Re: [RFC 12/17] irq: bypass: Extend skeleton for ARM forwarding control

Eric Auger
2015-07-03T13:12:48Z

Hi Paolo,
On 07/02/2015 03:40 PM, Paolo Bonzini wrote:
>
>
> On 02/07/2015 15:17, Eric Auger wrote:
>> - new fields are added on producer side: linux irq, vfio_device handle,
>> active which reflects whether the source is active (at interrupt
>> controller level or at VFIO level - automasked -) and finally an
>> opaque pointer which will be used to point to the vfio_platform_device
>> in this series.
>
> Linux IRQ and active should be okay. As to the vfio_device handle, you
> should link it from the vfio_platform_device instead. And for the
> vfio_platform_device, you can link it from the vfio_platform_irq instead.
For this last one, I don't think this is achievable since if I store the
vfio_platform_irq in the opaque, it matches irqs[i] of
vfio_platform_device and I don't have any mean to retrieve "i" when
calling container_of.

struct vfio_platform_irq *irq =
container_of(prod, struct vfio_platform_irq, producer);
struct vfio_platform_device *vpdev =
container_of(irq, struct vfio_platform_device, irqs[i?]);

struct vfio_platform_device {
../..
struct vfio_platform_irq *irqs;
../..
}
So I think I still need to pass vfio_platform_device in the opaque and
look on irqs array to identify the right vfio_platform_irq *.

Do I miss sthg?

- Eric

>
> Once you've done this, embed the irq_bypass_producer struct in the
> vfio_platform_irq struct; in the new kvm_arch_* functions, go back to
> the vfio_platform_irq struct via container_of. From there you can
> retrieve pointers to the vfio_platform_device and the vfio_device.
>
>> - new fields on consumer side: the kvm handle, the gsi
>
> You do not need to add these. Instead, add the kvm handle to irqfd
> only. Like above, embed the irq_bypass_consumer struct in the irqfd
> struct; in the new kvm_arch_* functions, go back to the
> vfio_platform_irq struct via container_of.
>
> Paolo
>