Re: [PATCH 3/3] KVM: arm: Enable vGICv2 software emulation

[Marc Zyngier <marc.zyngier@arm.com>]

On 29/06/15 10:53, Pavel Fedin wrote:
> The emulation code is automatically enabled when one of vGIC resources
> is missing from the device tree

Hold on a second. In your cover letter, your saying "RPi-2". The RPi-2
doesn't have a GIC at all, so I'd really like to know *how* you end-up
in the GICv2 probe function?

Thanks,

	M.

> 
> Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
> ---
>  virt/kvm/arm/vgic-v2.c | 29 ++++++++++++++---------------
>  virt/kvm/arm/vgic.c    | 10 ++++++----
>  2 files changed, 20 insertions(+), 19 deletions(-)
> 
> diff --git a/virt/kvm/arm/vgic-v2.c b/virt/kvm/arm/vgic-v2.c
> index f9b9c7c..b371a59 100644
> --- a/virt/kvm/arm/vgic-v2.c
> +++ b/virt/kvm/arm/vgic-v2.c
> @@ -180,22 +180,27 @@ int vgic_v2_probe(struct device_node *vgic_node,
>  		  const struct vgic_ops **ops,
>  		  const struct vgic_params **params)
>  {
> -	int ret;
> +	int ret = 0;
>  	struct resource vctrl_res;
>  	struct resource vcpu_res;
>  	struct vgic_params *vgic = &vgic_v2_params;
>  
> +	vgic->nr_lr = VGIC_V2_MAX_LRS;
> +
>  	vgic->maint_irq = irq_of_parse_and_map(vgic_node, 0);
>  	if (!vgic->maint_irq) {
>  		kvm_err("error getting vgic maintenance irq from DT\n");
> -		ret = -ENXIO;
> -		goto out;
> +		goto sw_emul;
>  	}
>  
> -	ret = of_address_to_resource(vgic_node, 2, &vctrl_res);
> -	if (ret) {
> +	if (of_address_to_resource(vgic_node, 2, &vctrl_res)) {
>  		kvm_err("Cannot obtain GICH resource\n");
> -		goto out;
> +		goto sw_emul;
> +	}
> +
> +	if (of_address_to_resource(vgic_node, 3, &vcpu_res)) {
> +		kvm_err("Cannot obtain GICV resource\n");
> +		goto sw_emul;
>  	}
>  
>  	vgic->vctrl_base = of_iomap(vgic_node, 2);
> @@ -216,12 +221,6 @@ int vgic_v2_probe(struct device_node *vgic_node,
>  		goto out_unmap;
>  	}
>  
> -	if (of_address_to_resource(vgic_node, 3, &vcpu_res)) {
> -		kvm_err("Cannot obtain GICV resource\n");
> -		ret = -ENXIO;
> -		goto out_unmap;
> -	}
> -
>  	if (!PAGE_ALIGNED(vcpu_res.start)) {
>  		kvm_err("GICV physical address 0x%llx not page aligned\n",
>  			(unsigned long long)vcpu_res.start);
> @@ -237,13 +236,13 @@ int vgic_v2_probe(struct device_node *vgic_node,
>  		goto out_unmap;
>  	}
>  
> -	vgic->can_emulate_gicv2 = true;
> -	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,
>  		 vctrl_res.start, vgic->maint_irq);
> +sw_emul:
> +	vgic->can_emulate_gicv2 = true;
> +	kvm_register_device_ops(&kvm_arm_vgic_v2_ops, KVM_DEV_TYPE_ARM_VGIC_V2);
>  
>  	vgic->type = VGIC_V2;
>  	vgic->max_gic_vcpus = VGIC_V2_MAX_CPUS;
> diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
> index aec6063..66e0cae 100644
> --- a/virt/kvm/arm/vgic.c
> +++ b/virt/kvm/arm/vgic.c
> @@ -2196,11 +2196,13 @@ int kvm_vgic_hyp_init(void)
>  	if (ret)
>  		return ret;
>  
> -	ret = request_percpu_irq(vgic->maint_irq, vgic_maintenance_handler,
> +	if (vgic->maint_irq) {
> +		ret = request_percpu_irq(vgic->maint_irq, vgic_maintenance_handler,
>  				 "vgic", kvm_get_running_vcpus());
> -	if (ret) {
> -		kvm_err("Cannot register interrupt %d\n", vgic->maint_irq);
> -		return ret;
> +		if (ret) {
> +			kvm_err("Cannot register interrupt %d\n", vgic->maint_irq);
> +			return ret;
> +		}
>  	}
>  
>  	ret = __register_cpu_notifier(&vgic_cpu_nb);
> 


-- 
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