Re: [PATCH v2 1/3] vfio/pci: Rename vfio_config_do_rw() to vfio_pci_config_rw_single() and export it

[Alex Williamson]

On Tue, 24 Feb 2026 13:34:32 +0100
Julian Ruess <julianr@xxxxxxxxxxxxx> wrote:

> A follow-up patch adds a new variant driver for s390 ISM devices. Since
> this device uses a 256 TiB BAR 0 that is never mapped, the variant
> driver needs its own ISM_VFIO_PCI_OFFSET_MASK. To minimally mirror the
> functionality of vfio_pci_config_rw() with such a custom mask, export
> vfio_config_do_rw(). To better distinguish the now exported function
> from vfio_pci_config_rw(), rename it to vfio_pci_config_rw_single()
> emphasizing that it does a single config space read or write.
> 
> Signed-off-by: Julian Ruess <julianr@xxxxxxxxxxxxx>
> ---
>  drivers/vfio/pci/vfio_pci_config.c | 8 +++++---
>  drivers/vfio/pci/vfio_pci_priv.h   | 4 ++++
>  2 files changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/vfio/pci/vfio_pci_config.c b/drivers/vfio/pci/vfio_pci_config.c
> index b4e39253f98da61a5e2b6dd0089b2f6aef4b85a0..a724fdd8f4860bd529c5c7501beb1f7156fae9b0 100644
> --- a/drivers/vfio/pci/vfio_pci_config.c
> +++ b/drivers/vfio/pci/vfio_pci_config.c
> @@ -1880,8 +1880,9 @@ static size_t vfio_pci_cap_remaining_dword(struct vfio_pci_core_device *vdev,
>  	return i;
>  }
>  
> -static ssize_t vfio_config_do_rw(struct vfio_pci_core_device *vdev, char __user *buf,
> -				 size_t count, loff_t *ppos, bool iswrite)
> +ssize_t vfio_pci_config_rw_single(struct vfio_pci_core_device *vdev,
> +			      char __user *buf, size_t count, loff_t *ppos,
> +			      bool iswrite)
>  {
>  	struct pci_dev *pdev = vdev->pdev;
>  	struct perm_bits *perm;
> @@ -1970,6 +1971,7 @@ static ssize_t vfio_config_do_rw(struct vfio_pci_core_device *vdev, char __user
>  
>  	return ret;
>  }
> +EXPORT_SYMBOL(vfio_pci_config_rw_single);

EXPORT_SYMBOL_GPL.  Thanks,

Alex


>  
>  ssize_t vfio_pci_config_rw(struct vfio_pci_core_device *vdev, char __user *buf,
>  			   size_t count, loff_t *ppos, bool iswrite)
> @@ -1981,7 +1983,7 @@ ssize_t vfio_pci_config_rw(struct vfio_pci_core_device *vdev, char __user *buf,
>  	pos &= VFIO_PCI_OFFSET_MASK;
>  
>  	while (count) {
> -		ret = vfio_config_do_rw(vdev, buf, count, &pos, iswrite);
> +		ret = vfio_pci_config_rw_single(vdev, buf, count, &pos, iswrite);
>  		if (ret < 0)
>  			return ret;
>  
> diff --git a/drivers/vfio/pci/vfio_pci_priv.h b/drivers/vfio/pci/vfio_pci_priv.h
> index 27ac280f00b975989f6cbc02c11aaca01f9badf3..28a3edf65aeecfa06cd1856637cd33eec1fa3006 100644
> --- a/drivers/vfio/pci/vfio_pci_priv.h
> +++ b/drivers/vfio/pci/vfio_pci_priv.h
> @@ -37,6 +37,10 @@ int vfio_pci_set_irqs_ioctl(struct vfio_pci_core_device *vdev, uint32_t flags,
>  ssize_t vfio_pci_config_rw(struct vfio_pci_core_device *vdev, char __user *buf,
>  			   size_t count, loff_t *ppos, bool iswrite);
>  
> +ssize_t vfio_pci_config_rw_single(struct vfio_pci_core_device *vdev,
> +			      char __user *buf, size_t count, loff_t *ppos,
> +			      bool iswrite);
> +
>  ssize_t vfio_pci_bar_rw(struct vfio_pci_core_device *vdev, char __user *buf,
>  			size_t count, loff_t *ppos, bool iswrite);
>  
>