commit 5e7ba401b71d18544a3e44b2a58b9e63fd5148d5
author Zhenzhong Duan <zhenzhong.duan@intel.com> Tue Nov 21 16:44:14 2023 +0800
committer Cédric Le Goater <clg@redhat.com> Tue Dec 19 19:03:38 2023 +0100
tree dae6c3e9c9e47f526ee6d9185e9eb4d6e3f47b00
parent 336f308958d598f3db351bb7d94cc57b4b2d448d

vfio/ap: Make vfio cdev pre-openable by passing a file handle

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>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>

hw/vfio/ap.c

diff --git a/hw/vfio/ap.c b/hw/vfio/ap.c
index 8062960..f180e4a 100644
--- a/hw/vfio/ap.c
+++ b/hw/vfio/ap.c
@@ -160,7 +160,10 @@
     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) < 0) {
+        return;
+    }
+
     vbasedev->ops = &vfio_ap_ops;
     vbasedev->type = VFIO_DEVICE_TYPE_AP;
     vbasedev->dev = dev;
@@ -230,11 +233,28 @@
     .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 @@
     .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,
 };