On Thu, Sep 11, 2014 at 12:09:15PM +0100, Marc Zyngier wrote: > 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). > > Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx> > --- > Documentation/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 7f4e91b..df8b0c7 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 e6ebdd3..8b51c1a 100644 > --- a/arch/arm/include/uapi/asm/kvm.h > +++ b/arch/arm/include/uapi/asm/kvm.h > @@ -173,6 +173,7 @@ 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 e633ff8..b5cd6ed 100644 > --- a/arch/arm64/include/uapi/asm/kvm.h > +++ b/arch/arm64/include/uapi/asm/kvm.h > @@ -159,6 +159,7 @@ 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 9180823..744388d 100644 > --- a/virt/kvm/arm/vgic.c > +++ b/virt/kvm/arm/vgic.c > @@ -2331,6 +2331,36 @@ 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; > + } > > } > > @@ -2367,6 +2397,11 @@ 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; > + } > > } > > @@ -2403,6 +2438,8 @@ 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; > } > -- > 2.0.4 > Reviewed-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html