Commit 5c94ac5d authored by Miaohe Lin's avatar Miaohe Lin Committed by Paolo Bonzini
Browse files

KVM: SVM: Fix potential wrong physical id in avic_handle_ldr_update 



Guest physical APIC ID may not equal to vcpu->vcpu_id in some case.
We may set the wrong physical id in avic_handle_ldr_update as we
always use vcpu->vcpu_id. Get physical APIC ID from vAPIC page
instead.
Export and use kvm_xapic_id here and in avic_handle_apic_id_update
as suggested by Vitaly.

Signed-off-by: default avatarMiaohe Lin <linmiaohe@huawei.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 20baa8e5

arch/x86/kvm/lapic.c

+0 −5
Original line number Diff line number Diff line
@@ -111,11 +111,6 @@ static inline int apic_enabled(struct kvm_lapic *apic) 
	(LVT_MASK | APIC_MODE_MASK | APIC_INPUT_POLARITY | \

	 APIC_LVT_REMOTE_IRR | APIC_LVT_LEVEL_TRIGGER)



static inline u8 kvm_xapic_id(struct kvm_lapic *apic)

{

	return kvm_lapic_get_reg(apic, APIC_ID) >> 24;

}



static inline u32 kvm_x2apic_id(struct kvm_lapic *apic)

{

	return apic->vcpu->vcpu_id;

arch/x86/kvm/lapic.h

+5 −0
Original line number Diff line number Diff line
@@ -242,4 +242,9 @@ static inline enum lapic_mode kvm_apic_mode(u64 apic_base) 
	return apic_base & (MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE);

}



static inline u8 kvm_xapic_id(struct kvm_lapic *apic)

{

	return kvm_lapic_get_reg(apic, APIC_ID) >> 24;

}



#endif

arch/x86/kvm/svm.c

+3 −3
Original line number Diff line number Diff line
@@ -4591,6 +4591,7 @@ static int avic_handle_ldr_update(struct kvm_vcpu *vcpu) 
	int ret = 0;

	struct vcpu_svm *svm = to_svm(vcpu);

	u32 ldr = kvm_lapic_get_reg(vcpu->arch.apic, APIC_LDR);

	u32 id = kvm_xapic_id(vcpu->arch.apic);



	if (ldr == svm->ldr_reg)

		return 0;
@@ -4598,7 +4599,7 @@ static int avic_handle_ldr_update(struct kvm_vcpu *vcpu) 
	avic_invalidate_logical_id_entry(vcpu);



	if (ldr)

		ret = avic_ldr_write(vcpu, vcpu->vcpu_id, ldr);

		ret = avic_ldr_write(vcpu, id, ldr);



	if (!ret)

		svm->ldr_reg = ldr;
@@ -4610,8 +4611,7 @@ static int avic_handle_apic_id_update(struct kvm_vcpu *vcpu) 
{

	u64 *old, *new;

	struct vcpu_svm *svm = to_svm(vcpu);

	u32 apic_id_reg = kvm_lapic_get_reg(vcpu->arch.apic, APIC_ID);

	u32 id = (apic_id_reg >> 24) & 0xff;

	u32 id = kvm_xapic_id(vcpu->arch.apic);



	if (vcpu->vcpu_id == id)

		return 0;

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