Re: [RFC PATCH kernel 4/5] vfio_pci: Allow mapping extra regions

[Alex Williamson <alex.williamson@redhat.com>]

On Thu,  7 Jun 2018 18:44:19 +1000
Alexey Kardashevskiy <aik@ozlabs.ru> wrote:

What's an "extra region", -ENOCOMMITLOG

> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> ---
>  drivers/vfio/pci/vfio_pci_private.h |  3 +++
>  drivers/vfio/pci/vfio_pci.c         | 10 ++++++++--
>  2 files changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/vfio/pci/vfio_pci_private.h b/drivers/vfio/pci/vfio_pci_private.h
> index cde3b5d..86aab05 100644
> --- a/drivers/vfio/pci/vfio_pci_private.h
> +++ b/drivers/vfio/pci/vfio_pci_private.h
> @@ -59,6 +59,9 @@ struct vfio_pci_regops {
>  		      size_t count, loff_t *ppos, bool iswrite);
>  	void	(*release)(struct vfio_pci_device *vdev,
>  			   struct vfio_pci_region *region);
> +	int	(*mmap)(struct vfio_pci_device *vdev,
> +			struct vfio_pci_region *region,
> +			struct vm_area_struct *vma);
>  };
>  
>  struct vfio_pci_region {
> diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
> index 3729937..7bddf1e 100644
> --- a/drivers/vfio/pci/vfio_pci.c
> +++ b/drivers/vfio/pci/vfio_pci.c
> @@ -1123,10 +1123,16 @@ static int vfio_pci_mmap(void *device_data, struct vm_area_struct *vma)
>  		return -EINVAL;
>  	if ((vma->vm_flags & VM_SHARED) = 0)
>  		return -EINVAL;
> +	if (index >= VFIO_PCI_NUM_REGIONS) {
> +		int regnum = index - VFIO_PCI_NUM_REGIONS;
> +		struct vfio_pci_region *region = vdev->region + regnum;
> +
> +		if (region && region->ops && region->ops->mmap)
> +			return region->ops->mmap(vdev, region, vma);
> +		return -EINVAL;
> +	}
>  	if (index >= VFIO_PCI_ROM_REGION_INDEX)
>  		return -EINVAL;
> -	if (!vdev->bar_mmap_supported[index])
> -		return -EINVAL;

This seems unrelated.  Thanks,

Alex
  
>  	phys_len = PAGE_ALIGN(pci_resource_len(pdev, index));
>  	req_len = vma->vm_end - vma->vm_start;