[Bug 236924] [NEW] E1000 driver enables TSOv6 for hardware that doesn't support it

Bhavesh Davda bhavesh at vmware.com
Mon Jun 2 21:37:13 UTC 2008

Public bug reported:

Binary package hint: linux-image

The linux-2.6.24-X kernels shipped with Ubuntu 8.04 include the
e1000-7.3.20-k2-NAPI driver for E1000 NICs.

lsb_release -rd
Description:    Ubuntu 8.04
Release:        8.04

I'm copy-pasting text from a similar bug report I filed at

How reproducible: 100%

Steps to Reproduce:
1. Boot Ubuntu-8.04 in a VMware VM, with an e1000 virtual NIC that emulates an 82545EM, which doesn't support TSO over IPv6.
2. ethtool -K ethX tso on
3. Transmit any TCP over IPv6 packet.
Actual results:

Hits an ASSERT in the VMware hypervisor which triggers if TSO6 is attempted to
be used on the 82545EM emulated vNIC.

Expected results:

TSO6 should not be used for NICs that don't support it.

Additional info:

The Intel version of the driver (http://e1000.sourceforge.net), at least
versions 7.6.12 and later that I looked at, conditionally advertise NETIF_F_TSO6
in e1000_set_tso, based on whether e1000_probe detected a mac type >= 82547_rev_2.

We could patch our emulation to not assert that TSO6 is being used for transmit,
but that would only be a workaround for an issue with the driver, which could
cause undefined behaviour with real E1000 hardware as well.

** Affects: linux-meta (Ubuntu)
     Importance: Undecided
         Status: New

E1000 driver enables TSOv6 for hardware that doesn't support it
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