Re: [PATCH v6 16/21] vfio/ccw: Allow the selection of a given iommu backend

[Cédric Le Goater]

On 11/14/23 11:09, Zhenzhong Duan wrote:
> Now we support two types of iommu backends, let's add the capability
> to select one of them. This depends on whether an iommufd object has
> been linked with the vfio-ccw device:
>
> If the user wants to use the legacy backend, it shall not
> link the vfio-ccw device with any iommufd object:
>
>   -device vfio-ccw,sysfsdev=/sys/bus/mdev/devices/XXX
>
> This is called the legacy mode/backend.
>
> If the user wants to use the iommufd backend (/dev/iommu) it
> shall pass an iommufd object id in the vfio-ccw device options:
>
>   -object iommufd,id=iommufd0
>   -device vfio-ccw,sysfsdev=/sys/bus/mdev/devices/XXX,iommufd=iommufd0
>
> Suggested-by: Alex Williamson <alex.williamson@redhat.com>
> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
> Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>


Reviewed-by: Cédric Le Goater <clg@redhat.com>

Thanks,

C.


> ---
>   hw/vfio/ccw.c | 6 ++++++
>   1 file changed, 6 insertions(+)
>
> diff --git a/hw/vfio/ccw.c b/hw/vfio/ccw.c
> index d857bb8d0f..d2d58bb677 100644
> --- a/hw/vfio/ccw.c
> +++ b/hw/vfio/ccw.c
> @@ -15,12 +15,14 @@
>    */
>   
>   #include "qemu/osdep.h"
> +#include CONFIG_DEVICES /* CONFIG_IOMMUFD */
>   #include <linux/vfio.h>
>   #include <linux/vfio_ccw.h>
>   #include <sys/ioctl.h>
>   
>   #include "qapi/error.h"
>   #include "hw/vfio/vfio-common.h"
> +#include "sysemu/iommufd.h"
>   #include "hw/s390x/s390-ccw.h"
>   #include "hw/s390x/vfio-ccw.h"
>   #include "hw/qdev-properties.h"
> @@ -677,6 +679,10 @@ static void vfio_ccw_unrealize(DeviceState *dev)
>   static Property vfio_ccw_properties[] = {
>       DEFINE_PROP_STRING("sysfsdev", VFIOCCWDevice, vdev.sysfsdev),
>       DEFINE_PROP_BOOL("force-orb-pfch", VFIOCCWDevice, force_orb_pfch, false),
> +#ifdef CONFIG_IOMMUFD
> +    DEFINE_PROP_LINK("iommufd", VFIOCCWDevice, vdev.iommufd,
> +                     TYPE_IOMMUFD_BACKEND, IOMMUFDBackend *),
> +#endif
>       DEFINE_PROP_END_OF_LIST(),
>   };
>