qemu/target-alpha
Markus Armbruster 4c315c2766 qdev: Protect device-list-properties against broken devices
Several devices don't survive object_unref(object_new(T)): they crash
or hang during cleanup, or they leave dangling pointers behind.

This breaks at least device-list-properties, because
qmp_device_list_properties() needs to create a device to find its
properties.  Broken in commit f4eb32b "qmp: show QOM properties in
device-list-properties", v2.1.  Example reproducer:

    $ qemu-system-aarch64 -nodefaults -display none -machine none -S -qmp stdio
    {"QMP": {"version": {"qemu": {"micro": 50, "minor": 4, "major": 2}, "package": ""}, "capabilities": []}}
    { "execute": "qmp_capabilities" }
    {"return": {}}
    { "execute": "device-list-properties", "arguments": { "typename": "pxa2xx-pcmcia" } }
    qemu-system-aarch64: /home/armbru/work/qemu/memory.c:1307: memory_region_finalize: Assertion `((&mr->subregions)->tqh_first == ((void *)0))' failed.
    Aborted (core dumped)
    [Exit 134 (SIGABRT)]

Unfortunately, I can't fix the problems in these devices right now.
Instead, add DeviceClass member cannot_destroy_with_object_finalize_yet
to mark them:

* Hang during cleanup (didn't debug, so I can't say why):
  "realview_pci", "versatile_pci".

* Dangling pointer in cpus: most CPUs, plus "allwinner-a10", "digic",
  "fsl,imx25", "fsl,imx31", "xlnx,zynqmp", because they create such
  CPUs

* Assert kvm_enabled(): "host-x86_64-cpu", host-i386-cpu",
  "host-powerpc64-cpu", "host-embedded-powerpc-cpu",
  "host-powerpc-cpu" (the powerpc ones can't currently reach the
  assertion, because the CPUs are only registered when KVM is enabled,
  but the assertion is arguably in the wrong place all the same)

Make qmp_device_list_properties() fail cleanly when the device is so
marked.  This improves device-list-properties from "crashes, hangs or
leaves dangling pointers behind" to "fails".  Not a complete fix, just
a better-than-nothing work-around.  In the above reproducer,
device-list-properties now fails with "Can't list properties of device
'pxa2xx-pcmcia'".

This also protects -device FOO,help, which uses the same machinery
since commit ef52358 "qdev-monitor: include QOM properties in -device
FOO, help output", v2.2.  Example reproducer:

    $ qemu-system-aarch64 -machine none -device pxa2xx-pcmcia,help

Before:

    qemu-system-aarch64: .../memory.c:1307: memory_region_finalize: Assertion `((&mr->subregions)->tqh_first == ((void *)0))' failed.

After:

    Can't list properties of device 'pxa2xx-pcmcia'

Cc: "Andreas Färber" <afaerber@suse.de>
Cc: "Edgar E. Iglesias" <edgar.iglesias@gmail.com>
Cc: Alexander Graf <agraf@suse.de>
Cc: Anthony Green <green@moxielogic.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Cc: Blue Swirl <blauwirbel@gmail.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Jia Liu <proljc@gmail.com>
Cc: Leon Alrae <leon.alrae@imgtec.com>
Cc: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Walle <michael@walle.cc>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: qemu-ppc@nongnu.org
Cc: qemu-stable@nongnu.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <1443689999-12182-10-git-send-email-armbru@redhat.com>
2015-10-09 15:25:57 +02:00
..
Makefile.objs target-alpha: Move VAX helpers to a new file 2015-05-18 13:03:46 -07:00
STATUS Replace Qemu by QEMU in internal documentation 2012-04-07 13:58:25 +00:00
cpu-qom.h target-alpha: Use cpu_exec_interrupt qom hook 2014-09-25 18:54:21 +01:00
cpu.c qdev: Protect device-list-properties against broken devices 2015-10-09 15:25:57 +02:00
cpu.h target-*: Drop cpu_gen_code define 2015-10-07 20:36:50 +11:00
fpu_helper.c target-alpha: Raise IOV from CVTQL 2015-05-18 13:03:47 -07:00
gdbstub.c target-alpha: Use separate TCGv temporaries for the shadow registers 2015-08-18 11:08:48 -07:00
helper.c target-alpha: Use separate TCGv temporaries for the shadow registers 2015-08-18 11:08:48 -07:00
helper.h cmpbge emulation improvements 2015-09-03 12:09:41 +01:00
int_helper.c target-alpha: Special case cmpbge with zero 2015-08-18 09:11:12 -07:00
machine.c target-alpha: Use separate TCGv temporaries for the shadow registers 2015-08-18 11:08:48 -07:00
mem_helper.c typofixes - v4 2015-09-11 10:45:43 +03:00
sys_helper.c s/cpu_get_real_ticks/cpu_get_host_ticks/ 2015-10-08 19:46:01 +03:00
translate.c tcg: Remove gen_intermediate_code_pc 2015-10-07 20:36:52 +11:00
vax_helper.c target-alpha: Move VAX helpers to a new file 2015-05-18 13:03:46 -07:00