Re: [PATCH net] ice: Clear default forwarding VSI during VSI release

[Marcin Szycik <marcin.szycik@linux.intel.com>]

On 23-Mar-22 18:54, Ivan Vecera wrote:
> On Wed, 23 Mar 2022 18:39:11 +0100
> Marcin Szycik <marcin.szycik@linux.intel.com> wrote:
> 
>> On 22-Mar-22 15:25, Ivan Vecera wrote:
>>> VSI is set as default forwarding one when promisc mode is set for
>>> PF interface, when PF is switched to switchdev mode or when VF
>>> driver asks to enable allmulticast or promisc mode for the VF
>>> interface (when vf-true-promisc-support priv flag is off).
>>> The third case is buggy because in that case VSI associated with
>>> VF remains as default one after VF removal.
>>>
>>> Reproducer:
>>> 1. Create VF
>>>    echo 1 > sys/class/net/ens7f0/device/sriov_numvfs
>>> 2. Enable allmulticast or promisc mode on VF
>>>    ip link set ens7f0v0 allmulticast on
>>>    ip link set ens7f0v0 promisc on
>>> 3. Delete VF
>>>    echo 0 > sys/class/net/ens7f0/device/sriov_numvfs
>>> 4. Try to enable promisc mode on PF
>>>    ip link set ens7f0 promisc on
>>>
>>> Although it looks that promisc mode on PF is enabled the opposite
>>> is true because ice_vsi_sync_fltr() responsible for IFF_PROMISC
>>> handling first checks if any other VSI is set as default forwarding
>>> one and if so the function does not do anything. At this point
>>> it is not possible to enable promisc mode on PF without re-probe
>>> device.
>>>
>>> To resolve the issue this patch clear default forwarding VSI
>>> during ice_vsi_release() when the VSI to be released is the default
>>> one.
>>>
>>> Fixes: 01b5e89aab49 ("ice: Add VF promiscuous support")
>>> Signed-off-by: Ivan Vecera <ivecera@redhat.com>
>>> ---
>>>  drivers/net/ethernet/intel/ice/ice_lib.c | 2 ++
>>>  1 file changed, 2 insertions(+)
>>>
>>> diff --git a/drivers/net/ethernet/intel/ice/ice_lib.c b/drivers/net/ethernet/intel/ice/ice_lib.c
>>> index 53256aca27c7..20d755822d43 100644
>>> --- a/drivers/net/ethernet/intel/ice/ice_lib.c
>>> +++ b/drivers/net/ethernet/intel/ice/ice_lib.c
>>> @@ -3147,6 +3147,8 @@ int ice_vsi_release(struct ice_vsi *vsi)
>>>  		}
>>>  	}
>>>  
>>> +	if (ice_is_vsi_dflt_vsi(pf->first_sw, vsi))
>>> +		ice_clear_dflt_vsi(pf->first_sw);  
>>
>> It would probably be good to check `ice_clear_dflt_vsi` return code.
> 
> Check and report potential warning when error occurs? because we are in ice_vsi_release() so
> any rollback does not make sense.

Right. ice_clear_dflt_vsi already reports errors so it should be good as is.
LGTM, thanks!

> 
> Ivan
>