From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39997) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ze3KA-0003FE-91 for qemu-devel@nongnu.org; Mon, 21 Sep 2015 11:48:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Ze3K6-0000hl-AR for qemu-devel@nongnu.org; Mon, 21 Sep 2015 11:48:14 -0400 References: <1442577640-11612-1-git-send-email-armbru@redhat.com> <1442577640-11612-6-git-send-email-armbru@redhat.com> <55FC5B2E.9090504@redhat.com> <20150918193252.GC4221@thinpad.lan.raisama.net> <87lhc0fgdb.fsf@blackfin.pond.sub.org> From: Thomas Huth Message-ID: <560026B3.2000903@redhat.com> Date: Mon, 21 Sep 2015 17:48:03 +0200 MIME-Version: 1.0 In-Reply-To: <87lhc0fgdb.fsf@blackfin.pond.sub.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 5/7] qdev: Protect device-list-properties against broken devices List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Markus Armbruster , Eduardo Habkost Cc: Peter Maydell , Peter Crosthwaite , qemu-devel@nongnu.org, qemu-stable@nongnu.org, Alexander Graf , Christian Borntraeger , qemu-ppc@nongnu.org, Antony Pavlov , stefanha@redhat.com, Cornelia Huck , Paolo Bonzini , Alistair Francis , afaerber@suse.de, Li Guang , Richard Henderson On 21/09/15 08:14, Markus Armbruster wrote: > Eduardo Habkost writes: > >> On Fri, Sep 18, 2015 at 08:42:54PM +0200, Thomas Huth wrote: >>> On 18/09/15 14:00, Markus Armbruster wrote: >>>> 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_even_create_with_object_new_yet >>>> to mark them: >>>> >>>> * Crash or hang during cleanup (didn't debug them, so I can't say >>>> why): "pxa2xx-pcmcia", "realview_pci", "versatile_pci", >>>> "s390-sclp-event-facility", "sclp" >>>> >>>> * Dangling pointers: all CPUs, plus "allwinner-a10", "digic", >>>> "fsl,imx25", "fsl,imx31", "xlnx,zynqmp", because they create CPUs >>>> >>>> * Assert kvm_enabled(): "host-x86_64-cpu", host-i386-cpu", >>>> "host-powerpc64-cpu", "host-embedded-powerpc-cpu", >>>> "host-powerpc-cpu" >>> >>> I just had a look at the powerpc code - you're likely talking about >>> the "assert(kvm_enabled());" in the kvmppc_host_cpu_initfn() in >>> target-ppc/kvm.c ? That should be fine, I think, because >>> kvm_ppc_register_host_cpu_type() is only done on ppc when KVM has been >>> enabled. > > Easy to verify on a KVM-capable PPC host: try -device C,help with KVM on > and off, where C is the appropriate host CPU. In both cases (KVM on and off), I simply get: # qemu-system-ppc64 -machine accel=tcg -device host-powerpc64-cpu,help 'host-powerpc64-cpu' is not a valid device model name # qemu-system-ppc64 -machine accel=kvm -device host-powerpc64-cpu,help 'host-powerpc64-cpu' is not a valid device model name No crash/abort here. Thomas