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From: David Christensen <drc@linux.vnet.ibm.com>
To: users@dpdk.org
Subject: Re: [dpdk-users] Fwd: use VF in promiscuous mode in dpdk to receive all traffic received by PF
Date: Thu, 14 Jan 2021 10:11:11 -0800
Message-ID: <29972d41-cb42-bdd2-46d8-2ee82cdc9c3a@linux.vnet.ibm.com> (raw)
In-Reply-To: <CAHygEmDCOG6v=09uRhe6H1Oitg4oxqegZVgbuXhQsNS-C+VNkA@mail.gmail.com>



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

      reply	other threads:[~2021-01-14 18:11 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-11 11:18 [dpdk-users] " Myth Ren
2021-01-14  5:59 ` [dpdk-users] Fwd: " Myth Ren
2021-01-14 18:11   ` David Christensen [this message]

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