[dpdk-users] use VF in promiscuous mode in dpdk to receive all traffic received by PF

[dpdk-users] use VF in promiscuous mode in dpdk to receive all traffic received by PF

[Myth Ren]

Hi， all
    is it possible we are mirror traffic from switch/router to PF, then a
program based on DPDK
read packet from a VF related to the PF, presume we are mirror the traffic
from PF to the VF （promiscuous），
while the PF device still managed by the kernel driver(if it's possible),
or managed by UIO driver.
at least, restart the DPDK based program will not influence the PF device
state.

    i have already read the the VFIO doc (
https://doc.dpdk.org/guides/linux_gsg/linux_drivers.html#vfio) and
test it, but not see what i want (maybe i mis-understood or take wrong
steps).

    if VFIO can do what i want? which device i should use, which version
kernel i should use, which driver i
should use?

    thank you

[dpdk-users] Fwd: use VF in promiscuous mode in dpdk to receive all traffic received by PF

[Myth Ren]

Hi， all
    is it possible we are mirror traffic from switch/router to PF, then a
program based on DPDK
read packet from a VF related to the PF, presume we are mirror the traffic
from PF to the VF （promiscuous），
while the PF device still managed by the kernel driver(if it's possible),
or managed by UIO driver.
at least, restart the DPDK based program will not influence the PF device
state.

    i have already read the the VFIO doc (
https://doc.dpdk.org/guides/linux_gsg/linux_drivers.html#vfio) and
test it, but not see what i want (maybe i mis-understood or take wrong
steps).

    if VFIO can do what i want? which device i should use, which version
kernel i should use, which driver i
should use?

    thank you

Re: [dpdk-users] Fwd: use VF in promiscuous mode in dpdk to receive all traffic received by PF

[David Christensen]

On 1/13/21 9:59 PM, Myth Ren wrote:
> Hi， all
>      is it possible we are mirror traffic from switch/router to PF, then a
> program based on DPDK
> read packet from a VF related to the PF, presume we are mirror the traffic
> from PF to the VF （promiscuous），
> while the PF device still managed by the kernel driver(if it's possible),
> or managed by UIO driver.
> at least, restart the DPDK based program will not influence the PF device
> state.

You should be specific about the NIC/PMD you're using here.  One use 
case for PF/VF is that the PF will run in the host operating system and 
the VF will be passed-through to a virtual machine.  Because of this, 
NICs will often support a feature to actively prevent a VF from snooping 
on the traffic seen by the PF for security, limiting it to only 
broadcast/multicast traffic and unicast traffic with a matching MAC 
address.  The ability for a VF to enable promiscuous mode and see PF 
traffic, if it is supported on the NIC, is likely to be NIC/PMD specific 
implementation.

And why the need for a VF in the first place? If the switch/router is 
external to the box and forwarding traffic into the PF, why not just 
catch the traffic from the PF?  You'll need a second PF anyway to send 
the traffic onward (like a bump-in-the-wire implementation), unless 
you're mangling the packets for some reason to change their address, 
adding a VLAN or other tag, etc.  A drawing of what you're trying to 
implement would be useful here.

Dave