From nobody Sun Feb 8 19:55:42 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; 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 208.118.235.17 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 [208.118.235.17]) by mx.zohomail.com with SMTPS id 1545333106740850.3742564664481; Thu, 20 Dec 2018 11:11:46 -0800 (PST) Received: from localhost ([::1]:39454 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ga3jU-00067C-ST for importer@patchew.org; Thu, 20 Dec 2018 14:11:44 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60585) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ga3F8-0005iw-0W for qemu-devel@nongnu.org; Thu, 20 Dec 2018 13:40:27 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ga3F5-0001wH-Rs for qemu-devel@nongnu.org; Thu, 20 Dec 2018 13:40:21 -0500 Received: from mx1.redhat.com ([209.132.183.28]:49628) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ga3F5-0001tt-GF for qemu-devel@nongnu.org; Thu, 20 Dec 2018 13:40:19 -0500 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B0B0F8AE77; Thu, 20 Dec 2018 18:40:18 +0000 (UTC) Received: from redhat.com (ovpn-122-182.rdu2.redhat.com [10.10.122.182]) by smtp.corp.redhat.com (Postfix) with SMTP id DF77D1001F3C; Thu, 20 Dec 2018 18:40:12 +0000 (UTC) Date: Thu, 20 Dec 2018 13:40:12 -0500 From: "Michael S. Tsirkin" To: qemu-devel@nongnu.org Message-ID: <20181220183059.20726-42-mst@redhat.com> References: <20181220183059.20726-1-mst@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20181220183059.20726-1-mst@redhat.com> X-Mutt-Fcc: =sent X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Thu, 20 Dec 2018 18:40:18 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL v3 41/44] pci: Adjust PCI config limit based on bus topology 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: Marcel Apfelbaum , Peter Maydell , Alex Williamson Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Alex Williamson A conventional PCI bus does not support config space accesses above the standard 256 byte configuration space. PCIe-to-PCI bridges are not permitted to forward transactions if the extended register address field is non-zero and must handle it as an unsupported request (PCIe bridge spec rev 1.0, 4.1.3, 4.1.4). Therefore, we should not support extended config space if there is a conventional bus anywhere on the path to a device. Signed-off-by: Alex Williamson Reviewed-by: Marcel Apfelbaum Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/pci/pci_host.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/hw/pci/pci_host.c b/hw/pci/pci_host.c index 5eaa935cb5..5f5345dbac 100644 --- a/hw/pci/pci_host.c +++ b/hw/pci/pci_host.c @@ -20,6 +20,7 @@ =20 #include "qemu/osdep.h" #include "hw/pci/pci.h" +#include "hw/pci/pci_bridge.h" #include "hw/pci/pci_host.h" #include "hw/pci/pci_bus.h" #include "trace.h" @@ -50,9 +51,29 @@ static inline PCIDevice *pci_dev_find_by_addr(PCIBus *bu= s, uint32_t addr) return pci_find_device(bus, bus_num, devfn); } =20 +static void pci_adjust_config_limit(PCIBus *bus, uint32_t *limit) +{ + if (*limit > PCI_CONFIG_SPACE_SIZE) { + if (!pci_bus_is_express(bus)) { + *limit =3D PCI_CONFIG_SPACE_SIZE; + return; + } + + if (!pci_bus_is_root(bus)) { + PCIDevice *bridge =3D pci_bridge_get_device(bus); + pci_adjust_config_limit(pci_get_bus(bridge), limit); + } + } +} + void pci_host_config_write_common(PCIDevice *pci_dev, uint32_t addr, uint32_t limit, uint32_t val, uint32_t l= en) { + pci_adjust_config_limit(pci_get_bus(pci_dev), &limit); + if (limit <=3D addr) { + return; + } + assert(len <=3D 4); /* non-zero functions are only exposed when function 0 is present, * allowing direct removal of unexposed functions. @@ -71,6 +92,11 @@ uint32_t pci_host_config_read_common(PCIDevice *pci_dev,= uint32_t addr, { uint32_t ret; =20 + pci_adjust_config_limit(pci_get_bus(pci_dev), &limit); + if (limit <=3D addr) { + return ~0x0; + } + assert(len <=3D 4); /* non-zero functions are only exposed when function 0 is present, * allowing direct removal of unexposed functions. --=20 MST