Subject: Re: [PATCH v7 3/3] drivers/vfio: EEH support for VFIO PCI device

From: Alexander Graf <[email-masked]>
Date: Wed, 28 May 2014 00:49:14 +0200

On 27.05.14 20:15, Alex Williamson wrote:
> On Tue, 2014-05-27 at 18:40 +1000, Gavin Shan wrote:
>> The patch adds new IOCTL commands for sPAPR VFIO container device
>> to support EEH functionality for PCI devices, which have been passed
>> through from host to somebody else via VFIO.
>>
>> Signed-off-by: Gavin Shan <[email-masked]>
>> ---
>>   Documentation/vfio.txt              | 92 ++++++++++++++++++++++++++++++++++++-
>>   drivers/vfio/pci/Makefile           |  1 +
>>   drivers/vfio/pci/vfio_pci.c         | 20 +++++---
>>   drivers/vfio/pci/vfio_pci_eeh.c     | 46 +++++++++++++++++++
>>   drivers/vfio/pci/vfio_pci_private.h |  5 ++
>>   drivers/vfio/vfio_iommu_spapr_tce.c | 85 ++++++++++++++++++++++++++++++++++
>>   include/uapi/linux/vfio.h           | 66 ++++++++++++++++++++++++++
>>   7 files changed, 308 insertions(+), 7 deletions(-)
>>   create mode 100644 drivers/vfio/pci/vfio_pci_eeh.c

[...]

>> +
>> +	return ret;
>> +}
>> +
>>   static long tce_iommu_ioctl(void *iommu_data,
>>   				 unsigned int cmd, unsigned long arg)
>>   {
>> @@ -283,6 +363,11 @@ static long tce_iommu_ioctl(void *iommu_data,
>>   		tce_iommu_disable(container);
>>   		mutex_unlock(&container->lock);
>>   		return 0;
>> +	case VFIO_EEH_PE_SET_OPTION:
>> +	case VFIO_EEH_PE_GET_STATE:
>> +	case VFIO_EEH_PE_RESET:
>> +	case VFIO_EEH_PE_CONFIGURE:
>> +		return tce_iommu_eeh_ioctl(iommu_data, cmd, arg);
> This is where it would have really made sense to have a single
> VFIO_EEH_OP ioctl with a data structure passed to indicate the sub-op.
> AlexG, are you really attached to splitting these out into separate
> ioctls?

I don't see the problem. We need to forward 4 ioctls to a separate piece 
of code, so we forward 4 ioctls to a separate piece of code :). Putting 
them into one ioctl just moves the switch() into another function.

Alex