From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joseph Gasparakis Subject: Re: [net-next v4 07/16] i40e: Rx checksum offload for VXLAN Date: Thu, 2 Jan 2014 12:57:56 -0800 (PST) Message-ID: References: <1388200940-9113-1-git-send-email-jeffrey.t.kirsher@intel.com> <1388200940-9113-8-git-send-email-jeffrey.t.kirsher@intel.com> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: "Kirsher, Jeffrey T" , "Gasparakis, Joseph" , David Miller , "netdev@vger.kernel.org" , "gospo@redhat.com" , "sassmann@redhat.com" , "Brandeburg, Jesse" To: Or Gerlitz Return-path: Received: from mga11.intel.com ([192.55.52.93]:59998 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752633AbaABUlE (ORCPT ); Thu, 2 Jan 2014 15:41:04 -0500 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Thu, 2 Jan 2014, Or Gerlitz wrote: > On Sat, Dec 28, 2013 at 5:22 AM, Jeff Kirsher > wrote: > > From: Joseph Gasparakis > > > > This implements receive offload for VXLAN for i40e. The hardware > > supports checksum offload/verification of the inner/outer header. > > > > Change-Id: I450db300af6713f2044fef1191a0d1d294c13369 > > Signed-off-by: Joseph Gasparakis > > Signed-off-by: Jesse Brandeburg > > Signed-off-by: Jeff Kirsher > > --- > > drivers/net/ethernet/intel/i40e/i40e.h | 1 + > > drivers/net/ethernet/intel/i40e/i40e_txrx.c | 57 ++++++++++++++++++++++++++--- > > drivers/net/ethernet/intel/i40e/i40e_type.h | 51 ++++++++++++++------------ > > 3 files changed, 81 insertions(+), 28 deletions(-) > > > > diff --git a/drivers/net/ethernet/intel/i40e/i40e.h b/drivers/net/ethernet/intel/i40e/i40e.h > > index 6f1edc1..34a54e7 100644 > > --- a/drivers/net/ethernet/intel/i40e/i40e.h > > +++ b/drivers/net/ethernet/intel/i40e/i40e.h > > @@ -29,6 +29,7 @@ > > #define _I40E_H_ > > > > #include > > +#include > > #include > > #include > > #include > > diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c > > index 01d0334..a978451 100644 > > --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c > > +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c > > @@ -860,12 +860,25 @@ static void i40e_receive_skb(struct i40e_ring *rx_ring, > > * @skb: skb currently being received and modified > > * @rx_status: status value of last descriptor in packet > > * @rx_error: error value of last descriptor in packet > > + * @rx_ptype: ptype value of last descriptor in packet > > **/ > > static inline void i40e_rx_checksum(struct i40e_vsi *vsi, > > struct sk_buff *skb, > > u32 rx_status, > > - u32 rx_error) > > + u32 rx_error, > > + u16 rx_ptype) > > { > > + bool ipv4_tunnel, ipv6_tunnel; > > + __wsum rx_udp_csum; > > + __sum16 csum; > > + struct iphdr *iph; > > + > > + ipv4_tunnel = (rx_ptype > I40E_RX_PTYPE_GRENAT4_MAC_PAY3) && > > + (rx_ptype < I40E_RX_PTYPE_GRENAT4_MACVLAN_IPV6_ICMP_PAY4); > > + ipv6_tunnel = (rx_ptype > I40E_RX_PTYPE_GRENAT6_MAC_PAY3) && > > + (rx_ptype < I40E_RX_PTYPE_GRENAT6_MACVLAN_IPV6_ICMP_PAY4); > > + > > + skb->encapsulation = ipv4_tunnel || ipv6_tunnel; skb->encapulation is set (or not) here. > > skb->ip_summed = CHECKSUM_NONE; > > > > /* Rx csum enabled and ip headers found? */ > > @@ -873,13 +886,43 @@ static inline void i40e_rx_checksum(struct i40e_vsi *vsi, > > rx_status & (1 << I40E_RX_DESC_STATUS_L3L4P_SHIFT))) > > return; > > > > - /* IP or L4 checksum error */ > > + /* IP or L4 or outmost IP checksum error */ > > if (rx_error & ((1 << I40E_RX_DESC_ERROR_IPE_SHIFT) | > > - (1 << I40E_RX_DESC_ERROR_L4E_SHIFT))) { > > + (1 << I40E_RX_DESC_ERROR_L4E_SHIFT) | > > + (1 << I40E_RX_DESC_ERROR_EIPE_SHIFT))) { > > vsi->back->hw_csum_rx_error++; > > return; > > } > > > > + if (ipv4_tunnel && > > + !(rx_status & (1 << I40E_RX_DESC_STATUS_UDP_0_SHIFT))) { > > + /* If VXLAN traffic has an outer UDPv4 checksum we need to check > > + * it in the driver, hardware does not do it for us. > > + * Since L3L4P bit was set we assume a valid IHL value (>=5) > > + * so the total length of IPv4 header is IHL*4 bytes > > + */ > > The comment says that the driver has to compute the udp checksum > **if** the packet has an outer udp checksum, > but the driver call to issue checksumming is done unconditionally > This code runs when the right bits are set in the rx hardware descriptor field (rx_ptype and rx_status), which implies the hardware has detected ipv4 tunneling and there is non zero UDP csum. > > + skb->transport_header = skb->mac_header + > > + sizeof(struct ethhdr) + > > + (ip_hdr(skb)->ihl * 4); > > + > > + /* Add 4 bytes for VLAN tagged packets */ > > + skb->transport_header += (skb->protocol == htons(ETH_P_8021Q) || > > + skb->protocol == htons(ETH_P_8021AD)) > > + ? VLAN_HLEN : 0; > > + > > + rx_udp_csum = udp_csum(skb); > > + iph = ip_hdr(skb); > > + csum = csum_tcpudp_magic( > > + iph->saddr, iph->daddr, > > + (skb->len - skb_transport_offset(skb)), > > + IPPROTO_UDP, rx_udp_csum); > > + > > + if (udp_hdr(skb)->check != csum) { > > + vsi->back->hw_csum_rx_error++; > > + return; > > + } > > + } > > + > > skb->ip_summed = CHECKSUM_UNNECESSARY; > > } > > Commit 0afb1666fe4 "vxlan: Add capability of Rx checksum offload for > inner packet" dictates that > the driver is expected to set the skb->encapsulation bit, this is > missing here, and indeed in vxlan_udp_encap_recv > your setting of ip_summed will be ignored and over-rided with > CHECKSUM_NONE, agree? It is setting skb->encapsulation when hw detects it. I have pointed it out above. > -- > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >