1 files changed, 73 insertions, 1 deletions

diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index d256ce589b..abe23d4ebe 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -81,6 +81,7 @@ enum VhostUserProtocolFeature {
     VHOST_USER_PROTOCOL_F_RESET_DEVICE = 13,
     /* Feature 14 reserved for VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS. */
     VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS = 15,
+    VHOST_USER_PROTOCOL_F_STATUS = 16,
     VHOST_USER_PROTOCOL_F_MAX
 };
 
@@ -126,6 +127,8 @@ typedef enum VhostUserRequest {
     VHOST_USER_GET_MAX_MEM_SLOTS = 36,
     VHOST_USER_ADD_MEM_REG = 37,
     VHOST_USER_REM_MEM_REG = 38,
+    VHOST_USER_SET_STATUS = 39,
+    VHOST_USER_GET_STATUS = 40,
     VHOST_USER_MAX
 } VhostUserRequest;
 
@@ -1452,6 +1455,43 @@ static int vhost_user_set_u64(struct vhost_dev *dev, int request, uint64_t u64,
     return 0;
 }
 
+static int vhost_user_set_status(struct vhost_dev *dev, uint8_t status)
+{
+    return vhost_user_set_u64(dev, VHOST_USER_SET_STATUS, status, false);
+}
+
+static int vhost_user_get_status(struct vhost_dev *dev, uint8_t *status)
+{
+    uint64_t value;
+    int ret;
+
+    ret = vhost_user_get_u64(dev, VHOST_USER_GET_STATUS, &value);
+    if (ret < 0) {
+        return ret;
+    }
+    *status = value;
+
+    return 0;
+}
+
+static int vhost_user_add_status(struct vhost_dev *dev, uint8_t status)
+{
+    uint8_t s;
+    int ret;
+
+    ret = vhost_user_get_status(dev, &s);
+    if (ret < 0) {
+        return ret;
+    }
+
+    if ((s & status) == status) {
+        return 0;
+    }
+    s |= status;
+
+    return vhost_user_set_status(dev, s);
+}
+
 static int vhost_user_set_features(struct vhost_dev *dev,
                                    uint64_t features)
 {
@@ -1460,6 +1500,7 @@ static int vhost_user_set_features(struct vhost_dev *dev,
      * backend is actually logging changes
      */
     bool log_enabled = features & (0x1ULL << VHOST_F_LOG_ALL);
+    int ret;
 
     /*
      * We need to include any extra backend only feature bits that
@@ -1467,9 +1508,18 @@ static int vhost_user_set_features(struct vhost_dev *dev,
      * VHOST_USER_F_PROTOCOL_FEATURES bit for enabling protocol
      * features.
      */
-    return vhost_user_set_u64(dev, VHOST_USER_SET_FEATURES,
+    ret = vhost_user_set_u64(dev, VHOST_USER_SET_FEATURES,
                               features | dev->backend_features,
                               log_enabled);
+
+    if (virtio_has_feature(dev->protocol_features,
+                           VHOST_USER_PROTOCOL_F_STATUS)) {
+        if (!ret) {
+            return vhost_user_add_status(dev, VIRTIO_CONFIG_S_FEATURES_OK);
+        }
+    }
+
+    return ret;
 }
 
 static int vhost_user_set_protocol_features(struct vhost_dev *dev,
@@ -2620,6 +2670,27 @@ void vhost_user_cleanup(VhostUserState *user)
     user->chr = NULL;
 }
 
+static int vhost_user_dev_start(struct vhost_dev *dev, bool started)
+{
+    if (!virtio_has_feature(dev->protocol_features,
+                            VHOST_USER_PROTOCOL_F_STATUS)) {
+        return 0;
+    }
+
+    /* Set device status only for last queue pair */
+    if (dev->vq_index + dev->nvqs != dev->vq_index_end) {
+        return 0;
+    }
+
+    if (started) {
+        return vhost_user_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
+                                          VIRTIO_CONFIG_S_DRIVER |
+                                          VIRTIO_CONFIG_S_DRIVER_OK);
+    } else {
+        return vhost_user_set_status(dev, 0);
+    }
+}
+
 const VhostOps user_ops = {
         .backend_type = VHOST_BACKEND_TYPE_USER,
         .vhost_backend_init = vhost_user_backend_init,
@@ -2654,4 +2725,5 @@ const VhostOps user_ops = {
         .vhost_backend_mem_section_filter = vhost_user_mem_section_filter,
         .vhost_get_inflight_fd = vhost_user_get_inflight_fd,
         .vhost_set_inflight_fd = vhost_user_set_inflight_fd,
+        .vhost_dev_start = vhost_user_dev_start,
 };