On Thu, Mar 18, 2010 at 10:25:34AM +1100, James Harper wrote:
> >
> > Yeah, I've seen that. It does not give that much information however.
> >
> > More specifically, I've tested with two dom0 pv_ops kernels now, and
> since
> > it's still
> > reproducable on the latest xen/stable platform, I'm guessing it either
> has to
> > do with vlan'ing or
> > the tg3 driver , in combination with netback.
> >
> > I was hoping some Xen developers could shed some light on this.
> > I already conversed with Jeremy about this, and he pointed me to this
> mailing
> > list.
> >
>
> This may not be relavant, but I have seen problems with the following
> combination:
>
> br0:
> eth0
> <netback devices>
>
> br1:
> eth0.2
> <netback devices>
>
> Some (most?) network hardware cannot provide checksum/large send offload
> functions for packets that use vlan tagging, but Linux doesn't quite
> understand that and gets confused, so when such a packet comes off of
> netback and is sent to eth0.2, the LSO/checksum function should be
> performed in software but isn't.
>
> I haven't yet figured out of the problem is that the driver is
> incorrectly reporting that offload is supported on the vlan device or if
> the rest of Linux isn't taking the appropriate action...
Hmm, just to set the record straight, there's vlan'ing on the switch (containing
several ports in a single physical network), but no tagging as far as I know.
However, I've read some previous problems using checksum offloading in the TG3
driver.
Perhaps the two are related (netback / tg3 checksums), but I have no way of
determining that.
Isn't there some way of patching the netback driver, so it does not support
checksumming?
Maybe I'm way off base here..
--
/\/\ Hostingvereniging Soleus | Community-driven
< ** > http://soleus.nu | Virtual Private Servers
\/\/ Sen (IEF) Verbrugge (CT ProLead) | & more ...
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
|
Home