On Thu, Sep 4, 2025 at 11:40 PM Jim Fehlig <[email protected]> wrote:
> 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.
>
>
Hello Jim,
Thanks for the feedback,
I realized that the commit description is wrong wrt to the actual code, my
bad.
I propose the let the discussions continue in this thread to gather all the
feedbacks but ultimately I will need to submit a v2
So here is the updated commit message:
This commit introduces following changes:
- install modules-load file for msr
this is only enabled:
- On x86 arch
- the file installation is enabled by default, it can be disabled via
a build option:
meson -Dmsr_module_load=false build
> 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
>
>
--
Hector CAO
Software Engineer – Partner Engineering Team
[email protected]
https://launc <https://launchpad.net/~hectorcao>hpad.net/~hectorcao
<https://launchpad.net/~hectorcao>
<https://launchpad.net/~hectorcao>
