Re: [PATCH v5 05/22] KVM: arm64: vgic-its: KVM_DEV_ARM_VGIC_GRP_ITS_REGS group

[Christoffer Dall <christoffer.dall@xxxxxxxxxx>]

On Fri, Apr 14, 2017 at 12:15:17PM +0200, Eric Auger wrote:
> The ITS KVM device exposes a new KVM_DEV_ARM_VGIC_GRP_ITS_REGS
> group which allows the userspace to save/restore ITS registers.
> 
> At this stage the get/set/has operations are not yet implemented.
> 
> Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>
> Reviewed-by: Andre Przywara <andre.przywara@xxxxxxx>
> Acked-by: Marc Zyngier <marc.zyngier@xxxxxxx>

Reviewed-by: Christoffer Dall <cdall@xxxxxxxxxx>

> 
> ---
> v4 -> v5:
> - Add Marc's A-b
> 
> v3 -> v4:
> - added Andre's R-b
> ---
>  arch/arm/include/uapi/asm/kvm.h   |  1 +
>  arch/arm64/include/uapi/asm/kvm.h |  1 +
>  virt/kvm/arm/vgic/vgic-its.c      | 36 +++++++++++++++++++++++++++++++++++-
>  3 files changed, 37 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h
> index 6ebd3e6..4beb83b 100644
> --- a/arch/arm/include/uapi/asm/kvm.h
> +++ b/arch/arm/include/uapi/asm/kvm.h
> @@ -192,6 +192,7 @@ struct kvm_arch_memory_slot {
>  #define KVM_DEV_ARM_VGIC_GRP_REDIST_REGS 5
>  #define KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS 6
>  #define KVM_DEV_ARM_VGIC_GRP_LEVEL_INFO  7
> +#define KVM_DEV_ARM_VGIC_GRP_ITS_REGS	8
>  #define KVM_DEV_ARM_VGIC_LINE_LEVEL_INFO_SHIFT	10
>  #define KVM_DEV_ARM_VGIC_LINE_LEVEL_INFO_MASK \
>  			(0x3fffffULL << KVM_DEV_ARM_VGIC_LINE_LEVEL_INFO_SHIFT)
> diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
> index c286035..7e8dd69 100644
> --- a/arch/arm64/include/uapi/asm/kvm.h
> +++ b/arch/arm64/include/uapi/asm/kvm.h
> @@ -212,6 +212,7 @@ struct kvm_arch_memory_slot {
>  #define KVM_DEV_ARM_VGIC_GRP_REDIST_REGS 5
>  #define KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS 6
>  #define KVM_DEV_ARM_VGIC_GRP_LEVEL_INFO  7
> +#define KVM_DEV_ARM_VGIC_GRP_ITS_REGS 8
>  #define KVM_DEV_ARM_VGIC_LINE_LEVEL_INFO_SHIFT	10
>  #define KVM_DEV_ARM_VGIC_LINE_LEVEL_INFO_MASK \
>  			(0x3fffffULL << KVM_DEV_ARM_VGIC_LINE_LEVEL_INFO_SHIFT)
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index 3ffcbbe..f687e91 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -1466,6 +1466,19 @@ static void vgic_its_destroy(struct kvm_device *kvm_dev)
>  	kfree(its);
>  }
>  
> +int vgic_its_has_attr_regs(struct kvm_device *dev,
> +			   struct kvm_device_attr *attr)
> +{
> +	return -ENXIO;
> +}
> +
> +int vgic_its_attr_regs_access(struct kvm_device *dev,
> +			      struct kvm_device_attr *attr,
> +			      u64 *reg, bool is_write)
> +{
> +	return -ENXIO;
> +}
> +
>  static int vgic_its_has_attr(struct kvm_device *dev,
>  			     struct kvm_device_attr *attr)
>  {
> @@ -1482,6 +1495,8 @@ static int vgic_its_has_attr(struct kvm_device *dev,
>  			return 0;
>  		}
>  		break;
> +	case KVM_DEV_ARM_VGIC_GRP_ITS_REGS:
> +		return vgic_its_has_attr_regs(dev, attr);
>  	}
>  	return -ENXIO;
>  }
> @@ -1521,6 +1536,15 @@ static int vgic_its_set_attr(struct kvm_device *dev,
>  			return 0;
>  		}
>  		break;
> +	case KVM_DEV_ARM_VGIC_GRP_ITS_REGS: {
> +		u64 __user *uaddr = (u64 __user *)(long)attr->addr;
> +		u64 reg;
> +
> +		if (get_user(reg, uaddr))
> +			return -EFAULT;
> +
> +		return vgic_its_attr_regs_access(dev, attr, &reg, true);
> +	}
>  	}
>  	return -ENXIO;
>  }
> @@ -1541,10 +1565,20 @@ static int vgic_its_get_attr(struct kvm_device *dev,
>  		if (copy_to_user(uaddr, &addr, sizeof(addr)))
>  			return -EFAULT;
>  		break;
> +	}
> +	case KVM_DEV_ARM_VGIC_GRP_ITS_REGS: {
> +		u64 __user *uaddr = (u64 __user *)(long)attr->addr;
> +		u64 reg;
> +		int ret;
> +
> +		ret = vgic_its_attr_regs_access(dev, attr, &reg, false);
> +		if (ret)
> +			return ret;
> +		return put_user(reg, uaddr);
> +	}
>  	default:
>  		return -ENXIO;
>  	}
> -	}
>  
>  	return 0;
>  }
> -- 
> 2.5.5
>