From nobody Sun Feb 8 17:48:10 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 154886404757275.58543122845583; Wed, 30 Jan 2019 08:00:47 -0800 (PST) Received: from localhost ([127.0.0.1]:40260 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gosI8-0000ns-Ru for importer@patchew.org; Wed, 30 Jan 2019 11:00:44 -0500 Received: from eggs.gnu.org ([209.51.188.92]:46774) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gosFJ-00074G-Ez for qemu-devel@nongnu.org; Wed, 30 Jan 2019 10:57:50 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gosFH-0008Tg-Ez for qemu-devel@nongnu.org; Wed, 30 Jan 2019 10:57:49 -0500 Received: from mx1.redhat.com ([209.132.183.28]:57754) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gosFG-0008Ps-VH; Wed, 30 Jan 2019 10:57:47 -0500 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 29AFD64385; Wed, 30 Jan 2019 15:57:41 +0000 (UTC) Received: from t460s.redhat.com (ovpn-116-235.ams2.redhat.com [10.36.116.235]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4D4BB1A914; Wed, 30 Jan 2019 15:57:39 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Date: Wed, 30 Jan 2019 16:57:28 +0100 Message-Id: <20190130155733.32742-2-david@redhat.com> In-Reply-To: <20190130155733.32742-1-david@redhat.com> References: <20190130155733.32742-1-david@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Wed, 30 Jan 2019 15:57:41 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v2 1/6] s390x/pci: Fix primary bus number for PCI bridges X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Thomas Huth , Pierre Morel , David Hildenbrand , Cornelia Huck , Collin Walling , Christian Borntraeger , qemu-s390x@nongnu.org, Richard Henderson Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" The primary bus number corresponds always to the bus number of the bus the bridge is attached to. Right now, if we have two bridges attached to the same bus (e.g. root bus) this is however not the case. The first bridge will have primary bus 0, the second bridge primary bus 1, which is wrong. Fix the assignment. While at it, drop setting the PCI_SUBORDINATE_BUS temporarily to 0xff. Setting it temporarily to that value (as discussed e.g. in [1]), is only relevant for a running system that probes the buses. The value is effectively unused for us just doing a DFS. Also add a comment why we have to reassign during every reset (which I found to be surprising. Please note that hotplugging of bridges is in general still broken, will be fixed next. [1] http://www.science.unitn.it/~fiorella/guidelinux/tlk/node76.html Reviewed-by: Thomas Huth Signed-off-by: David Hildenbrand Reviewed-by: Collin Walling --- hw/s390x/s390-pci-bus.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/hw/s390x/s390-pci-bus.c b/hw/s390x/s390-pci-bus.c index f017c1ded0..b7c4613fde 100644 --- a/hw/s390x/s390-pci-bus.c +++ b/hw/s390x/s390-pci-bus.c @@ -862,7 +862,8 @@ static void s390_pcihost_plug(HotplugHandler *hotplug_d= ev, DeviceState *dev, qbus_set_hotplug_handler(bus, DEVICE(s), errp); =20 if (dev->hotplugged) { - pci_default_write_config(pdev, PCI_PRIMARY_BUS, s->bus_no, 1); + pci_default_write_config(pdev, PCI_PRIMARY_BUS, + pci_dev_bus_num(pdev), 1); s->bus_no +=3D 1; pci_default_write_config(pdev, PCI_SECONDARY_BUS, s->bus_no, 1= ); do { @@ -1016,8 +1017,6 @@ static void s390_pci_enumerate_bridge(PCIBus *bus, PC= IDevice *pdev, void *opaque) { S390pciState *s =3D opaque; - unsigned int primary =3D s->bus_no; - unsigned int subordinate =3D 0xff; PCIBus *sec_bus =3D NULL; =20 if ((pci_default_read_config(pdev, PCI_HEADER_TYPE, 1) !=3D @@ -1026,7 +1025,7 @@ static void s390_pci_enumerate_bridge(PCIBus *bus, PC= IDevice *pdev, } =20 (s->bus_no)++; - pci_default_write_config(pdev, PCI_PRIMARY_BUS, primary, 1); + pci_default_write_config(pdev, PCI_PRIMARY_BUS, pci_dev_bus_num(pdev),= 1); pci_default_write_config(pdev, PCI_SECONDARY_BUS, s->bus_no, 1); pci_default_write_config(pdev, PCI_SUBORDINATE_BUS, s->bus_no, 1); =20 @@ -1035,7 +1034,7 @@ static void s390_pci_enumerate_bridge(PCIBus *bus, PC= IDevice *pdev, return; } =20 - pci_default_write_config(pdev, PCI_SUBORDINATE_BUS, subordinate, 1); + /* Assign numbers to all child bridges. The last is the highest number= . */ pci_for_each_device(sec_bus, pci_bus_num(sec_bus), s390_pci_enumerate_bridge, s); pci_default_write_config(pdev, PCI_SUBORDINATE_BUS, s->bus_no, 1); @@ -1046,6 +1045,10 @@ static void s390_pcihost_reset(DeviceState *dev) S390pciState *s =3D S390_PCI_HOST_BRIDGE(dev); PCIBus *bus =3D s->parent_obj.bus; =20 + /* + * When resetting a PCI bridge, the assigned numbers are set to 0. So + * on every system reset, we also have to reassign numbers. + */ s->bus_no =3D 0; pci_for_each_device(bus, pci_bus_num(bus), s390_pci_enumerate_bridge, = s); } --=20 2.17.2