On Wed, May 12, 2021, Ilias Stamatis wrote:
> Store L1's scaling ratio in that struct like we already do for L1's TSC
s/that struct/kvm_vcpu_arch. Forcing the reader to look at the subject to
understand the changelog is annoying, especially when it saves all of a handful
of characters. E.g. I often read patches without the subject in scope.
> offset. This allows for easy save/restore when we enter and then exit
> the nested guest.
>
> Signed-off-by: Ilias Stamatis <ilstam@xxxxxxxxxx>
> Reviewed-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
> ---
...
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 9b6bca616929..07cf5d7ece38 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -2185,6 +2185,7 @@ static int set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz, bool scale)
>
> /* Guest TSC same frequency as host TSC? */
> if (!scale) {
> + vcpu->arch.l1_tsc_scaling_ratio = kvm_default_tsc_scaling_ratio;
> vcpu->arch.tsc_scaling_ratio = kvm_default_tsc_scaling_ratio;
Looks like these are always set as a pair, maybe add a helper, e.g.
static void kvm_set_l1_tsc_scaling_ratio(u64 ratio)
{
vcpu->arch.l1_tsc_scaling_ratio = ratio;
vcpu->arch.tsc_scaling_ratio = ratio;
}
> return 0;
> }
> @@ -2211,7 +2212,7 @@ static int set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz, bool scale)
> return -1;
> }
>
> - vcpu->arch.tsc_scaling_ratio = ratio;
> + vcpu->arch.l1_tsc_scaling_ratio = vcpu->arch.tsc_scaling_ratio = ratio;
> return 0;
> }
>
> @@ -2223,6 +2224,7 @@ static int kvm_set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz)
> /* tsc_khz can be zero if TSC calibration fails */
> if (user_tsc_khz == 0) {
> /* set tsc_scaling_ratio to a safe value */
> + vcpu->arch.l1_tsc_scaling_ratio = kvm_default_tsc_scaling_ratio;
> vcpu->arch.tsc_scaling_ratio = kvm_default_tsc_scaling_ratio;
> return -1;
> }
> @@ -2459,7 +2461,7 @@ static inline void adjust_tsc_offset_guest(struct kvm_vcpu *vcpu,
>
> static inline void adjust_tsc_offset_host(struct kvm_vcpu *vcpu, s64 adjustment)
> {
> - if (vcpu->arch.tsc_scaling_ratio != kvm_default_tsc_scaling_ratio)
> + if (vcpu->arch.l1_tsc_scaling_ratio != kvm_default_tsc_scaling_ratio)
> WARN_ON(adjustment < 0);
> adjustment = kvm_scale_tsc(vcpu, (u64) adjustment);
> adjust_tsc_offset_guest(vcpu, adjustment);
> --
> 2.17.1
>
