From 64aa47bfc45323040d5db8f30cbd6851f2606c7d Mon Sep 17 00:00:00 2001 From: Radim Krčmář Date: Tue, 12 Jul 2016 22:09:18 +0200 Subject: KVM: x86: add kvm_apic_map_get_dest_lapic MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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: Radim Krčmář Signed-off-by: Paolo Bonzini --- arch/x86/kvm/lapic.c | 230 ++++++++++++++++++++++----------------------------- 1 file changed, 98 insertions(+), 132 deletions(-) (limited to 'arch') diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 22a6474af220..2987843657db 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -671,102 +671,120 @@ 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) -{ - struct kvm_apic_map *map; - unsigned long bitmap = 1; - struct kvm_lapic **dst; - int i; - bool ret, x2apic_ipi; +/* 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) +{ + int i, lowest; + bool x2apic_ipi; + u16 cid; + + if (irq->shorthand == APIC_DEST_SELF && src) { + *dst = src; + *bitmap = 1; + return true; + } else if (irq->shorthand) + return false; - *r = -1; + x2apic_ipi = src && *src && apic_x2apic_mode(*src); + if (irq->dest_id == (x2apic_ipi ? X2APIC_BROADCAST : APIC_BROADCAST)) + return false; - if (irq->shorthand == APIC_DEST_SELF) { - *r = kvm_apic_set_irq(src->vcpu, irq, dest_map); + if (!map) + return false; + + if (irq->dest_mode == APIC_DEST_PHYSICAL) { + if (irq->dest_id >= ARRAY_SIZE(map->phys_map)) { + *bitmap = 0; + } else { + *dst = &map->phys_map[irq->dest_id]; + *bitmap = 1; + } return true; } - if (irq->shorthand) + if (!kvm_apic_logical_map_valid(map)) return false; - x2apic_ipi = 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); + apic_logical_id(map, irq->dest_id, &cid, (u16 *)bitmap); - if (!map) { - ret = false; - goto out; + if (cid >= ARRAY_SIZE(map->logical_map)) { + *bitmap = 0; + return true; } - if (irq->dest_mode == APIC_DEST_PHYSICAL) { - if (irq->dest_id >= ARRAY_SIZE(map->phys_map)) - goto out; + *dst = map->logical_map[cid]; - dst = &map->phys_map[irq->dest_id]; - } else { - u16 cid; + if (!kvm_lowest_prio_delivery(irq)) + return true; - if (!kvm_apic_logical_map_valid(map)) { - ret = false; - goto out; + if (!kvm_vector_hashing_enabled()) { + lowest = -1; + for_each_set_bit(i, bitmap, 16) { + if (!(*dst)[i]) + continue; + if (lowest < 0) + lowest = i; + else if (kvm_apic_compare_prio((*dst)[i]->vcpu, + (*dst)[lowest]->vcpu) < 0) + lowest = i; } + } else { + if (!*bitmap) + return true; - apic_logical_id(map, irq->dest_id, &cid, (u16 *)&bitmap); + lowest = kvm_vector_to_index(irq->vector, hweight16(*bitmap), + bitmap, 16); - if (cid >= ARRAY_SIZE(map->logical_map)) - goto out; + if (!(*dst)[lowest]) { + kvm_apic_disabled_lapic_found(kvm); + *bitmap = 0; + return true; + } + } - dst = map->logical_map[cid]; + *bitmap = (lowest >= 0) ? 1 << lowest : 0; - 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]) - continue; - if (l < 0) - l = i; - else if (kvm_apic_compare_prio(dst[i]->vcpu, - dst[l]->vcpu) < 0) - l = i; - } - bitmap = (l >= 0) ? 1 << l : 0; - } else { - int idx; - unsigned int dest_vcpus; +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; - dest_vcpus = hweight16(bitmap); - if (dest_vcpus == 0) - goto out; + *r = -1; - idx = kvm_vector_to_index(irq->vector, - dest_vcpus, &bitmap, 16); + if (irq->shorthand == APIC_DEST_SELF) { + *r = kvm_apic_set_irq(src->vcpu, irq, dest_map); + return true; + } - if (!dst[idx]) { - kvm_apic_disabled_lapic_found(kvm); - goto out; - } + rcu_read_lock(); + map = rcu_dereference(kvm->arch.apic_map); - bitmap = (idx >= 0) ? 1 << idx : 0; + 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; + if (*r < 0) + *r = 0; + *r += kvm_apic_set_irq(dst[i]->vcpu, irq, dest_map); } - } -set_irq: - for_each_set_bit(i, &bitmap, 16) { - if (!dst[i]) - continue; - if (*r < 0) - *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_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; + if (kvm_apic_map_get_dest_lapic(kvm, NULL, irq, map, &dst, &bitmap) && + hweight16(bitmap) == 1) { + unsigned long i = find_first_bit(&bitmap, 16); - 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; } -- cgit v1.2.3