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

Alex Williamson
2019-06-03T22:31:40Z

On Sun, 26 May 2019 18:10:03 +0200
Eric Auger <eric.auger@redhat.com> 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@redhat.com>
> ---
> 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,

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
> };
>