Re: [PATCH 2/2] KVM: LAPIC: Guarantee the timer is in tsc-deadline mode when setting

From: Sean Christopherson
Date: Tue Aug 04 2020 - 17:19:46 EST


On Tue, Aug 04, 2020 at 02:10:48PM +0800, Wanpeng Li wrote:
> From: Wanpeng Li <wanpengli@xxxxxxxxxxx>
>
> Check apic_lvtt_tscdeadline() mode directly instead of apic_lvtt_oneshot()
> and apic_lvtt_period() to guarantee the timer is in tsc-deadline mode when
> wrmsr MSR_IA32_TSCDEADLINE.
>
> Signed-off-by: Wanpeng Li <wanpengli@xxxxxxxxxxx>
> ---
> arch/x86/kvm/lapic.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
> index d89ab48..7b11fa8 100644
> --- a/arch/x86/kvm/lapic.c
> +++ b/arch/x86/kvm/lapic.c
> @@ -2193,8 +2193,8 @@ void kvm_set_lapic_tscdeadline_msr(struct kvm_vcpu *vcpu, u64 data)
> {
> struct kvm_lapic *apic = vcpu->arch.apic;
>
> - if (!kvm_apic_present(vcpu) || apic_lvtt_oneshot(apic) ||
> - apic_lvtt_period(apic))
> + if (!kvm_apic_present(vcpu) ||
> + !apic_lvtt_tscdeadline(apic))

Definitely prefer to fix the indentation here since both lines are touched
anyways.

> return;
>
> hrtimer_cancel(&apic->lapic_timer.timer);
> --
> 2.7.4
>