Re: [PATCH v2 3/5] intel_idle: Sync up the SPEC_CTRL MSR value to x86_spec_ctrl_current

From: Peter Zijlstra
Date: Wed Jun 21 2023 - 03:39:08 EST


On Tue, Jun 20, 2023 at 10:06:23AM -0400, Waiman Long wrote:
> When intel_idle_ibrs() is called, it modifies the SPEC_CTRL MSR to 0
> in order disable IBRS. However, the new MSR value isn't reflected in
> x86_spec_ctrl_current. That will cause the new spec_ctrl_msrs debugfs
> file to show incorrect result. Fix that by updating x86_spec_ctrl_current
> percpu value to always match the content of the SPEC_CTRL MSR.

What debugfs file?