[RFC V1 13/13] vduse: new owner capability

[Steve Sistare]

The vduse device supports ownership transfer to a new process, so
advertise VHOST_BACKEND_F_NEW_OWNER.  User virtual addresses are used
by the software iommu, so VHOST_IOTLB_REMAP is required after
VHOST_NEW_OWNER, so advertise VHOST_BACKEND_F_IOTLB_REMAP.

Signed-off-by: Steve Sistare <steven.sistare@xxxxxxxxxx>
---
 drivers/vdpa/vdpa_user/vduse_dev.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
index 6b25457a037d..67815f6391db 100644
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -25,6 +25,7 @@
 #include <linux/sched/mm.h>
 #include <uapi/linux/vduse.h>
 #include <uapi/linux/vdpa.h>
+#include <uapi/linux/vhost_types.h>
 #include <uapi/linux/virtio_config.h>
 #include <uapi/linux/virtio_ids.h>
 #include <uapi/linux/virtio_blk.h>
@@ -608,6 +609,12 @@ static u32 vduse_vdpa_get_vq_align(struct vdpa_device *vdpa)
 	return dev->vq_align;
 }
 
+static u64 vduse_vdpa_get_backend_features(const struct vdpa_device *vdpa)
+{
+	return BIT_ULL(VHOST_BACKEND_F_IOTLB_REMAP) |
+	       BIT_ULL(VHOST_BACKEND_F_NEW_OWNER);
+}
+
 static u64 vduse_vdpa_get_device_features(struct vdpa_device *vdpa)
 {
 	struct vduse_dev *dev = vdpa_to_vduse(vdpa);
@@ -801,6 +808,7 @@ static const struct vdpa_config_ops vduse_vdpa_config_ops = {
 	.set_vq_state		= vduse_vdpa_set_vq_state,
 	.get_vq_state		= vduse_vdpa_get_vq_state,
 	.get_vq_align		= vduse_vdpa_get_vq_align,
+	.get_backend_features	= vduse_vdpa_get_backend_features,
 	.get_device_features	= vduse_vdpa_get_device_features,
 	.set_driver_features	= vduse_vdpa_set_driver_features,
 	.get_driver_features	= vduse_vdpa_get_driver_features,
-- 
2.39.3