On Tue, Aug 06, 2024 at 02:01:55AM +0000, Michael Kelley wrote: > From: Wei Liu <wei.liu@xxxxxxxxxx> Sent: Friday, August 2, 2024 4:50 PM > > > > On Tue, Jun 11, 2024 at 07:51:48AM -0700, Roman Kisel wrote: > > > > > > > > > On 6/5/2024 7:55 PM, mhkelley58@xxxxxxxxx wrote: > > > > From: Michael Kelley <mhklinux@xxxxxxxxxxx> > > > > > > > > A Linux guest on Hyper-V gets the TSC frequency from a synthetic MSR, if > > > > available. In this case, set X86_FEATURE_TSC_KNOWN_FREQ so that Linux > > > > doesn't unnecessarily do refined TSC calibration when setting up the TSC > > > > clocksource. > > > > > > > > With this change, a message such as this is no longer output during boot > > > > when the TSC is used as the clocksource: > > > > > > > > [ 1.115141] tsc: Refined TSC clocksource calibration: 2918.408 MHz > > > > > > > > Furthermore, the guest and host will have exactly the same view of the > > > > TSC frequency, which is important for features such as the TSC deadline > > > > timer that are emulated by the Hyper-V host. > > > > > > > > Signed-off-by: Michael Kelley <mhklinux@xxxxxxxxxxx> > > > > --- > > > > arch/x86/kernel/cpu/mshyperv.c | 1 + > > > > 1 file changed, 1 insertion(+) > > > > > > > > diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c > > > > index e0fd57a8ba84..c3e38eaf6d2f 100644 > > > > --- a/arch/x86/kernel/cpu/mshyperv.c > > > > +++ b/arch/x86/kernel/cpu/mshyperv.c > > > > @@ -424,6 +424,7 @@ static void __init ms_hyperv_init_platform(void) > > > > ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE) { > > > > x86_platform.calibrate_tsc = hv_get_tsc_khz; > > > > x86_platform.calibrate_cpu = hv_get_tsc_khz; > > > > + setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ); > > > > } > > > > if (ms_hyperv.priv_high & HV_ISOLATION) { > > > > > > LGTM > > > > > > Reviewed-by: Roman Kisel <romank@xxxxxxxxxxxxxxxxxxx> > > > > Applied to hyperv-fixes. Thanks! > > Wei -- > > hyperv-fixes isn't showing this patch, or any of the others that your > emails said you applied last Friday. Hence the patches aren't in > linux-next either. Did something go awry? The push was not successful. They should show up now. Sorry for the delay. Thanks, Wei. > > Michael