use the vhost_force_iommu callback to force enable feature bit VIRTIO_F_IOMMU_PLATFORM

Signed-off-by: Cindy Lu <lulu@redhat.com>
---
 hw/virtio/vhost.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 1e083a8976..1a1384e7a6 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -810,6 +810,11 @@ static int vhost_dev_set_features(struct vhost_dev *dev,
     if (!vhost_dev_has_iommu(dev)) {
         features &= ~(0x1ULL << VIRTIO_F_IOMMU_PLATFORM);
     }
+    if (dev->vhost_ops->vhost_force_iommu) {
+        if (dev->vhost_ops->vhost_force_iommu(dev) == true) {
+            features |= 0x1ULL << VIRTIO_F_IOMMU_PLATFORM;
+       }
+    }
     r = dev->vhost_ops->vhost_set_features(dev, features);
     if (r < 0) {
         VHOST_OPS_DEBUG("vhost_set_features failed");
-- 
2.21.1