[RFC PATCH for 8.1 3/6] vdpa: add vhost_vdpa_set_dev_features_fd

["Eugenio Pérez" <eperezma@redhat.com>]

This allows to set the features of a vhost-vdpa device from external
subsystems like vhost-net.  It is used in subsequent patches to
negotiate features and probe for CVQ ASID isolation.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
 include/hw/virtio/vhost-vdpa.h |  1 +
 hw/virtio/vhost-vdpa.c         | 20 +++++++++++++-------
 2 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/include/hw/virtio/vhost-vdpa.h b/include/hw/virtio/vhost-vdpa.h
index 28de7da91e..a9cb6f3a32 100644
--- a/include/hw/virtio/vhost-vdpa.h
+++ b/include/hw/virtio/vhost-vdpa.h
@@ -55,6 +55,7 @@ typedef struct vhost_vdpa {
 } VhostVDPA;
 
 void vhost_vdpa_reset_status_fd(int fd);
+int vhost_vdpa_set_dev_features_fd(int fd, uint64_t features);
 int vhost_vdpa_get_iova_range(int fd, struct vhost_vdpa_iova_range *iova_range);
 
 int vhost_vdpa_dma_map(struct vhost_vdpa *v, uint32_t asid, hwaddr iova,
diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index 7a2053b8d9..acd5be46a9 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -651,11 +651,22 @@ static int vhost_vdpa_set_mem_table(struct vhost_dev *dev,
     return 0;
 }
 
+int vhost_vdpa_set_dev_features_fd(int fd, uint64_t features)
+{
+    int ret;
+
+    ret = vhost_vdpa_call_fd(fd, VHOST_SET_FEATURES, &features);
+    if (ret) {
+        return ret;
+    }
+
+    return vhost_vdpa_add_status_fd(fd, VIRTIO_CONFIG_S_FEATURES_OK);
+}
+
 static int vhost_vdpa_set_features(struct vhost_dev *dev,
                                    uint64_t features)
 {
     struct vhost_vdpa *v = dev->opaque;
-    int ret;
 
     if (!vhost_vdpa_first_dev(dev)) {
         return 0;
@@ -678,12 +689,7 @@ static int vhost_vdpa_set_features(struct vhost_dev *dev,
     }
 
     trace_vhost_vdpa_set_features(dev, features);
-    ret = vhost_vdpa_call(dev, VHOST_SET_FEATURES, &features);
-    if (ret) {
-        return ret;
-    }
-
-    return vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_FEATURES_OK);
+    return vhost_vdpa_set_dev_features_fd(vhost_vdpa_dev_fd(dev), features);
 }
 
 static int vhost_vdpa_set_backend_cap(struct vhost_dev *dev)
-- 
2.31.1