diff options
Diffstat (limited to 'arch/x86/kvm/lapic.c')
| -rw-r--r-- | arch/x86/kvm/lapic.c | 24 |
1 files changed, 21 insertions, 3 deletions
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 12f2f7dc121f..e0fa6fc0b2d8 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -1481,6 +1481,26 @@ static bool lapic_timer_int_injected(struct kvm_vcpu *vcpu) return false; } +static inline void __wait_lapic_expire(struct kvm_vcpu *vcpu, u64 guest_cycles) +{ + u64 timer_advance_ns = vcpu->arch.apic->lapic_timer.timer_advance_ns; + + /* + * If the guest TSC is running at a different ratio than the host, then + * convert the delay to nanoseconds to achieve an accurate delay. Note + * that __delay() uses delay_tsc whenever the hardware has TSC, thus + * always for VMX enabled hardware. + */ + if (vcpu->arch.tsc_scaling_ratio == kvm_default_tsc_scaling_ratio) { + __delay(min(guest_cycles, + nsec_to_cycles(vcpu, timer_advance_ns))); + } else { + u64 delay_ns = guest_cycles * 1000000ULL; + do_div(delay_ns, vcpu->arch.virtual_tsc_khz); + ndelay(min_t(u32, delay_ns, timer_advance_ns)); + } +} + void wait_lapic_expire(struct kvm_vcpu *vcpu) { struct kvm_lapic *apic = vcpu->arch.apic; @@ -1501,10 +1521,8 @@ void wait_lapic_expire(struct kvm_vcpu *vcpu) guest_tsc = kvm_read_l1_tsc(vcpu, rdtsc()); trace_kvm_wait_lapic_expire(vcpu->vcpu_id, guest_tsc - tsc_deadline); - /* __delay is delay_tsc whenever the hardware has TSC, thus always. */ if (guest_tsc < tsc_deadline) - __delay(min(tsc_deadline - guest_tsc, - nsec_to_cycles(vcpu, timer_advance_ns))); + __wait_lapic_expire(vcpu, tsc_deadline - guest_tsc); if (!apic->lapic_timer.timer_advance_adjust_done) { /* too early */ |