On 24.01.2022 09:25, Jan Beulich wrote:
> --- a/xen/arch/x86/time.c
> +++ b/xen/arch/x86/time.c
> @@ -287,9 +287,47 @@ static char *freq_string(u64 freq)
> return s;
> }
>
> -static uint64_t adjust_elapsed(uint64_t elapsed, uint32_t actual,
> - uint32_t
Calibration logic assumes that the platform timer (HPET or ACPI PM
timer) and the TSC are read at about the same time. This assumption may
not hold when a long latency event (e.g. SMI or NMI) occurs between the
two reads. Reduce the risk of reading uncorrelated values by doing at
least four pairs
