Re: [PATCH v2 2/4] KVM: ARM: vgic: register kvm_device_ops dynamically

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

On Wed, Jul 09 2014 at  5:05:20 pm BST, Paolo Bonzini <pbonzini@redhat.com> wrote:
> Il 01/07/2014 16:45, Will Deacon ha scritto:
>> Now that we have a dynamic means to register kvm_device_ops, use that
>> for the ARM VGIC, instead of relying on the static table.
>>
>> Cc: Gleb Natapov <gleb@kernel.org>
>> Cc: Paolo Bonzini <pbonzini@redhat.com>
>> Cc: Marc Zyngier <marc.zyngier@arm.com>
>> Cc: Christoffer Dall <christoffer.dall@linaro.org>
>> Signed-off-by: Will Deacon <will.deacon@arm.com>
>> ---
>>  include/linux/kvm_host.h |   1 -
>>  virt/kvm/arm/vgic.c      | 156 +++++++++++++++++++++++------------------------
>>  virt/kvm/kvm_main.c      |   4 --
>>  3 files changed, 78 insertions(+), 83 deletions(-)
>>
>> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
>> index b75faaf0d76d..4317fdd10696 100644
>> --- a/include/linux/kvm_host.h
>> +++ b/include/linux/kvm_host.h
>> @@ -1088,7 +1088,6 @@ int kvm_register_device_ops(struct kvm_device_ops *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_vfio_ops;
>> -extern struct kvm_device_ops kvm_arm_vgic_v2_ops;
>>  extern struct kvm_device_ops kvm_flic_ops;
>>
>>  #ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT
>> diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
>> index 795ab482333d..d9d0bcebad2b 100644
>> --- a/virt/kvm/arm/vgic.c
>> +++ b/virt/kvm/arm/vgic.c
>> @@ -1502,83 +1502,6 @@ int kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu)
>>  	return 0;
>>  }
>>
>> -static void vgic_init_maintenance_interrupt(void *info)
>> -{
>> -	enable_percpu_irq(vgic->maint_irq, 0);
>> -}
>> -
>> -static int vgic_cpu_notify(struct notifier_block *self,
>> -			   unsigned long action, void *cpu)
>> -{
>> -	switch (action) {
>> -	case CPU_STARTING:
>> -	case CPU_STARTING_FROZEN:
>> -		vgic_init_maintenance_interrupt(NULL);
>> -		break;
>> -	case CPU_DYING:
>> -	case CPU_DYING_FROZEN:
>> -		disable_percpu_irq(vgic->maint_irq);
>> -		break;
>> -	}
>> -
>> -	return NOTIFY_OK;
>> -}
>> -
>> -static struct notifier_block vgic_cpu_nb = {
>> -	.notifier_call = vgic_cpu_notify,
>> -};
>> -
>> -static const struct of_device_id vgic_ids[] = {
>> -	{ .compatible = "arm,cortex-a15-gic", .data = vgic_v2_probe, },
>> -	{ .compatible = "arm,gic-v3", .data = vgic_v3_probe, },
>> -	{},
>> -};
>> -
>> -int kvm_vgic_hyp_init(void)
>> -{
>> -	const struct of_device_id *matched_id;
>> -	int (*vgic_probe)(struct device_node *,const struct vgic_ops **,
>> -			  const struct vgic_params **);
>> -	struct device_node *vgic_node;
>> -	int ret;
>> -
>> -	vgic_node = of_find_matching_node_and_match(NULL,
>> -						    vgic_ids, &matched_id);
>> -	if (!vgic_node) {
>> -		kvm_err("error: no compatible GIC node found\n");
>> -		return -ENODEV;
>> -	}
>> -
>> -	vgic_probe = matched_id->data;
>> -	ret = vgic_probe(vgic_node, &vgic_ops, &vgic);
>> -	if (ret)
>> -		return ret;
>> -
>> -	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;
>> -	}
>> -
>> -	ret = __register_cpu_notifier(&vgic_cpu_nb);
>> -	if (ret) {
>> -		kvm_err("Cannot register vgic CPU notifier\n");
>> -		goto out_free_irq;
>> -	}
>> -
>> -	on_each_cpu(vgic_init_maintenance_interrupt, NULL, 1);
>> -
>> -	/* Callback into for arch code for setup */
>> -	vgic_arch_setup(vgic);
>> -
>> -	return 0;
>> -
>> -out_free_irq:
>> -	free_percpu_irq(vgic->maint_irq, kvm_get_running_vcpus());
>> -	return ret;
>> -}
>> -
>>  /**
>>   * kvm_vgic_init - Initialize global VGIC state before running any VCPUs
>>   * @kvm: pointer to the kvm struct
>> @@ -2042,7 +1965,7 @@ static int vgic_create(struct kvm_device *dev, u32 type)
>>  	return kvm_vgic_create(dev->kvm);
>>  }
>>
>> -struct kvm_device_ops kvm_arm_vgic_v2_ops = {
>> +static struct kvm_device_ops kvm_arm_vgic_v2_ops = {
>>  	.name = "kvm-arm-vgic",
>>  	.create = vgic_create,
>>  	.destroy = vgic_destroy,
>> @@ -2050,3 +1973,80 @@ struct kvm_device_ops kvm_arm_vgic_v2_ops = {
>>  	.get_attr = vgic_get_attr,
>>  	.has_attr = vgic_has_attr,
>>  };
>> +
>> +static void vgic_init_maintenance_interrupt(void *info)
>> +{
>> +	enable_percpu_irq(vgic->maint_irq, 0);
>> +}
>> +
>> +static int vgic_cpu_notify(struct notifier_block *self,
>> +			   unsigned long action, void *cpu)
>> +{
>> +	switch (action) {
>> +	case CPU_STARTING:
>> +	case CPU_STARTING_FROZEN:
>> +		vgic_init_maintenance_interrupt(NULL);
>> +		break;
>> +	case CPU_DYING:
>> +	case CPU_DYING_FROZEN:
>> +		disable_percpu_irq(vgic->maint_irq);
>> +		break;
>> +	}
>> +
>> +	return NOTIFY_OK;
>> +}
>> +
>> +static struct notifier_block vgic_cpu_nb = {
>> +	.notifier_call = vgic_cpu_notify,
>> +};
>> +
>> +static const struct of_device_id vgic_ids[] = {
>> +	{ .compatible = "arm,cortex-a15-gic", .data = vgic_v2_probe, },
>> +	{ .compatible = "arm,gic-v3", .data = vgic_v3_probe, },
>> +	{},
>> +};
>> +
>> +int kvm_vgic_hyp_init(void)
>> +{
>> +	const struct of_device_id *matched_id;
>> +	int (*vgic_probe)(struct device_node *,const struct vgic_ops **,
>> +			  const struct vgic_params **);
>> +	struct device_node *vgic_node;
>> +	int ret;
>> +
>> +	vgic_node = of_find_matching_node_and_match(NULL,
>> +						    vgic_ids, &matched_id);
>> +	if (!vgic_node) {
>> +		kvm_err("error: no compatible GIC node found\n");
>> +		return -ENODEV;
>> +	}
>> +
>> +	vgic_probe = matched_id->data;
>> +	ret = vgic_probe(vgic_node, &vgic_ops, &vgic);
>> +	if (ret)
>> +		return ret;
>> +
>> +	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;
>> +	}
>> +
>> +	ret = __register_cpu_notifier(&vgic_cpu_nb);
>> +	if (ret) {
>> +		kvm_err("Cannot register vgic CPU notifier\n");
>> +		goto out_free_irq;
>> +	}
>> +
>> +	on_each_cpu(vgic_init_maintenance_interrupt, NULL, 1);
>> +
>> +	/* Callback into for arch code for setup */
>> +	vgic_arch_setup(vgic);
>> +	return kvm_register_device_ops(&kvm_arm_vgic_v2_ops,
>> +				       KVM_DEV_TYPE_ARM_VGIC_V2);
>> +
>> +out_free_irq:
>> +	free_percpu_irq(vgic->maint_irq, kvm_get_running_vcpus());
>> +	return ret;
>> +}
>> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
>> index a8539ae10247..7eab47222dcf 100644
>> --- a/virt/kvm/kvm_main.c
>> +++ b/virt/kvm/kvm_main.c
>> @@ -2271,10 +2271,6 @@ static struct kvm_device_ops *kvm_device_ops_table[KVM_DEV_TYPE_MAX] = {
>>  	[KVM_DEV_TYPE_VFIO]		= &kvm_vfio_ops,
>>  #endif
>>
>> -#ifdef CONFIG_KVM_ARM_VGIC
>> -	[KVM_DEV_TYPE_ARM_VGIC_V2]	= &kvm_arm_vgic_v2_ops,
>> -#endif
>> -
>>  #ifdef CONFIG_S390
>>  	[KVM_DEV_TYPE_FLIC]		= &kvm_flic_ops,
>>  #endif
>>
>
> Christopher, Marc, can you review/ack this?

I though I had replied already, but apparently not... The proximity
effect, probably! ;-)

Acked-by: Marc Zyngier <marc.zyngier@arm.com>

	M.
-- 
Without deviation from the norm, progress is not possible.