On 1/5/2021 9:02 AM, Simon Ellmann wrote:

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

quoted

On 12/18/2020 2:34 AM, Wang, Haiyue wrote:

quoted

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-----Original Message-----
From: Simon Ellmann <redacted>
Sent: Friday, December 18, 2020 01:15
To: Guo, Jia <redacted>; Wang, Haiyue <redacted>
Cc: dev@dpdk.org; Simon Ellmann <redacted>
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

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Signed-off-by: Simon Ellmann <redacted>
---
  drivers/net/ixgbe/base/ixgbe_vf.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

Good catch, thanks!

Acked-by: Haiyue Wang <redacted>

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.

Most probably you are right, but when I tried to test this, the HW I have 
doesn't let me set more than 4 queues for the VF, so I was a little suspicious 
about hardcoded 8 value.

What do you think using 'hw->mac.max_rx_queues' instead? Which seems used a few 
other places to walk the queues?

Also can you please point the equivalent code in the Linux driver? As far as I 
can see it also uses 'adapter->num_rx_queues', but I wonder if is there any 
hardcoded value there.