Commit de63ad4c authored by Longpeng(Mike)'s avatar Longpeng(Mike) Committed by Paolo Bonzini
Browse files

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

arch/x86/include/asm/kvm_host.h

+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 {

arch/x86/kvm/hyperv.c

+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:

arch/x86/kvm/svm.c

+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;

}

arch/x86/kvm/vmx.c

+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);

}

arch/x86/kvm/x86.c

+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)