Re: [PATCH 1/1] Drivers: hv: vmbus: Fail VMBus module init for non-nested root partition

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Returning -ENODEV in the root partition prevents the hv_vmbus module from loading, which breaks the loading of the mshv_root module when both are configured as loadable modules.
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--- Patch [1]: [PATCH 1/1] Drivers: hv: vmbus: Fail VMBus module init for non-nested root partition ---
commit 49405a084beb024e2ba8a360ff4836611b21617d
Author: Michael Kelley <mhkelley58@gmail.com>

Drivers: hv: vmbus: Fail VMBus module init for non-nested root partition

This commit changes the VMBus module initialization to return -ENODEV instead
of 0 when running directly in the root partition and not nested. This is
intended to prevent the module from successfully loading and later causing
memory faults or a panic during unload when resources were never initialized.

Closes: https://lore.kernel.org/linux-hyperv/20260721154943.A09BD1F00A3D@smtp.kernel.org/

> diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
> index 6824bd7cb3c4f..7d5021ceea84f 100644
> --- a/drivers/hv/vmbus_drv.c
> +++ b/drivers/hv/vmbus_drv.c
> @@ -2982,7 +2982,7 @@ static int __init hv_acpi_init(void)
>  		return -ENODEV;
>  
>  	if (hv_root_partition() && !hv_nested)
> -		return 0;
> +		return -ENODEV;

[Severity: High]
Does returning -ENODEV here break dependent modules when both are built as
loadable modules?

If the VMBus initialization returns an error on a non-nested root partition,
the hv_vmbus module will fail to load and its symbols (like hv_vmbus_exists())
will not be exported.

This would prevent the mshv_root module from loading on the root partition
since it depends on those exported symbols, completely breaking mshv_root
functionality in its only intended environment.

>  
>  	/*
>  	 * Get ACPI resources first.

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Sashiko AI review · https://sashiko.dev/#/patchset/20260804190517.101981-1-mhklinux@outlook.com?part=1