[PATCH net-next] hyperv: Add support for Virtual Receive Side Scaling (vRSS)

[Haiyang Zhang]

> -----Original Message-----
> From: Tom Herbert [mailto:therbert at google.com]
> Sent: Thursday, December 19, 2013 2:59 PM
> To: Haiyang Zhang
> Cc: Daniel Borkmann; Ben Hutchings; davem at davemloft.net;
> netdev at vger.kernel.org; KY Srinivasan; olaf at aepfle.de;
> jasowang at redhat.com; linux-kernel at vger.kernel.org; driverdev-
> devel at linuxdriverproject.org
> Subject: Re: [PATCH net-next] hyperv: Add support for Virtual Receive Side
> Scaling (vRSS)
> 
> I posted an implementation of library functions for Toeplitz (see [PATCH 1/2]
> net: Toeplitz library functions).  This includes some pre-computation of the
> table to get reasonable performance in the host. Please take a look.
> 
> On the other hand, if you're computing a hash in the host, do you really need
> Toeplitz, flow_dissector already supports a good hash computation and can
> parse many more packets than just plain UDP/TCP.
> We probably only should be doing Toeplitz in the host if we need to match
> HW computed values.

The Hyper-V host requires the guest to select channel based on Toeplitz hash, so
we need to compute it on the guest. 

Regarding the Toeplitz function, do you mean this patch?
http://patchwork.ozlabs.org/patch/277344/
This doesn't contain the implementation. Could you point me to the actual code?

Thanks,
- Haiyang