[RFC 08/10] vdpa-dev: implement the get_features interface

[Longpeng(Mike)]

From: Longpeng <longpeng2@huawei.com>

Implements the .get_features interface.

Signed-off-by: Longpeng <longpeng2@huawei.com>
---
 hw/virtio/vdpa-dev.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/hw/virtio/vdpa-dev.c b/hw/virtio/vdpa-dev.c
index 4f97a7521b..32b3117c4b 100644
--- a/hw/virtio/vdpa-dev.c
+++ b/hw/virtio/vdpa-dev.c
@@ -184,7 +184,14 @@ static uint64_t 
vhost_vdpa_device_get_features(VirtIODevice *vdev,
                                                uint64_t features,
                                                Error **errp)
 {
-    return (uint64_t)-1;
+    VhostVdpaDevice *s = VHOST_VDPA_DEVICE(vdev);
+    uint64_t backend_features = s->dev.features;
+
+    if (!virtio_has_feature(features, VIRTIO_F_IOMMU_PLATFORM)) {
+        virtio_clear_feature(&backend_features, VIRTIO_F_IOMMU_PLATFORM);
+    }
+
+    return backend_features;
 }
 
 static void vhost_vdpa_device_set_status(VirtIODevice *vdev, uint8_t status)
-- 
2.23.0