Red Hat Bugzilla – Bug 449175
E1000 driver enables TSOv6 for hardware that doesn't support it
Last modified: 2014-06-29 19:00:20 EDT
Description of problem:
Version-Release number of selected component (if applicable):
How reproducible: 100%
Steps to Reproduce:
1. Boot RHEL5.1 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.
Hits an ASSERT in the VMware hypervisor which triggers if TSO6 is attempted to
be used on the 82545EM emulated vNIC.
TSO6 should not be used for NICs that don't support it.
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.
Created attachment 308836 [details]
I didn't look at the sourceforge driver, but I see the error in the logic in
e1000_set_tso. This patch should do the trick.
If you get a chance to build a kernel and test it that would be great. If not
I will integrate it into my test kernels later this week and post a link to
them in this bugzilla when they are ready.
My test kernels have been updated to include a patch for this bugzilla.
Please test them and report back your results.
The patch looks good, and we'll give the new kernel a spin and let you know soon
on whether it fixes the problem. I fully expect it to fix the issue, but stay
Thanks for the quick turnaround!
is this bug resolved?
This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux maintenance release. Product Management has requested
further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed
products. This request is not yet committed for inclusion in an Update
I'm sure it does, but I never heard back. We'll get this in the next update.
Updating PM score.
You can download this test kernel from http://people.redhat.com/dzickus/el5
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to provide a comment indicating that this fix has been verified.
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
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