Re: [PATCH v11 17/22] vfio_platform: Updated to use vfio_set_irqs_validate_and_prepare()

[Kirti Wankhede <kwankhede@nvidia.com>]

On 11/8/2016 2:22 PM, Alexey Kardashevskiy wrote:
> On 05/11/16 08:10, Kirti Wankhede wrote:
>> Updated vfio_platform_common.c file to use
>> vfio_set_irqs_validate_and_prepare()
>>
>> Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
>> Signed-off-by: Neo Jia <cjia@nvidia.com>
>> Change-Id: Id87cd6b78ae901610b39bf957974baa6f40cd7b0
>> ---
>>  drivers/vfio/platform/vfio_platform_common.c | 31 +++++++---------------------
>>  1 file changed, 8 insertions(+), 23 deletions(-)
>>
>> diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
>> index d78142830754..4c27f4be3c3d 100644
>> --- a/drivers/vfio/platform/vfio_platform_common.c
>> +++ b/drivers/vfio/platform/vfio_platform_common.c
>> @@ -364,36 +364,21 @@ static long vfio_platform_ioctl(void *device_data,
>>  		struct vfio_irq_set hdr;
>>  		u8 *data = NULL;
>>  		int ret = 0;
>> +		size_t data_size = 0;
>>  
>>  		minsz = offsetofend(struct vfio_irq_set, count);
>>  
>>  		if (copy_from_user(&hdr, (void __user *)arg, minsz))
>>  			return -EFAULT;
>>  
>> -		if (hdr.argsz < minsz)
>> -			return -EINVAL;
>> -
>> -		if (hdr.index >= vdev->num_irqs)
>> -			return -EINVAL;
>> -
>> -		if (hdr.flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK |
>> -				  VFIO_IRQ_SET_ACTION_TYPE_MASK))
>> -			return -EINVAL;
>> -
>> -		if (!(hdr.flags & VFIO_IRQ_SET_DATA_NONE)) {
>> -			size_t size;
>> -
>> -			if (hdr.flags & VFIO_IRQ_SET_DATA_BOOL)
>> -				size = sizeof(uint8_t);
>> -			else if (hdr.flags & VFIO_IRQ_SET_DATA_EVENTFD)
>> -				size = sizeof(int32_t);
>> -			else
>> -				return -EINVAL;
>> -
>> -			if (hdr.argsz - minsz < size)
>> -				return -EINVAL;
>> +		ret = vfio_set_irqs_validate_and_prepare(&hdr, vdev->num_irqs,
>> +						 vdev->num_irqs, &data_size);
> 
> The patch does not change this but I am still curious:
> 
> is not the second vdev->num_irqs supposed to be one of
> VFIO_PCI_INTX_IRQ_INDEX..VFIO_PCI_NUM_IRQS, not the actual number of
> interrupt vectors (as in vfio-pci)?
> 
> 

Those are PCI specific. I don't think those counts are applicable here.

If you see the prototype, second argument and third argument have
different meaning.

int vfio_set_irqs_validate_and_prepare(struct vfio_irq_set *hdr, int
num_irqs, int max_irq_type, size_t *data_size)

- num_irqs are number of irqs caller want to setup and
- max_irq_type is the one which is return to user in
VFIO_DEVICE_GET_INFO ioctl's info.num_irqs.

For platform these two are same.

Thanks,
Kirti

> 
> 
>> +		if (ret)
>> +			return ret;
>>  
>> -			data = memdup_user((void __user *)(arg + minsz), size);
>> +		if (data_size) {
>> +			data = memdup_user((void __user *)(arg + minsz),
>> +					    data_size);
>>  			if (IS_ERR(data))
>>  				return PTR_ERR(data);
>>  		}
>>
> 
>