On Thu, Nov 02, 2023 at 11:23:34AM +0530, Nikunj A. Dadhania wrote: > On 10/30/2023 10:48 PM, Dave Hansen wrote: > > On 10/29/23 23:36, Nikunj A Dadhania wrote: > > ... > >> diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c > >> index 15f97c0abc9d..b0a8546d3703 100644 > >> --- a/arch/x86/kernel/tsc.c > >> +++ b/arch/x86/kernel/tsc.c > >> @@ -1241,7 +1241,7 @@ static void __init check_system_tsc_reliable(void) > >> tsc_clocksource_reliable = 1; > >> } > >> #endif > >> - if (boot_cpu_has(X86_FEATURE_TSC_RELIABLE)) > >> + if (boot_cpu_has(X86_FEATURE_TSC_RELIABLE) || cc_platform_has(CC_ATTR_GUEST_SECURE_TSC)) > >> tsc_clocksource_reliable = 1; > > > > Why can't you just set X86_FEATURE_TSC_RELIABLE? > > Last time when I tried, I had removed my kvmclock changes and I had set > the X86_FEATURE_TSC_RELIABLE similar to Kirill's patch[1], this did not > select the SecureTSC. > > Let me try setting X86_FEATURE_TSC_RELIABLE and retaining my patch for > skipping kvmclock. kvmclock lowers its rating if TSC is good enough: if (boot_cpu_has(X86_FEATURE_CONSTANT_TSC) && boot_cpu_has(X86_FEATURE_NONSTOP_TSC) && !check_tsc_unstable()) kvm_clock.rating = 299; Does your TSC meet the requirements? -- Kiryl Shutsemau / Kirill A. Shutemov
