Re: [PATCH v3 4/4] drivers/vfio: Enable VFIO if EEH is not supported

[Alex Williamson <alex.williamson@redhat.com>]

On Wed, 2014-08-06 at 19:49 +1000, Gavin Shan wrote:
> From: Alexey Kardashevskiy <aik@ozlabs.ru>
> 
> The existing vfio_pci_open() fails upon error returned from
> vfio_spapr_pci_eeh_open(), which breaks POWER7's P5IOC2 PHB
> support which this patch brings back.
> 
> The patch fixes the issue by dropping the return value of
> vfio_spapr_pci_eeh_open().
> 
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
> ---
> v3: Drop return value of vfio_spapr_pci_eeh_open()
> ---
>  drivers/vfio/pci/vfio_pci.c   | 6 +-----
>  drivers/vfio/vfio_spapr_eeh.c | 4 ++--
>  include/linux/vfio.h          | 5 ++---
>  3 files changed, 5 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
> index e2ee80f..32d69c8 100644
> --- a/drivers/vfio/pci/vfio_pci.c
> +++ b/drivers/vfio/pci/vfio_pci.c
> @@ -178,11 +178,7 @@ static int vfio_pci_open(void *device_data)
>  		if (ret)
>  			goto error;
>  
> -		ret = vfio_spapr_pci_eeh_open(vdev->pdev);
> -		if (ret) {
> -			vfio_pci_disable(vdev);
> -			goto error;
> -		}
> +		vfio_spapr_pci_eeh_open(vdev->pdev);
>  	}
>  
>  	return 0;
> diff --git a/drivers/vfio/vfio_spapr_eeh.c b/drivers/vfio/vfio_spapr_eeh.c
> index 4779cac..86dfceb 100644
> --- a/drivers/vfio/vfio_spapr_eeh.c
> +++ b/drivers/vfio/vfio_spapr_eeh.c
> @@ -19,9 +19,9 @@
>  #define DRIVER_DESC	"VFIO IOMMU SPAPR EEH"
>  
>  /* We might build address mapping here for "fast" path later */
> -int vfio_spapr_pci_eeh_open(struct pci_dev *pdev)
> +void vfio_spapr_pci_eeh_open(struct pci_dev *pdev)
>  {
> -	return eeh_dev_open(pdev);
> +	eeh_dev_open(pdev);

Wasn't there some intent to provide a warning message, that would now be
done here?  Has that idea been dropped?

>  }
>  EXPORT_SYMBOL_GPL(vfio_spapr_pci_eeh_open);
>  
> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
> index 224128a..d320411 100644
> --- a/include/linux/vfio.h
> +++ b/include/linux/vfio.h
> @@ -100,15 +100,14 @@ extern long vfio_external_check_extension(struct vfio_group *group,
>  
>  struct pci_dev;
>  #ifdef CONFIG_EEH
> -extern int vfio_spapr_pci_eeh_open(struct pci_dev *pdev);
> +extern void vfio_spapr_pci_eeh_open(struct pci_dev *pdev);
>  extern void vfio_spapr_pci_eeh_release(struct pci_dev *pdev);
>  extern long vfio_spapr_iommu_eeh_ioctl(struct iommu_group *group,
>  				       unsigned int cmd,
>  				       unsigned long arg);
>  #else
> -static inline int vfio_spapr_pci_eeh_open(struct pci_dev *pdev)
> +static inline void vfio_spapr_pci_eeh_open(struct pci_dev *pdev)
>  {
> -	return 0;
>  }
>  
>  static inline void vfio_spapr_pci_eeh_release(struct pci_dev *pdev)