Re: [PATCH v15 09/13] tsc: Use the GUEST_TSC_FREQ MSR for discovering TSC frequency

Nikunj A. Dadhania
2025-01-02T05:10:20Z

On 1/1/2025 9:45 PM, Borislav Petkov wrote:
> On Wed, Jan 01, 2025 at 02:26:04PM +0530, Nikunj A. Dadhania wrote:
>> As kvm-clock would have set the callbacks, I need to point them to securetsc_get_tsc_khz().
>>
>> arch/x86/kernel/kvmclock.c: x86_platform.calibrate_tsc = kvm_get_tsc_khz;
>> arch/x86/kernel/kvmclock.c: x86_platform.calibrate_cpu = kvm_get_tsc_khz;
>>
>> For virtualized environments, I see that all of them are assigning the same functions to different function ptrs.
>
> So just because the others do it, you should do it too without even figuring
> out *why*?

Again: As kvm-clock has over-ridden both the callbacks, SecureTSC needs to override them with its own.

Regards,
Nikunj