Oct. 27, 2023, 9:28 a.m. UTC
  1. overwrite the comments of fields of 'rte_eth_rss_conf'.
2. Add comments for RTE_ETH_HASH_FUNCTION_DEFAULT.

Signed-off-by: Jie Hai <haijie1@huawei.com>
---
 lib/ethdev/rte_ethdev.h | 33 ++++++++++++++++++---------------
 lib/ethdev/rte_flow.h   |  1 +
 2 files changed, 19 insertions(+), 15 deletions(-)
  

Comments

Ori Kam Oct. 29, 2023, 7:26 a.m. UTC | #1
Hi Jei,

> -----Original Message-----
> From: Jie Hai <haijie1@huawei.com>
> Sent: Friday, October 27, 2023 12:28 PM
> 
> 1. overwrite the comments of fields of 'rte_eth_rss_conf'.
> 2. Add comments for RTE_ETH_HASH_FUNCTION_DEFAULT.
> 
> Signed-off-by: Jie Hai <haijie1@huawei.com>
> ---
>  lib/ethdev/rte_ethdev.h | 33 ++++++++++++++++++---------------
>  lib/ethdev/rte_flow.h   |  1 +
>  2 files changed, 19 insertions(+), 15 deletions(-)
> 
> diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h
> index 2fd3cd808dbf..37fd5afef48a 100644
> --- a/lib/ethdev/rte_ethdev.h
> +++ b/lib/ethdev/rte_ethdev.h
> @@ -448,24 +448,27 @@ struct rte_vlan_filter_conf {
>  /**
>   * A structure used to configure the Receive Side Scaling (RSS) feature
>   * of an Ethernet port.
> - * If not NULL, the *rss_key* pointer of the *rss_conf* structure points
> - * to an array holding the RSS key to use for hashing specific header
> - * fields of received packets. The length of this array should be indicated
> - * by *rss_key_len* below. Otherwise, a default random hash key is used by
> - * the device driver.
> - *
> - * The *rss_key_len* field of the *rss_conf* structure indicates the length
> - * in bytes of the array pointed by *rss_key*. To be compatible, this length
> - * will be checked in i40e only. Others assume 40 bytes to be used as before.
> - *
> - * The *rss_hf* field of the *rss_conf* structure indicates the different
> - * types of IPv4/IPv6 packets to which the RSS hashing must be applied.
> - * Supplying an *rss_hf* equal to zero disables the RSS feature.
>   */
>  struct rte_eth_rss_conf {
> -	uint8_t *rss_key;    /**< If not NULL, 40-byte hash key. */
> +	/**
> +	 * In rte_eth_dev_rss_hash_conf_get(), the *rss_key_len* should be
> +	 * greater than or equal to the hash_key_size which get from
> +	 * rte_eth_dev_info_get() API. And the *rss_key* should contain at
> least
> +	 * *rss_key_len* bytes. If not meet these requirements, the query
> result
> +	 * is unreliable even the operation returns success.
> +	 *
> +	 * In rte_eth_dev_rss_hash_update() or rte_eth_dev_configure(), the
> +	 * *rss_key_len* indicates the length of the *rss_key* in bytes of
> +	 * the array pointed by *rss_key*. Drivers are free to ignore the
> +	 * *rss_key_len* and assume key length is 40 bytes.

In the original comment, it is stated that if no RSS key is given rss_key = NULL , then the PMD selects a random hash key,
Is this behavior changed?

> +	 */
> +	uint8_t *rss_key;
>  	uint8_t rss_key_len; /**< hash key length in bytes. */
> -	uint64_t rss_hf;     /**< Hash functions to apply - see below. */
> +	/**
> +	 * Indicates the type of packets or the specific part of packets to
> +	 * which RSS hashing is to be applied.
> +	 */
> +	uint64_t rss_hf;
>  };
> 
>  /*
> diff --git a/lib/ethdev/rte_flow.h b/lib/ethdev/rte_flow.h
> index edefa34c10da..25f1dffd1f30 100644
> --- a/lib/ethdev/rte_flow.h
> +++ b/lib/ethdev/rte_flow.h
> @@ -3226,6 +3226,7 @@ struct rte_flow_query_count {
>   * Hash function types.
>   */
>  enum rte_eth_hash_function {
> +	/** DEFAULT means driver decides which hash algorithm to pick. */
>  	RTE_ETH_HASH_FUNCTION_DEFAULT = 0,
>  	RTE_ETH_HASH_FUNCTION_TOEPLITZ, /**< Toeplitz */
>  	RTE_ETH_HASH_FUNCTION_SIMPLE_XOR, /**< Simple XOR */
> --
> 2.30.0
  
Jie Hai Nov. 1, 2023, 6:06 a.m. UTC | #2
On 2023/10/29 15:26, Ori Kam wrote:
> Hi Jei,
> 
>> -----Original Message-----
>> From: Jie Hai <haijie1@huawei.com>
>> Sent: Friday, October 27, 2023 12:28 PM
>>
>> 1. overwrite the comments of fields of 'rte_eth_rss_conf'.
>> 2. Add comments for RTE_ETH_HASH_FUNCTION_DEFAULT.
>>
>> Signed-off-by: Jie Hai <haijie1@huawei.com>
>> ---
>>   lib/ethdev/rte_ethdev.h | 33 ++++++++++++++++++---------------
>>   lib/ethdev/rte_flow.h   |  1 +
>>   2 files changed, 19 insertions(+), 15 deletions(-)
>>
>> diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h
>> index 2fd3cd808dbf..37fd5afef48a 100644
>> --- a/lib/ethdev/rte_ethdev.h
>> +++ b/lib/ethdev/rte_ethdev.h
>> @@ -448,24 +448,27 @@ struct rte_vlan_filter_conf {
>>   /**
>>    * A structure used to configure the Receive Side Scaling (RSS) feature
>>    * of an Ethernet port.
>> - * If not NULL, the *rss_key* pointer of the *rss_conf* structure points
>> - * to an array holding the RSS key to use for hashing specific header
>> - * fields of received packets. The length of this array should be indicated
>> - * by *rss_key_len* below. Otherwise, a default random hash key is used by
>> - * the device driver.
>> - *
>> - * The *rss_key_len* field of the *rss_conf* structure indicates the length
>> - * in bytes of the array pointed by *rss_key*. To be compatible, this length
>> - * will be checked in i40e only. Others assume 40 bytes to be used as before.
>> - *
>> - * The *rss_hf* field of the *rss_conf* structure indicates the different
>> - * types of IPv4/IPv6 packets to which the RSS hashing must be applied.
>> - * Supplying an *rss_hf* equal to zero disables the RSS feature.
>>    */
>>   struct rte_eth_rss_conf {
>> -	uint8_t *rss_key;    /**< If not NULL, 40-byte hash key. */
>> +	/**
>> +	 * In rte_eth_dev_rss_hash_conf_get(), the *rss_key_len* should be
>> +	 * greater than or equal to the hash_key_size which get from
>> +	 * rte_eth_dev_info_get() API. And the *rss_key* should contain at
>> least
>> +	 * *rss_key_len* bytes. If not meet these requirements, the query
>> result
>> +	 * is unreliable even the operation returns success.
>> +	 *
>> +	 * In rte_eth_dev_rss_hash_update() or rte_eth_dev_configure(), the
>> +	 * *rss_key_len* indicates the length of the *rss_key* in bytes of
>> +	 * the array pointed by *rss_key*. Drivers are free to ignore the
>> +	 * *rss_key_len* and assume key length is 40 bytes.
> 
> In the original comment, it is stated that if no RSS key is given rss_key = NULL , then the PMD selects a random hash key,
> Is this behavior changed?
Thanks for your comment.

Some drivers select a random key, e.g. cpfl_ethdev, bnx2x_vfpf, ena.
Some drivers use their default key, which is fixed, e.g. igb.
And some just ignore this configuration on rss_key, e.g. cxgbe_ethdev.

I will correct that.

> 
>> +	 */
>> +	uint8_t *rss_key;
>>   	uint8_t rss_key_len; /**< hash key length in bytes. */
>> -	uint64_t rss_hf;     /**< Hash functions to apply - see below. */
>> +	/**
>> +	 * Indicates the type of packets or the specific part of packets to
>> +	 * which RSS hashing is to be applied.
>> +	 */
>> +	uint64_t rss_hf;
>>   };
>>
>>   /*
>> diff --git a/lib/ethdev/rte_flow.h b/lib/ethdev/rte_flow.h
>> index edefa34c10da..25f1dffd1f30 100644
>> --- a/lib/ethdev/rte_flow.h
>> +++ b/lib/ethdev/rte_flow.h
>> @@ -3226,6 +3226,7 @@ struct rte_flow_query_count {
>>    * Hash function types.
>>    */
>>   enum rte_eth_hash_function {
>> +	/** DEFAULT means driver decides which hash algorithm to pick. */
>>   	RTE_ETH_HASH_FUNCTION_DEFAULT = 0,
>>   	RTE_ETH_HASH_FUNCTION_TOEPLITZ, /**< Toeplitz */
>>   	RTE_ETH_HASH_FUNCTION_SIMPLE_XOR, /**< Simple XOR */
>> --
>> 2.30.0
>
  

Patch

diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h
index 2fd3cd808dbf..37fd5afef48a 100644
--- a/lib/ethdev/rte_ethdev.h
+++ b/lib/ethdev/rte_ethdev.h
@@ -448,24 +448,27 @@  struct rte_vlan_filter_conf {
 /**
  * A structure used to configure the Receive Side Scaling (RSS) feature
  * of an Ethernet port.
- * If not NULL, the *rss_key* pointer of the *rss_conf* structure points
- * to an array holding the RSS key to use for hashing specific header
- * fields of received packets. The length of this array should be indicated
- * by *rss_key_len* below. Otherwise, a default random hash key is used by
- * the device driver.
- *
- * The *rss_key_len* field of the *rss_conf* structure indicates the length
- * in bytes of the array pointed by *rss_key*. To be compatible, this length
- * will be checked in i40e only. Others assume 40 bytes to be used as before.
- *
- * The *rss_hf* field of the *rss_conf* structure indicates the different
- * types of IPv4/IPv6 packets to which the RSS hashing must be applied.
- * Supplying an *rss_hf* equal to zero disables the RSS feature.
  */
 struct rte_eth_rss_conf {
-	uint8_t *rss_key;    /**< If not NULL, 40-byte hash key. */
+	/**
+	 * In rte_eth_dev_rss_hash_conf_get(), the *rss_key_len* should be
+	 * greater than or equal to the hash_key_size which get from
+	 * rte_eth_dev_info_get() API. And the *rss_key* should contain at least
+	 * *rss_key_len* bytes. If not meet these requirements, the query result
+	 * is unreliable even the operation returns success.
+	 *
+	 * In rte_eth_dev_rss_hash_update() or rte_eth_dev_configure(), the
+	 * *rss_key_len* indicates the length of the *rss_key* in bytes of
+	 * the array pointed by *rss_key*. Drivers are free to ignore the
+	 * *rss_key_len* and assume key length is 40 bytes.
+	 */
+	uint8_t *rss_key;
 	uint8_t rss_key_len; /**< hash key length in bytes. */
-	uint64_t rss_hf;     /**< Hash functions to apply - see below. */
+	/**
+	 * Indicates the type of packets or the specific part of packets to
+	 * which RSS hashing is to be applied.
+	 */
+	uint64_t rss_hf;
 };
 
 /*
diff --git a/lib/ethdev/rte_flow.h b/lib/ethdev/rte_flow.h
index edefa34c10da..25f1dffd1f30 100644
--- a/lib/ethdev/rte_flow.h
+++ b/lib/ethdev/rte_flow.h
@@ -3226,6 +3226,7 @@  struct rte_flow_query_count {
  * Hash function types.
  */
 enum rte_eth_hash_function {
+	/** DEFAULT means driver decides which hash algorithm to pick. */
 	RTE_ETH_HASH_FUNCTION_DEFAULT = 0,
 	RTE_ETH_HASH_FUNCTION_TOEPLITZ, /**< Toeplitz */
 	RTE_ETH_HASH_FUNCTION_SIMPLE_XOR, /**< Simple XOR */