Re: [PATCH v8 28/29] vfio-pci: Add VFIO_PCI_DMA_FAULT_IRQ_INDEX

[Auger Eric]

Hi Alex,

On 6/4/19 12:31 AM, Alex Williamson wrote:
> On Sun, 26 May 2019 18:10:03 +0200
> Eric Auger <eric.auger@xxxxxxxxxx> wrote:
> 
>> Add a new VFIO_PCI_DMA_FAULT_IRQ_INDEX index. This allows to
>> set/unset an eventfd that will be triggered when DMA translation
>> faults are detected at physical level when the nested mode is used.
>>
>> Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>
>> ---
>>  drivers/vfio/pci/vfio_pci.c       |  3 +++
>>  drivers/vfio/pci/vfio_pci_intrs.c | 19 +++++++++++++++++++
>>  include/uapi/linux/vfio.h         |  1 +
>>  3 files changed, 23 insertions(+)
> 
> 
> Note that I suggested to Intel folks trying to add a GVT-g page
> flipping eventfd to convert to device specific interrupts the same way
> we added device specific regions:
> 
> https://patchwork.kernel.org/patch/10962337/
> 
> I'd probably suggest the same here so we can optionally expose it when
> supported.  Thanks,

Agreed, I will follow the other thread.

Thanks

Eric
> 
> Alex
> 
>> diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
>> index a9c8af2a774a..65a1e6814f5c 100644
>> --- a/drivers/vfio/pci/vfio_pci.c
>> +++ b/drivers/vfio/pci/vfio_pci.c
>> @@ -746,6 +746,8 @@ static int vfio_pci_get_irq_count(struct vfio_pci_device *vdev, int irq_type)
>>  			return 1;
>>  	} else if (irq_type == VFIO_PCI_REQ_IRQ_INDEX) {
>>  		return 1;
>> +	} else if (irq_type == VFIO_PCI_DMA_FAULT_IRQ_INDEX) {
>> +		return 1;
>>  	}
>>  
>>  	return 0;
>> @@ -1082,6 +1084,7 @@ static long vfio_pci_ioctl(void *device_data,
>>  		switch (info.index) {
>>  		case VFIO_PCI_INTX_IRQ_INDEX ... VFIO_PCI_MSIX_IRQ_INDEX:
>>  		case VFIO_PCI_REQ_IRQ_INDEX:
>> +		case VFIO_PCI_DMA_FAULT_IRQ_INDEX:
>>  			break;
>>  		case VFIO_PCI_ERR_IRQ_INDEX:
>>  			if (pci_is_pcie(vdev->pdev))
>> diff --git a/drivers/vfio/pci/vfio_pci_intrs.c b/drivers/vfio/pci/vfio_pci_intrs.c
>> index 1c46045b0e7f..28a96117daf3 100644
>> --- a/drivers/vfio/pci/vfio_pci_intrs.c
>> +++ b/drivers/vfio/pci/vfio_pci_intrs.c
>> @@ -622,6 +622,18 @@ static int vfio_pci_set_req_trigger(struct vfio_pci_device *vdev,
>>  					       count, flags, data);
>>  }
>>  
>> +static int vfio_pci_set_dma_fault_trigger(struct vfio_pci_device *vdev,
>> +					  unsigned index, unsigned start,
>> +					  unsigned count, uint32_t flags,
>> +					  void *data)
>> +{
>> +	if (index != VFIO_PCI_DMA_FAULT_IRQ_INDEX || start != 0 || count > 1)
>> +		return -EINVAL;
>> +
>> +	return vfio_pci_set_ctx_trigger_single(&vdev->dma_fault_trigger,
>> +					       count, flags, data);
>> +}
>> +
>>  int vfio_pci_set_irqs_ioctl(struct vfio_pci_device *vdev, uint32_t flags,
>>  			    unsigned index, unsigned start, unsigned count,
>>  			    void *data)
>> @@ -671,6 +683,13 @@ int vfio_pci_set_irqs_ioctl(struct vfio_pci_device *vdev, uint32_t flags,
>>  			break;
>>  		}
>>  		break;
>> +	case VFIO_PCI_DMA_FAULT_IRQ_INDEX:
>> +		switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
>> +		case VFIO_IRQ_SET_ACTION_TRIGGER:
>> +			func = vfio_pci_set_dma_fault_trigger;
>> +			break;
>> +		}
>> +		break;
>>  	}
>>  
>>  	if (!func)
>> diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
>> index 13e041b84d48..66b6b08c4a38 100644
>> --- a/include/uapi/linux/vfio.h
>> +++ b/include/uapi/linux/vfio.h
>> @@ -559,6 +559,7 @@ enum {
>>  	VFIO_PCI_MSIX_IRQ_INDEX,
>>  	VFIO_PCI_ERR_IRQ_INDEX,
>>  	VFIO_PCI_REQ_IRQ_INDEX,
>> +	VFIO_PCI_DMA_FAULT_IRQ_INDEX,
>>  	VFIO_PCI_NUM_IRQS
>>  };
>>  
>