From 18b6e8931b3aebefbbccf545165ccc6fcdd09a1e Mon Sep 17 00:00:00 2001
From: Markus Armbruster <armbru@redhat.com>
Date: Fri, 17 May 2019 06:51:10 +0200
Subject: [PATCH 43/53] sysbus: Fix latent bug with onboard devices
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RH-Author: Markus Armbruster <armbru@redhat.com>
Message-id: <20190517065120.12028-22-armbru@redhat.com>
Patchwork-id: 87995
O-Subject: [RHEL-7.7 qemu-kvm-rhev PATCH v3 21/31] sysbus: Fix latent bug with onboard devices
Bugzilla: 1624009
RH-Acked-by: Philippe Mathieu-Daudé <philmd@redhat.com>
RH-Acked-by: Thomas Huth <thuth@redhat.com>
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
The first call of sysbus_get_default() creates the main system bus and
stores it in QOM as "/machine/unattached/sysbus". This must not
happen before main() creates "/machine", or else container_get() would
"helpfully" create it as "container" object, and the real creation of
"/machine" would later abort with "attempt to add duplicate property
'machine' to object (type 'container')". Has been that way ever since
we wired up busses in QOM (commit f968fc6892d, v1.2.0).
I believe the bug is latent. I got it to bite by trying to
qdev_create() a sysbus device from a machine's .instance_init()
method.
The fix is obvious: store the main system bus in QOM right after
creating "/machine".
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20190308131445.17502-5-armbru@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
(cherry picked from commit e2fb3fbbf9ce6b8eed00b53a91d3a316362f1b0d)
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
hw/core/sysbus.c | 3 ---
vl.c | 4 ++++
2 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/hw/core/sysbus.c b/hw/core/sysbus.c
index 5d0887f..db95cb0 100644
--- a/hw/core/sysbus.c
+++ b/hw/core/sysbus.c
@@ -359,9 +359,6 @@ static void main_system_bus_create(void)
qbus_create_inplace(main_system_bus, system_bus_info.instance_size,
TYPE_SYSTEM_BUS, NULL, "main-system-bus");
OBJECT(main_system_bus)->free = g_free;
- object_property_add_child(container_get(qdev_get_machine(),
- "/unattached"),
- "sysbus", OBJECT(main_system_bus), NULL);
}
BusState *sysbus_get_default(void)
diff --git a/vl.c b/vl.c
index d46dff6..d89ac3a 100644
--- a/vl.c
+++ b/vl.c
@@ -4162,6 +4162,10 @@ int main(int argc, char **argv, char **envp)
}
object_property_add_child(object_get_root(), "machine",
OBJECT(current_machine), &error_abort);
+ object_property_add_child(container_get(OBJECT(current_machine),
+ "/unattached"),
+ "sysbus", OBJECT(sysbus_get_default()),
+ NULL);
if (machine_class->minimum_page_bits) {
if (!set_preferred_target_page_bits(machine_class->minimum_page_bits)) {
--
1.8.3.1