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Commit de63ad4c authored by Longpeng(Mike)'s avatar Longpeng(Mike) Committed by Paolo Bonzini
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KVM: X86: implement the logic for spinlock optimization



get_cpl requires vcpu_load, so we must cache the result (whether the
vcpu was preempted when its cpl=0) in kvm_vcpu_arch.

Signed-off-by: default avatarLongpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 199b5763
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+3 −0
Original line number Diff line number Diff line
@@ -688,6 +688,9 @@ struct kvm_vcpu_arch {

	/* GPA available (AMD only) */
	bool gpa_available;

	/* be preempted when it's in kernel-mode(cpl=0) */
	bool preempted_in_kernel;
};

struct kvm_lpage_info {
+1 −1
Original line number Diff line number Diff line
@@ -1274,7 +1274,7 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)

	switch (code) {
	case HVCALL_NOTIFY_LONG_SPIN_WAIT:
		kvm_vcpu_on_spin(vcpu, false);
		kvm_vcpu_on_spin(vcpu, true);
		break;
	case HVCALL_POST_MESSAGE:
	case HVCALL_SIGNAL_EVENT:
+4 −1
Original line number Diff line number Diff line
@@ -3749,7 +3749,10 @@ static int interrupt_window_interception(struct vcpu_svm *svm)

static int pause_interception(struct vcpu_svm *svm)
{
	kvm_vcpu_on_spin(&svm->vcpu, false);
	struct kvm_vcpu *vcpu = &svm->vcpu;
	bool in_kernel = (svm_get_cpl(vcpu) == 0);

	kvm_vcpu_on_spin(vcpu, in_kernel);
	return 1;
}

+7 −1
Original line number Diff line number Diff line
@@ -6781,7 +6781,13 @@ static int handle_pause(struct kvm_vcpu *vcpu)
	if (ple_gap)
		grow_ple_window(vcpu);

	kvm_vcpu_on_spin(vcpu, false);
	/*
	 * Intel sdm vol3 ch-25.1.3 says: The "PAUSE-loop exiting"
	 * VM-execution control is ignored if CPL > 0. OTOH, KVM
	 * never set PAUSE_EXITING and just set PLE if supported,
	 * so the vcpu must be CPL=0 if it gets a PAUSE exit.
	 */
	kvm_vcpu_on_spin(vcpu, true);
	return kvm_skip_emulated_instruction(vcpu);
}

+6 −1
Original line number Diff line number Diff line
@@ -2873,6 +2873,10 @@ static void kvm_steal_time_set_preempted(struct kvm_vcpu *vcpu)
void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
{
	int idx;

	if (vcpu->preempted)
		vcpu->arch.preempted_in_kernel = !kvm_x86_ops->get_cpl(vcpu);

	/*
	 * Disable page faults because we're in atomic context here.
	 * kvm_write_guest_offset_cached() would call might_fault()
@@ -7985,6 +7989,7 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
	kvm_pmu_init(vcpu);

	vcpu->arch.pending_external_vector = -1;
	vcpu->arch.preempted_in_kernel = false;

	kvm_hv_vcpu_init(vcpu);

@@ -8434,7 +8439,7 @@ int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu)

bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu)
{
	return false;
	return vcpu->arch.preempted_in_kernel;
}

int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)