[PATCH v1 1/1] usertools/devbind: allow changing UID/GID for VFIO

[Burakov, Anatoly]

On 9/2/2024 3:57 PM, Anatoly Burakov wrote:
> Currently, when binding a device to VFIO, the UID/GID for the device will
> always stay as system default (`root`). Yet, when running DPDK as non-root
> user, one has to change the UID/GID of the device to match the user's
> UID/GID to use the device.
> 
> This patch adds an option to `dpdk-devbind.py` to change the UID/GID of
> the device when binding it to VFIO.
> 
> Signed-off-by: Anatoly Burakov <anatoly.burakov at intel.com>
> ---

<snip>

>   
> +def own_one(dev_id, uid, gid):
> +    """Set the IOMMU group ownership for a device"""
> +    # find IOMMU group for a particular device
> +    iommu_grp_base_path = os.path.join("/sys/bus/pci/devices", dev_id, "iommu_group")
> +    try:
> +        iommu_grp = os.path.basename(os.readlink(iommu_grp_base_path))
> +        # we found IOMMU group, now find the device
> +        dev_path = os.path.join("/dev/vfio", iommu_grp)
> +        # set the ownership
> +        _uid = pwd.getpwnam(uid).pw_uid if uid else -1
> +        _gid = grp.getgrnam(gid).gr_gid if gid else -1
> +        os.chown(dev_path, _uid, _gid)
> +    except OSError as err:
> +        sys.exit(f"Error: failed to read IOMMU group for {dev_id}: {err}")

On another thought, perhaps sys.exit() here is a bit too drastic... Will 
replace with error message in v2

-- 
Thanks,
Anatoly