diff --git a/hw/display/vhost-user-gpu.c b/hw/display/vhost-user-gpu.c
index 63c64ddde6..c0c66910f1 100644
--- a/hw/display/vhost-user-gpu.c
+++ b/hw/display/vhost-user-gpu.c
@@ -390,7 +390,7 @@ vhost_user_gpu_chr_read(void *opaque)
     }
 
     msg->request = request;
-    msg->flags = size;
+    msg->flags = flags;
     msg->size = size;
 
     if (request == VHOST_USER_GPU_CURSOR_UPDATE ||
diff --git a/hw/i386/x86-common.c b/hw/i386/x86-common.c
index c0c66a0eb5..992ea1f25e 100644
--- a/hw/i386/x86-common.c
+++ b/hw/i386/x86-common.c
@@ -665,8 +665,11 @@ void x86_load_linux(X86MachineState *x86ms,
         exit(1);
     }
 
-    /* kernel protocol version */
-    if (ldl_p(header + 0x202) == 0x53726448) {
+    /*
+     * kernel protocol version.
+     * Please see https://www.kernel.org/doc/Documentation/x86/boot.txt
+     */
+    if (ldl_p(header + 0x202) == 0x53726448) /* Magic signature "HdrS" */ {
         protocol = lduw_p(header + 0x206);
     } else {
         /*
diff --git a/system/vl.c b/system/vl.c
index 41d53d2456..01b8b8e77a 100644
--- a/system/vl.c
+++ b/system/vl.c
@@ -1679,10 +1679,10 @@ static MachineClass *select_machine(QDict *qdict, Error **errp)
 
     if (machine_type) {
         machine_class = find_machine(machine_type, machines);
-        qdict_del(qdict, "type");
         if (!machine_class) {
-            error_setg(errp, "unsupported machine type: \"%s\"", optarg);
+            error_setg(errp, "unsupported machine type: \"%s\"", machine_type);
         }
+        qdict_del(qdict, "type");
     } else {
         machine_class = find_default_machine(machines);
         if (!machine_class) {