contrib/libvhost-user: enable virtio config space messages

Enable VHOST_USER_GET_CONFIG/VHOST_USER_SET_CONFIG messages in
libvhost-user library, users can implement their own I/O target
based on the library. This enable the virtio config space delivered
between QEMU host device and the I/O target.

Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 42 insertions, 0 deletions

diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c
index f409bd3d41..27cc59791b 100644
--- a/contrib/libvhost-user/libvhost-user.c
+++ b/contrib/libvhost-user/libvhost-user.c
@@ -84,6 +84,8 @@ vu_request_to_string(unsigned int req)
         REQ(VHOST_USER_SET_SLAVE_REQ_FD),
         REQ(VHOST_USER_IOTLB_MSG),
         REQ(VHOST_USER_SET_VRING_ENDIAN),
+        REQ(VHOST_USER_GET_CONFIG),
+        REQ(VHOST_USER_SET_CONFIG),
         REQ(VHOST_USER_MAX),
     };
 #undef REQ
@@ -798,6 +800,42 @@ vu_set_slave_req_fd(VuDev *dev, VhostUserMsg *vmsg)
 }
 
 static bool
+vu_get_config(VuDev *dev, VhostUserMsg *vmsg)
+{
+    int ret = -1;
+
+    if (dev->iface->get_config) {
+        ret = dev->iface->get_config(dev, vmsg->payload.config.region,
+                                     vmsg->payload.config.size);
+    }
+
+    if (ret) {
+        /* resize to zero to indicate an error to master */
+        vmsg->size = 0;
+    }
+
+    return true;
+}
+
+static bool
+vu_set_config(VuDev *dev, VhostUserMsg *vmsg)
+{
+    int ret = -1;
+
+    if (dev->iface->set_config) {
+        ret = dev->iface->set_config(dev, vmsg->payload.config.region,
+                                     vmsg->payload.config.offset,
+                                     vmsg->payload.config.size,
+                                     vmsg->payload.config.flags);
+        if (ret) {
+            vu_panic(dev, "Set virtio configuration space failed");
+        }
+    }
+
+    return false;
+}
+
+static bool
 vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
 {
     int do_reply = 0;
@@ -862,6 +900,10 @@ vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
         return vu_set_vring_enable_exec(dev, vmsg);
     case VHOST_USER_SET_SLAVE_REQ_FD:
         return vu_set_slave_req_fd(dev, vmsg);
+    case VHOST_USER_GET_CONFIG:
+        return vu_get_config(dev, vmsg);
+    case VHOST_USER_SET_CONFIG:
+        return vu_set_config(dev, vmsg);
     case VHOST_USER_NONE:
         break;
     default: