re-enable Ubuntu FAN in the Noble kernel

[Andrea Righi]

[Impact]

In LP: #2063298, we have opted to deprecate Ubuntu FAN support because of the maintenance overhead and the possibility of regressions / conflicts with the new networking eBPF APIs in kernels >= 6.8.

However, we cannot disable this feature in HWE/backport kernels, so it seems safer to adjust the Ubuntu FAN kernel patch set to ensure proper co-existence with the updated vxlan policy requirements in newer 6.8 kernels.

The re-introduction of Ubuntu FAN should be considered as a temporary measure, aimed at facilitating a smooth transition during its deprecation without disrupting existing users (specifically Juju), and enabling the backporting of 6.8 kernels to older releases.

The main plan is still to deprecate Ubuntu FAN in newer releases.

[Test case]

Rely on the specific Ubuntu FAN regression test to validate the proper kernel support of this feature:

https://git.launchpad.net/~canonical-kernel-team/+git/autotest-client-tests/tree/ubuntu_fan_smoke_test?h=autotest3

[Fix]

Re-apply the Ubuntu FAN patch set to the latest Noble kernel 6.8 and integrate the IFLA_VXLAN_FAN_MAP attribute type in vxlan_policy to satisfy the strict length validation check.

[Regression potential]

We may experience regressions with eBPF vxlan capabilities and potentially specific use cases of the Ubuntu FAN technology (Juju installations).

[Andrea Righi (arighi)]

Patch set to re-enable Ubuntu FAN in the 6.8 Noble kernel:
https://lists.ubuntu.com/archives/kernel-team/2024-May/150684.html

[Andrea Righi (arighi)]

Test result with the patch set applied (ubuntu_fan_smoke_test):

11:48:05 INFO | Writing results to /home/ubuntu/autotest/client/results/default
11:48:05 INFO | START ---- ---- timestamp=1714564085 localtime=May 01 11:48:05
11:48:05 INFO | START ubuntu_fan_smoke_test.setup ubuntu_fan_smoke_test.setup timeout=1200 timestamp=1714564085 localtime=May 01 11:48:05
11:48:07 INFO | GOOD ubuntu_fan_smoke_test.setup ubuntu_fan_smoke_test.setup timestamp=1714564087 localtime=May 01 11:48:07 completed successfully
11:48:07 INFO | END GOOD ubuntu_fan_smoke_test.setup ubuntu_fan_smoke_test.setup timestamp=1714564087 localtime=May 01 11:48:07
11:48:07 INFO | START ubuntu_fan_smoke_test.fan-smoke-test ubuntu_fan_smoke_test.fan-smoke-test timeout=1800 timestamp=1714564087 localtime=May 01 11:48:07
11:51:46 INFO | Testing Fan Networking (pre-0.13.0 API)
11:51:46 INFO | docker pull --platform linux/amd64 ubuntu: PASSED
11:51:46 INFO | enable disable fan test: PASSED
11:51:46 INFO | fanctl show test: PASSED
11:51:46 INFO | fanctl check bridge config test: PASSED
11:51:46 INFO | fanatic docker test(--dns=192.168.122.1): PASSED
11:51:47 INFO | GOOD ubuntu_fan_smoke_test.fan-smoke-test ubuntu_fan_smoke_test.fan-smoke-test timestamp=1714564307 localtime=May 01 11:51:47 completed successfully
11:51:47 INFO | END GOOD ubuntu_fan_smoke_test.fan-smoke-test ubuntu_fan_smoke_test.fan-smoke-test timestamp=1714564307 localtime=May 01 11:51:47
11:51:47 INFO | END GOOD ---- ---- timestamp=1714564307 localtime=May 01 11:51:47
11:51:47 INFO | Report successfully generated at /home/ubuntu/autotest/client/results/default/job_report.html

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux/6.8.0-38.38 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-noble-linux' to 'verification-done-noble-linux'. If the problem still exists, change the tag 'verification-needed-noble-linux' to 'verification-failed-noble-linux'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Simon Déziel (sdeziel)]

This -38.38 package fixed our cluster test that required FAN to be working. Marked as verified, thanks!

# uname -a
Linux n1 6.8.0-38-generic #38-Ubuntu SMP PREEMPT_DYNAMIC Fri Jun 7 15:25:01 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux-nvidia-lowlatency/6.8.0-1009.9.1 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-noble-linux-nvidia-lowlatency' to 'verification-done-noble-linux-nvidia-lowlatency'. If the problem still exists, change the tag 'verification-needed-noble-linux-nvidia-lowlatency' to 'verification-failed-noble-linux-nvidia-lowlatency'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 6.8.0-38.38

---------------
linux (6.8.0-38.38) noble; urgency=medium

  * noble/linux: 6.8.0-38.38 -proposed tracker (LP: #2068318)

  * race_sched in ubuntu_stress_smoke_test will cause kernel panic on 6.8 with
    Azure Standard_A2_v2 instance (LP: #2068024)
    - sched/eevdf: Prevent vlag from going out of bounds in reweight_eevdf()

  * Noble: btrfs: re-introduce 'norecovery' mount option (LP: #2068591)
    - btrfs: re-introduce 'norecovery' mount option

  * Fix system hang while entering suspend with AMD Navi3x graphics
    (LP: #2063417)
    - drm/amdgpu/mes: fix use-after-free issue

  * Noble update: v6.8.8 upstream stable release (LP: #2068087)
    - io_uring: Fix io_cqring_wait() not restoring sigmask on get_timespec64()
      failure
    - drm/i915/cdclk: Fix voltage_level programming edge case
    - Revert "vmgenid: emit uevent when VMGENID updates"
    - SUNRPC: Fix rpcgss_context trace event acceptor field
    - selftests/ftrace: Limit length in subsystem-enable tests
    - random: handle creditable entropy from atomic process context
    - scsi: core: Fix handling of SCMD_FAIL_IF_RECOVERING
    - net: usb: ax88179_178a: avoid writing the mac address before first reading
    - btrfs: do not wait for short bulk allocation
    - btrfs: zoned: do not flag ZEROOUT on non-dirty extent buffer
    - r8169: fix LED-related deadlock on module removal
    - r8169: add missing conditional compiling for call to r8169_remove_leds
    - scsi: ufs: qcom: Add missing interconnect bandwidth values for Gear 5
    - netfilter: nf_tables: Fix potential data-race in __nft_expr_type_get()
    - netfilter: nf_tables: Fix potential data-race in __nft_obj_type_get()
    - netfilter: br_netfilter: skip conntrack input hook for promisc packets
    - netfilter: nft_set_pipapo: constify lookup fn args where possible
    - netfilter: nft_set_pipapo: walk over current view on netlink dump
    - netfilter: flowtable: validate pppoe header
    - netfilter: flowtable: incorrect pppoe tuple
    - af_unix: Call manage_oob() for every skb in unix_stream_read_generic().
    - af_unix: Don't peek OOB data without MSG_OOB.
    - net: sparx5: flower: fix fragment flags handling
    - net/mlx5: Lag, restore buckets number to default after hash LAG deactivation
    - net/mlx5: Restore mistakenly dropped parts in register devlink flow
    - net/mlx5e: Prevent deadlock while disabling aRFS
    - net: change maximum number of UDP segments to 128
    - octeontx2-pf: fix FLOW_DIS_IS_FRAGMENT implementation
    - selftests/tcp_ao: Make RST tests less flaky
    - selftests/tcp_ao: Zero-init tcp_ao_info_opt
    - selftests/tcp_ao: Fix fscanf() call for format-security
    - selftests/tcp_ao: Printing fixes to confirm with format-security
    - net: stmmac: Apply half-duplex-less constraint for DW QoS Eth only
    - net: stmmac: Fix max-speed being ignored on queue re-init
    - net: stmmac: Fix IP-cores specific MAC capabilities
    - ice: tc: check src_vsi in case of traffic from VF
    - ice: tc: allow zero flags in parsing tc flower
    - ice: Fix checking for unsupported keys on non-tunnel device
    - tun: limit printing rate whe...

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux-gke/6.8.0-1006.9 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-noble-linux-gke' to 'verification-done-noble-linux-gke'. If the problem still exists, change the tag 'verification-needed-noble-linux-gke' to 'verification-failed-noble-linux-gke'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux-nvidia/6.8.0-1009.9 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-noble-linux-nvidia' to 'verification-done-noble-linux-nvidia'. If the problem still exists, change the tag 'verification-needed-noble-linux-nvidia' to 'verification-failed-noble-linux-nvidia'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux-ibm/6.8.0-1008.8 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-noble-linux-ibm' to 'verification-done-noble-linux-ibm'. If the problem still exists, change the tag 'verification-needed-noble-linux-ibm' to 'verification-failed-noble-linux-ibm'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux-hwe-6.8/6.8.0-38.38~22.04.1 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-jammy-linux-hwe-6.8' to 'verification-done-jammy-linux-hwe-6.8'. If the problem still exists, change the tag 'verification-needed-jammy-linux-hwe-6.8' to 'verification-failed-jammy-linux-hwe-6.8'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux-azure-6.8/6.8.0-1010.10~22.04.1 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-jammy-linux-azure-6.8' to 'verification-done-jammy-linux-azure-6.8'. If the problem still exists, change the tag 'verification-needed-jammy-linux-azure-6.8' to 'verification-failed-jammy-linux-azure-6.8'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux-lowlatency-hwe-6.8/6.8.0-38.38.1~22.04.2 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-jammy-linux-lowlatency-hwe-6.8' to 'verification-done-jammy-linux-lowlatency-hwe-6.8'. If the problem still exists, change the tag 'verification-needed-jammy-linux-lowlatency-hwe-6.8' to 'verification-failed-jammy-linux-lowlatency-hwe-6.8'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux-raspi-realtime/6.8.0-2006.6 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-noble-linux-raspi-realtime' to 'verification-done-noble-linux-raspi-realtime'. If the problem still exists, change the tag 'verification-needed-noble-linux-raspi-realtime' to 'verification-failed-noble-linux-raspi-realtime'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux-ibm-6.8/6.8.0-1008.8~22.04.1 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-jammy-linux-ibm-6.8' to 'verification-done-jammy-linux-ibm-6.8'. If the problem still exists, change the tag 'verification-needed-jammy-linux-ibm-6.8' to 'verification-failed-jammy-linux-ibm-6.8'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux-aws-6.8/6.8.0-1011.12~22.04.1 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-jammy-linux-aws-6.8' to 'verification-done-jammy-linux-aws-6.8'. If the problem still exists, change the tag 'verification-needed-jammy-linux-aws-6.8' to 'verification-failed-jammy-linux-aws-6.8'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux-nvidia-6.8/6.8.0-1009.9~22.04.1 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-jammy-linux-nvidia-6.8' to 'verification-done-jammy-linux-nvidia-6.8'. If the problem still exists, change the tag 'verification-needed-jammy-linux-nvidia-6.8' to 'verification-failed-jammy-linux-nvidia-6.8'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux-riscv/6.8.0-38.38.1 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-noble-linux-riscv' to 'verification-done-noble-linux-riscv'. If the problem still exists, change the tag 'verification-needed-noble-linux-riscv' to 'verification-failed-noble-linux-riscv'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux-oracle/6.8.0-1008.8 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-noble-linux-oracle' to 'verification-done-noble-linux-oracle'. If the problem still exists, change the tag 'verification-needed-noble-linux-oracle' to 'verification-failed-noble-linux-oracle'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux-riscv-6.8/6.8.0-38.38.1~22.04.1 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-jammy-linux-riscv-6.8' to 'verification-done-jammy-linux-riscv-6.8'. If the problem still exists, change the tag 'verification-needed-jammy-linux-riscv-6.8' to 'verification-failed-jammy-linux-riscv-6.8'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!