From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id A3EC544037; Wed, 15 May 2024 17:52:12 +0200 (CEST) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 3DA0F4025C; Wed, 15 May 2024 17:52:12 +0200 (CEST) Received: from mail-ed1-f49.google.com (mail-ed1-f49.google.com [209.85.208.49]) by mails.dpdk.org (Postfix) with ESMTP id 91AE54021D for ; Wed, 15 May 2024 17:49:27 +0200 (CEST) Received: by mail-ed1-f49.google.com with SMTP id 4fb4d7f45d1cf-574ea5184abso2170774a12.3 for ; Wed, 15 May 2024 08:49:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1715788167; x=1716392967; darn=dpdk.org; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=c2hm0IxWjt84AcgOM+feasE2fB+cmHke0+pANzkWZ80=; b=Oa0hGVxbpHUGWYwzd0JM2aNiLC/oSQhjkWTdI+fV14x7kEAbWQ8PRw91IhjHSgMlUS W6MT+C+dKrjNM6F/yOksN9qf8ySH3kd9GEbabjskq0uGmepc282+KQDRYeA7vcsNcxjg OamL692BXlBlzUp+ewRY7Ks0IYJFMDKfE34l22xSnahmUPe4AZRzFMuGd3EwNNoeW/Ec DnHYj7izivCvqUYiwNFrbXMA94ZUR/ZWQ9qRiIqtu/j33uNgZAzrF8nX2VpUYFqAbNE+ jJb3mj8hEnG/trKuIhNFp77Vjkb9fo53X+bJ6HI8niNbmQdXd/J3XVWrb7qOGc2+DQKx 6mlQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1715788167; x=1716392967; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=c2hm0IxWjt84AcgOM+feasE2fB+cmHke0+pANzkWZ80=; b=s/GvrfyjQLw3XnYJWIbKxXTCCVqot1tI7JjCQJ9CNIMJJyP4ClWoGUs/j3XvFTC6gO SOeWca9Nav7H0pytO/Ci+fUop5Umml61J51vu3n5vU3hwWOsEvH40XMcnR5yIIJIcv+Z Cu0MPJgD6+OrUhCo9V3/eM+Rcmkqx7iUcL/TCC4RyM6TB7bIol1/rfCFAr4IfpXisNU6 IvUjWEZ6hOkZNSzhIk40CFaIQ6KrraSrIbU+nsOmqyX6XRvfrvY7X6uxBFQuGkaU+4x/ Y8dZoXn7++1lMGVWudCn8ASh39yLRuuwGIw68PXktSt2LHDFoN89+PMSBxBOLjqhFKcW qYWg== X-Gm-Message-State: AOJu0YzmUmZ0recgA7Taxk4gvfgzGEmUh9QGRSqd3uNEDceA6/dE8uMw JSa/fyhD8JD9W/D9qq32fixKrgSbrNmPdVGXEnTP1JF+V+2BkYgymqyuneI+cWMcyql2jG1sduT HizKYOo12ogFR7PugIeoE7EwM4QoP X-Google-Smtp-Source: AGHT+IH5EDHKF/KwOeVYn3/9cekoMSkSB8L4ap/5rWCR//7qOT2vlClirtHJgU86HHofl0uCkGrqTpX7K0YoHzSCx+s= X-Received: by 2002:a17:906:2b0d:b0:a59:be21:3575 with SMTP id a640c23a62f3a-a5a2d672ee4mr1198234066b.51.1715788166731; Wed, 15 May 2024 08:49:26 -0700 (PDT) MIME-Version: 1.0 References: <20240515080434.33abfd44@hermes.local> In-Reply-To: <20240515080434.33abfd44@hermes.local> From: Nagesh Mallappa Date: Wed, 15 May 2024 21:19:15 +0530 Message-ID: Subject: Re: RSS Hash value returned by the gvnic pmd dpdk driver not matching Toeplitz To: Stephen Hemminger Cc: dev@dpdk.org Content-Type: multipart/alternative; boundary="000000000000301d6b06188010ef" X-Mailman-Approved-At: Wed, 15 May 2024 17:52:10 +0200 X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org --000000000000301d6b06188010ef Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Hi Stephen, Thanks for your response, I have verified that too, but that is not the case. Thanks, Nagesh On Wed, May 15, 2024 at 8:34=E2=80=AFPM Stephen Hemminger < stephen@networkplumber.org> wrote: > On Wed, 15 May 2024 13:50:38 +0530 > Nagesh Mallappa wrote: > > > Hi Team, > > > > We are using a C3 GCP instance having GVNIC with DPDK enabled. > > We are using latest version of DPDK ( dpdk-24.03 ) to configure RSS key= , > we > > understand C3 GCP instance with gvnic supports Toeplitz rss algorithm ( > > Reference - > > > https://github.com/google/compute-virtual-ethernet-dpdk/blob/main/gve_eth= dev.c > > ), > > but we are hitting below issue. > > > > *Problem Statement - The RSS Hash value returned by the gvnic driver is > > different and is not matching the one computed by Toeplitz.* > > > > Using below script to compute rss hash value from Toeplitz. > > (https://gist.github.com/joongh/16867705b03b49e393cbf91da3cb42a7) > > > > Consider below data to compute RSS Hash value - > > > > Source IP - 79.124.62.122 > > Destination IP - 192.168.7.28 > > Source Port - 49442 > > Destination Port - 55327 > > RSS Key - {0x94e3e97e, 0x4abac401, 0x1e0edbf, 0xe059e1f4, 0xb6e27dff, > > 0xdf55c916, 0xe9e6e4db, 0x1f9fb82c, 0x1e0edbf, 0xe059e1f4} > > > > *Hash Value returned by Toeplitz - 0x8bbafd0f* > > > > Gvnic dpdk pmd driver which uses Toeplitz RSS hash algorithm too is > > expected to compute above RSS Hash value but we see the Hash value stor= ed > > in dpdk mbuf to be 0xc6a15941 which is not right. > > From the DPDK side we have ensured RSS offloading configuration is done > > appropriately, but still we are seeing above mismatch. > > > > We request you to please help us understand why this mismatch is > happening > > and is this expected behavior of gvnic on C3 instance. > > Could you see if it is a driver byte order issue by byteswapping the key? > --000000000000301d6b06188010ef Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Hi Stephen,

Thanks for your response,
I have verified that too, but that is not the case.

=
Thanks,
Nagesh

On Wed, May 15, 2024 at 8:34=E2=80= =AFPM Stephen Hemminger <s= tephen@networkplumber.org> wrote:
On Wed, 15 May 2024 13:50:38 +0530
Nagesh Mallappa <mallappanagesh@gmail.com> wrote:

> Hi Team,
>
> We are using a C3 GCP instance having GVNIC with DPDK enabled.
> We are using latest version of DPDK ( dpdk-24.03 ) to configure RSS ke= y, we
> understand C3 GCP instance with gvnic supports Toeplitz rss algorithm = (
> Reference -
> https://github.co= m/google/compute-virtual-ethernet-dpdk/blob/main/gve_ethdev.c
> ),
> but we are hitting below issue.
>
> *Problem Statement - The RSS Hash value returned by the gvnic driver i= s
> different and is not matching the one computed by Toeplitz.*
>
> Using below script to compute rss hash value from Toeplitz.
> (https://gist.github.com/joongh/= 16867705b03b49e393cbf91da3cb42a7)
>
> Consider below data to compute RSS Hash value -
>
> Source IP - 79.124.62.122
> Destination IP - 192.168.7.28
> Source Port - 49442
> Destination Port - 55327
> RSS Key - {0x94e3e97e, 0x4abac401, 0x1e0edbf, 0xe059e1f4, 0xb6e27dff,<= br> > 0xdf55c916, 0xe9e6e4db, 0x1f9fb82c, 0x1e0edbf, 0xe059e1f4}
>
> *Hash Value returned by Toeplitz - 0x8bbafd0f*
>
> Gvnic dpdk pmd driver which uses Toeplitz RSS hash algorithm too is > expected to compute above RSS Hash value but we see the Hash value sto= red
> in dpdk mbuf to be 0xc6a15941 which is not right.
> From the DPDK side we have ensured RSS offloading configuration is don= e
> appropriately, but still we are seeing above mismatch.
>
> We request you to please help us understand why this mismatch is happe= ning
> and is this expected behavior of gvnic on C3 instance.

Could you see if it is a driver byte order issue by byteswapping the key?
--000000000000301d6b06188010ef--