Re: [PATCH v2 1/5] x86/speculation: Provide a debugfs file to dump SPEC_CTRL MSRs

From: Waiman Long
Date: Wed Jun 21 2023 - 10:07:46 EST



On 6/21/23 04:24, Borislav Petkov wrote:
On Wed, Jun 21, 2023 at 09:41:05AM +0200, Peter Zijlstra wrote:
On Tue, Jun 20, 2023 at 10:06:21AM -0400, Waiman Long wrote:
Sometimes it is useful to know the states the SPEC_CTRL MSRs to see what
mitigations are enabled at run time. Provide a new x86/spec_ctrl_msrs
debugfs file to dump the cached versions of the current SPEC_CTRL MSRs.

Pff, clearly I can't even read email anymore..

We don't do this for any of the other MSRs, so why start now?
Hell no.

There's /sys/devices/system/cpu/vulnerabilities/ for that.

We are abstracting MSRs away from APIs - not do the backwards thing.

OK, as I have said. This is not central to the main purpose of this patch series. It is mostly there for verification purpose. I can certainly take this out.

Cheers,
Longman