KVM: LAPIC: Narrow down the kick target vCPU (68ca7663) · Commits · 戴 / test

The kick after setting KVM_REQ_PENDING_TIMER is used to handle the timer fires on a different pCPU which vCPU is running on. This kick costs about 1000 clock cycles and we don't need this when injecting already-expired timer or when using the VMX preemption timer because kvm_lapic_expired_hv_timer() is called from the target vCPU. Reviewed-by:

Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by:

Wanpeng Li <wanpengli@tencent.com> Message-Id: <1599731444-3525-6-git-send-email-wanpengli@tencent.com> Signed-off-by:

Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/lapic.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -1642,7 +1642,9 @@ static void apic_timer_expired(struct kvm_lapic *apic, bool from_timer_fn)
		}

		atomic_inc(&apic->lapic_timer.pending);
		kvm_set_pending_timer(vcpu);
		kvm_make_request(KVM_REQ_PENDING_TIMER, vcpu);
		if (from_timer_fn)
		kvm_vcpu_kick(vcpu);
		}

		static void start_sw_tscdeadline(struct kvm_lapic *apic)

arch/x86/kvm/x86.c

+0 −6

Original line number	Diff line number	Diff line
		@@ -1774,12 +1774,6 @@ static s64 get_kvmclock_base_ns(void)
		}
		#endif

		void kvm_set_pending_timer(struct kvm_vcpu *vcpu)
		{
		kvm_make_request(KVM_REQ_PENDING_TIMER, vcpu);
		kvm_vcpu_kick(vcpu);
		}

		static void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock)
		{
		int version;

arch/x86/kvm/x86.h

+0 −1

Original line number	Diff line number	Diff line
		@@ -246,7 +246,6 @@ static inline bool kvm_vcpu_latch_init(struct kvm_vcpu *vcpu)
		return is_smm(vcpu) \|\| kvm_x86_ops.apic_init_signal_blocked(vcpu);
		}

		void kvm_set_pending_timer(struct kvm_vcpu *vcpu);
		void kvm_inject_realmode_interrupt(struct kvm_vcpu *vcpu, int irq, int inc_eip);

		void kvm_write_tsc(struct kvm_vcpu vcpu, struct msr_data msr);

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