Note: This bug is displayed in read-only format because
the product is no longer active in Red Hat Bugzilla.
RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.
Created attachment 550811[details]
this file is generated by cmd "tcpdump -i switch -w host62_guest62_e1000_tso_on.dump"
Description of problem:
there is no packet longer than MTU when tso is on in e1000
Version-Release number of selected component (if applicable):
qemu-kvm-0.12.1.2-2.213.el6.x86_64
How reproducible:
100%
Steps to Reproduce:
1. boot a guest with e1000 nic and open tso on guest:
ethtool -K eth0 tso on
2. scp from guest to host
3. use tcpdump to capture the packets on host
tcpdump -i switch -w host62_guest62_e1000_tso_on.dump
4. analyze the result, there is no packet longer than MTU
wireshark host62_guest62_e1000_tso_on.dump
Actual results:
there is no packet longer than MTU
Expected results:
there are packets longer than MTU
Additional info:
1. virtio nic
rhel6.2 guest --> pass
2. e1000 nic
rhel6.2 guest --> Failed
(In reply to comment #0)
> Created attachment 550811[details]
> this file is generated by cmd "tcpdump -i switch -w
> host62_guest62_e1000_tso_on.dump"
>
> Description of problem:
> there is no packet longer than MTU when tso is on in e1000
>
> Version-Release number of selected component (if applicable):
> qemu-kvm-0.12.1.2-2.213.el6.x86_64
>
> How reproducible:
> 100%
>
> Steps to Reproduce:
> 1. boot a guest with e1000 nic and open tso on guest:
> ethtool -K eth0 tso on
>
> 2. scp from guest to host
>
> 3. use tcpdump to capture the packets on host
> tcpdump -i switch -w host62_guest62_e1000_tso_on.dump
>
> 4. analyze the result, there is no packet longer than MTU
> wireshark host62_guest62_e1000_tso_on.dump
>
> Actual results:
> there is no packet longer than MTU
>
> Expected results:
> there are packets longer than MTU
This is not the expected result, you can not get a packet larger than MTU even for a real e1000 card. The reason why virtio can is that it passes GSO packet to host directly.
>
> Additional info:
>
> 1. virtio nic
> rhel6.2 guest --> pass
>
> 2. e1000 nic
> rhel6.2 guest --> Failed
(In reply to comment #2)
> (In reply to comment #0)
> > Created attachment 550811[details]
> > this file is generated by cmd "tcpdump -i switch -w
> > host62_guest62_e1000_tso_on.dump"
> >
> > Description of problem:
> > there is no packet longer than MTU when tso is on in e1000
> >
> > Version-Release number of selected component (if applicable):
> > qemu-kvm-0.12.1.2-2.213.el6.x86_64
> >
> > How reproducible:
> > 100%
> >
> > Steps to Reproduce:
> > 1. boot a guest with e1000 nic and open tso on guest:
> > ethtool -K eth0 tso on
> >
> > 2. scp from guest to host
> >
> > 3. use tcpdump to capture the packets on host
> > tcpdump -i switch -w host62_guest62_e1000_tso_on.dump
Hi siyuan,
| autotest/client/tests/ethtool.py :(+125)
| logging.debug("Listen using command: %s", tcpdump_cmd)
| session2.sendline(tcpdump_cmd)
^^^^^^^ tcpdump is executed in guest, large packets would be cut by emulated e1000 nic (not guest protocol layer, TSO is enabled).
| if not virt_utils.wait_for(
| lambda:session.cmd_status("pgrep tcpdump") == 0, 30):
Please try to capture packets in guest.
Created attachment 550811 [details] this file is generated by cmd "tcpdump -i switch -w host62_guest62_e1000_tso_on.dump" Description of problem: there is no packet longer than MTU when tso is on in e1000 Version-Release number of selected component (if applicable): qemu-kvm-0.12.1.2-2.213.el6.x86_64 How reproducible: 100% Steps to Reproduce: 1. boot a guest with e1000 nic and open tso on guest: ethtool -K eth0 tso on 2. scp from guest to host 3. use tcpdump to capture the packets on host tcpdump -i switch -w host62_guest62_e1000_tso_on.dump 4. analyze the result, there is no packet longer than MTU wireshark host62_guest62_e1000_tso_on.dump Actual results: there is no packet longer than MTU Expected results: there are packets longer than MTU Additional info: 1. virtio nic rhel6.2 guest --> pass 2. e1000 nic rhel6.2 guest --> Failed