Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging

* Fix pr-manager-helper (Markus)

# gpg: Signature made Wed 05 Jun 2019 15:15:34 BST
# gpg:                using RSA key BFFBD25F78C7AE83
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" [full]
# gpg:                 aka "Paolo Bonzini <pbonzini@redhat.com>" [full]
# Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4  E2F7 7E15 100C CD36 69B1
#      Subkey fingerprint: F133 3857 4B66 2389 866C  7682 BFFB D25F 78C7 AE83

* remotes/bonzini/tags/for-upstream:
  vl: Document why objects are delayed
  vl: Fix -drive / -blockdev persistent reservation management
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

vl.c

@@ -2751,20 +2751,25 @@ static bool object_create_initial(const char *type, QemuOpts *opts)
         exit(0);
     }
 
-    if (g_str_equal(type, "rng-egd") ||
-        g_str_has_prefix(type, "pr-manager-")) {
+    /*
+     * Objects should not be made "delayed" without a reason.  If you
+     * add one, state the reason in a comment!
+     */
+
+    /* Reason: rng-egd property "chardev" */
+    if (g_str_equal(type, "rng-egd")) {
         return false;
     }
 
 #if defined(CONFIG_VHOST_USER) && defined(CONFIG_LINUX)
+    /* Reason: cryptodev-vhost-user property "chardev" */
     if (g_str_equal(type, "cryptodev-vhost-user")) {
         return false;
     }
 #endif
 
     /*
-     * return false for concrete netfilters since
-     * they depend on netdevs already existing
+     * Reason: filter-* property "netdev" etc.
      */
     if (g_str_equal(type, "filter-buffer") ||
         g_str_equal(type, "filter-dump") ||