Re: Bug#1086520: linux-image-6.11.2-amd64: makes opensm fail to start

Leon Romanovsky
2024-11-27T20:04:50Z

On Wed, Nov 27, 2024 at 06:48:03PM +0100, Francesco Poli wrote:
> On Mon, 25 Nov 2024 21:38:37 +0200 Leon Romanovsky wrote:
>
> > On Mon, Nov 25, 2024 at 07:54:43PM +0100, Francesco Poli wrote:
> [...]
> > > I will try to continue to bisect by testing the resulting kernels on a
> > > compute node: there's no OpenSM there and it cannot run anyway, if
> > > there's another OpenSM on the same InfiniBand network.
> > > However, I can check whether those issm* symlinks are created in
> > > /sys/class/infiniband_mad/
> > > I really hope that this is enough to pinpoint the first bad
> > > commit...
> >
> > Yes, these symlinks should be there. Your test scenario is correct one.
>
> OK, I have completed the bisect on a compute node without OpenSM, by
> looking at the issm* symlinks, as I said.
>
> See below.
>
> >
> > >
> > > Any better ideas?
> >
> > I think that commit: 2a5db20fa532 ("RDMA/mlx5: Add support to multi-plane device and port")
> > is the one which is causing to troubles, which leads me to suspect FW.
> [...]
>
> Thanks to your guess about the possibly troublesome commit, the bisect was completed in a few steps:
>
> $ git checkout 2a5db20fa532
> $ make -j 12 my_defconfig bindeb-pkg
>
> [install this version on a compute node test image and reboot
> one compute node with that image: the InfiniBand network was
> working for that node, that's no surprise, since OpenSM was running
> on the head node, but no issm* symlink was created; please note
> that, surprisingly, the Ethernet network was not working, I mean
> that the Ethernet interfaces were not found by the kernel...]
>
> root@node # ls -altrF /sys/class/infiniband_mad/
> total 0
> drwxr-xr-x 60 root root 0 Nov 26 17:06 ../
> lrwxrwxrwx 1 root root 0 Nov 26 17:06 umad0 -> ../../devices/pci0000:00/0000:00:01.1/0000:01:00.0/infiniband_mad/umad0/
> -r--r--r-- 1 root root 4096 Nov 26 17:06 abi_version
> lrwxrwxrwx 1 root root 0 Nov 26 17:06 umad1 -> ../../devices/pci0000:00/0000:00:01.1/0000:01:00.1/infiniband_mad/umad1/
> drwxr-xr-x 2 root root 0 Nov 26 17:08 ./
>
> $ git bisect bad
> Bisecting: 0 revisions left to test after this (roughly 0 steps)
> [65528cfb21fdb68de8ae6dccae19af180d93e143] net/mlx5: mlx5_ifc update for multi-plane support
> $ make -j 12 my_defconfig bindeb-pkg
>
> [install this version on the compute node test image and reboot
> one compute node with that image: the InfiniBand network again
> working for that node, issm* symlinks were created;
> Ethernet network again not working for that node...]
>
> root@node # ls -altrF /sys/class/infiniband_mad/
> total 0
> drwxr-xr-x 60 root root 0 Nov 26 17:31 ../
> lrwxrwxrwx 1 root root 0 Nov 26 17:31 umad0 -> ../../devices/pci0000:00/0000:00:01.1/0000:01:00.0/infiniband_mad/umad0/
> -r--r--r-- 1 root root 4096 Nov 26 17:31 abi_version
> lrwxrwxrwx 1 root root 0 Nov 26 17:31 umad1 -> ../../devices/pci0000:00/0000:00:01.1/0000:01:00.1/infiniband_mad/umad1/
> lrwxrwxrwx 1 root root 0 Nov 26 17:36 issm1 -> ../../devices/pci0000:00/0000:00:01.1/0000:01:00.1/infiniband_mad/issm1/
> lrwxrwxrwx 1 root root 0 Nov 26 17:36 issm0 -> ../../devices/pci0000:00/0000:00:01.1/0000:01:00.0/infiniband_mad/issm0/
> drwxr-xr-x 2 root root 0 Nov 26 17:36 ./
>
> $ git bisect good
> 2a5db20fa532198639671713c6213f96ff285b85 is the first bad commit
> commit 2a5db20fa532198639671713c6213f96ff285b85
> Author: Mark Zhang <markzhang@nvidia.com>
> Date: Sun Jun 16 19:08:35 2024 +0300
>
> RDMA/mlx5: Add support to multi-plane device and port
>
> When multi-plane is supported, a logical port, which is aggregation of
> multiple physical plane ports, is exposed for data transmission.
> Compared with a normal mlx5 IB port, this logical port supports all
> functionalities except Subnet Management.
>
> Signed-off-by: Mark Zhang <markzhang@nvidia.com>
> Link: https://lore.kernel.org/r/7e37c06c9cb243be9ac79930cd17053903785b95.1718553901.git.leon@kernel.org
> Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
>
> drivers/infiniband/hw/mlx5/main.c | 60 +++++++++++++++++++++----
> drivers/infiniband/hw/mlx5/mlx5_ib.h | 2 +
> drivers/net/ethernet/mellanox/mlx5/core/vport.c | 1 +
> include/linux/mlx5/driver.h | 1 +
> 4 files changed, 55 insertions(+), 9 deletions(-)
>
>
> In other words, bingo!, your guess looks correct, the first bad commit
> is the one you mentioned.
>
>
> Now, I will try to upgrade the firmware of the InfiniBand NICs, as you
> suggested, and check whether this solves the issue with the recent
> Linux kernel versions.
>
> Please confirm that the procedure to be followed is the one described in
> <https://docs.nvidia.com/networking/display/ubuntu2204/firmware+burning>

Yes, it looks correct procedure.
If you didn't upgrade FW, this diff will achieve same result for you:

diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
index c2314797afc9..110ce177c305 100644
--- a/drivers/infiniband/hw/mlx5/main.c
+++ b/drivers/infiniband/hw/mlx5/main.c
@@ -2846,7 +2846,7 @@ static int mlx5_ib_get_plane_num(struct mlx5_core_dev *mdev, u8 *num_plane)
if (err)
return err;

- *num_plane = vport_ctx.num_plane;
+ *num_plane = (vport_ctx.num_plane > 1) ? vport_ctx.num_plane : 0;
return 0;
}

The culprit of your issue that in some FW versions, the vport_ctx.num_plane
was 1 and not 0 for devices which don't support that mode, while for the driver
everything that is not 0 means supported.

Thanks

>
> Thanks for your time and patience, and for all the help you are kindly
> providing! :-)
>
>
> --
> http://www.inventati.org/frx/
> There's not a second to spare! To the laboratory!
> ..................................................... Francesco Poli .
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