[PATCH v4 06/19] arm/arm64: KVM: move kvm_register_device_ops() into vGIC probing

[Eric Auger]

On 11/14/2014 11:07 AM, Andre Przywara wrote:
> Currently we unconditionally register the GICv2 emulation device
> during the host's KVM initialization. Since with GICv3 support we
> may end up with only v2 or only v3 or both supported, we move the
> registration into the GIC probing function, where we will later know
> which combination is valid.
> 
> Signed-off-by: Andre Przywara <andre.przywara at arm.com>
> Acked-by: Christoffer Dall <christoffer.dall at linaro.org>
> ---
> Changelog v3...v4:
> - add Acked-by
> 
>  include/linux/kvm_host.h |    1 +
>  virt/kvm/arm/vgic-v2.c   |    2 ++
>  virt/kvm/arm/vgic-v3.c   |    1 +
>  virt/kvm/arm/vgic.c      |    5 ++---
>  4 files changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index ea53b04..326ba7a 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -1084,6 +1084,7 @@ void kvm_unregister_device_ops(u32 type);
>  
>  extern struct kvm_device_ops kvm_mpic_ops;
>  extern struct kvm_device_ops kvm_xics_ops;
> +extern struct kvm_device_ops kvm_arm_vgic_v2_ops;
>  
>  #ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT
>  
> diff --git a/virt/kvm/arm/vgic-v2.c b/virt/kvm/arm/vgic-v2.c
> index 2935405..e1cd3cb 100644
> --- a/virt/kvm/arm/vgic-v2.c
> +++ b/virt/kvm/arm/vgic-v2.c
> @@ -229,6 +229,8 @@ int vgic_v2_probe(struct device_node *vgic_node,
>  		goto out_unmap;
>  	}
>  
> +	kvm_register_device_ops(&kvm_arm_vgic_v2_ops, KVM_DEV_TYPE_ARM_VGIC_V2);
> +
>  	vgic->vcpu_base = vcpu_res.start;
>  
>  	kvm_info("%s@%llx IRQ%d\n", vgic_node->name,
> diff --git a/virt/kvm/arm/vgic-v3.c b/virt/kvm/arm/vgic-v3.c
> index 1c2c8ee..d14c75f 100644
> --- a/virt/kvm/arm/vgic-v3.c
> +++ b/virt/kvm/arm/vgic-v3.c
> @@ -230,6 +230,7 @@ int vgic_v3_probe(struct device_node *vgic_node,
>  		ret = -ENXIO;
>  		goto out;
>  	}
> +	kvm_register_device_ops(&kvm_arm_vgic_v2_ops, KVM_DEV_TYPE_ARM_VGIC_V2);
I did not find any unregistration? I am wrong or isn't it relevant? If
confirmed might be added in kvm_arch_exit. Saw KVM-VFIO device ops
unregistration is done in kvm_exit/kvm_vfio_ops_exit.

Eric
>  
>  	vgic->vcpu_base = vcpu_res.start;
>  	vgic->vctrl_base = NULL;
> diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
> index 963b84e..e8003ca 100644
> --- a/virt/kvm/arm/vgic.c
> +++ b/virt/kvm/arm/vgic.c
> @@ -2540,7 +2540,7 @@ static int vgic_create(struct kvm_device *dev, u32 type)
>  	return kvm_vgic_create(dev->kvm, type);
>  }
>  
> -static struct kvm_device_ops kvm_arm_vgic_v2_ops = {
> +struct kvm_device_ops kvm_arm_vgic_v2_ops = {
>  	.name = "kvm-arm-vgic",
>  	.create = vgic_create,
>  	.destroy = vgic_destroy,
> @@ -2619,8 +2619,7 @@ int kvm_vgic_hyp_init(void)
>  
>  	on_each_cpu(vgic_init_maintenance_interrupt, NULL, 1);
>  
> -	return kvm_register_device_ops(&kvm_arm_vgic_v2_ops,
> -				       KVM_DEV_TYPE_ARM_VGIC_V2);
> +	return 0;
>  
>  out_free_irq:
>  	free_percpu_irq(vgic->maint_irq, kvm_get_running_vcpus());
>