On Tue, Oct 29, 2024 at 11:22:19AM +0100, Stefan Sperling wrote:
> On Tue, Oct 29, 2024 at 10:05:21AM +0000, Stuart Henderson wrote:
> > So to summarize what is clear from the recent findings:
> >
> > - em(4) is doing something that trips problems
> > - either the path from LRO->TSO, or something with LRO itself,
> > is doing something that trips problems
> >
> > and (mentioned elsewhere but including it for tech@ readers) -
> > mbuf handling in wg(4) is broken.
> >
> > So on some systems disabling tcplro on interfaces ("ifconfig
> > vio0 -tcplro", "ifconfig ix0 -tcplro" etc) may help work around
> > the problem. On others (like the em case) that won't help.
> >
> > With the em case with no TSO, possibly running wg(4) in a VM and
> > disabling tcplro on vio in the guest may help sidestep the wg(4)
> > problems. (And if it's not that, net.inet.tcp.tso=0 might be worth
> > a try).
>
> To add another data point (not sure if it helps):
>
> On a vmd host which uses ix(4), a vmd guest running wg(4) has
> been stable for half a year of uptime. No crashes at all.
> Both systems are still running 7.5. Haven't upgraded yet.
Also another data point here, I have a system with four Intel i210 em(4)
interfaces in it that has been running wg(4) with all of my local
traffic running through it in a tunnel as well as multiple other wg(4)
in two rdomains without a single hiccup for more than a year now. It is
now up to 7.6 without issue.
# ifconfig em0 hwfeatures
em0:
flags=248843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST,AUTOCONF6TEMP,AUTOCONF6>
mtu 1500
hwfeatures=31b7<CSUM_IPv4,CSUM_TCPv4,CSUM_UDPv4,VLAN_MTU,VLAN_HWTAGGING,CSUM_TCPv6,CSUM_UDPv6,TSOv4,TSOv6>
hardmtu 9216
Also, OpenBSD/octeon was mentioned. I have an EdgeRouter 12 that has
been running since about OpenBSD 7.2 with a wg(4) tunnel for management and
has never crashed. This bug is concerning but I have never hit it.
Bryan
