3 files changed, 20 insertions, 15 deletions
diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index e9ba752f6b..10c47c2934 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -49,13 +49,11 @@ static const VirtIOFeature feature_sizes[] = {
     {}
 };
 
-static void virtio_blk_set_config_size(VirtIOBlock *s, uint64_t host_features)
-{
-    s->config_size = MAX(VIRTIO_BLK_CFG_SIZE,
-        virtio_feature_get_config_size(feature_sizes, host_features));
-
-    assert(s->config_size <= sizeof(struct virtio_blk_config));
-}
+static const VirtIOConfigSizeParams cfg_size_params = {
+    .min_size = VIRTIO_BLK_CFG_SIZE,
+    .max_size = sizeof(struct virtio_blk_config),
+    .feature_sizes = feature_sizes
+};
 
 static void virtio_blk_init_request(VirtIOBlock *s, VirtQueue *vq,
                                     VirtIOBlockReq *req)
@@ -1204,8 +1202,8 @@ static void virtio_blk_device_realize(DeviceState *dev, Error **errp)
         return;
     }
 
-    virtio_blk_set_config_size(s, s->host_features);
-
+    s->config_size = virtio_get_config_size(&cfg_size_params,
+                                            s->host_features);
     virtio_init(vdev, VIRTIO_ID_BLOCK, s->config_size);
 
     s->blk = conf->conf.blk;
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 63a8332cd0..e9f696b4cf 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -106,6 +106,12 @@ static const VirtIOFeature feature_sizes[] = {
     {}
 };
 
+static const VirtIOConfigSizeParams cfg_size_params = {
+    .min_size = endof(struct virtio_net_config, mac),
+    .max_size = sizeof(struct virtio_net_config),
+    .feature_sizes = feature_sizes
+};
+
 static VirtIONetQueue *virtio_net_get_subqueue(NetClientState *nc)
 {
     VirtIONet *n = qemu_get_nic_opaque(nc);
@@ -3241,8 +3247,7 @@ static void virtio_net_set_config_size(VirtIONet *n, uint64_t host_features)
 {
     virtio_add_feature(&host_features, VIRTIO_NET_F_MAC);
 
-    n->config_size = virtio_feature_get_config_size(feature_sizes,
-                                                    host_features);
+    n->config_size = virtio_get_config_size(&cfg_size_params, host_features);
 }
 
 void virtio_net_set_netclient_name(VirtIONet *n, const char *name,
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 97a6307c0f..2cc1d7d24a 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -3006,11 +3006,12 @@ int virtio_set_features(VirtIODevice *vdev, uint64_t val)
     return ret;
 }
 
-size_t virtio_feature_get_config_size(const VirtIOFeature *feature_sizes,
-                                      uint64_t host_features)
+size_t virtio_get_config_size(const VirtIOConfigSizeParams *params,
+                              uint64_t host_features)
 {
-    size_t config_size = 0;
-    int i;
+    size_t config_size = params->min_size;
+    const VirtIOFeature *feature_sizes = params->feature_sizes;
+    size_t i;
 
     for (i = 0; feature_sizes[i].flags != 0; i++) {
         if (host_features & feature_sizes[i].flags) {
@@ -3018,6 +3019,7 @@ size_t virtio_feature_get_config_size(const VirtIOFeature *feature_sizes,
         }
     }
 
+    assert(config_size <= params->max_size);
     return config_size;
 }