* [PATCH] docs: networking: Remove VLAN_TAG_PRESENT from openvswitch doc
@ 2025-01-29 16:06 Andreas Karis
2025-02-02 0:53 ` Jakub Kicinski
2025-02-02 20:55 ` Ilya Maximets
0 siblings, 2 replies; 3+ messages in thread
From: Andreas Karis @ 2025-01-29 16:06 UTC (permalink / raw)
To: linux-doc; +Cc: ak.karis, linux-kernel, davem, netdev, corbet
Since commit 0c4b2d370514cb4f3454dd3b18f031d2651fab73
("net: remove VLAN_TAG_PRESENT"), the kernel no longer sets the DEI/CFI
bit in __vlan_hwaccel_put_tag to indicate the presence of a VLAN tag.
Update the openvswitch documentation which still contained an outdated
reference to this mechanism.
Signed-off-by: Andreas Karis <ak.karis@gmail•com>
---
Documentation/networking/openvswitch.rst | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/Documentation/networking/openvswitch.rst b/Documentation/networking/openvswitch.rst
index 1a8353dbf1b6..5699bbadea47 100644
--- a/Documentation/networking/openvswitch.rst
+++ b/Documentation/networking/openvswitch.rst
@@ -230,11 +230,9 @@ an all-zero-bits vlan and an empty encap attribute, like this::
eth(...), eth_type(0x8100), vlan(0), encap()
Unlike a TCP packet with source and destination ports 0, an
-all-zero-bits VLAN TCI is not that rare, so the CFI bit (aka
-VLAN_TAG_PRESENT inside the kernel) is ordinarily set in a vlan
-attribute expressly to allow this situation to be distinguished.
-Thus, the flow key in this second example unambiguously indicates a
-missing or malformed VLAN TCI.
+all-zero-bits VLAN TCI is not that rare and the flow key in
+this second example cannot indicate a missing or malformed
+VLAN TCI.
Other rules
-----------
--
2.48.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] docs: networking: Remove VLAN_TAG_PRESENT from openvswitch doc 2025-01-29 16:06 [PATCH] docs: networking: Remove VLAN_TAG_PRESENT from openvswitch doc Andreas Karis @ 2025-02-02 0:53 ` Jakub Kicinski 2025-02-02 20:55 ` Ilya Maximets 1 sibling, 0 replies; 3+ messages in thread From: Jakub Kicinski @ 2025-02-02 0:53 UTC (permalink / raw) To: Andreas Karis; +Cc: linux-doc, linux-kernel, davem, netdev, corbet On Wed, 29 Jan 2025 17:06:25 +0100 Andreas Karis wrote: > Since commit 0c4b2d370514cb4f3454dd3b18f031d2651fab73 > ("net: remove VLAN_TAG_PRESENT"), the kernel no longer sets the DEI/CFI > bit in __vlan_hwaccel_put_tag to indicate the presence of a VLAN tag. > Update the openvswitch documentation which still contained an outdated > reference to this mechanism. Hi Andreas! Thanks for the fix! Could you please trim the commit ID to the customary 12 characters and repost with CC extended to include: - authors and reviewers of the cited commit; - ovs addresses from MAINTAINERS: pshelar@ovn•org, dev@openvswitch•org -- pw-bot: cr ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] docs: networking: Remove VLAN_TAG_PRESENT from openvswitch doc 2025-01-29 16:06 [PATCH] docs: networking: Remove VLAN_TAG_PRESENT from openvswitch doc Andreas Karis 2025-02-02 0:53 ` Jakub Kicinski @ 2025-02-02 20:55 ` Ilya Maximets 1 sibling, 0 replies; 3+ messages in thread From: Ilya Maximets @ 2025-02-02 20:55 UTC (permalink / raw) To: Andreas Karis, linux-doc Cc: linux-kernel, davem, netdev, corbet, Jakub Kicinski, Eric Dumazet, ovs-dev, i.maximets, Paolo Abeni On 1/29/25 17:06, Andreas Karis wrote: > Since commit 0c4b2d370514cb4f3454dd3b18f031d2651fab73 > ("net: remove VLAN_TAG_PRESENT"), the kernel no longer sets the DEI/CFI > bit in __vlan_hwaccel_put_tag to indicate the presence of a VLAN tag. > Update the openvswitch documentation which still contained an outdated > reference to this mechanism. > > Signed-off-by: Andreas Karis <ak.karis@gmail•com> > --- > Documentation/networking/openvswitch.rst | 8 +++----- > 1 file changed, 3 insertions(+), 5 deletions(-) > > diff --git a/Documentation/networking/openvswitch.rst b/Documentation/networking/openvswitch.rst > index 1a8353dbf1b6..5699bbadea47 100644 > --- a/Documentation/networking/openvswitch.rst > +++ b/Documentation/networking/openvswitch.rst > @@ -230,11 +230,9 @@ an all-zero-bits vlan and an empty encap attribute, like this:: > eth(...), eth_type(0x8100), vlan(0), encap() > > Unlike a TCP packet with source and destination ports 0, an > -all-zero-bits VLAN TCI is not that rare, so the CFI bit (aka > -VLAN_TAG_PRESENT inside the kernel) is ordinarily set in a vlan > -attribute expressly to allow this situation to be distinguished. > -Thus, the flow key in this second example unambiguously indicates a > -missing or malformed VLAN TCI. > +all-zero-bits VLAN TCI is not that rare and the flow key in > +this second example cannot indicate a missing or malformed > +VLAN TCI. Hi, Andreas. While mentioning of the VLAN_TAG_PRESENT bit is clearly outdated, I don't think the other parts of the paragraph should be changed. The openvswitch module is still using VLAN_CFI bit in the flow key extracted from the packet as an indicator of the vlan presence. See the parse_vlan() function in net/openvswitch/flow.c. And it's still required for userspace to have this bit set on the flow key for vlan packets to be correctly matched. So, while not directly set in the skb, this bit is still set in the flow key and that's how the flow key can still indicate a missing or malformed VLAN header. So, while the VLAN_TAG_PRESENT remark inside the parenthesis can be removed, the rest of the text should stay intact. Best regards, Ilya Maximets. ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2025-02-02 20:55 UTC | newest] Thread overview: 3+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2025-01-29 16:06 [PATCH] docs: networking: Remove VLAN_TAG_PRESENT from openvswitch doc Andreas Karis 2025-02-02 0:53 ` Jakub Kicinski 2025-02-02 20:55 ` Ilya Maximets
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