Re: [PATCH v4 5/7] KVM: arm/arm64: build a default routing table

[Eric Auger <eric.auger@linaro.org>]

On 04/14/2016 02:05 PM, Christoffer Dall wrote:
> On Mon, Apr 04, 2016 at 10:47:35AM +0200, Eric Auger wrote:
>> Implement a default routing table made of flat irqchip routing
>> entries (gsi = irqchip.pin) covering the VGIC SPI indexes.
>> This routing table is overwritten by the first user-space call
>> to KVM_SET_GSI_ROUTING ioctl.
>>
>> Signed-off-by: Eric Auger <eric.auger@linaro.org>
>>
> 
> so before applying this patch, but after applying the previous patch,
> will our current GICv2m-based MSI injection work?

If you don't apply that patch and kernel does not build a default table,
userspace is obliged to do the job. if it doesn't the irqfd-> virtual
gsi forwarding will fail. So effectively it makes sense to squash both
patches.

> 
> If not, is there a better split of these patches (e.g. squash this one
> into the previous one)?
> 
>> ---
>> ---
>>  virt/kvm/arm/vgic/vgic_init.c | 24 ++++++++++++++++++++++++
>>  1 file changed, 24 insertions(+)
>>
>> diff --git a/virt/kvm/arm/vgic/vgic_init.c b/virt/kvm/arm/vgic/vgic_init.c
>> index e4459e3..041443b 100644
>> --- a/virt/kvm/arm/vgic/vgic_init.c
>> +++ b/virt/kvm/arm/vgic/vgic_init.c
>> @@ -261,6 +261,10 @@ int vgic_init(struct kvm *kvm)
>>  	kvm_for_each_vcpu(i, vcpu, kvm)
>>  		kvm_vgic_vcpu_init(vcpu);
>>  
>> +	ret = kvm_setup_default_irq_routing(kvm);
>> +	if (ret)
>> +		goto out;
>> +
>>  	dist->initialized = true;
>>  out:
>>  	return ret;
>> @@ -454,3 +458,23 @@ out_free_irq:
>>  			kvm_get_running_vcpus());
>>  	return ret;
>>  }
>> +
>> +int kvm_setup_default_irq_routing(struct kvm *kvm)
>> +{
>> +	struct kvm_irq_routing_entry *entries;
>> +	struct vgic_dist *dist = &kvm->arch.vgic;
>> +	u32 nr = dist->nr_spis;
>> +	int i, ret;
>> +
>> +	entries = kcalloc(nr, sizeof(struct kvm_kernel_irq_routing_entry),
>> +			  GFP_KERNEL);
> 
> I think you need to check if the allocation succeeded here or not...
sure

thanks

Eric
> 
>> +	for (i = 0; i < nr; i++) {
>> +		entries[i].gsi = i;
>> +		entries[i].type = KVM_IRQ_ROUTING_IRQCHIP;
>> +		entries[i].u.irqchip.irqchip = 0;
>> +		entries[i].u.irqchip.pin = i;
>> +	}
>> +	ret = kvm_set_irq_routing(kvm, entries, nr, 0);
>> +	kfree(entries);
>> +	return ret;
>> +}
>> -- 
>> 1.9.1
>>