On Wed, 24 Mar 2021 10:17:55 +0100
Paolo Bonzini <pbonz...@redhat.com> wrote:
> On 24/03/21 00:35, Philippe Mathieu-Daudé wrote:
> > Hmmm does this assert() matches your comment?
> >
> > -- >8 --
> > diff --git a/hw/core/qdev.c b/hw/core/qdev.c
> > index cefc5eaa0a9..41cbee77d14 100644
> > --- a/hw/core/qdev.c
> > +++ b/hw/core/qdev.c
> > @@ -1130,6 +1130,8 @@ Object *qdev_get_machine(void)
> > {
> > static Object *dev;
> >
> > + assert(phase_check(PHASE_MACHINE_CREATED));
> > +
>
> Very nice use of phase_check! Kudos.
>
It seems promising at first sight but qdev_get_machine() gets
called under qemu_create_machine() long before phase is advanced
to PHASE_MACHINE_CREATED.
qemu-system-ppc64: ../../hw/core/qdev.c:1133: qdev_get_machine: Assertion
`phase_check(PHASE_MACHINE_CREATED)' failed.
(gdb) bt
#0 0x00007ffff64a3708 in raise () at /lib64/power9/libc.so.6
#1 0x00007ffff6483bcc in abort () at /lib64/power9/libc.so.6
#2 0x00007ffff6497210 in __assert_fail_base () at /lib64/power9/libc.so.6
#3 0x00007ffff64972b4 in __assert_fail () at /lib64/power9/libc.so.6
#4 0x00000001009e7820 in qdev_get_machine () at ../../hw/core/qdev.c:1133
#5 0x00000001009e7820 in qdev_get_machine () at ../../hw/core/qdev.c:1129
#6 0x0000000100747894 in memory_region_do_init (mr=0x101261200, owner=0x0,
name=<optimized out>, size=<optimized out>) at ../../softmmu/memory.c:1177
#7 0x00000001007fccc4 in memory_map_init () at ../../softmmu/physmem.c:2630
#8 0x00000001007fccc4 in cpu_exec_init_all () at ../../softmmu/physmem.c:3034
#9 0x00000001007e9c9c in qemu_create_machine
(machine_class=machine_class@entry=0x1014b96d0) at ../../softmmu/vl.c:2086
#10 0x00000001007eb8c0 in qemu_init (argc=<optimized out>, argv=<optimized
out>, envp=<optimized out>) at ../../softmmu/vl.c:1640
#11 0x00000001002f53c8 in main (argc=<optimized out>, argv=<optimized out>,
envp=<optimized out>) at ../../softmmu/main.c:49
static void memory_region_do_init(MemoryRegion *mr,
Object *owner,
const char *name,
uint64_t size)
{
[...]
if (!owner) {
owner = container_get(qdev_get_machine(), "/unattached");
}
The true condition for qdev_get_machine() to be functional is
actually that the following happened already:
object_property_add_child(object_get_root(), "machine",
OBJECT(current_machine));
This is the case with the call stack ^^ and I don't see any valid
reason to forbid use of qdev_get_machine() here.
So I'm wondering if we shouldn't rather check the existence of the
"/machine" path in the QOM tree instead of checking the phase.
> Paolo
>
