Commit 64aa47bf authored by Radim Krčmář's avatar Radim Krčmář Committed by Paolo Bonzini
Browse files

KVM: x86: add kvm_apic_map_get_dest_lapic 



kvm_irq_delivery_to_apic_fast and kvm_intr_is_single_vcpu_fast both
compute the interrupt destination.  Factor the code.

'struct kvm_lapic **dst = NULL' had to be added to silence GCC.
GCC might complain about potential NULL access in the future, because it
missed conditions that avoided uninitialized uses of dst.

Signed-off-by: default avatarRadim Krčmář <rkrcmar@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 757883de

arch/x86/kvm/lapic.c

+98 −132
Original line number Diff line number Diff line
@@ -671,94 +671,112 @@ static void kvm_apic_disabled_lapic_found(struct kvm *kvm) 
	}

}



bool kvm_irq_delivery_to_apic_fast(struct kvm *kvm, struct kvm_lapic *src,

		struct kvm_lapic_irq *irq, int *r, struct dest_map *dest_map)

/* Return true if the interrupt can be handled by using *bitmap as index mask

 * for valid destinations in *dst array.

 * Return false if kvm_apic_map_get_dest_lapic did nothing useful.

 * Note: we may have zero kvm_lapic destinations when we return true, which

 * means that the interrupt should be dropped.  In this case, *bitmap would be

 * zero and *dst undefined.

 */

static inline bool kvm_apic_map_get_dest_lapic(struct kvm *kvm,

		struct kvm_lapic **src, struct kvm_lapic_irq *irq,

		struct kvm_apic_map *map, struct kvm_lapic ***dst,

		unsigned long *bitmap)

{

	struct kvm_apic_map *map;

	unsigned long bitmap = 1;

	struct kvm_lapic **dst;

	int i;

	bool ret, x2apic_ipi;



	*r = -1;

	int i, lowest;

	bool x2apic_ipi;

	u16 cid;



	if (irq->shorthand == APIC_DEST_SELF) {

		*r = kvm_apic_set_irq(src->vcpu, irq, dest_map);

	if (irq->shorthand == APIC_DEST_SELF && src) {

		*dst = src;

		*bitmap = 1;

		return true;

	}



	if (irq->shorthand)

	} else if (irq->shorthand)

		return false;



	x2apic_ipi = src && apic_x2apic_mode(src);

	x2apic_ipi = src && *src && apic_x2apic_mode(*src);

	if (irq->dest_id == (x2apic_ipi ? X2APIC_BROADCAST : APIC_BROADCAST))

		return false;



	ret = true;

	rcu_read_lock();

	map = rcu_dereference(kvm->arch.apic_map);



	if (!map) {

		ret = false;

		goto out;

	}

	if (!map)

		return false;



	if (irq->dest_mode == APIC_DEST_PHYSICAL) {

		if (irq->dest_id >= ARRAY_SIZE(map->phys_map))

			goto out;



		dst = &map->phys_map[irq->dest_id];

		if (irq->dest_id >= ARRAY_SIZE(map->phys_map)) {

			*bitmap = 0;

		} else {

		u16 cid;



		if (!kvm_apic_logical_map_valid(map)) {

			ret = false;

			goto out;

			*dst = &map->phys_map[irq->dest_id];

			*bitmap = 1;

		}

		return true;

	}



		apic_logical_id(map, irq->dest_id, &cid, (u16 *)&bitmap);

	if (!kvm_apic_logical_map_valid(map))

		return false;



		if (cid >= ARRAY_SIZE(map->logical_map))

			goto out;

	apic_logical_id(map, irq->dest_id, &cid, (u16 *)bitmap);



		dst = map->logical_map[cid];

	if (cid >= ARRAY_SIZE(map->logical_map)) {

		*bitmap = 0;

		return true;

	}



	*dst = map->logical_map[cid];



	if (!kvm_lowest_prio_delivery(irq))

			goto set_irq;

		return true;



	if (!kvm_vector_hashing_enabled()) {

			int l = -1;

			for_each_set_bit(i, &bitmap, 16) {

				if (!dst[i])

		lowest = -1;

		for_each_set_bit(i, bitmap, 16) {

			if (!(*dst)[i])

				continue;

				if (l < 0)

					l = i;

				else if (kvm_apic_compare_prio(dst[i]->vcpu,

							dst[l]->vcpu) < 0)

					l = i;

			if (lowest < 0)

				lowest = i;

			else if (kvm_apic_compare_prio((*dst)[i]->vcpu,

						(*dst)[lowest]->vcpu) < 0)

				lowest = i;

		}

			bitmap = (l >= 0) ? 1 << l : 0;

	} else {

			int idx;

			unsigned int dest_vcpus;



			dest_vcpus = hweight16(bitmap);

			if (dest_vcpus == 0)

				goto out;

		if (!*bitmap)

			return true;



			idx = kvm_vector_to_index(irq->vector,

				dest_vcpus, &bitmap, 16);

		lowest = kvm_vector_to_index(irq->vector, hweight16(*bitmap),

				bitmap, 16);



			if (!dst[idx]) {

		if (!(*dst)[lowest]) {

			kvm_apic_disabled_lapic_found(kvm);

				goto out;

			*bitmap = 0;

			return true;

		}

	}



			bitmap = (idx >= 0) ? 1 << idx : 0;

	*bitmap = (lowest >= 0) ? 1 << lowest : 0;



	return true;

}



bool kvm_irq_delivery_to_apic_fast(struct kvm *kvm, struct kvm_lapic *src,

		struct kvm_lapic_irq *irq, int *r, struct dest_map *dest_map)

{

	struct kvm_apic_map *map;

	unsigned long bitmap;

	struct kvm_lapic **dst = NULL;

	int i;

	bool ret;



	*r = -1;



	if (irq->shorthand == APIC_DEST_SELF) {

		*r = kvm_apic_set_irq(src->vcpu, irq, dest_map);

		return true;

	}



set_irq:

	rcu_read_lock();

	map = rcu_dereference(kvm->arch.apic_map);



	ret = kvm_apic_map_get_dest_lapic(kvm, &src, irq, map, &dst, &bitmap);

	if (ret)

		for_each_set_bit(i, &bitmap, 16) {

			if (!dst[i])

				continue;
@@ -766,7 +784,7 @@ set_irq: 
				*r = 0;

			*r += kvm_apic_set_irq(dst[i]->vcpu, irq, dest_map);

		}

out:



	rcu_read_unlock();

	return ret;

}
@@ -789,8 +807,9 @@ bool kvm_intr_is_single_vcpu_fast(struct kvm *kvm, struct kvm_lapic_irq *irq, 
			struct kvm_vcpu **dest_vcpu)

{

	struct kvm_apic_map *map;

	unsigned long bitmap;

	struct kvm_lapic **dst = NULL;

	bool ret = false;

	struct kvm_lapic *dst = NULL;



	if (irq->shorthand)

		return false;
@@ -798,69 +817,16 @@ bool kvm_intr_is_single_vcpu_fast(struct kvm *kvm, struct kvm_lapic_irq *irq, 
	rcu_read_lock();

	map = rcu_dereference(kvm->arch.apic_map);



	if (!map)

		goto out;



	if (irq->dest_mode == APIC_DEST_PHYSICAL) {

		if (irq->dest_id == 0xFF)

			goto out;



		if (irq->dest_id >= ARRAY_SIZE(map->phys_map))

			goto out;



		dst = map->phys_map[irq->dest_id];

		if (dst && kvm_apic_present(dst->vcpu))

			*dest_vcpu = dst->vcpu;

		else

			goto out;

	} else {

		u16 cid;

		unsigned long bitmap = 1;

		int i, r = 0;

	if (kvm_apic_map_get_dest_lapic(kvm, NULL, irq, map, &dst, &bitmap) &&

			hweight16(bitmap) == 1) {

		unsigned long i = find_first_bit(&bitmap, 16);



		if (!kvm_apic_logical_map_valid(map))

			goto out;



		apic_logical_id(map, irq->dest_id, &cid, (u16 *)&bitmap);



		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);



			dst = map->logical_map[cid][idx];

			if (!dst) {

				kvm_apic_disabled_lapic_found(kvm);

				goto out;

			}



			*dest_vcpu = dst->vcpu;

		} else {

			for_each_set_bit(i, &bitmap, 16) {

				dst = map->logical_map[cid][i];

				if (++r == 2)

					goto out;

			}



			if (dst && kvm_apic_present(dst->vcpu))

				*dest_vcpu = dst->vcpu;

			else

				goto out;

		if (dst[i]) {

			*dest_vcpu = dst[i]->vcpu;

			ret = true;

		}

	}



	ret = true;

out:

	rcu_read_unlock();

	return ret;

}

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