From a98f26f183801685ef57333de4bafd4bbc692c7c Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 8 Jul 2014 12:09:07 +0100 Subject: arm/arm64: KVM: vgic: make number of irqs a configurable attribute In order to make the number of interrupts configurable, use the new fancy device management API to add KVM_DEV_ARM_VGIC_GRP_NR_IRQS as a VGIC configurable attribute. Userspace can now specify the exact size of the GIC (by increments of 32 interrupts). Reviewed-by: Christoffer Dall Signed-off-by: Marc Zyngier --- virt/kvm/arm/vgic.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) (limited to 'virt') diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c index ac2b44d58e60..b6fab0f25f3b 100644 --- a/virt/kvm/arm/vgic.c +++ b/virt/kvm/arm/vgic.c @@ -2253,6 +2253,36 @@ static int vgic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr) return vgic_attr_regs_access(dev, attr, ®, true); } + case KVM_DEV_ARM_VGIC_GRP_NR_IRQS: { + u32 __user *uaddr = (u32 __user *)(long)attr->addr; + u32 val; + int ret = 0; + + if (get_user(val, uaddr)) + return -EFAULT; + + /* + * We require: + * - at least 32 SPIs on top of the 16 SGIs and 16 PPIs + * - at most 1024 interrupts + * - a multiple of 32 interrupts + */ + if (val < (VGIC_NR_PRIVATE_IRQS + 32) || + val > VGIC_MAX_IRQS || + (val & 31)) + return -EINVAL; + + mutex_lock(&dev->kvm->lock); + + if (vgic_initialized(dev->kvm) || dev->kvm->arch.vgic.nr_irqs) + ret = -EBUSY; + else + dev->kvm->arch.vgic.nr_irqs = val; + + mutex_unlock(&dev->kvm->lock); + + return ret; + } } @@ -2289,6 +2319,11 @@ static int vgic_get_attr(struct kvm_device *dev, struct kvm_device_attr *attr) r = put_user(reg, uaddr); break; } + case KVM_DEV_ARM_VGIC_GRP_NR_IRQS: { + u32 __user *uaddr = (u32 __user *)(long)attr->addr; + r = put_user(dev->kvm->arch.vgic.nr_irqs, uaddr); + break; + } } @@ -2325,6 +2360,8 @@ static int vgic_has_attr(struct kvm_device *dev, struct kvm_device_attr *attr) case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: offset = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK; return vgic_has_attr_regs(vgic_cpu_ranges, offset); + case KVM_DEV_ARM_VGIC_GRP_NR_IRQS: + return 0; } return -ENXIO; } -- cgit v1.2.3-59-g8ed1b