Re: [PATCH v16 12/13] x86/tsc: Switch to native sched clock

[Nikunj A. Dadhania]

On 1/8/2025 10:32 PM, Sean Christopherson wrote:
> On Wed, Jan 08, 2025, Borislav Petkov wrote:
>> On Wed, Jan 08, 2025 at 06:00:59AM -0800, Sean Christopherson wrote:

> For TDX guests, the TSC is _always_ "secure".  So similar to singling out kvmclock,
> handling SNP's STSC but not the TDX case again leaves the kernel in an inconsistent
> state.  Which is why I originally suggested[*] fixing the sched_clock mess in a
> generically; 
> doing so would avoid the need to special case SNP or TDX in code> that doesn't/shouldn't care about SNP or TDX.

That is what I have attempted in this patch[1] where irrespective of SNP/TDX, whenever
TSC is picked up as a clock source, sched-clock will start using TSC instead of any
PV sched clock. This does not have any special case for STSC/SNP/TDX. 

> [*] https://lore.kernel.org/all/ZurCbP7MesWXQbqZ@xxxxxxxxxx

Regards
Nikunj

1. https://lore.kernel.org/kvm/20250106124633.1418972-13-nikunj@xxxxxxx/