Commit ac480170 authored by Neeraj Upadhyay's avatar Neeraj Upadhyay Committed by Sean Christopherson
Browse files

KVM: x86: Open code setting/clearing of bits in the ISR 



Remove __apic_test_and_set_vector() and __apic_test_and_clear_vector(),
because the _only_ register that's safe to modify with a non-atomic
operation is ISR, because KVM isn't running the vCPU, i.e. hardware can't
service an IRQ or process an EOI for the relevant (virtual) APIC.

No functional change intended.

Suggested-by: default avatarSean Christopherson <seanjc@google.com>
Signed-off-by: default avatarNeeraj Upadhyay <Neeraj.Upadhyay@amd.com>
Acked-by: default avatarSean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20250709033242.267892-2-Neeraj.Upadhyay@amd.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent d7b8f8e2

arch/x86/kvm/lapic.c

+7 −12
Original line number Diff line number Diff line
@@ -125,16 +125,6 @@ bool kvm_apic_pending_eoi(struct kvm_vcpu *vcpu, int vector) 
		apic_test_vector(vector, apic->regs + APIC_IRR);

}



static inline int __apic_test_and_set_vector(int vec, void *bitmap)

{

	return __test_and_set_bit(VEC_POS(vec), (bitmap) + REG_POS(vec));

}



static inline int __apic_test_and_clear_vector(int vec, void *bitmap)

{

	return __test_and_clear_bit(VEC_POS(vec), (bitmap) + REG_POS(vec));

}



__read_mostly DEFINE_STATIC_KEY_FALSE(kvm_has_noapic_vcpu);

EXPORT_SYMBOL_GPL(kvm_has_noapic_vcpu);
@@ -744,9 +734,14 @@ void kvm_apic_clear_irr(struct kvm_vcpu *vcpu, int vec) 
}

EXPORT_SYMBOL_GPL(kvm_apic_clear_irr);



static void *apic_vector_to_isr(int vec, struct kvm_lapic *apic)

{

	return apic->regs + APIC_ISR + REG_POS(vec);

}



static inline void apic_set_isr(int vec, struct kvm_lapic *apic)

{

	if (__apic_test_and_set_vector(vec, apic->regs + APIC_ISR))

	if (__test_and_set_bit(VEC_POS(vec), apic_vector_to_isr(vec, apic)))

		return;



	/*
@@ -789,7 +784,7 @@ static inline int apic_find_highest_isr(struct kvm_lapic *apic) 


static inline void apic_clear_isr(int vec, struct kvm_lapic *apic)

{

	if (!__apic_test_and_clear_vector(vec, apic->regs + APIC_ISR))

	if (!__test_and_clear_bit(VEC_POS(vec), apic_vector_to_isr(vec, apic)))

		return;



	/*