diff options
Diffstat (limited to 'virt/kvm/arm/vgic/vgic.c')
| -rw-r--r-- | virt/kvm/arm/vgic/vgic.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c index bce17dea4677..08a862a98442 100644 --- a/virt/kvm/arm/vgic/vgic.c +++ b/virt/kvm/arm/vgic/vgic.c @@ -307,3 +307,195 @@ int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int intid, { return vgic_update_irq_pending(kvm, cpuid, intid, level, false); } + +/** + * vgic_prune_ap_list - Remove non-relevant interrupts from the list + * + * @vcpu: The VCPU pointer + * + * Go over the list of "interesting" interrupts, and prune those that we + * won't have to consider in the near future. + */ +static void vgic_prune_ap_list(struct kvm_vcpu *vcpu) +{ + struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu; + struct vgic_irq *irq, *tmp; + +retry: + spin_lock(&vgic_cpu->ap_list_lock); + + list_for_each_entry_safe(irq, tmp, &vgic_cpu->ap_list_head, ap_list) { + struct kvm_vcpu *target_vcpu, *vcpuA, *vcpuB; + + spin_lock(&irq->irq_lock); + + BUG_ON(vcpu != irq->vcpu); + + target_vcpu = vgic_target_oracle(irq); + + if (!target_vcpu) { + /* + * We don't need to process this interrupt any + * further, move it off the list. + */ + list_del(&irq->ap_list); + irq->vcpu = NULL; + spin_unlock(&irq->irq_lock); + continue; + } + + if (target_vcpu == vcpu) { + /* We're on the right CPU */ + spin_unlock(&irq->irq_lock); + continue; + } + + /* This interrupt looks like it has to be migrated. */ + + spin_unlock(&irq->irq_lock); + spin_unlock(&vgic_cpu->ap_list_lock); + + /* + * Ensure locking order by always locking the smallest + * ID first. + */ + if (vcpu->vcpu_id < target_vcpu->vcpu_id) { + vcpuA = vcpu; + vcpuB = target_vcpu; + } else { + vcpuA = target_vcpu; + vcpuB = vcpu; + } + + spin_lock(&vcpuA->arch.vgic_cpu.ap_list_lock); + spin_lock_nested(&vcpuB->arch.vgic_cpu.ap_list_lock, + SINGLE_DEPTH_NESTING); + spin_lock(&irq->irq_lock); + + /* + * If the affinity has been preserved, move the + * interrupt around. Otherwise, it means things have + * changed while the interrupt was unlocked, and we + * need to replay this. + * + * In all cases, we cannot trust the list not to have + * changed, so we restart from the beginning. + */ + if (target_vcpu == vgic_target_oracle(irq)) { + struct vgic_cpu *new_cpu = &target_vcpu->arch.vgic_cpu; + + list_del(&irq->ap_list); + irq->vcpu = target_vcpu; + list_add_tail(&irq->ap_list, &new_cpu->ap_list_head); + } + + spin_unlock(&irq->irq_lock); + spin_unlock(&vcpuB->arch.vgic_cpu.ap_list_lock); + spin_unlock(&vcpuA->arch.vgic_cpu.ap_list_lock); + goto retry; + } + + spin_unlock(&vgic_cpu->ap_list_lock); +} + +static inline void vgic_process_maintenance_interrupt(struct kvm_vcpu *vcpu) +{ +} + +static inline void vgic_fold_lr_state(struct kvm_vcpu *vcpu) +{ +} + +/* Requires the irq_lock to be held. */ +static inline void vgic_populate_lr(struct kvm_vcpu *vcpu, + struct vgic_irq *irq, int lr) +{ + DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&irq->irq_lock)); +} + +static inline void vgic_clear_lr(struct kvm_vcpu *vcpu, int lr) +{ +} + +static inline void vgic_set_underflow(struct kvm_vcpu *vcpu) +{ +} + +/* Requires the ap_list_lock to be held. */ +static int compute_ap_list_depth(struct kvm_vcpu *vcpu) +{ + struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu; + struct vgic_irq *irq; + int count = 0; + + DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&vgic_cpu->ap_list_lock)); + + list_for_each_entry(irq, &vgic_cpu->ap_list_head, ap_list) { + spin_lock(&irq->irq_lock); + /* GICv2 SGIs can count for more than one... */ + if (vgic_irq_is_sgi(irq->intid) && irq->source) + count += hweight8(irq->source); + else + count++; + spin_unlock(&irq->irq_lock); + } + return count; +} + +/* Requires the VCPU's ap_list_lock to be held. */ +static void vgic_flush_lr_state(struct kvm_vcpu *vcpu) +{ + struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu; + struct vgic_irq *irq; + int count = 0; + + DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&vgic_cpu->ap_list_lock)); + + if (compute_ap_list_depth(vcpu) > kvm_vgic_global_state.nr_lr) { + vgic_set_underflow(vcpu); + vgic_sort_ap_list(vcpu); + } + + list_for_each_entry(irq, &vgic_cpu->ap_list_head, ap_list) { + spin_lock(&irq->irq_lock); + + if (unlikely(vgic_target_oracle(irq) != vcpu)) + goto next; + + /* + * If we get an SGI with multiple sources, try to get + * them in all at once. + */ + do { + vgic_populate_lr(vcpu, irq, count++); + } while (irq->source && count < kvm_vgic_global_state.nr_lr); + +next: + spin_unlock(&irq->irq_lock); + + if (count == kvm_vgic_global_state.nr_lr) + break; + } + + vcpu->arch.vgic_cpu.used_lrs = count; + + /* Nuke remaining LRs */ + for ( ; count < kvm_vgic_global_state.nr_lr; count++) + vgic_clear_lr(vcpu, count); +} + +/* Sync back the hardware VGIC state into our emulation after a guest's run. */ +void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu) +{ + vgic_process_maintenance_interrupt(vcpu); + vgic_fold_lr_state(vcpu); + vgic_prune_ap_list(vcpu); +} + +/* Flush our emulation state into the GIC hardware before entering the guest. */ +void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu) +{ + spin_lock(&vcpu->arch.vgic_cpu.ap_list_lock); + vgic_flush_lr_state(vcpu); + spin_unlock(&vcpu->arch.vgic_cpu.ap_list_lock); +} |