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>
NICs defined with -net nic are for board initialization to wire up.
Board code examines nd_table[] to find them, and creates devices with
their qdev NIC properties set accordingly.
Except "allwinner-a10" goes on a fishing expedition for NIC
configuration instead of exposing the usual NIC properties for board
code to set: it uses nd_table[0] in its instance_init() method.
Picking up the first -net nic option's configuration that way works
when the device is created by board code. But it's inappropriate for
-device and device_add. Not only is it inconsistent with how the
other block device models work (they get their configuration from
properties "mac", "vlan", "netdev"), it breaks when nd_table[0] has
been picked up by the board or a previous -device / device_add
already.
Example:
$ qemu-system-arm -S -M cubieboard -device allwinner-a10
qemu-system-arm: -device allwinner-a10: Property 'allwinner-emac.netdev' can't take value 'hub0port0', it's in use
Aborted (core dumped)
It also breaks in other entertaining ways:
$ qemu-system-arm -M highbank -device allwinner-a10
qemu-system-arm: -device allwinner-a10: Unsupported NIC model: xgmac
$ qemu-system-arm -M highbank -net nic,model=allwinner-emac -device allwinner-a10
qemu-system-arm: Unsupported NIC model: allwinner-emac
Mark the mistake with a FIXME comment.
Cc: Li Guang <lig.fnst@cn.fujitsu.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Character devices defined with -serial and -parallel are for board
initialization to wire up. Board code examines serial_hds[] and
parallel_hds[] to find them, and creates devices with their qdev
chardev properties set accordingly.
Except a few devices go on a fishing expedition for a suitable backend
instead of exposing a chardev property for board code to set: they use
serial_hds[] (often via qemu_char_get_next_serial()) or parallel_hds[]
in their realize() or init() method to connect to a backend.
Picking up backends that way works when the devices are created by
board code. But it's inappropriate for -device or device_add. Not
only is it inconsistent with how the other characrer device models
work (they connect to a backend explicitly identified by a "chardev"
property), it breaks when the backend has been picked up by the board
or a previous -device / device_add already.
Example:
$ qemu-system-ppc64 -M bamboo -S -device i82378 -device pc87312 -device pc87312
qemu-system-ppc64: -device pc87312: Property 'isa-parallel.chardev' can't take value 'parallel0', it's in use
Mark them with suitable FIXME comments.
Cc: Li Guang <lig.fnst@cn.fujitsu.com>
Cc: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Cc: Antony Pavlov <antonynpavlov@gmail.com>
Cc: "Edgar E. Iglesias" <edgar.iglesias@gmail.com>
Cc: Michael Walle <michael@walle.cc>
Cc: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Cc: "Andreas Färber" <andreas.faerber@web.de>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
