On 21/11/24 19:03, Peter Xu wrote:
On Thu, Nov 21, 2024 at 06:29:06PM +0100, Philippe Mathieu-Daudé wrote:
On 21/11/24 18:17, Peter Xu wrote:
On Thu, Nov 21, 2024 at 02:01:45PM +0100, Philippe Mathieu-Daudé wrote:
On 21/11/24 11:30, Daniel P. Berrangé wrote:
On Wed, Nov 20, 2024 at 04:57:01PM -0500, Peter Xu wrote:
Always explicitly create QEMU system containers upfront.
Root containers will be created when trying to fetch the root object the
1st time. Machine sub-containers will be created only until machine is
being initialized.
Signed-off-by: Peter Xu <pet...@redhat.com>
---
hw/core/machine.c | 19 ++++++++++++++++---
qom/object.c | 16 +++++++++++++++-
2 files changed, 31 insertions(+), 4 deletions(-)
diff --git a/qom/object.c b/qom/object.c
index 214d6eb4c1..810e6f2bd9 100644
--- a/qom/object.c
+++ b/qom/object.c
@@ -1734,12 +1734,26 @@ const char *object_property_get_type(Object *obj, const
char *name, Error **errp
return prop->type;
}
+static Object *object_root_initialize(void)
+{
+ Object *root = object_new(TYPE_CONTAINER);
+
+ /*
+ * Create all QEMU system containers. "machine" and its sub-containers
+ * are only created when machine initializes (qemu_create_machine()).
+ */
+ container_create(root, "chardevs");
+ container_create(root, "objects");
This is where I would expect 'backend' to have been created
rather than ui/console.c, though you could potentially make
a case to create it from the machine function, snice console
stuff can't be used outside of the machine context, while
chardevs/objects can be used in qemu-img/qemu-nbd, etc
Would it hurt if we do it altogether here even if it won't be used in
qemu-img/qemu-nbd?
IMHO we should either make it simple (assuming empty containers won't hurt
there..), or we should just leave "backend" to ui/ code, so we don't assume
which binary is using the ui code: whoever uses it will create the container.
What about creating "backend" container in qemu_create_machine()?
I remember I started with that but it didn't work. IIRC that's because
machine_initfn() (or somewhere around the init code) requires the
containers to present, hence it's too late even if we create the containers
right after this line:
current_machine =
MACHINE(object_new_with_class(OBJECT_CLASS(machine_class)));
So qemu_create_machine_containers() really belongs to qemu_create_machine()
=)
Frankly, I don't immediately get this line..
"machine_initfn requires the containers to be present" -> machine_initfn
isn't the place to create them, it has to be before or after. Since it
can't be before, the "after" place is qemu_create_machine_containers().
Sorry for not being very clear :/
But when I was trying again just to check my memory, I can't see anything
crash anymore, moving things over.
So while I'll test some more, I can switch to that if I cannot reproduce
any issue with it. That's:
===8<===
diff --git a/hw/core/machine.c b/hw/core/machine.c
index ed613ec4cb..a72c001c3d 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -1193,27 +1193,11 @@ static void machine_class_base_init(ObjectClass *oc,
void *data)
}
}
-static const char *const machine_containers[] = {
- "unattached",
- "peripheral",
- "peripheral-anon"
-};
-
-static void qemu_create_machine_containers(Object *machine)
-{
- int i;
-
- for (i = 0; i < ARRAY_SIZE(machine_containers); i++) {
- object_property_add_new_container(machine, machine_containers[i]);
- }
-}
-
static void machine_initfn(Object *obj)
{
MachineState *ms = MACHINE(obj);
MachineClass *mc = MACHINE_GET_CLASS(obj);
- qemu_create_machine_containers(obj);
ms->dump_guest_core = true;
ms->mem_merge = (QEMU_MADV_MERGEABLE != QEMU_MADV_INVALID);
ms->enable_graphics = true;
diff --git a/system/vl.c b/system/vl.c
index 822f7ff656..cdc0b6e10c 100644
--- a/system/vl.c
+++ b/system/vl.c
@@ -2112,6 +2112,21 @@ static void parse_memory_options(void)
loc_pop(&loc);
}
+static const char *const machine_containers[] = {
+ "unattached",
+ "peripheral",
+ "peripheral-anon"
+};
+
+static void qemu_create_machine_containers(Object *machine)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(machine_containers); i++) {
+ object_property_add_new_container(machine, machine_containers[i]);
+ }
+}
+
static void qemu_create_machine(QDict *qdict)
{
MachineClass *machine_class = select_machine(qdict, &error_fatal);
@@ -2120,6 +2135,7 @@ static void qemu_create_machine(QDict *qdict)
current_machine =
MACHINE(object_new_with_class(OBJECT_CLASS(machine_class)));
object_property_add_child(object_get_root(), "machine",
OBJECT(current_machine));
+ qemu_create_machine_containers(OBJECT(current_machine));
object_property_add_child(machine_get_container("unattached"),
"sysbus", OBJECT(sysbus_get_default()));
Yes, this is exactly what I was thinking of / expecting :)
