Re: [PATCH v6 14/21] vfio/ap: 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-ap device:
>
> if the user wants to use the legacy backend, it shall not
> link the vfio-ap device with any iommufd object:
>
>   -device vfio-ap,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-ap device options:
>
>   -object iommufd,id=iommufd0
>   -device vfio-ap,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/ap.c | 6 ++++++
>   1 file changed, 6 insertions(+)
>
> diff --git a/hw/vfio/ap.c b/hw/vfio/ap.c
> index bbf69ff55a..80629609ae 100644
> --- a/hw/vfio/ap.c
> +++ b/hw/vfio/ap.c
> @@ -11,10 +11,12 @@
>    */
>   
>   #include "qemu/osdep.h"
> +#include CONFIG_DEVICES /* CONFIG_IOMMUFD */
>   #include <linux/vfio.h>
>   #include <sys/ioctl.h>
>   #include "qapi/error.h"
>   #include "hw/vfio/vfio-common.h"
> +#include "sysemu/iommufd.h"
>   #include "hw/s390x/ap-device.h"
>   #include "qemu/error-report.h"
>   #include "qemu/event_notifier.h"
> @@ -204,6 +206,10 @@ static void vfio_ap_unrealize(DeviceState *dev)
>   
>   static Property vfio_ap_properties[] = {
>       DEFINE_PROP_STRING("sysfsdev", VFIOAPDevice, vdev.sysfsdev),
> +#ifdef CONFIG_IOMMUFD
> +    DEFINE_PROP_LINK("iommufd", VFIOAPDevice, vdev.iommufd,
> +                     TYPE_IOMMUFD_BACKEND, IOMMUFDBackend *),
> +#endif
>       DEFINE_PROP_END_OF_LIST(),
>   };
>