[PATCH ethtool-next v3] rxclass: Make output for RSS context action explicit

[PATCH ethtool-next v3] rxclass: Make output for RSS context action explicit

[Daniel Xu]

Currently `ethtool -n` prints out misleading output if the action for an
ntuple rule is to redirect to an RSS context. For example:

    # ethtool -X eth0 hfunc toeplitz context new start 24 equal 8
    New RSS context is 1

    # ethtool -N eth0 flow-type ip6 dst-ip $IP6 context 1
    Added rule with ID 0

    # ethtool -n eth0 rule 0
    Filter: 0
            Rule Type: Raw IPv6
            Src IP addr: :: mask: ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff
            Dest IP addr: <redacted> mask: ::
            Traffic Class: 0x0 mask: 0xff
            Protocol: 0 mask: 0xff
            L4 bytes: 0x0 mask: 0xffffffff
            RSS Context ID: 1
            Action: Direct to queue 0

The above output suggests that the HW will direct to queue 0 where in
reality queue 0 is just the base offset from which the redirection table
lookup in the RSS context is added to.

Fix by making output more clear. Also suppress base offset queue for the
common case of 0. Example of new output:

    # ./ethtool -n eth0 rule 0
    Filter: 0
            Rule Type: Raw IPv6
            Src IP addr: :: mask: ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff
            Dest IP addr: <redacted> mask: ::
            Traffic Class: 0x0 mask: 0xff
            Protocol: 0 mask: 0xff
            L4 bytes: 0x0 mask: 0xffffffff
            Action: Direct to RSS context id 1

Reviewed-by: Edward Cree <ecree.xilinx@gmail.com>
Tested-by: Joe Damato <jdamato@fastly.com>
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
---
Changes from v2:
* Change capitalization and formatting

Changes from v1:
* Fix compile error
* Add queue base offset

 rxclass.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/rxclass.c b/rxclass.c
index f17e3a5..1e202cc 100644
--- a/rxclass.c
+++ b/rxclass.c
@@ -248,13 +248,17 @@ static void rxclass_print_nfc_rule(struct ethtool_rx_flow_spec *fsp,
 
 	rxclass_print_nfc_spec_ext(fsp);
 
-	if (fsp->flow_type & FLOW_RSS)
-		fprintf(stdout, "\tRSS Context ID: %u\n", rss_context);
-
 	if (fsp->ring_cookie == RX_CLS_FLOW_DISC) {
 		fprintf(stdout, "\tAction: Drop\n");
 	} else if (fsp->ring_cookie == RX_CLS_FLOW_WAKE) {
 		fprintf(stdout, "\tAction: Wake-on-LAN\n");
+	} else if (fsp->flow_type & FLOW_RSS) {
+		u64 queue = ethtool_get_flow_spec_ring(fsp->ring_cookie);
+
+		fprintf(stdout, "\tAction: Direct to RSS Context %u", rss_context);
+		if (queue)
+			fprintf(stdout, " (queue base offset: %llu)", queue);
+		fprintf(stdout, "\n");
 	} else {
 		u64 vf = ethtool_get_flow_spec_ring_vf(fsp->ring_cookie);
 		u64 queue = ethtool_get_flow_spec_ring(fsp->ring_cookie);
-- 
2.46.0

Re: [PATCH ethtool-next v3] rxclass: Make output for RSS context action explicit

[Jakub Kicinski]

On Tue, 12 Nov 2024 18:45:43 -0700 Daniel Xu wrote:
>     # ./ethtool -n eth0 rule 0
>     Filter: 0
>             Rule Type: Raw IPv6
>             Src IP addr: :: mask: ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff
>             Dest IP addr: <redacted> mask: ::
>             Traffic Class: 0x0 mask: 0xff
>             Protocol: 0 mask: 0xff
>             L4 bytes: 0x0 mask: 0xffffffff
>             Action: Direct to RSS context id 1

Acked-by: Jakub Kicinski <kuba@kernel.org>

Re: [PATCH ethtool-next v3] rxclass: Make output for RSS context action explicit

[Edward Cree]

On 13/11/2024 01:45, Daniel Xu wrote:
> Fix by making output more clear. Also suppress base offset queue for the
> common case of 0. Example of new output:
> 
>     # ./ethtool -n eth0 rule 0
>     Filter: 0
>             Rule Type: Raw IPv6
>             Src IP addr: :: mask: ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff
>             Dest IP addr: <redacted> mask: ::
>             Traffic Class: 0x0 mask: 0xff
>             Protocol: 0 mask: 0xff
>             L4 bytes: 0x0 mask: 0xffffffff
>             Action: Direct to RSS context id 1

Commit comment hasn't been updated to match the current patch.