Bug 2165879 - [openvswitch] DPDK interfaces dp-packet headroom and data buffer can't be dynamically adjusted
Summary: [openvswitch] DPDK interfaces dp-packet headroom and data buffer can't be dyn...
Keywords:
Status: NEW
Alias: None
Product: Red Hat Enterprise Linux Fast Datapath
Classification: Red Hat
Component: openvswitch
Version: FDP 18.04
Hardware: All
OS: All
unspecified
low
Target Milestone: ---
: ---
Assignee: David Marchand
QA Contact: qding
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2023-01-31 10:55 UTC by David Marchand
Modified: 2023-07-13 07:25 UTC (History)
3 users (show)

Fixed In Version:
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System ID Private Priority Status Summary Last Updated
Red Hat Issue Tracker FD-2658 0 None None None 2023-01-31 10:55:54 UTC

Description David Marchand 2023-01-31 10:55:14 UTC
This is kind of a theoretical issue.

DPDK based dp-packets points to data buffers that can't be expanded dynamically.
One potential issue would be when encapsulating a packet received from a DPDK interface, and require more than 128 bytes of headroom.
In such a setup, OVS would hit an assert when trying to expand this dp-packet (in dp_packet_resize()).

This can be reproduced with 3 levels of vxlan tunnels, for example.

Comment 1 David Marchand 2023-01-31 10:56:24 UTC
One fix has been posted upstream but still needs some work (adding a unit test): https://patchwork.ozlabs.org/project/openvswitch/patch/20220318153339.31083-1-david.marchand@redhat.com/


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