Page MenuHomeFreeBSD
Differential D52546

vtnet: deprecate loader tunable fixup_needs_csum
ClosedPublic
Actions

Authored by timo.voelker_fh-muenster.de on Sep 15 2025, 10:05 AM.
Tags
None
Referenced Files
Unknown Object (File)
Fri, Nov 14, 11:06 AM
Unknown Object (File)
Tue, Nov 11, 5:44 AM
Unknown Object (File)
Tue, Nov 11, 4:42 AM
Unknown Object (File)
Mon, Nov 10, 7:19 AM
Unknown Object (File)
Sat, Nov 1, 8:36 PM
Unknown Object (File)
Wed, Oct 29, 10:10 AM
Unknown Object (File)
Wed, Oct 29, 8:39 AM
Unknown Object (File)
Wed, Oct 29, 8:38 AM
View All 32 Files
Subscribers
imp
ziaee

Details

Reviewers
tuexen
kevans
markj
bryanv
jhb
vmaffione
Commits
rGa16c7286b5c4: vtnet: deprecate loader tunable fixup_needs_csum
rG28f2d9b86de5: vtnet: deprecate loader tunable fixup_needs_csum
rG5da388d93917: vtnet: deprecate loader tunable fixup_needs_csum
Summary

Deprecate loader tunable fixup_needs_csum of the vtnet interface.

If this tunable is enabled and vtnet receives a packet with VIRTIO_NET_HDR_F_NEEDS_CSUM set, vtnet computes the TCP/UDP checksum and writes it in the checksum field. This was somewhat useful in the time when vtnet pretended that such a packet has a correct checksum and set the mbuf flag CSUM_DATA_VALID. However, since D51686, this is not the case anymore.

Furthermore, the guest can avoid receiving packets with an incorrect checksum and VIRTIO_NET_HDR_F_NEEDS_CSUM set by disabling the feature VIRTIO_NET_F_GUEST_CSUM. With vtnet, this is possible by disabling RXCSUM on the interface.

Diff Detail

Repository
rG FreeBSD src repository
Lint
Lint Skipped
Unit
Tests Skipped

Event Timeline

timo.voelker_fh-muenster.de created this revision.Sep 15 2025, 10:05 AM
Herald added subscribers: ziaee, imp. · View Herald TranscriptSep 15 2025, 10:05 AM
timo.voelker_fh-muenster.de requested review of this revision.Sep 15 2025, 10:05 AM
tuexen added inline comments.Sep 15 2025, 11:55 AM
share/man/man4/vtnet.4
87

I guess you want something like

This tunable is deprecated and will be removed in
.Fx 16 .
timo.voelker_fh-muenster.de updated this revision to Diff 162143.Sep 16 2025, 12:31 PM

Addressed comment from @tuexen

timo.voelker_fh-muenster.de marked an inline comment as done.Sep 16 2025, 12:32 PM
timo.voelker_fh-muenster.de added inline comments.
share/man/man4/vtnet.4
87

Yes, that's probably better. Thanks!

tuexen accepted this revision.Sep 16 2025, 9:37 PM
This revision is now accepted and ready to land.Sep 16 2025, 9:37 PM
Closed by commit rG5da388d93917: vtnet: deprecate loader tunable fixup_needs_csum (authored by timo.voelker_fh-muenster.de, committed by tuexen). · Explain WhySep 16 2025, 9:44 PM
This revision was automatically updated to reflect the committed changes.
tuexen added a commit: rG5da388d93917: vtnet: deprecate loader tunable fixup_needs_csum.
tuexen added a commit: rG28f2d9b86de5: vtnet: deprecate loader tunable fixup_needs_csum.Sep 22 2025, 7:24 PM
tuexen added a commit: rGa16c7286b5c4: vtnet: deprecate loader tunable fixup_needs_csum.Sep 22 2025, 7:31 PM

Revision Contents
Changeset List

PathSize
share/
man/
man4/
2 lines

Diff 162143

View Options

share/man/man4/vtnet.4

Loading...