[dpdk-dev] FW: nic loopback

[Zhu, Heqing]

One line comment inline. 

> -----Original Message-----
> From: dev [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
> 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.

> 
> 
> From: Alex Markuze [mailto:alex at weka.io]
> Sent: Tuesday, October 21, 2014 11:16 PM
> To: Liang, Cunming
> Cc: 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>> wrote:
> 
> 
> > -----Original Message-----
> > From: dev
> [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>
> > 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.