Re: [dpdk-dev] [PATCH] net/ixgbe: clear registers of all queues on VF reset

[Simon Ellmann <simon.ellmann@tum.de>]

On 1/4/21 4:56 PM, Ferruh Yigit wrote:

> On 12/18/2020 2:34 AM, Wang, Haiyue wrote:
>>> -----Original Message-----
>>> From: Simon Ellmann <simon.ellmann@tum.de>
>>> Sent: Friday, December 18, 2020 01:15
>>> To: Guo, Jia <jia.guo@intel.com>; Wang, Haiyue <haiyue.wang@intel.com>
>>> Cc: dev@dpdk.org; Simon Ellmann <simon.ellmann@tum.de>
>>> Subject: [PATCH] net/ixgbe: clear registers of all queues on VF reset
>>>
>>> ixgbe devices support up to 8 Rx and Tx queues per virtual function.
>>> Currently, the registers of only seven queues are set to default when
>>> resetting a VF.
>>>
>>
>> Fixes: d17d0b7a2407 ("ixgbe/base: reset VF registers")
>> Cc: stable@dpdk.org
>>
>>> Signed-off-by: Simon Ellmann <simon.ellmann@tum.de>
>>> ---
>>>   drivers/net/ixgbe/base/ixgbe_vf.c | 2 +-
>>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>
>> Good catch, thanks!
>>
>> Acked-by: Haiyue Wang <haiyue.wang@intel.com>
>>
>
> This seems a very long lived defect, I am just suspicious if there was 
> a reason to limit queue number to 7.
>
>
> Simon,
>
> How did you find the defect? And did you test/verify it with the 
> update? (assuming you are using all 8 queues for the VF)

Hi Ferruh,

I was implementing ixgbevf for ixy.rs (https://ixy.rs/) by reading the 
code in DPDK and Linux. While doing that I noticed that DPDK was only 
resetting 7 queues which looked like a off-by-one error to me. I would 
have expected a comment if this behaviour was intentional. I haven't 
checked the update.

Simon