From a98f26f183801685ef57333de4bafd4bbc692c7c Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 8 Jul 2014 12:09:07 +0100 Subject: [PATCH] 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 --- .../virtual/kvm/devices/arm-vgic.txt | 10 +++++ arch/arm/include/uapi/asm/kvm.h | 1 + arch/arm64/include/uapi/asm/kvm.h | 1 + virt/kvm/arm/vgic.c | 37 +++++++++++++++++++ 4 files changed, 49 insertions(+) diff --git a/Documentation/virtual/kvm/devices/arm-vgic.txt b/Documentation/virtual/kvm/devices/arm-vgic.txt index 7f4e91b1316b..df8b0c7540b6 100644 --- a/Documentation/virtual/kvm/devices/arm-vgic.txt +++ b/Documentation/virtual/kvm/devices/arm-vgic.txt @@ -71,3 +71,13 @@ Groups: Errors: -ENODEV: Getting or setting this register is not yet supported -EBUSY: One or more VCPUs are running + + KVM_DEV_ARM_VGIC_GRP_NR_IRQS + Attributes: + A value describing the number of interrupts (SGI, PPI and SPI) for + this GIC instance, ranging from 64 to 1024, in increments of 32. + + Errors: + -EINVAL: Value set is out of the expected range + -EBUSY: Value has already be set, or GIC has already been initialized + with default values. diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h index 51257fda254b..09ee408c1a67 100644 --- a/arch/arm/include/uapi/asm/kvm.h +++ b/arch/arm/include/uapi/asm/kvm.h @@ -174,6 +174,7 @@ struct kvm_arch_memory_slot { #define KVM_DEV_ARM_VGIC_CPUID_MASK (0xffULL << KVM_DEV_ARM_VGIC_CPUID_SHIFT) #define KVM_DEV_ARM_VGIC_OFFSET_SHIFT 0 #define KVM_DEV_ARM_VGIC_OFFSET_MASK (0xffffffffULL << KVM_DEV_ARM_VGIC_OFFSET_SHIFT) +#define KVM_DEV_ARM_VGIC_GRP_NR_IRQS 3 /* KVM_IRQ_LINE irq field index values */ #define KVM_ARM_IRQ_TYPE_SHIFT 24 diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h index f4ec5a674d05..8e38878c87c6 100644 --- a/arch/arm64/include/uapi/asm/kvm.h +++ b/arch/arm64/include/uapi/asm/kvm.h @@ -160,6 +160,7 @@ struct kvm_arch_memory_slot { #define KVM_DEV_ARM_VGIC_CPUID_MASK (0xffULL << KVM_DEV_ARM_VGIC_CPUID_SHIFT) #define KVM_DEV_ARM_VGIC_OFFSET_SHIFT 0 #define KVM_DEV_ARM_VGIC_OFFSET_MASK (0xffffffffULL << KVM_DEV_ARM_VGIC_OFFSET_SHIFT) +#define KVM_DEV_ARM_VGIC_GRP_NR_IRQS 3 /* KVM_IRQ_LINE irq field index values */ #define KVM_ARM_IRQ_TYPE_SHIFT 24 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; } -- 2.20.1