On 9/3/25 06:49, Hector Cao wrote:
> On recent Intel CPUs, some of the CPU features (mostly
> vmx-* subfeatures) are listed and controlled via the
> MSRs (Model Specific Registers) instead of the traditional
> CPUID instruction method.
>
> To be able to read the MSR's values, the kernel module msr
> has to be loaded and the values can be read via /dev/cpu/*/msr.
>
> This commit introduces following changes:
>
> - install modules-load file for msr
>    this is only enabled:
>     - On x86 arch
>     - If user asks for it explicitly via a build option:
>       meson -Dmsr_module_load=true build
>       By default, it is disabled.

Thanks for the build option, and having it disabled by default! Some distros or
distro flavors may not want this functionality.

Also, AFAIK it's only needed for the qemu driver. If libvirt is built with
support for multiple hypervisors, the file will be installed on those
deployments too. E.g. it would needlessly be installed on a Xen deployment when
libvirt is built with '-Ddriver_qemu=enabled -Ddriver_libxl=enabled
-Dmsr_module_load=true'.

Regards,
Jim