From c6ccd30e0de384f506449474ca780ff680ad4217 Mon Sep 17 00:00:00 2001 From: Christoffer Dall Date: Thu, 4 May 2017 13:24:20 +0200 Subject: KVM: arm/arm64: Introduce an allocator for in-kernel irq lines Having multiple devices being able to signal the same interrupt line is very confusing and almost certainly guarantees a configuration error. Therefore, introduce a very simple allocator which allows a device to claim an interrupt line from the vgic for a given VM. Signed-off-by: Christoffer Dall Acked-by: Marc Zyngier --- virt/kvm/arm/vgic/vgic.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) (limited to 'virt/kvm/arm/vgic/vgic.c') diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c index c66feaca2a5d..9628945234e4 100644 --- a/virt/kvm/arm/vgic/vgic.c +++ b/virt/kvm/arm/vgic/vgic.c @@ -434,6 +434,39 @@ int kvm_vgic_unmap_phys_irq(struct kvm_vcpu *vcpu, unsigned int virt_irq) return 0; } +/** + * kvm_vgic_set_owner - Set the owner of an interrupt for a VM + * + * @vcpu: Pointer to the VCPU (used for PPIs) + * @intid: The virtual INTID identifying the interrupt (PPI or SPI) + * @owner: Opaque pointer to the owner + * + * Returns 0 if intid is not already used by another in-kernel device and the + * owner is set, otherwise returns an error code. + */ +int kvm_vgic_set_owner(struct kvm_vcpu *vcpu, unsigned int intid, void *owner) +{ + struct vgic_irq *irq; + int ret = 0; + + if (!vgic_initialized(vcpu->kvm)) + return -EAGAIN; + + /* SGIs and LPIs cannot be wired up to any device */ + if (!irq_is_ppi(intid) && !vgic_valid_spi(vcpu->kvm, intid)) + return -EINVAL; + + irq = vgic_get_irq(vcpu->kvm, vcpu, intid); + spin_lock(&irq->irq_lock); + if (irq->owner && irq->owner != owner) + ret = -EEXIST; + else + irq->owner = owner; + spin_unlock(&irq->irq_lock); + + return ret; +} + /** * vgic_prune_ap_list - Remove non-relevant interrupts from the list * -- cgit