Subject: Re: [RFC PATCH net-next 1/5] ixgbe: Add a RETA query command to VF-PF channel API

From: Vlad Zolotarov <[email-masked]>
Date: Tue, 30 Dec 2014 21:28:33 +0200

On 12/30/14 21:21, Jeff Kirsher wrote:
> On Tue, Dec 30, 2014 at 8:30 AM, Vlad Zolotarov
> <[email-masked]> wrote:
>> 82599 VFs and PF share the same RSS redirection table (RETA). Therefore we
>> just return it for all VFs.
>>
>> RETA table is an array of 32 registers and the maximum number of registers
>> that may be delivered in a single VF-PF channel command is 15. Therefore
>> we will deliver the whole table in 3 steps: 12, 12 and 8 registers in each
>> step correspondingly. Thus this patch does the following:
>>
>>    - Adds a new API version (to specify a new commands set).
>>    - Adds the IXGBE_VF_GET_RETA_[0,1,2] commands to the VF-PF commands set.
>>
>> Signed-off-by: Vlad Zolotarov <[email-masked]>
>> ---
>>   drivers/net/ethernet/intel/ixgbe/ixgbe_mbx.h   |  6 +++++
>>   drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c | 35 ++++++++++++++++++++++++++
>>   2 files changed, 41 insertions(+)
>>
>> diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_mbx.h b/drivers/net/ethernet/intel/ixgbe/ixgbe_mbx.h
>> index a5cb755..c1123d9 100644
>> --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_mbx.h
>> +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_mbx.h
>> @@ -73,6 +73,7 @@ enum ixgbe_pfvf_api_rev {
>>          ixgbe_mbox_api_10,      /* API version 1.0, linux/freebsd VF driver */
>>          ixgbe_mbox_api_20,      /* API version 2.0, solaris Phase1 VF driver */
>>          ixgbe_mbox_api_11,      /* API version 1.1, linux/freebsd VF driver */
>> +       ixgbe_mbox_api_12,      /* API version 1.2, linux/freebsd VF driver */
>>          /* This value should always be last */
>>          ixgbe_mbox_api_unknown, /* indicates that API version is not known */
>>   };
>> @@ -91,6 +92,11 @@ enum ixgbe_pfvf_api_rev {
>>   /* mailbox API, version 1.1 VF requests */
>>   #define IXGBE_VF_GET_QUEUES    0x09 /* get queue configuration */
>>
>> +/* mailbox API, version 1.2 VF requests */
>> +#define IXGBE_VF_GET_RETA_0    0x0a /* get RETA[0..11]  */
>> +#define IXGBE_VF_GET_RETA_1    0x0b /* get RETA[12..23] */
>> +#define IXGBE_VF_GET_RETA_2    0x0c /* get RETA[24..31] */
>> +
>>   /* GET_QUEUES return data indices within the mailbox */
>>   #define IXGBE_VF_TX_QUEUES     1       /* number of Tx queues supported */
>>   #define IXGBE_VF_RX_QUEUES     2       /* number of Rx queues supported */
>> diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c
>> index c76ba90..84db1a5 100644
>> --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c
>> +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c
>> @@ -427,6 +427,7 @@ static s32 ixgbe_set_vf_lpe(struct ixgbe_adapter *adapter, u32 *msgbuf, u32 vf)
>>   #endif /* CONFIG_FCOE */
>>                  switch (adapter->vfinfo[vf].vf_api) {
>>                  case ixgbe_mbox_api_11:
>> +               case ixgbe_mbox_api_12:
>>                          /*
>>                           * Version 1.1 supports jumbo frames on VFs if PF has
>>                           * jumbo frames enabled which means legacy VFs are
>> @@ -894,6 +895,7 @@ static int ixgbe_negotiate_vf_api(struct ixgbe_adapter *adapter,
>>          switch (api) {
>>          case ixgbe_mbox_api_10:
>>          case ixgbe_mbox_api_11:
>> +       case ixgbe_mbox_api_12:
>>                  adapter->vfinfo[vf].vf_api = api;
>>                  return 0;
>>          default:
>> @@ -917,6 +919,7 @@ static int ixgbe_get_vf_queues(struct ixgbe_adapter *adapter,
>>          switch (adapter->vfinfo[vf].vf_api) {
>>          case ixgbe_mbox_api_20:
>>          case ixgbe_mbox_api_11:
>> +       case ixgbe_mbox_api_12:
>>                  break;
>>          default:
>>                  return -1;
>> @@ -944,6 +947,29 @@ static int ixgbe_get_vf_queues(struct ixgbe_adapter *adapter,
>>          return 0;
>>   }
>>
>> +static int ixgbe_get_vf_reta(struct ixgbe_adapter *adapter,
>> +                            u32 *msgbuf, u32 vf, int reta_offset_dw,
>> +                            size_t dwords)
>> +{
>> +       struct ixgbe_hw *hw = &adapter->hw;
>> +       int i;
>> +       u32 *reta = &msgbuf[1];
>> +
>> +       /* verify the PF is supporting the correct API */
>> +       switch (adapter->vfinfo[vf].vf_api) {
>> +       case ixgbe_mbox_api_12:
>> +               break;
>> +       default:
>> +               return -EPERM;
>> +       }
> A switch statement is overkill for a single case.  It would be far
> simpler to just have
>
> if (adapter->vfinfo[vf].vf_api != ixgbe_mbox_api_12)
>          return -EPERM;
>
> Later on, if there are multiple API's or future API's that also
> support this, then we could move to a case statement.

I thought about it to but decided to make it future-proof. NP. Will make 
it an "if" in a non-RFC series. Thanks.