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config-wsl: CONFIG_INFINIBAND disabled in 6.18.58.1 kernel, breaking RDMA and Soft-RoCE #42255
Description
Windows Version
Microsoft Windows [Version 10.0.26200.9911]
WSL Version
3.0.5.0
Are you using WSL 1, WSL 2, or WSLC?
- WSL 2
- WSL 1
- WSLC
Kernel Version
6.18.58.1-microsoft-standard-WSL2
Distro Version
Ubuntu 24.04.5 LTS (Noble Numbat)
Other Software
rdma-core 50.0-2ubuntu0.2
iproute2 6.1.0-1ubuntu6.4
Repro Steps
-
Install or update to WSL 3.0.5.0, which includes kernel 6.18.58.1.
-
Start a WSL 2 distribution.
-
Run:
uname -r grep '^CONFIG_INFINIBAND=' /boot/config-$(uname -r) modinfo rdma_rxe
-
Compare the WSL kernel configurations:
The 6.18.33.2 configuration contains CONFIG_INFINIBAND=m. In 6.18.58.1 it was changed to # CONFIG_INFINIBAND is not set.
Expected Behavior
The WSL kernel should retain CONFIG_INFINIBAND=m, as it did in kernel 6.18.33.2, so RDMA applications and ABI-matched external RDMA modules can work.
It would also be useful for the standard WSL kernel to provide CONFIG_RDMA_RXE=m for Soft-RoCE support.
Actual Behavior
WSL 3.0.5.0 uses kernel 6.18.58.1, where CONFIG_INFINIBAND is disabled.
As a result, the InfiniBand/RDMA core is unavailable and Soft-RoCE cannot be used. rdma_rxe is not included in the standard kernel, and an external ABI-matched RXE module cannot load without the required RDMA core support.
This worked with our previous WSL environment based on kernel 6.18.33.2, where CONFIG_INFINIBAND=m was enabled.
Diagnostic Logs
Current output:
WSL version: 3.0.5.0
Kernel version: 6.18.58.1-1
Windows version: 10.0.26200.9911
Distribution: Ubuntu 24.04.5 LTS
$ uname -r
6.18.58.1-microsoft-standard-WSL2
$ grep '^CONFIG_INFINIBAND=' /boot/config-$(uname -r)
<no output; option is unset>
$ modinfo rdma_rxe
modinfo: ERROR: Module rdma_rxe not found.
The upstream config-wsl files linked in the reproduction steps show the configuration regression directly.
Activity
github-actions commentedon Nov 12, 2026
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sbenmelech commentedon Nov 12, 2026
This is critical for Azure Boost next Gen (Overlake 4) as currently we work purely on simulators based on WSL and have no other way to develop / test without RXE support.
OneBlue commentedon Nov 12, 2026
Mitchell Levy (@chessturo): Can we bring this back in the next kernel (potentially as module) ?
sbenmelech commentedon Nov 13, 2026
Hi Blue (@OneBlue) , Mitchell Levy (@chessturo) , Sorry to nudge but it seems some of our devboxes started to get WSL updates and now blocking development (or forcing to downgrade every other day).
Is there a way to expedite this?
Thanks!
Ziy1-Tan commentedon Nov 15, 2026
Restoring
CONFIG_INFINIBAND(this issue) does not give Soft-RoCE.CONFIG_RDMA_RXEhas never been set in any WSL kernel, somodprobe rdma_rxefails withModule rdma_rxe not found.Requested in
arch/x86/configs/config-wsl:No new dependency chain:
INET,PCI,NET_UDP_TUNNELare already set,INFINIBAND_VIRT_DMAcomes with IB core. Ship the.koinartifacts.vhdtoo.