HEADS-UP: IFLIB implementations of sys/dev/e1000 em, lem, igb pending

[Michael Tuexen]

> On 10 Jan 2017, at 04:32, Sean Bruno <sbruno at freebsd.org> wrote:
> 
> tl;dir --> you get to keep your igbX devices(thanks jhb), no POLA
> violations this week.
> 
> I've updated sys/dev/e1000 at svn R311849 to match Matt Macy's work on
> IFLIB in the kernel.
> 
> At this point, the driver deviates from Intel's code dramatically and
> you now get to yell directly into the freebsd-net@ megaphone for things
> that I may have broken.
My testing shows that sending SCTP/IPv4, SCTP/IPv6, TCP/IPv6, and UDP/IPV6
is broken since the checksum offload doesn't work.

The following patch fixes the issue:

Index: if_em.h
===================================================================
--- if_em.h     (revision 311887)
+++ if_em.h     (working copy)
@@ -330,7 +330,7 @@
 #define EM_MSIX_LINK           0x01000000 /* For 82574 use */
 #define ETH_ZLEN               60
 #define ETH_ADDR_LEN           6
-#define CSUM_OFFLOAD           7       /* Offload bits in mbuf flag */
+#define CSUM_OFFLOAD           0xE0F   /* Offload bits in mbuf flag */

 #define IGB_PKTTYPE_MASK       0x0000FFF0
 #define IGB_DMCTLX_DCFLUSH_DIS 0x80000000  /* Disable DMA Coalesce Flush */

The magic number 7 is CSUM_IP | CSUM_IP_UDP | CSUM_IP_TCP, which means
that checksum offloading is working for TCP/IPv4 and UDP/IPv4.
It should be 0xE0F, which is
CSUM_IP | CSUM_IP_UDP | CSUM_IP_TCP | CSUM_IP_SCTP | CSUM_IP6_UDP | CSUM_IP6_TCP | CSUM_IP6_SCTP.

I have tested the above patch with an igb card which supports all these offloads.

Best regards
Michael
> 
> man page updates are coming up next.  Please let us know if this
> revision has made things better, worse or none-of-the above on whatever
> Intel Gigabit NIC you happen to have lying around.
> 
> sean
> 
> On 01/05/17 20:18, Sean Bruno wrote:
>> tl;dr --> igbX devices will become emX devices
>> 
>> We're about to commit an update to sys/dev/e1000 that will implement and
>> activate IFLIB for em(4), lem(4) & igb(4) and would appreciate all folks
>> who can test and poke at the drivers to do so this week.  This will have
>> some really great changes for performance and standardization that have
>> been bouncing around inside of various FreeBSD shops that have been
>> collaborating with Matt Macy over the last year.
>> 
>> This will implement multiple queues for certain em(4) devices that are
>> capable of such things and add some new sysctl's for you to poke at in
>> your monitoring tools.
>> 
>> Due to limitations of device registration, igbX devices will become emX
>> devices.  So, you'll need to make a minor update to your rc.conf and
>> scripts that manipulate the network devices.
>> 
>> UPDATING will be bumped to reflect these changes.
>> 
>> MFC to stable/11 will have a legacy implementation that doesn't use
>> IFLIB for compatibility reasons.
>> 
>> A documentation and man page update will follow in the next few days
>> explaining how to work with the changed driver.
>> 
>> sean
>> 
>> bcc net@ current@ re@
>> 
>> 
>> 
>> 
>> 
>