Subject: Re: [PATCH net] ice: fix setting RSS VSI hash for E830

From: Vadim Fedorenko <[email-masked]>
Date: Mon, 12 Jan 2026 11:15:44 +0000

On 12/01/2026 09:36, Marcin Szycik wrote:
> 
> 
> On 09.01.2026 17:44, Vadim Fedorenko wrote:
>> On 09/01/2026 08:53, Marcin Szycik wrote:
>>> ice_set_rss_hfunc() performs a VSI update, in which it sets hashing
>>> function, leaving other VSI options unchanged. However, ::q_opt_flags is
>>> mistakenly set to the value of another field, instead of its original
>>> value, probably due to a typo. What happens next is hardware-dependent:
>>>
>>> On E810, only the first bit is meaningful (see
>>> ICE_AQ_VSI_Q_OPT_PE_FLTR_EN) and can potentially end up in a different
>>> state than before VSI update.
>>>
>>> On E830, some of the remaining bits are not reserved. Setting them
>>> to some unrelated values can cause the firmware to reject the update
>>> because of invalid settings, or worse - succeed.
>>>
>>> Reproducer:
>>>     sudo ethtool -X $PF1 equal 8
>>>
>>> Output in dmesg:
>>>     Failed to configure RSS hash for VSI 6, error -5
>>>
>>> Fixes: 352e9bf23813 ("ice: enable symmetric-xor RSS for Toeplitz hash function")
>>> Reviewed-by: Aleksandr Loktionov <[email-masked]>
>>> Reviewed-by: Przemek Kitszel <[email-masked]>
>>> Signed-off-by: Marcin Szycik <[email-masked]>
>>> ---
>>>    drivers/net/ethernet/intel/ice/ice_main.c | 2 +-
>>>    1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
>>> index cf8ba5a85384..08268f1a03da 100644
>>> --- a/drivers/net/ethernet/intel/ice/ice_main.c
>>> +++ b/drivers/net/ethernet/intel/ice/ice_main.c
>>> @@ -8038,7 +8038,7 @@ int ice_set_rss_hfunc(struct ice_vsi *vsi, u8 hfunc)
>>>        ctx->info.q_opt_rss |=
>>>            FIELD_PREP(ICE_AQ_VSI_Q_OPT_RSS_HASH_M, hfunc);
>>>        ctx->info.q_opt_tc = vsi->info.q_opt_tc;
>>> -    ctx->info.q_opt_flags = vsi->info.q_opt_rss;
>>> +    ctx->info.q_opt_flags = vsi->info.q_opt_flags;
>>
>> The very same typo pattern is in ice_vc_handle_rss_cfg() in
>> ice/virt/rss.c
>>
>> I believe both places have to be fixed.
> 
> Hmm... where exactly? ice_vc_rss_hash_update() (called from ice_vc_handle_rss_cfg()) looks correct.

Sorry, it was fixed in 3a6d87e2eaac ("ice: implement GTP RSS context
tracking and configuration") when the logic was moved to
ice_vc_rss_hash_update(), but this code was never backported, the
problem exists in 6.18...

> 
> Thanks for reviewing,
> Marcin
> 
>>
>>>          err = ice_update_vsi(hw, vsi->idx, ctx, NULL);
>>>        if (err) {
>>
>