[PATCH v6 15/21] vfio/ap: Make vfio cdev pre-openable by passing a file handle

Zhenzhong Duan posted 21 patches 1 year ago
There is a newer version of this series
[PATCH v6 15/21] vfio/ap: Make vfio cdev pre-openable by passing a file handle
Posted by Zhenzhong Duan 1 year ago
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>
---
 hw/vfio/ap.c | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/hw/vfio/ap.c b/hw/vfio/ap.c
index 80629609ae..b21f92291e 100644
--- a/hw/vfio/ap.c
+++ b/hw/vfio/ap.c
@@ -160,7 +160,10 @@ static void vfio_ap_realize(DeviceState *dev, Error **errp)
     VFIOAPDevice *vapdev = VFIO_AP_DEVICE(dev);
     VFIODevice *vbasedev = &vapdev->vdev;
 
-    vbasedev->name = g_path_get_basename(vbasedev->sysfsdev);
+    if (vfio_device_get_name(vbasedev, errp)) {
+        return;
+    }
+
     vbasedev->ops = &vfio_ap_ops;
     vbasedev->type = VFIO_DEVICE_TYPE_AP;
     vbasedev->dev = dev;
@@ -230,11 +233,28 @@ static const VMStateDescription vfio_ap_vmstate = {
     .unmigratable = 1,
 };
 
+static void vfio_ap_instance_init(Object *obj)
+{
+    VFIOAPDevice *vapdev = VFIO_AP_DEVICE(obj);
+
+    vapdev->vdev.fd = -1;
+}
+
+#ifdef CONFIG_IOMMUFD
+static void vfio_ap_set_fd(Object *obj, const char *str, Error **errp)
+{
+    vfio_device_set_fd(&VFIO_AP_DEVICE(obj)->vdev, str, errp);
+}
+#endif
+
 static void vfio_ap_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
 
     device_class_set_props(dc, vfio_ap_properties);
+#ifdef CONFIG_IOMMUFD
+    object_class_property_add_str(klass, "fd", NULL, vfio_ap_set_fd);
+#endif
     dc->vmsd = &vfio_ap_vmstate;
     dc->desc = "VFIO-based AP device assignment";
     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
@@ -249,6 +269,7 @@ static const TypeInfo vfio_ap_info = {
     .name = TYPE_VFIO_AP_DEVICE,
     .parent = TYPE_AP_DEVICE,
     .instance_size = sizeof(VFIOAPDevice),
+    .instance_init = vfio_ap_instance_init,
     .class_init = vfio_ap_class_init,
 };
 
-- 
2.34.1
Re: [PATCH v6 15/21] vfio/ap: Make vfio cdev pre-openable by passing a file handle
Posted by Cédric Le Goater 1 year ago
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/ap.c | 23 ++++++++++++++++++++++-
>   1 file changed, 22 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/vfio/ap.c b/hw/vfio/ap.c
> index 80629609ae..b21f92291e 100644
> --- a/hw/vfio/ap.c
> +++ b/hw/vfio/ap.c
> @@ -160,7 +160,10 @@ static void vfio_ap_realize(DeviceState *dev, Error **errp)
>       VFIOAPDevice *vapdev = VFIO_AP_DEVICE(dev);
>       VFIODevice *vbasedev = &vapdev->vdev;
>   
> -    vbasedev->name = g_path_get_basename(vbasedev->sysfsdev);
> +    if (vfio_device_get_name(vbasedev, errp)) {
> +        return;
> +    }
> +
>       vbasedev->ops = &vfio_ap_ops;
>       vbasedev->type = VFIO_DEVICE_TYPE_AP;
>       vbasedev->dev = dev;
> @@ -230,11 +233,28 @@ static const VMStateDescription vfio_ap_vmstate = {
>       .unmigratable = 1,
>   };
>   
> +static void vfio_ap_instance_init(Object *obj)
> +{
> +    VFIOAPDevice *vapdev = VFIO_AP_DEVICE(obj);
> +
> +    vapdev->vdev.fd = -1;
> +}
> +
> +#ifdef CONFIG_IOMMUFD
> +static void vfio_ap_set_fd(Object *obj, const char *str, Error **errp)
> +{
> +    vfio_device_set_fd(&VFIO_AP_DEVICE(obj)->vdev, str, errp);
> +}
> +#endif
> +
>   static void vfio_ap_class_init(ObjectClass *klass, void *data)
>   {
>       DeviceClass *dc = DEVICE_CLASS(klass);
>   
>       device_class_set_props(dc, vfio_ap_properties);
> +#ifdef CONFIG_IOMMUFD
> +    object_class_property_add_str(klass, "fd", NULL, vfio_ap_set_fd);
> +#endif
>       dc->vmsd = &vfio_ap_vmstate;
>       dc->desc = "VFIO-based AP device assignment";
>       set_bit(DEVICE_CATEGORY_MISC, dc->categories);
> @@ -249,6 +269,7 @@ static const TypeInfo vfio_ap_info = {
>       .name = TYPE_VFIO_AP_DEVICE,
>       .parent = TYPE_AP_DEVICE,
>       .instance_size = sizeof(VFIOAPDevice),
> +    .instance_init = vfio_ap_instance_init,
>       .class_init = vfio_ap_class_init,
>   };
>