From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=45973 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PKxKF-0005jh-Vd for qemu-devel@nongnu.org; Tue, 23 Nov 2010 13:10:45 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PKxKE-0003PD-Ja for qemu-devel@nongnu.org; Tue, 23 Nov 2010 13:10:43 -0500 Received: from mx1.redhat.com ([209.132.183.28]:40036) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PKxKE-0003P5-BC for qemu-devel@nongnu.org; Tue, 23 Nov 2010 13:10:42 -0500 Date: Tue, 23 Nov 2010 20:10:26 +0200 From: "Michael S. Tsirkin" Message-ID: <20101123181026.GA2752@redhat.com> References: <20101122075402.GA6892@redhat.com> <20101122104337.GB24265@valinux.co.jp> <20101122225312.GA1359@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20101122225312.GA1359@redhat.com> Subject: [Qemu-devel] Re: [PATCH v2 0/6] qdev reset refactoring and pci bus reset List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Isaku Yamahata Cc: skandasa@cisco.com, etmartin@cisco.com, wexu2@cisco.com, qemu-devel@nongnu.org, kraxel@redhat.com, pbonzini@redhat.com 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? ---> 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 --- diff --git a/hw/pci.c b/hw/pci.c index d02f980..60bdded 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) {