From de651299014ae67b110a2abbff4a9e544b215b2b Mon Sep 17 00:00:00 2001
From: Kevin Wolf <kwolf@redhat.com>
Date: Wed, 6 Nov 2013 14:41:21 +0100
Subject: [PATCH 45/81] qdev: Do not let the user try to device_add when it cannot work

RH-Author: Kevin Wolf <kwolf@redhat.com>
Message-id: <1383748882-22831-17-git-send-email-kwolf@redhat.com>
Patchwork-id: 55542
O-Subject: [RHEL-7.0 qemu-kvm PATCH v2 16/17] qdev: Do not let the user try to device_add when it cannot work
Bugzilla: 1001216
RH-Acked-by: Marcel Apfelbaum <marcel.a@redhat.com>
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
RH-Acked-by: Kevin Wolf <kwolf@redhat.com>
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>

From: Markus Armbruster <armbru@redhat.com>

Such devices have always been unavailable and omitted from the list of
available devices shown by device_add help.  Until commit 18b6dad
silently broke the former, setting up nasty traps for unwary users,
like this one:

    $ qemu-system-x86_64 -nodefaults -monitor stdio -display none
    QEMU 1.6.50 monitor - type 'help' for more information
    (qemu) device_add apic
    Segmentation fault (core dumped)

I call that a regression.  Fix it.
(cherry picked from pending upstream submission)

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 qdev-monitor.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 qdev-monitor.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/qdev-monitor.c b/qdev-monitor.c
index f54cb21..39d030b 100644
--- a/qdev-monitor.c
+++ b/qdev-monitor.c
@@ -477,13 +477,13 @@ DeviceState *qdev_device_add(QemuOpts *opts)
         }
     }
 
-    if (!obj) {
+    k = DEVICE_CLASS(obj);
+
+    if (!k || k->cannot_instantiate_with_device_add_yet) {
         qerror_report(QERR_INVALID_PARAMETER_VALUE, "driver", "device type");
         return NULL;
     }
 
-    k = DEVICE_CLASS(obj);
-
     /* find bus */
     path = qemu_opt_get(opts, "bus");
     if (path != NULL) {
-- 
1.7.1