Commit 4e19c36f authored by Suravee Suthikulpanit's avatar Suravee Suthikulpanit Committed by Paolo Bonzini
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kvm: x86: Introduce APICv inhibit reason bits 



There are several reasons in which a VM needs to deactivate APICv
e.g. disable APICv via parameter during module loading, or when
enable Hyper-V SynIC support. Additional inhibit reasons will be
introduced later on when dynamic APICv is supported,

Introduce KVM APICv inhibit reason bits along with a new variable,
apicv_inhibit_reasons, to help keep track of APICv state for each VM,

Initially, the APICV_INHIBIT_REASON_DISABLE bit is used to indicate
the case where APICv is disabled during KVM module load.
(e.g. insmod kvm_amd avic=0 or insmod kvm_intel enable_apicv=0).

Signed-off-by: default avatarSuravee Suthikulpanit <suravee.suthikulpanit@amd.com>
[Do not use get_enable_apicv; consider irqchip_split in svm.c. - Paolo]
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent b26a695a

arch/x86/include/asm/kvm_host.h

+5 −0
Original line number Diff line number Diff line
@@ -873,6 +873,8 @@ enum kvm_irqchip_mode { 
	KVM_IRQCHIP_SPLIT,        /* created with KVM_CAP_SPLIT_IRQCHIP */

};



#define APICV_INHIBIT_REASON_DISABLE    0



struct kvm_arch {

	unsigned long n_used_mmu_pages;

	unsigned long n_requested_mmu_pages;
@@ -904,6 +906,7 @@ struct kvm_arch { 
	struct kvm_apic_map *apic_map;



	bool apic_access_page_done;

	unsigned long apicv_inhibit_reasons;



	gpa_t wall_clock;
@@ -1478,6 +1481,8 @@ gpa_t kvm_mmu_gva_to_gpa_system(struct kvm_vcpu *vcpu, gva_t gva, 
				struct x86_exception *exception);



void kvm_vcpu_deactivate_apicv(struct kvm_vcpu *vcpu);

bool kvm_apicv_activated(struct kvm *kvm);

void kvm_apicv_init(struct kvm *kvm, bool enable);



int kvm_emulate_hypercall(struct kvm_vcpu *vcpu);

arch/x86/kvm/svm.c

+13 −1
Original line number Diff line number Diff line
@@ -2052,6 +2052,18 @@ free_avic: 
	return err;

}



static int svm_vm_init(struct kvm *kvm)

{

	if (avic) {

		int ret = avic_vm_init(kvm);

		if (ret)

			return ret;

	}



	kvm_apicv_init(kvm, avic && irqchip_split(kvm));

	return 0;

}



static inline int

avic_update_iommu_vcpu_affinity(struct kvm_vcpu *vcpu, int cpu, bool r)

{
@@ -7274,7 +7286,7 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = { 


	.vm_alloc = svm_vm_alloc,

	.vm_free = svm_vm_free,

	.vm_init = avic_vm_init,

	.vm_init = svm_vm_init,

	.vm_destroy = svm_vm_destroy,



	.prepare_guest_switch = svm_prepare_guest_switch,

arch/x86/kvm/vmx/vmx.c

+1 −0
Original line number Diff line number Diff line
@@ -6813,6 +6813,7 @@ static int vmx_vm_init(struct kvm *kvm) 
			break;

		}

	}

	kvm_apicv_init(kvm, enable_apicv);

	return 0;

}

arch/x86/kvm/x86.c

+19 −1
Original line number Diff line number Diff line
@@ -7469,6 +7469,23 @@ void kvm_vcpu_deactivate_apicv(struct kvm_vcpu *vcpu) 
	kvm_x86_ops->refresh_apicv_exec_ctrl(vcpu);

}



bool kvm_apicv_activated(struct kvm *kvm)

{

	return (READ_ONCE(kvm->arch.apicv_inhibit_reasons) == 0);

}

EXPORT_SYMBOL_GPL(kvm_apicv_activated);



void kvm_apicv_init(struct kvm *kvm, bool enable)

{

	if (enable)

		clear_bit(APICV_INHIBIT_REASON_DISABLE,

			  &kvm->arch.apicv_inhibit_reasons);

	else

		set_bit(APICV_INHIBIT_REASON_DISABLE,

			&kvm->arch.apicv_inhibit_reasons);

}

EXPORT_SYMBOL_GPL(kvm_apicv_init);



static void kvm_sched_yield(struct kvm *kvm, unsigned long dest_id)

{

	struct kvm_vcpu *target = NULL;
@@ -9219,10 +9236,11 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu) 
		return r;



	if (irqchip_in_kernel(vcpu->kvm)) {

		vcpu->arch.apicv_active = kvm_x86_ops->get_enable_apicv(vcpu->kvm);

		r = kvm_create_lapic(vcpu, lapic_timer_advance_ns);

		if (r < 0)

			goto fail_mmu_destroy;

		if (kvm_apicv_activated(vcpu->kvm))

			vcpu->arch.apicv_active = true;

	} else

		static_key_slow_inc(&kvm_no_apic_vcpu);

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