Re: [PATCH v9 10/12] vfio: Add function to get device_api string from vfio_device_info.flags

[Alex Williamson]

On Tue, 18 Oct 2016 02:52:10 +0530
Kirti Wankhede <kwankhede@xxxxxxxxxx> wrote:

> Function vfio_device_api_string() returns string based on flag set in
> vfio_device_info's flag. This should be used by vendor driver to get string
> based on flag for device_api attribute.
> 
> Signed-off-by: Kirti Wankhede <kwankhede@xxxxxxxxxx>
> Signed-off-by: Neo Jia <cjia@xxxxxxxxxx>
> Change-Id: I42d29f475f02a7132ce13297fbf2b48f1da10995
> ---
>  drivers/vfio/vfio.c  | 15 +++++++++++++++
>  include/linux/vfio.h |  2 ++
>  2 files changed, 17 insertions(+)
> 
> diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
> index 10ef1c5fa762..aec470454a13 100644
> --- a/drivers/vfio/vfio.c
> +++ b/drivers/vfio/vfio.c
> @@ -1917,6 +1917,21 @@ int vfio_set_irqs_validate_and_prepare(struct vfio_irq_set *hdr, int num_irqs,
>  }
>  EXPORT_SYMBOL(vfio_set_irqs_validate_and_prepare);
>  
> +const char *vfio_device_api_string(u32 flags)
> +{
> +	if (flags & VFIO_DEVICE_FLAGS_PCI)
> +		return "vfio-pci";
> +
> +	if (flags & VFIO_DEVICE_FLAGS_PLATFORM)
> +		return "vfio-platform";
> +
> +	if (flags & VFIO_DEVICE_FLAGS_AMBA)
> +		return "vfio-amba";
> +
> +	return "";
> +}
> +EXPORT_SYMBOL(vfio_device_api_string);
> +
>  /*
>   * Pin a set of guest PFNs and return their associated host PFNs for local
>   * domain only.
> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
> index 31d059f1649b..fca2bf23c4f1 100644
> --- a/include/linux/vfio.h
> +++ b/include/linux/vfio.h
> @@ -116,6 +116,8 @@ extern int vfio_set_irqs_validate_and_prepare(struct vfio_irq_set *hdr,
>  					      int num_irqs, int max_irq_type,
>  					      size_t *data_size);
>  
> +extern const char *vfio_device_api_string(u32 flags);
> +
>  struct pci_dev;
>  #ifdef CONFIG_EEH
>  extern void vfio_spapr_pci_eeh_open(struct pci_dev *pdev);

Couldn't this simply be a #define in the uapi header?

#define VFIO_DEVICE_PCI_API_STRING "vfio-pci"

I don't really see why we need a lookup function.