From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54396) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1drPkg-0006bD-TK for qemu-devel@nongnu.org; Mon, 11 Sep 2017 10:31:55 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1drPkb-0001Uj-43 for qemu-devel@nongnu.org; Mon, 11 Sep 2017 10:31:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47242) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1drPka-0001U4-RP for qemu-devel@nongnu.org; Mon, 11 Sep 2017 10:31:49 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id A7F8311AD08 for ; Mon, 11 Sep 2017 14:31:47 +0000 (UTC) References: <1504776162-31400-1-git-send-email-thuth@redhat.com> <20170911145344.4f2e192c@nial.brq.redhat.com> From: Thomas Huth Message-ID: Date: Mon, 11 Sep 2017 16:31:39 +0200 MIME-Version: 1.0 In-Reply-To: <20170911145344.4f2e192c@nial.brq.redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH] hw/core/qdev: Do not allow hot-plugging without hotplug controller List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Igor Mammedov Cc: qemu-devel@nongnu.org, Paolo Bonzini , Eduardo Habkost , "Michael S. Tsirkin" , Markus Armbruster , "Dr. David Alan Gilbert" , Juan Quintela On 11.09.2017 14:53, Igor Mammedov wrote: > On Thu, 7 Sep 2017 11:22:42 +0200 > Thomas Huth wrote: >=20 >> qdev_unplug() bails out with an assertion if the user tries to device_= del >> a hot-plugged device that does not have a hotplug controller. Unfortun= ately, >> our devices are all marked with hotpluggable =3D true by default (see = the >> device_class_init() function in qdev.c), so it currently can happen th= at >> the user runs into this situation and QEMU gets terminated unexpectedl= y: >> >> $ qemu-system-aarch64 -M virt -nographic -nodefaults -monitor stdio -S >> QEMU 2.10.50 monitor - type 'help' for more information >> (qemu) device_add aux-to-i2c-bridge,id=3Dx >> (qemu) device_del x >> ** >> ERROR:qdev-monitor.c:872:qdev_unplug: assertion failed: (hotplug_ctrl) >> Aborted (core dumped) >> Hotplugging devices without a hotplug controller does not make much se= nse, >> so we should disallow this during the device_add process already! >> >> Suggested-by: Paolo Bonzini >> Signed-off-by: Thomas Huth >> --- >> hw/core/qdev.c | 5 +++++ >> 1 file changed, 5 insertions(+) >> >> diff --git a/hw/core/qdev.c b/hw/core/qdev.c >> index 606ab53..d9ccce6 100644 >> --- a/hw/core/qdev.c >> +++ b/hw/core/qdev.c >> @@ -908,6 +908,11 @@ static void device_set_realized(Object *obj, bool= value, Error **errp) >> if (local_err !=3D NULL) { >> goto fail; >> } >> + } else if (dev->hotplugged) { >> + /* Hot-plugged device without hotplug controller? No way!= */ >> + error_setg(&local_err, QERR_DEVICE_NO_HOTPLUG, >> + object_get_typename(obj)); >> + goto fail; >> } >> =20 >> if (dc->realize) { >=20 > maybe it should be other way around, i.e, fix device so that following = would work >=20 > device_set_realized() > if (dev->hotplugged && !dc->hotpluggable) { = =20 > error_setg(errp, QERR_DEVICE_NO_HOTPLUG, object_get_typename(ob= j)); =20 > return; = =20 > } >=20 > instead of leaving device broken, like in yours > 84ebd3e watchdog/wdt_diag288: Mark diag288 watchdog as non-hotpluggabl= e No, that apparently does not work right for new devices since people keep forgetting to set hotpluggable =3D false there. Both, Paolo and Pete= r suggested that we should not allow hot-plugging if there's no hot plug controller - it indeed does not make sense, so we should not allow it. Thomas