From patchwork Tue Jul 2 06:08:50 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Gibson X-Patchwork-Id: 1125983 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=gibson.dropbear.id.au Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=gibson.dropbear.id.au header.i=@gibson.dropbear.id.au header.b="hIpGBaEm"; dkim-atps=neutral Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 45dDny6JX3z9s4Y for ; Tue, 2 Jul 2019 16:28:22 +1000 (AEST) Received: from localhost ([::1]:49504 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hiCH6-0004ty-1T for incoming@patchwork.ozlabs.org; Tue, 02 Jul 2019 02:28:20 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:58734) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hiBzE-0005J1-Th for qemu-devel@nongnu.org; Tue, 02 Jul 2019 02:09:54 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hiBzD-0003Df-DA for qemu-devel@nongnu.org; Tue, 02 Jul 2019 02:09:52 -0400 Received: from bilbo.ozlabs.org ([2401:3900:2:1::2]:41149 helo=ozlabs.org) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hiBzC-0003Cj-OO; Tue, 02 Jul 2019 02:09:51 -0400 Received: by ozlabs.org (Postfix, from userid 1007) id 45dDMl62V4z9sR2; Tue, 2 Jul 2019 16:09:07 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1562047747; bh=BoQiYE/mVURYA3U/YJzA8w1BMJeYj/dzSkDSUvcQtmw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hIpGBaEmsnZqHnnd3D5129y+f5H+nwTzuhvUGv1Wj71q/6AJDLQoAlISCMuIcGX+n +V4EEmkwXTv5jMz/eO4VL6hpgu9Enmq/VW1nt46Q/Bo+tTWYvpMGGVYtkSS3Vw2XYY 9Kf8EzKLg/gI/eaaSc9Yub6GZ8AA9Wn5U/Ktc7r0= From: David Gibson To: peter.maydell@linaro.org Date: Tue, 2 Jul 2019 16:08:50 +1000 Message-Id: <20190702060857.3926-43-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190702060857.3926-1-david@gibson.dropbear.id.au> References: <20190702060857.3926-1-david@gibson.dropbear.id.au> MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2401:3900:2:1::2 Subject: [Qemu-devel] [PULL 42/49] spapr_pci: Unregister listeners before destroying the IOMMU address space X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: lvivier@redhat.com, aik@ozlabs.ru, qemu-devel@nongnu.org, groug@kaod.org, qemu-ppc@nongnu.org, clg@kaod.org, David Gibson , rth@twiddle.net Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Greg Kurz Hot-unplugging a PHB with a VFIO device connected to it crashes QEMU: -device spapr-pci-host-bridge,index=1,id=phb1 \ -device vfio-pci,host=0034:01:00.3,id=vfio0 (qemu) device_del phb1 [ 357.207183] iommu: Removing device 0001:00:00.0 from group 1 [ 360.375523] rpadlpar_io: slot PHB 1 removed qemu-system-ppc64: memory.c:2742: do_address_space_destroy: Assertion `QTAILQ_EMPTY(&as->listeners)' failed. 'as' is the IOMMU address space, which indeed has a listener registered to by vfio_connect_container() when the VFIO device is realized. This listener is supposed to be unregistered by vfio_disconnect_container() when the VFIO device is finalized. Unfortunately, the VFIO device hasn't reached finalize yet at the time the PHB unrealize function is called, and address_space_destroy() gets called with the VFIO listener still being registered. All regions have just been unmapped from the address space. Listeners aren't needed anymore at this point. Remove them before destroying the address space. The VFIO code will try to remove them _again_ at device finalize, but it is okay since memory_listener_unregister() is idempotent. Signed-off-by: Greg Kurz Message-Id: <156110925375.92514.11649846071216864570.stgit@bahia.lan> Reviewed-by: Alexey Kardashevskiy [dwg: Correct spelling error pointed out by aik] Signed-off-by: David Gibson --- hw/ppc/spapr_pci.c | 6 ++++++ include/exec/memory.h | 10 ++++++++++ memory.c | 7 +++++++ 3 files changed, 23 insertions(+) diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c index 5591723bb2..9003fe9010 100644 --- a/hw/ppc/spapr_pci.c +++ b/hw/ppc/spapr_pci.c @@ -1788,6 +1788,12 @@ static void spapr_phb_unrealize(DeviceState *dev, Error **errp) memory_region_del_subregion(&sphb->iommu_root, &sphb->msiwindow); + /* + * An attached PCI device may have memory listeners, eg. VFIO PCI. We have + * unmapped all sections. Remove the listeners now, before destroying the + * address space. + */ + address_space_remove_listeners(&sphb->iommu_as); address_space_destroy(&sphb->iommu_as); qbus_set_hotplug_handler(BUS(phb->bus), NULL, &error_abort); diff --git a/include/exec/memory.h b/include/exec/memory.h index e6140e8a04..2c5cdffa31 100644 --- a/include/exec/memory.h +++ b/include/exec/memory.h @@ -1757,6 +1757,16 @@ void address_space_init(AddressSpace *as, MemoryRegion *root, const char *name); */ void address_space_destroy(AddressSpace *as); +/** + * address_space_remove_listeners: unregister all listeners of an address space + * + * Removes all callbacks previously registered with memory_listener_register() + * for @as. + * + * @as: an initialized #AddressSpace + */ +void address_space_remove_listeners(AddressSpace *as); + /** * address_space_rw: read from or write to an address space. * diff --git a/memory.c b/memory.c index 0a089a73ae..480f3d989b 100644 --- a/memory.c +++ b/memory.c @@ -2723,6 +2723,13 @@ void memory_listener_unregister(MemoryListener *listener) listener->address_space = NULL; } +void address_space_remove_listeners(AddressSpace *as) +{ + while (!QTAILQ_EMPTY(&as->listeners)) { + memory_listener_unregister(QTAILQ_FIRST(&as->listeners)); + } +} + void address_space_init(AddressSpace *as, MemoryRegion *root, const char *name) { memory_region_ref(root);