Commit c2207bbc authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: x86: Add a helper to deduplicate I/O APIC EOI interception logic 



Extract the vCPU specific EOI interception logic for I/O APIC emulation
into a common helper for userspace and in-kernel emulation in anticipation
of optimizing the "pending EOI" case.

No functional change intended.

Reviewed-by: default avatarKai Huang <kai.huang@intel.com>
Link: https://lore.kernel.org/r/20250304013335.4155703-3-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent b1f7723a

arch/x86/kvm/ioapic.c

+2 −5
Original line number Diff line number Diff line
@@ -296,11 +296,8 @@ void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, ulong *ioapic_handled_vectors) 
		    index == RTC_GSI) {

			u16 dm = kvm_lapic_irq_dest_mode(!!e->fields.dest_mode);



			if (kvm_apic_match_dest(vcpu, NULL, APIC_DEST_NOSHORT,

						e->fields.dest_id, dm) ||

			    kvm_apic_pending_eoi(vcpu, e->fields.vector))

				__set_bit(e->fields.vector,

					  ioapic_handled_vectors);

			kvm_scan_ioapic_irq(vcpu, e->fields.dest_id, dm,

					    e->fields.vector, ioapic_handled_vectors);

		}

	}

	spin_unlock(&ioapic->lock);

arch/x86/kvm/ioapic.h

+2 −0
Original line number Diff line number Diff line
@@ -120,4 +120,6 @@ void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, 
			   ulong *ioapic_handled_vectors);

void kvm_scan_ioapic_routes(struct kvm_vcpu *vcpu,

			    ulong *ioapic_handled_vectors);

void kvm_scan_ioapic_irq(struct kvm_vcpu *vcpu, u32 dest_id, u16 dest_mode,

			 u8 vector, unsigned long *ioapic_handled_vectors);

#endif

arch/x86/kvm/irq_comm.c

+17 −4
Original line number Diff line number Diff line
@@ -402,6 +402,21 @@ void kvm_arch_post_irq_routing_update(struct kvm *kvm) 
	kvm_make_scan_ioapic_request(kvm);

}



void kvm_scan_ioapic_irq(struct kvm_vcpu *vcpu, u32 dest_id, u16 dest_mode,

			 u8 vector, unsigned long *ioapic_handled_vectors)

{

	/*

	 * Intercept EOI if the vCPU is the target of the new IRQ routing, or

	 * the vCPU has a pending IRQ from the old routing, i.e. if the vCPU

	 * may receive a level-triggered IRQ in the future, or already received

	 * level-triggered IRQ.  The EOI needs to be intercepted and forwarded

	 * to I/O APIC emulation so that the IRQ can be de-asserted.

	 */

	if (kvm_apic_match_dest(vcpu, NULL, APIC_DEST_NOSHORT, dest_id, dest_mode) ||

	    kvm_apic_pending_eoi(vcpu, vector))

		__set_bit(vector, ioapic_handled_vectors);

}



void kvm_scan_ioapic_routes(struct kvm_vcpu *vcpu,

			    ulong *ioapic_handled_vectors)

{
@@ -427,10 +442,8 @@ void kvm_scan_ioapic_routes(struct kvm_vcpu *vcpu, 
			if (!irq.trig_mode)

				continue;



			if (kvm_apic_match_dest(vcpu, NULL, APIC_DEST_NOSHORT,

						irq.dest_id, irq.dest_mode) ||

			     kvm_apic_pending_eoi(vcpu, irq.vector))

				__set_bit(irq.vector, ioapic_handled_vectors);

			kvm_scan_ioapic_irq(vcpu, irq.dest_id, irq.dest_mode,

					    irq.vector, ioapic_handled_vectors);

		}

	}

	srcu_read_unlock(&kvm->irq_srcu, idx);