From patchwork Wed Nov 24 05:27:58 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Michael S. Tsirkin" X-Patchwork-Id: 72791 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [199.232.76.165]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 672C6B70A7 for ; Wed, 24 Nov 2010 16:29:02 +1100 (EST) Received: from localhost ([127.0.0.1]:52344 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PL7uc-00032a-7a for incoming@patchwork.ozlabs.org; Wed, 24 Nov 2010 00:28:58 -0500 Received: from [140.186.70.92] (port=33428 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PL7ty-00032U-49 for qemu-devel@nongnu.org; Wed, 24 Nov 2010 00:28:19 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PL7tw-0007Bb-Kp for qemu-devel@nongnu.org; Wed, 24 Nov 2010 00:28:18 -0500 Received: from mx1.redhat.com ([209.132.183.28]:35034) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PL7tw-0007BU-7M for qemu-devel@nongnu.org; Wed, 24 Nov 2010 00:28:16 -0500 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id oAO5SCk3030985 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 24 Nov 2010 00:28:12 -0500 Received: from redhat.com (vpn-6-215.tlv.redhat.com [10.35.6.215]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with SMTP id oAO5S8RC018912; Wed, 24 Nov 2010 00:28:09 -0500 Date: Wed, 24 Nov 2010 07:27:58 +0200 From: "Michael S. Tsirkin" To: Isaku Yamahata Message-ID: <20101124052758.GA19320@redhat.com> References: <20101122075402.GA6892@redhat.com> <20101122104337.GB24265@valinux.co.jp> <20101122225312.GA1359@redhat.com> <20101123181026.GA2752@redhat.com> <20101124023725.GC9591@valinux.co.jp> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20101124023725.GC9591@valinux.co.jp> User-Agent: Mutt/1.5.21 (2010-09-15) X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. Cc: skandasa@cisco.com, etmartin@cisco.com, wexu2@cisco.com, qemu-devel@nongnu.org, kraxel@redhat.com, pbonzini@redhat.com Subject: [Qemu-devel] Re: [PATCH v2 0/6] qdev reset refactoring and pci bus reset X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org On Wed, Nov 24, 2010 at 11:37:25AM +0900, Isaku Yamahata wrote: > On Tue, Nov 23, 2010 at 08:10:26PM +0200, Michael S. Tsirkin wrote: > > On Tue, Nov 23, 2010 at 12:53:12AM +0200, Michael S. Tsirkin wrote: > > > On Mon, Nov 22, 2010 at 07:43:37PM +0900, Isaku Yamahata wrote: > > > > On Mon, Nov 22, 2010 at 09:54:02AM +0200, Michael S. Tsirkin wrote: > > > > > On Fri, Nov 19, 2010 at 06:55:57PM +0900, Isaku Yamahata wrote: > > > > > > Here is v2. I updated the comments, and dropped the pci qdev reset patch. > > > > > > > > > > > > Patch description: > > > > > > The goal of this patch series is to implement secondary bus reset > > > > > > emulation in pci-to-pci bridge. > > > > > > At first, this patch series refactors qdev reset, > > > > > > and then cleans up pci bus reset. Lastly implements pci bridge control > > > > > > secondary bus reset bit. > > > > > > > > > > > > This patch series is for pci bus reset, which is ported > > > > > > from the following repo. > > > > > > git://repo.or.cz/qemu/aliguori.git qdev-refactor > > > > > > > > > > I've put the series on my pci branch, tweaking patches 5 and 6 in the > > > > > process. Out of time to compile-tested only for now. > > > > > > > > Thank you. The tweaking looks good. > > > > Do you still want me to send another patch to add a comment on RST#? > > > > > > OK, I got response, and yes, we need to fix code to avoid claiming > > > transactions by devices on the secondary bus while secondary bus is in > > > RST# for both pci and express. > > > > I guess the following fixes it? > > Almost. The following if claouse also needs modification. > > commit 120fe782a198b787e13a9d4681afae8dc66dee50 > Author: "Michael S. Tsirkin" > Date: Wed Nov 24 11:34:59 2010 +0900 > > pci: don't access bus while it's reset > > Devices on a bus should not respond while RST# > is asserted, which is controlled by PCI_BRIDGE_CTL_BUS_RESET. > Simply skip such a bus when propagating the configuration cycle. > > Signed-off-by: Michael S. Tsirkin > Signed-off-by: Isaku Yamahata > > diff --git a/hw/pci.c b/hw/pci.c > index d02f980..e7df612 100644 > --- a/hw/pci.c > +++ b/hw/pci.c > @@ -1554,7 +1554,9 @@ PCIBus *pci_find_bus(PCIBus *bus, int bus_num) > > /* try child bus */ > if (!bus->parent_dev /* host pci bridge */ || > - (bus->parent_dev->config[PCI_SECONDARY_BUS] < bus_num && > + (!(pci_get_word(bus->parent_dev->config + PCI_BRIDGE_CONTROL) & > + PCI_BRIDGE_CTL_BUS_RESET) /* Don't walk the bus if it's reset. */ && > + bus->parent_dev->config[PCI_SECONDARY_BUS] < bus_num && > bus_num <= bus->parent_dev->config[PCI_SUBORDINATE_BUS])) { > for (; bus; bus = sec) { > QLIST_FOREACH(sec, &bus->child, sibling) { > @@ -1562,8 +1564,11 @@ PCIBus *pci_find_bus(PCIBus *bus, int bus_num) > if (sec->parent_dev->config[PCI_SECONDARY_BUS] == bus_num) { > return sec; > } > - if (sec->parent_dev->config[PCI_SECONDARY_BUS] < bus_num && > - bus_num <= sec->parent_dev->config[PCI_SUBORDINATE_BUS]) { > + if (pci_get_word(sec->parent_dev->config + > + PCI_BRIDGE_CONTROL) & PCI_BRIDGE_CTL_BUS_RESET > + /* Don't walk the bus if it's reset. */ || > + bus_num < sec->parent_dev->config[PCI_SECONDARY_BUS] || > + sec->parent_dev->config[PCI_SUBORDINATE_BUS] < bus_num) { > break; > } > } Right. So let's add an inline helper to avoid code duplication here? pci: fix bus walk under secondary bus reset Take into account secondary bus reset bit for bus walk: devices behind a reset bus should not respond to configuration cycles. Signed-off-by: Michael S. Tsirkin > -- > yamahata diff --git a/hw/pci.c b/hw/pci.c index d02f980..0c15b13 100644 --- a/hw/pci.c +++ b/hw/pci.c @@ -1540,6 +1540,16 @@ void pci_bridge_update_mappings(PCIBus *b) } } +/* Whether a given bus number is in range of the secondary + * bus of the given bridge device. */ +static bool pci_secondary_bus_in_range(PCIDevice *dev, int bus_num) +{ + return !(pci_get_word(dev->config + PCI_BRIDGE_CONTROL) & + PCI_BRIDGE_CTL_BUS_RESET) /* Don't walk the bus if it's reset. */ && + dev->config[PCI_SECONDARY_BUS] < bus_num && + bus_num <= dev->config[PCI_SUBORDINATE_BUS]; +} + PCIBus *pci_find_bus(PCIBus *bus, int bus_num) { PCIBus *sec; @@ -1552,20 +1562,21 @@ PCIBus *pci_find_bus(PCIBus *bus, int bus_num) return bus; } + /* Consider all bus numbers in range for the host pci bridge. */ + if (bus->parent_dev && + !pci_secondary_bus_in_range(bus->parent_dev, bus_num)) { + return NULL; + } + /* try child bus */ - if (!bus->parent_dev /* host pci bridge */ || - (bus->parent_dev->config[PCI_SECONDARY_BUS] < bus_num && - bus_num <= bus->parent_dev->config[PCI_SUBORDINATE_BUS])) { - for (; bus; bus = sec) { - QLIST_FOREACH(sec, &bus->child, sibling) { - assert(sec->parent_dev); - if (sec->parent_dev->config[PCI_SECONDARY_BUS] == bus_num) { - return sec; - } - if (sec->parent_dev->config[PCI_SECONDARY_BUS] < bus_num && - bus_num <= sec->parent_dev->config[PCI_SUBORDINATE_BUS]) { - break; - } + for (; bus; bus = sec) { + QLIST_FOREACH(sec, &bus->child, sibling) { + assert(sec->parent_dev); + if (sec->parent_dev->config[PCI_SECONDARY_BUS] == bus_num) { + return sec; + } + if (pci_secondary_bus_in_range(sec->parent_dev, bus_num)) { + break; } } }