Re: CALL FOR TEST axgbe promisc mode

From: Zhenlei Huang <zlei_at_FreeBSD.org>
Date: Mon, 07 Oct 2024 14:52:19 UTC

> On Oct 2, 2024, at 3:42 PM, Mark Johnston <markj@freebsd.org> wrote:
> 
> On Tue, Oct 01, 2024 at 12:46:07PM +0000, Franco Fichtner wrote:
>> Hi,
>> 
>>> On 1. Oct 2024, at 02:47, Zhenlei Huang <zlei@FreeBSD.org> wrote:
>>> 
>>> The test plan is simple, either of the following should suffice:
>>> 
>>> • Do traffic sniffing on axgbe interface. The interface will enter promisc mode and should see packets not for us.
>> 
>> I tested this with and without the patch and it's inconclusive:
>> 
>> 1. tcpdump sees foreign packets with and without patch
>> 2. tcpdump -p sees foreign packets with and without patch
> 
> That's somewhat surprising.

Maybe the firmware / hardware happens to been ( wrongly ) set to promisc mode already ?

> 
>> 
>> This oddly enough matches my expectation that nobody raised issues about
>> promisc not working so far, but it leaves the question if we are/I am testing the
>> right thing?
> 
> I think you are.  BPF uses ifpromisc() to enable promiscuous mode, and
> tcpdump uses that interface rather than setting IFF_PPROMISC directly,
> and without the patch I expect that that's a bit broken.
> 
> There is perhaps an unrelated driver bug there.  I wonder what flags get
> printed by ifconfig before and during your experiments.  It'd also be
> useful to try enabling debug logging (sysctl
> dev.ax.0.axgbe_debug_level=1, I think) to see if axgbe_if_promisc_set()
> is getting executed as expected.

Probably I should firstly check D46794 in. Any idea ?

> 
>> 
>> 
>> Cheers,
>> Franco
>> 
>> ax0: <AMD 10 Gigabit Ethernet Driver> mem 0x80160000-0x8017ffff,0x80140000-0x8015ffff,0x80188000-0x80189fff at device 0.4 on pci6
>> ax0: Using 512 TX descriptors and 512 RX descriptors
>> ax0: Using 4 RX queues 4 TX queues
>> ax0: Using MSI-X interrupts with 8 vectors
>> ax0: Ethernet address: XX:XX:XX:XX:XX:XX
>> ax0: xgbe_config_sph_mode: SPH disabled in channel 0
>> ax0: xgbe_config_sph_mode: SPH disabled in channel 1
>> ax0: xgbe_config_sph_mode: SPH disabled in channel 2
>> ax0: xgbe_config_sph_mode: SPH disabled in channel 3
>> ax0: RSS Enabled
>> ax0: Receive checksum offload Enabled
>> ax0: VLAN filtering Enabled
>> ax0: VLAN Stripping Enabled
>> ax0: Checking GPIO expander validity
>> ax0: GPIO configuration valid
>> ax0: SFP detected:
>> ax0:   vendor: FS               ax0:   part number:    SFP-10G-T        ax0:   revision level: A    ax0:   serial number:  XXXXXXXXXXX      ax0: netmap queues/slots: TX 4/512, RX 4/512
>> ax0: Link is UP - 10Gbps/Full - flow control off
>> ax0: link state changed to UP
>> ax0: xgbe_config_sph_mode: SPH disabled in channel 0
>> ax0: xgbe_config_sph_mode: SPH disabled in channel 1
>> ax0: xgbe_config_sph_mode: SPH disabled in channel 2
>> ax0: xgbe_config_sph_mode: SPH disabled in channel 3
>> ax0: RSS Enabled
>> ax0: Receive checksum offload Disabled
>> ax0: VLAN filtering Disabled
>> ax0: VLAN Stripping Disabled
>> ax0: promiscuous mode enabled
>> ax0: promiscuous mode disabled