From patchwork Thu Nov 19 10:23:24 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cornelia Huck X-Patchwork-Id: 1402884 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) 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=fail (p=none dis=none) header.from=redhat.com Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=IK255Rd2; 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 4CcG4c2McMz9sTv for ; Thu, 19 Nov 2020 21:24:14 +1100 (AEDT) Received: from localhost ([::1]:43050 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kfh6q-0001IJ-SE for incoming@patchwork.ozlabs.org; Thu, 19 Nov 2020 05:24:12 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:49048) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kfh6J-0001FL-HI for qemu-devel@nongnu.org; Thu, 19 Nov 2020 05:23:39 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:24423) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kfh6H-0004GI-Pc for qemu-devel@nongnu.org; Thu, 19 Nov 2020 05:23:39 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1605781417; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=zuVWm2w10Zr6XqrL9ypcZsqyy3otSI98W6NTCepA+4s=; b=IK255Rd2tMZqCBfRZUgtk6f+FHmOcodblH3JZcdh3oFwrE+XD9xUQdA1wX15edE9D5AOTQ kLpgyDgA2GSQVfWRj0ehg4BQ3uV4V9DuIah3ay+Fay8vkPoj5wmtn+euOSRN1jH6qF+rPP NFiiwfRnhEtnMTfW8WFNM2kNlOe3gT0= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-507-mbI9BjUSMAe4z4rPWLiA0A-1; Thu, 19 Nov 2020 05:23:34 -0500 X-MC-Unique: mbI9BjUSMAe4z4rPWLiA0A-1 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 mimecast-mx01.redhat.com (Postfix) with ESMTPS id 298F218B613D; Thu, 19 Nov 2020 10:23:33 +0000 (UTC) Received: from gondolin.redhat.com (ovpn-113-214.ams2.redhat.com [10.36.113.214]) by smtp.corp.redhat.com (Postfix) with ESMTP id 747AB5D9C0; Thu, 19 Nov 2020 10:23:31 +0000 (UTC) From: Cornelia Huck To: Peter Maydell Subject: [PULL for-5.2 2/3] s390x/pci: Unregister listeners before destroying IOMMU address space Date: Thu, 19 Nov 2020 11:23:24 +0100 Message-Id: <20201119102325.1314765-3-cohuck@redhat.com> In-Reply-To: <20201119102325.1314765-1-cohuck@redhat.com> References: <20201119102325.1314765-1-cohuck@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=cohuck@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=216.205.24.124; envelope-from=cohuck@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/11/19 03:44:58 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action 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: Thomas Huth , Matthew Rosato , Pierre Morel , Niklas Schnelle , Cornelia Huck , qemu-devel@nongnu.org, qemu-s390x@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Matthew Rosato Hot-unplugging a vfio-pci device on s390x causes a QEMU crash: qemu-system-s390x: ../softmmu/memory.c:2772: do_address_space_destroy: Assertion `QTAILQ_EMPTY(&as->listeners)' failed. In s390, the IOMMU address space is freed during device unplug but the associated vfio-pci device may not yet be finalized and therefore may still have a listener registered to the IOMMU address space. Commit a2166410ad74 ("spapr_pci: Unregister listeners before destroying the IOMMU address space") previously resolved this issue for spapr_pci. We are now seeing this in s390x; it would seem the possibility for this issue was already present but based on a bisect commit 2d24a6466154 ("device-core: use RCU for list of children of a bus") has now changed the timing such that it is now readily reproducible. Add logic to ensure listeners are removed before destroying the address space. Reported-by: Niklas Schnelle Signed-off-by: Matthew Rosato Tested-by: Niklas Schnelle Reviewed-by: Pierre Morel Reviewed-by: Thomas Huth Message-Id: <1605562955-21152-1-git-send-email-mjrosato@linux.ibm.com> Signed-off-by: Cornelia Huck --- hw/s390x/s390-pci-bus.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/hw/s390x/s390-pci-bus.c b/hw/s390x/s390-pci-bus.c index 48a3be802f8e..e0dc20ce4a56 100644 --- a/hw/s390x/s390-pci-bus.c +++ b/hw/s390x/s390-pci-bus.c @@ -732,6 +732,13 @@ static void s390_pci_iommu_free(S390pciState *s, PCIBus *bus, int32_t devfn) table->iommu[PCI_SLOT(devfn)] = NULL; g_hash_table_destroy(iommu->iotlb); + /* + * An attached PCI device may have memory listeners, eg. VFIO PCI. + * The associated subregion will already have been unmapped in + * s390_pci_iommu_disable in response to the guest deconfigure request. + * Remove the listeners now before destroying the address space. + */ + address_space_remove_listeners(&iommu->as); address_space_destroy(&iommu->as); object_unparent(OBJECT(&iommu->mr)); object_unparent(OBJECT(iommu));