Subject: [RFC v5 08/13] KVM: kvm-vfio: wrappers for vfio_external_{mask|is_active|set_automasked}

From: [email-masked] (Alex Williamson)
Date: Tue, 31 Mar 2015 11:20:18 -0600

On Thu, 2015-03-19 at 15:55 +0100, Eric Auger wrote:
> Those 3 new wrapper functions call the respective VFIO external
> functions.
> 
> Signed-off-by: Eric Auger <[email-masked]>
> 
> ---
> 
> v4: creation
> ---
>  include/linux/vfio.h |  8 +++-----
>  virt/kvm/vfio.c      | 44 ++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 47 insertions(+), 5 deletions(-)
> 
> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
> index 7aa6330..78c1202 100644
> --- a/include/linux/vfio.h
> +++ b/include/linux/vfio.h
> @@ -108,14 +108,12 @@ extern struct device *vfio_external_base_device(struct vfio_device *vdev);
>  struct vfio_platform_device;
>  extern void vfio_external_mask(struct vfio_platform_device *vdev, int index);
>  /*
> - * returns whether the VFIO IRQ is active:
> - * true if not yet deactivated at interrupt controller level or if
> - * automasked (level sensitive IRQ). Unfortunately there is no way to
> - * discriminate between handler auto-masking and user-space masking
> + * returns whether the VFIO IRQ is active at interrupt controller level
> + * or VFIO-masked. Note that if the use-space masked the IRQ index it
> + * cannot be discriminated from automasked handler situation.
>   */
>  extern bool vfio_external_is_active(struct vfio_platform_device *vdev,
>  				    int index);
> -
>  extern void vfio_external_set_automasked(struct vfio_platform_device *vdev,
>  					 int index, bool automasked);
>  
> diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c
> index 80a45e4..c995e51 100644
> --- a/virt/kvm/vfio.c
> +++ b/virt/kvm/vfio.c
> @@ -134,6 +134,50 @@ static void kvm_vfio_put_vfio_device(struct vfio_device *vdev)
>  	kvm_vfio_device_put_external_user(vdev);
>  }
>  
> +bool kvm_vfio_external_is_active(struct vfio_platform_device *vpdev,
> +				 int index)
> +{
> +	bool (*fn)(struct vfio_platform_device *, int index);
> +	bool active;
> +
> +	fn = symbol_get(vfio_external_is_active);
> +	if (!fn)
> +		return -1;
> +
> +	active = fn(vpdev, index);
> +
> +	symbol_put(vfio_external_is_active);
> +	return active;
> +}
> +
> +void kvm_vfio_external_mask(struct vfio_platform_device *vpdev,
> +			    int index)
> +{
> +	void (*fn)(struct vfio_platform_device *, int index);
> +
> +	fn = symbol_get(vfio_external_mask);
> +	if (!fn)
> +		return;
> +
> +	fn(vpdev, index);
> +
> +	symbol_put(vfio_external_mask);
> +}
> +
> +void kvm_vfio_external_set_automasked(struct vfio_platform_device *vpdev,
> +				      int index, bool automasked)
> +{
> +	void (*fn)(struct vfio_platform_device *, int index, bool automasked);
> +
> +	fn = symbol_get(vfio_external_set_automasked);
> +	if (!fn)
> +		return;
> +
> +	fn(vpdev, index, automasked);
> +
> +	symbol_put(vfio_external_set_automasked);
> +}
> +

I think we'd really prefer not to be dealing with vfio_platform_devices
here.

>  static bool kvm_vfio_group_is_coherent(struct vfio_group *vfio_group)
>  {
>  	long (*fn)(struct vfio_group *, unsigned long);