[PATCH net] selftests: drv-net: rss_ctx: fix persist tests skip on IPv6 setups

[PATCH net] selftests: drv-net: rss_ctx: fix persist tests skip on IPv6 setups

[Gal Pressman]

test_rss_context_persist_ifupdown() cycles the interface down/up and
pings the remote host before verifying the contexts survived.

When using IPv6, the down operation deletes the configured IPv6 address
(default keep_addr_on_down=0) and nothing restores it after the up, so
all ping attempts fail and both tests skip with "Cannot reach remote
host after interface up".

Set the interface's keep_addr_on_down sysctl around the flap to retain
the address.

Fixes: ce5a0f4612db ("selftests: drv-net: rss_ctx: test RSS contexts persist after ifdown/up")
Reviewed-by: Nimrod Oren <noren@nvidia.com>
Signed-off-by: Gal Pressman <gal@nvidia.com>
---
Disclaimer: I'm not sure if this should go to net or net-next.
---
 tools/testing/selftests/drivers/net/hw/rss_ctx.py | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/tools/testing/selftests/drivers/net/hw/rss_ctx.py b/tools/testing/selftests/drivers/net/hw/rss_ctx.py
index f36f76d6ca59..eeea2fb292ac 100755
--- a/tools/testing/selftests/drivers/net/hw/rss_ctx.py
+++ b/tools/testing/selftests/drivers/net/hw/rss_ctx.py
@@ -938,6 +938,13 @@ def test_rss_context_persist_ifupdown(cfg, pre_down=False):
     ethtool(f"-X {cfg.ifname} equal 2")
     defer(ethtool, f"-X {cfg.ifname} default")
 
+    # IPv6 addresses are deleted on admin down and not restored on up
+    knob = f"net/ipv6/conf/{cfg.ifname}/keep_addr_on_down"
+    probe = cmd(f"sysctl -n {knob}", fail=False)
+    if probe.ret == 0:
+        cmd(f"sysctl -qw {knob}=1")
+        defer(cmd, f"sysctl -qw {knob}={probe.stdout.strip()}")
+
     ifup = defer(ip, f"link set dev {cfg.ifname} up")
     if pre_down:
         ip(f"link set dev {cfg.ifname} down")
-- 
2.54.0

Re: [PATCH net] selftests: drv-net: rss_ctx: fix persist tests skip on IPv6 setups

[Bobby Eshleman]

On Wed, Jul 22, 2026 at 03:38:44PM +0300, Gal Pressman wrote:
> test_rss_context_persist_ifupdown() cycles the interface down/up and
> pings the remote host before verifying the contexts survived.
> 
> When using IPv6, the down operation deletes the configured IPv6 address
> (default keep_addr_on_down=0) and nothing restores it after the up, so
> all ping attempts fail and both tests skip with "Cannot reach remote
> host after interface up".
> 
> Set the interface's keep_addr_on_down sysctl around the flap to retain
> the address.
> 
> Fixes: ce5a0f4612db ("selftests: drv-net: rss_ctx: test RSS contexts persist after ifdown/up")
> Reviewed-by: Nimrod Oren <noren@nvidia.com>
> Signed-off-by: Gal Pressman <gal@nvidia.com>
> ---
> Disclaimer: I'm not sure if this should go to net or net-next.
> ---
>  tools/testing/selftests/drivers/net/hw/rss_ctx.py | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/tools/testing/selftests/drivers/net/hw/rss_ctx.py b/tools/testing/selftests/drivers/net/hw/rss_ctx.py
> index f36f76d6ca59..eeea2fb292ac 100755
> --- a/tools/testing/selftests/drivers/net/hw/rss_ctx.py
> +++ b/tools/testing/selftests/drivers/net/hw/rss_ctx.py
> @@ -938,6 +938,13 @@ def test_rss_context_persist_ifupdown(cfg, pre_down=False):
>      ethtool(f"-X {cfg.ifname} equal 2")
>      defer(ethtool, f"-X {cfg.ifname} default")
>  
> +    # IPv6 addresses are deleted on admin down and not restored on up
> +    knob = f"net/ipv6/conf/{cfg.ifname}/keep_addr_on_down"
> +    probe = cmd(f"sysctl -n {knob}", fail=False)
> +    if probe.ret == 0:
> +        cmd(f"sysctl -qw {knob}=1")
> +        defer(cmd, f"sysctl -qw {knob}={probe.stdout.strip()}")
> +
>      ifup = defer(ip, f"link set dev {cfg.ifname} up")
>      if pre_down:
>          ip(f"link set dev {cfg.ifname} down")
> -- 
> 2.54.0
> 

Makes sense to me.

Reviewed-by: Bobby Eshleman <bobbyeshleman@meta.com>

Re: [PATCH net] selftests: drv-net: rss_ctx: fix persist tests skip on IPv6 setups

[Jakub Kicinski]

On Wed, 22 Jul 2026 15:38:44 +0300 Gal Pressman wrote:
> test_rss_context_persist_ifupdown() cycles the interface down/up and
> pings the remote host before verifying the contexts survived.

This is expected to be configured on the system where tests run, without
sprinkling it in every tests. See the env setup scripts in NIPA repo for
example.
-- 
pw-bot: reject