netdev - Re: [PATCH net-next 1/5] net: ethtool: only allow set_rxnfc with rss + ring

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <b0f84914-c4bf-9071-b72d-cc2cc4a517f9@gmail.com>
Date: Mon, 25 Nov 2024 13:21:30 +0000
From: Edward Cree <ecree.xilinx@...il.com>
To: Gal Pressman <gal@...dia.com>, edward.cree@....com, davem@...emloft.net,
 kuba@...nel.org, edumazet@...gle.com, pabeni@...hat.com,
 Ahmed Zaki <ahmed.zaki@...el.com>
Cc: netdev@...r.kernel.org, habetsm.xilinx@...il.com,
 linux-net-drivers@....com, horms@...nel.org, andrew+netdev@...n.ch,
 shuah@...nel.org, linux-kselftest@...r.kernel.org
Subject: Re: [PATCH net-next 1/5] net: ethtool: only allow set_rxnfc with rss
 + ring_cookie if driver opts in

On 25/11/2024 07:11, Gal Pressman wrote:
> On 13/11/2024 14:13, edward.cree@....com wrote:
>> Ethtool ntuple filters with FLOW_RSS were originally defined as adding
>>  the base queue ID (ring_cookie) to the value from the indirection table,
>>  so that the same table could distribute over more than one set of queues
>>  when used by different filters.
> 
> TBH, I'm not sure I understand the difference? Perhaps you can share an
> example?

Something like this:

ethtool -X $intf context new equal 2
# creates context ID 1, table filled with 0s and 1s
ethtool -N $intf <match fields...> context 1
# filter distributes traffic to queues 0 and 1
ethtool -N $intf <match fields...> context 1 action 2
# filter distributes traffic to queues 2 and 3

See the selftest in patch 4 for a concrete example of this.
Some NICs were apparently sending the traffic from both filters to
 queues 0 and 1, and ignoring the 'action 2' on the second filter.

>> @@ -992,6 +992,11 @@ static noinline_for_stack int ethtool_set_rxnfc(struct net_device *dev,
>>  	if (rc)
>>  		return rc;
>>  
>> +	/* Nonzero ring with RSS only makes sense if NIC adds them together */
>> +	if (info.flow_type & FLOW_RSS && !ops->cap_rss_rxnfc_adds &&
>> +	    ethtool_get_flow_spec_ring(info.fs.ring_cookie))
>> +		return -EINVAL;
> 
> I believe this check shouldn't happen when we do ETHTOOL_SRXCLSRLDEL as
> flow_type is garbage, WDYT?

Agreed; this check should only apply to ETHTOOL_SRXCLSRLINS.  Do you want
 to send the fix or shall I?

Also, the check below it, dealing with sym-xor, looks like it's only
 relevant to ETHTOOL_SRXFH, since info.data is garbage for other commands.
 Ahmed, is my understanding correct there?