Commit b3c045d3 authored by Paolo Bonzini's avatar Paolo Bonzini Committed by Radim Krčmář
Browse files

KVM: lapic: remove unnecessary KVM_REQ_EVENT on PPR update 



PPR needs to be updated whenever on every IRR read because we
may have missed TPR writes that _increased_ PPR.  However, these
writes need not generate KVM_REQ_EVENT, because either KVM_REQ_EVENT
has been set already in __apic_accept_irq, or we are going to
process the interrupt right away.

Reviewed-by: default avatarRoman Kagan <rkagan@virtuozzo.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent eb90f341

arch/x86/kvm/lapic.c

+24 −12
Original line number Diff line number Diff line
@@ -570,7 +570,15 @@ static void pv_eoi_clr_pending(struct kvm_vcpu *vcpu) 
	__clear_bit(KVM_APIC_PV_EOI_PENDING, &vcpu->arch.apic_attention);

}



static void apic_update_ppr(struct kvm_lapic *apic)

static int apic_has_interrupt_for_ppr(struct kvm_lapic *apic, u32 ppr)

{

	int highest_irr = apic_find_highest_irr(apic);

	if (highest_irr == -1 || (highest_irr & 0xF0) <= ppr)

		return -1;

	return highest_irr;

}



static bool __apic_update_ppr(struct kvm_lapic *apic, u32 *new_ppr)

{

	u32 tpr, isrv, ppr, old_ppr;

	int isr;
@@ -588,11 +596,19 @@ static void apic_update_ppr(struct kvm_lapic *apic) 
	apic_debug("vlapic %p, ppr 0x%x, isr 0x%x, isrv 0x%x",

		   apic, ppr, isr, isrv);



	if (old_ppr != ppr) {

	*new_ppr = ppr;

	if (old_ppr != ppr)

		kvm_lapic_set_reg(apic, APIC_PROCPRI, ppr);

		if (ppr < old_ppr)

			kvm_make_request(KVM_REQ_EVENT, apic->vcpu);



	return ppr < old_ppr;

}



static void apic_update_ppr(struct kvm_lapic *apic)

{

	u32 ppr;



	if (__apic_update_ppr(apic, &ppr))

		kvm_make_request(KVM_REQ_EVENT, apic->vcpu);

}



void kvm_apic_update_ppr(struct kvm_vcpu *vcpu)
@@ -2056,17 +2072,13 @@ nomem: 
int kvm_apic_has_interrupt(struct kvm_vcpu *vcpu)

{

	struct kvm_lapic *apic = vcpu->arch.apic;

	int highest_irr;

	u32 ppr;



	if (!apic_enabled(apic))

		return -1;



	apic_update_ppr(apic);

	highest_irr = apic_find_highest_irr(apic);

	if ((highest_irr == -1) ||

	    ((highest_irr & 0xF0) <= kvm_lapic_get_reg(apic, APIC_PROCPRI)))

		return -1;

	return highest_irr;

	__apic_update_ppr(apic, &ppr);

	return apic_has_interrupt_for_ppr(apic, ppr);

}



int kvm_apic_accept_pic_intr(struct kvm_vcpu *vcpu)

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