KVM: x86: prevent setup of invalid routes (8231f50d) · Commits · 戴 / test

The check in kvm_set_pic_irq() and kvm_set_ioapic_irq() was just a temporary measure until the code improved enough for us to do this. This changes APIC in a case when KVM_SET_GSI_ROUTING is called to set up pic and ioapic routes before KVM_CREATE_IRQCHIP. Those rules would get overwritten by KVM_CREATE_IRQCHIP at best, so it is pointless to allow it. Userspaces hopefully noticed that things don't work if they do that and don't do that. Reviewed-by:

Paolo Bonzini <pbonzini@redhat.com> Reviewed-by:

David Hildenbrand <david@redhat.com> Signed-off-by:

Radim Krčmář <rkrcmar@redhat.com> Signed-off-by:

Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/irq_comm.c

+6 −13

Original line number	Diff line number	Diff line
		@@ -41,15 +41,6 @@ static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
		bool line_status)
		{
		struct kvm_pic *pic = pic_irqchip(kvm);

		/*
		* XXX: rejecting pic routes when pic isn't in use would be better,
		* but the default routing table is installed while kvm->arch.vpic is
		* NULL and KVM_CREATE_IRQCHIP can race with KVM_IRQ_LINE.
		*/
		if (!pic)
		return -1;

		return kvm_pic_set_irq(pic, e->irqchip.pin, irq_source_id, level);
		}

		@@ -58,10 +49,6 @@ static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
		bool line_status)
		{
		struct kvm_ioapic *ioapic = kvm->arch.vioapic;

		if (!ioapic)
		return -1;

		return kvm_ioapic_set_irq(ioapic, e->irqchip.pin, irq_source_id, level,
		line_status);
		}
		@@ -301,10 +288,16 @@ int kvm_set_routing_entry(struct kvm *kvm,
		delta = 8;
		/* fall through */
		case KVM_IRQCHIP_PIC_MASTER:
		if (!pic_in_kernel(kvm))
		goto out;

		e->set = kvm_set_pic_irq;
		max_pin = PIC_NUM_PINS;
		break;
		case KVM_IRQCHIP_IOAPIC:
		if (!ioapic_in_kernel(kvm))
		goto out;

		max_pin = KVM_IOAPIC_NUM_PINS;
		e->set = kvm_set_ioapic_irq;
		break;

Admin message