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

Uwe Kleine-König
2024-12-04T16:43:12Z

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Hello Francesco,

On Wed, Nov 27, 2024 at 10:04:13PM +0200, Leon Romanovsky wrote:
> 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.

I wonder if you could test a firmware upgrade or the above patch. Would
be nice to know if there are still some things to do for us (= Debian
kernel team) here.

If everything is fine for you, I'd like to close this bug.

Best regards
Uwe

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