On 2026/6/16 3:12, Stephen Hemminger wrote:
On Fri, 12 Jun 2026 16:14:11 +0800
Xingui Yang <[email protected]> wrote:
The tx_vlan set command currently only accepts a VLAN ID in range
[0, 4095]. This patch adds support for an extended format that includes
802.1p priority and CFI bits, allowing users to set the VLAN priority
tag when inserting VLAN headers in TX packets.
The extended format is:
bit 0-11: VLAN ID (0-4095)
bit 12: CFI (Canonical Format Indicator)
bit 13-15: Priority (0-7, 802.1p CoS)
This is consistent with the VLAN tag structure used by
rte_eth_dev_set_vlan_pvid() where the PVID field encodes VLAN ID, CFI
and priority in the same format.
A new command line option --enable-vlan-priority is added to enable this
feature. By default, the feature is disabled to maintain backward
compatibility with existing users. When enabled, the
vlan_id_is_invalid() function allows any 16-bit value to pass, while the
full 16-bit value (including CFI and priority bits) is passed to the
driver for hardware VLAN insertion.
Signed-off-by: Xingui Yang <[email protected]>
---
Having ability to set priority bits is good, and testpmd should allow it.
The mbuf vlan_tci is already a full 16-bit TCI (priority/CFI/VID), and
the TX insert path copies tx_vlan_id straight into it. So priority
insert already works; the only thing in the way is the < 4096 check.
Do you actually need a new option for this? Both of_push_vlan +
of_set_vlan_pcp (rte_flow) and "tx_vlan set pvid" already let you set
the priority bits today, with no new code.
If you still want "tx_vlan set" itself to carry priority, I'd suggest
a smaller change: relax only the TX insert validators and drop the
option and the global. Don't touch rx_vft_set -- it feeds the VLAN
filter, which only takes a VLAN ID and rejects > 4095 anyway, so the
flag just turns a clear error into a confusing one.
Either way, if the option stays, please document it, and add a release note.
The commit message why the existing paths aren't enough.
Thank you for the suggestion. I have implemented the simpler approach in v2.
Thanks,
Xingui
