[dpdk-dev] FW: nic loopback

Liang, Cunming cunming.liang at intel.com
Wed Oct 22 10:04:07 CEST 2014



From: alex [mailto:alex at weka.io]
Sent: Wednesday, October 22, 2014 3:42 PM
To: Zhu, Heqing
Cc: Liang, Cunming; dev at dpdk.org
Subject: Re: FW: [dpdk-dev] nic loopback



On Wed, Oct 22, 2014 at 7:37 AM, Zhu, Heqing <heqing.zhu at intel.com<mailto:heqing.zhu at intel.com>> wrote:
One line comment inline.

> -----Original Message-----
> From: dev [mailto:dev-bounces at dpdk.org<mailto:dev-bounces at dpdk.org>] On Behalf Of Liang, Cunming
> Sent: Tuesday, October 21, 2014 8:33 PM
> To: Alex Markuze
> Cc: dev at dpdk.org<mailto:dev at dpdk.org>
> Subject: Re: [dpdk-dev] nic loopback
>
> It’s a pain VF can’t set the register directly.
> As kernel ixgbe don’t support to set the value, I’m afraid you have to modify
> kernel ixgbe.
> If your purpose is mainly for testing purpose.
> One option is you can just set the register bit value to full 1 during device
> initialization.
> Another option is you can choose to use DPDK as host PF.
> Running testpmd in host, and set such register by interactive command line.
>
> Ideally it’s better to add a kind of VF to PF mailbox message.
> Host PF delegate VF to enable the local pool loopback.
> So during runtime, VF can proactive to enable/disable the ability.

[heqing] Such a proposal has been discussed a few times, but the kernel driver does not accept this due to the security concern.

I will try a different approach, Is there a tool available by intel for 82599 nics that can access the NIC's configuration and modify these registers manually? w/o Modifying hypervisor drivers and/or using PF?
[Liang, Cunming] I don’t know. I think it’s not hard for you to make it, but with security concern.

>
>
> From: Alex Markuze [mailto:alex at weka.io<mailto:alex at weka.io>]
> Sent: Tuesday, October 21, 2014 11:16 PM
> To: Liang, Cunming
> Cc: dev at dpdk.org<mailto:dev at dpdk.org>
> Subject: Re: [dpdk-dev] nic loopback
>
> How can I set/query this bit (LLE(PFVMTXSW[n]), intel 82599 ) on ESX, or any
> other friendlier environment like Linux?
>
> On Tue, Oct 21, 2014 at 4:18 AM, Liang, Cunming
> <cunming.liang at intel.com<mailto:cunming.liang at intel.com><mailto:cunming.liang at intel.com<mailto:cunming.liang at intel.com>>> wrote:
>
>
> > -----Original Message-----
> > From: dev
> [mailto:dev-bounces at dpdk.org<mailto:dev-bounces at dpdk.org><mailto:dev-bounces at dpdk.org<mailto:dev-bounces at dpdk.org>>]
> > On Behalf Of Alex Markuze
> > Sent: Tuesday, October 21, 2014 12:24 AM
> > To: dev at dpdk.org<mailto:dev at dpdk.org><mailto:dev at dpdk.org<mailto:dev at dpdk.org>>
> > Subject: [dpdk-dev] nic loopback
> >
> > Hi,
> > I'm trying to send packets from an application to it self, meaning
> > smac  == dmac.
> > I'm working with intel 82599 virtual function. But it seems that these
> > packets are lost.
> >
> > Is there a software/hw limitation I'm missing here (some additional
> > anti-spoofing)? AFAIK modern NICs with sriov are mini switches so the
> > hw loopback should work, at least thats the theory.
> >
> [Liang, Cunming] You could have a check on register LLE(PFVMTXSW[n]).
> Which allow an individual pool to be able to send traffic and have it loopback
> to itself.
> >
> > Thanks.



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