Re: [PATCH v2] x86/acrn: Set X86_FEATURE_TSC_KNOWN_FREQ
From: Fei Li
Date: Mon Nov 07 2022 - 04:52:33 EST
On 2022-11-01 at 13:30:19 +0800, Fei Li wrote:
> If the TSC frequency is known from the acrn_get_tsc_khz(),
> the TSC frequency does not need to be recalibrated.
>
> Avoiding recalibration by setting X86_FEATURE_TSC_KNOWN_FREQ.
> This patch also removes `inline` for acrn_get_tsc_khz() since
> it doesn't make sense.
>
> Signed-off-by: Fei Li <fei1.li@xxxxxxxxx>
> Reviewed-by: Yin, Fengwei <fengwei.yin@xxxxxxxxx>
>
> ---
> v2:
> - Detail the commit message
Ping ...
> ---
> arch/x86/include/asm/acrn.h | 5 -----
> arch/x86/kernel/cpu/acrn.c | 6 ++++++
> 2 files changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/arch/x86/include/asm/acrn.h b/arch/x86/include/asm/acrn.h
> index 1dd14381bcb6..aa12c74ea959 100644
> --- a/arch/x86/include/asm/acrn.h
> +++ b/arch/x86/include/asm/acrn.h
> @@ -30,11 +30,6 @@ static inline u32 acrn_cpuid_base(void)
> return 0;
> }
>
> -static inline unsigned long acrn_get_tsc_khz(void)
> -{
> - return cpuid_eax(ACRN_CPUID_TIMING_INFO);
> -}
> -
> /*
> * Hypercalls for ACRN
> *
> diff --git a/arch/x86/kernel/cpu/acrn.c b/arch/x86/kernel/cpu/acrn.c
> index 485441b7f030..c5ff75b6a949 100644
> --- a/arch/x86/kernel/cpu/acrn.c
> +++ b/arch/x86/kernel/cpu/acrn.c
> @@ -24,6 +24,12 @@ static u32 __init acrn_detect(void)
> return acrn_cpuid_base();
> }
>
> +static unsigned long acrn_get_tsc_khz(void)
> +{
> + setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ);
> + return cpuid_eax(ACRN_CPUID_TIMING_INFO);
> +}
> +
> static void __init acrn_init_platform(void)
> {
> /* Setup the IDT for ACRN hypervisor callback */
>
> base-commit: 5aaef24b5c6d4246b2cac1be949869fa36577737
> --
> 2.34.1
>