KVM: x86: Add lowest-priority support for vt-d posted-interrupts (6228a0da) · Commits · 戴 / test

arch/x86/kvm/lapic.c

+49 −7

Original line number	Diff line number	Diff line
		@@ -798,6 +798,20 @@ out:
		return ret;
		}

		/*
		* This routine tries to handler interrupts in posted mode, here is how
		* it deals with different cases:
		* - For single-destination interrupts, handle it in posted mode
		* - Else if vector hashing is enabled and it is a lowest-priority
		* interrupt, handle it in posted mode and use the following mechanism
		* to find the destinaiton vCPU.
		* 1. For lowest-priority interrupts, store all the possible
		* destination vCPUs in an array.
		* 2. Use "guest vector % max number of destination vCPUs" to find
		* the right destination vCPU in the array for the lowest-priority
		* interrupt.
		* - Otherwise, use remapped mode to inject the interrupt.
		*/
		bool kvm_intr_is_single_vcpu_fast(struct kvm kvm, struct kvm_lapic_irq irq,
		struct kvm_vcpu **dest_vcpu)
		{
		@@ -839,6 +853,33 @@ bool kvm_intr_is_single_vcpu_fast(struct kvm kvm, struct kvm_lapic_irq irq,
		if (cid >= ARRAY_SIZE(map->logical_map))
		goto out;

		if (kvm_vector_hashing_enabled() &&
		kvm_lowest_prio_delivery(irq)) {
		int idx;
		unsigned int dest_vcpus;

		dest_vcpus = hweight16(bitmap);
		if (dest_vcpus == 0)
		goto out;

		idx = kvm_vector_to_index(irq->vector, dest_vcpus,
		&bitmap, 16);

		/*
		* We may find a hardware disabled LAPIC here, if that
		* is the case, print out a error message once for each
		* guest and return
		*/
		dst = map->logical_map[cid][idx];
		if (!dst && !kvm->arch.disabled_lapic_found) {
		kvm->arch.disabled_lapic_found = true;
		printk(KERN_INFO
		"Disabled LAPIC found during irq injection\n");
		goto out;
		}

		*dest_vcpu = dst->vcpu;
		} else {
		for_each_set_bit(i, &bitmap, 16) {
		dst = map->logical_map[cid][i];
		if (++r == 2)
		@@ -850,6 +891,7 @@ bool kvm_intr_is_single_vcpu_fast(struct kvm kvm, struct kvm_lapic_irq irq,
		else
		goto out;
		}
		}

		ret = true;
		out:

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