From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH v3 1/4] net: Add support for hardware-offloaded encapsulation Date: Fri, 07 Dec 2012 14:52:39 -0500 (EST) Message-ID: <20121207.145239.1408511750725975741.davem@davemloft.net> References: <20121207.143725.1501926484331042018.davem@davemloft.net> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: bhutchings@solarflare.com, alexander.h.duyck@intel.com, shemminger@vyatta.com, chrisw@sous-sol.org, gospo@redhat.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, dmitry@broadcom.com, saeed.bishara@gmail.com, peter.p.waskiewicz.jr@intel.com To: joseph.gasparakis@intel.com Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: Joseph Gasparakis Date: Fri, 7 Dec 2012 11:52:43 -0800 (PST) > > > On Fri, 7 Dec 2012, David Miller wrote: > >> From: Joseph Gasparakis >> Date: Fri, 7 Dec 2012 11:41:46 -0800 (PST) >> >> > >> > >> > On Fri, 7 Dec 2012, David Miller wrote: >> > >> >> From: Joseph Gasparakis >> >> Date: Fri, 7 Dec 2012 10:24:17 -0800 (PST) >> >> >> >> > So the idea here is that the driver will use the headers for checksumming >> >> > if the skb->encapsulation bit is on. The bit should be set in the protocol >> >> > driver. >> >> > >> >> > To answer the second comment, the flags that we use in this series of >> >> > patches is NETIF_F_IP_CSUM, NETIF_F_IPV6_CSUM and NETIF_F_SG. These are >> >> > the bits that we propose will be used for checksumming of encapsulation. >> >> > As per a previous comment in v2, the hw_enc_features field should be used >> >> > also in the future when NICs have more encap offloads, so one could >> >> > indicate these features there from the driver. >> >> > >> >> > Furthermore, I submitted a patch for Rx checksumming, where NETIF_F_RXCSUM >> >> > is used, again in conjunction with skb->encapsulation flag. As I mention >> >> > in my logs, the driver is expected to set the ip_summed to UNNECESSARY and >> >> > turn the skb->encapsulation on, to indicate that the inner headers are >> >> > already HW checksummed. >> >> > >> >> >> >> This is the kind of language that belongs in the commit message and >> >> code comments. >> >> >> > Sure. I'll wait to gather some more feedback if there is any and I will >> > re-spin this off adding more code comments and clarify this in the logs. >> >> Great. >> >> Please note that this request applies to your receive side change too. >> > I believe the logs are sufficient in the rx patch: > > This patch adds capability in vxlan to identify received > checksummed inner packets and signal them to the upper layers of > the stack. The driver needs to set the skb->encapsulation bit > and also set the skb->ip_summed to CHECKSUM_UNNECESSARY. > > ...but I can add more comments to the code if this is what you are > referring to. Yes, please do.