Re: [PATCH v6 17/21] vfio/ccw: Make vfio cdev pre-openable by passing a file handle

[Cédric Le Goater]

On 11/14/23 11:09, Zhenzhong Duan wrote:
> This gives management tools like libvirt a chance to open the vfio
> cdev with privilege and pass FD to qemu. This way qemu never needs
> to have privilege to open a VFIO or iommu cdev node.
>
> 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 | 25 ++++++++++++++++++++++---
>   1 file changed, 22 insertions(+), 3 deletions(-)
>
> diff --git a/hw/vfio/ccw.c b/hw/vfio/ccw.c
> index d2d58bb677..b116b10fe7 100644
> --- a/hw/vfio/ccw.c
> +++ b/hw/vfio/ccw.c
> @@ -590,11 +590,12 @@ static void vfio_ccw_realize(DeviceState *dev, Error 
> **errp)
>           }
>       }
>   
> +    if (vfio_device_get_name(vbasedev, errp)) {
> +        return;
> +    }
> +
>       vbasedev->ops = &vfio_ccw_ops;
>       vbasedev->type = VFIO_DEVICE_TYPE_CCW;
> -    vbasedev->name = g_strdup_printf("%x.%x.%04x", vcdev->cdev.hostid.cssid,
> -                           vcdev->cdev.hostid.ssid,
> -                           vcdev->cdev.hostid.devid);
>       vbasedev->dev = dev;
>   
>       /*
> @@ -691,12 +692,29 @@ static const VMStateDescription vfio_ccw_vmstate = {
>       .unmigratable = 1,
>   };
>   
> +static void vfio_ccw_instance_init(Object *obj)
> +{
> +    VFIOCCWDevice *vcdev = VFIO_CCW(obj);
> +
> +    vcdev->vdev.fd = -1;
> +}
> +
> +#ifdef CONFIG_IOMMUFD
> +static void vfio_ccw_set_fd(Object *obj, const char *str, Error **errp)
> +{
> +    vfio_device_set_fd(&VFIO_CCW(obj)->vdev, str, errp);
> +}
> +#endif
> +
>   static void vfio_ccw_class_init(ObjectClass *klass, void *data)
>   {
>       DeviceClass *dc = DEVICE_CLASS(klass);
>       S390CCWDeviceClass *cdc = S390_CCW_DEVICE_CLASS(klass);
>   
>       device_class_set_props(dc, vfio_ccw_properties);
> +#ifdef CONFIG_IOMMUFD
> +    object_class_property_add_str(klass, "fd", NULL, vfio_ccw_set_fd);
> +#endif
>       dc->vmsd = &vfio_ccw_vmstate;
>       dc->desc = "VFIO-based subchannel assignment";
>       set_bit(DEVICE_CATEGORY_MISC, dc->categories);
> @@ -714,6 +732,7 @@ static const TypeInfo vfio_ccw_info = {
>       .name = TYPE_VFIO_CCW,
>       .parent = TYPE_S390_CCW,
>       .instance_size = sizeof(VFIOCCWDevice),
> +    .instance_init = vfio_ccw_instance_init,
>       .class_init = vfio_ccw_class_init,
>   };
>