Re: [PATCH v7 2/6] Documentation/kernel-parameters: Add multi-device config_acs example

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The documentation incorrectly advises using single quotes around the `pci=config_acs=...` parameter, which the kernel's command-line parser does not strip, potentially causing the parameter to be silently ignored.
--

commit e6c4062a908e58f90ebe300f02b6a7483906b994
Author: Wei Wang <wei.w.wang@hotmail.com>

Documentation/kernel-parameters: Add multi-device config_acs example

This commit adds an example to the kernel parameters documentation for
configuring ACS settings for multiple PCI devices. It also adds a note
recommending quoting the parameter to prevent bootloaders from misinterpreting
the semicolon separator.

> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
[ ... ]
>  				Note: this may remove isolation between devices
>  				and may put more devices in an IOMMU group.
> +				- 'pci=config_acs=10x@0000:04:00.0;1x101@0000:84:00.0'

Will the kernel's command-line parser correctly handle single quotes here?

Looking at next_arg() in lib/cmdline.c, the kernel explicitly detects and
strips double quotes ("), but it treats single quotes (') as literal text
characters.

If a bootloader passes the quoted string verbatim to the kernel, the parameter
will be extracted as 'pci rather than pci. This will fail the early_param()
check for "pci", causing the ACS configuration to be silently ignored.

Should the documentation recommend using double quotes instead?
(e.g., "- "pci=config_acs=..."")

> +				configures two devices with different ACS settings.
> +				Note: Some bootloaders interpret ';' as a command
> +				separator. If so, quote the entire parameter to
> +				ensure it is passed to the kernel unchanged.
> +

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/SI2PR01MB439385689A32A1DDA9CEABE1DC3F2@SI2PR01MB4393.apcprd01.prod.exchangelabs.com?part=2