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

From: Gavin Shan <[email-masked]>
Date: Thu, 7 Aug 2014 12:10:07 +1000

On Wed, Aug 06, 2014 at 11:05:43PM +1000, Alexey Kardashevskiy wrote:
>On 08/06/2014 10:50 PM, Alex Williamson wrote:
>> On Wed, 2014-08-06 at 19:49 +1000, Gavin Shan wrote:
>>> From: Alexey Kardashevskiy <[email-masked]>
>>>
>>> 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 <[email-masked]>
>>> Signed-off-by: Gavin Shan <[email-masked]>
>>> ---
>>> 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?
>
>
>Comrade Gavin just forgot it :)
>
>Gavin, please add it. Thanks!
>

Sure, I'll add following warning message in eeh_dev_open() in
separate patch in v4 in case nobody objects.

int eeh_dev_open(struct pci_dev *pdev)
{
        :
        /* No EEH device or PE ? */
        edev = pci_dev_to_eeh_dev(pdev);
        if (!edev || !edev->pe) {
		pr_warn_once("%s: Device %s not supported\n",
			     __func__, pci_name(pdev));
                goto out;
        }
        :
}

Thanks,
Gavin

>
>
>> 
>>>  }
>>>  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)
>> 
>> 
>> 
>
>
>-- 
>Alexey
>