From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6F320C35671 for ; Mon, 24 Feb 2020 12:37:08 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 3B8BD20828 for ; Mon, 24 Feb 2020 12:37:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="S+ToiSGT" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3B8BD20828 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:35730 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j6Cyx-0007rv-GC for qemu-devel@archiver.kernel.org; Mon, 24 Feb 2020 07:37:07 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:34008) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j6CyK-0007Pv-1D for qemu-devel@nongnu.org; Mon, 24 Feb 2020 07:36:29 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1j6CyI-0007lS-IR for qemu-devel@nongnu.org; Mon, 24 Feb 2020 07:36:27 -0500 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:50947 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1j6CyI-0007l8-EV for qemu-devel@nongnu.org; Mon, 24 Feb 2020 07:36:26 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1582547785; h=from:from:reply-to: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=/sQKXA/vIJD8x4wO/9gpqU5mLEVmJZfQsa+odjyIjR4=; b=S+ToiSGT4VMWX/qOaXnPQN0P1vCuqOcAjcx86fvJYULobabRsPEI/D4y6kskDqopL7MoJE f4TSp5yFWiUVipQLQAHc+PdwXi17mWwOrWvMEFTFqzGlcobRp7p5oa+xriE0HTODO256yA NkrzxsQGhIdINLt+mi5M06kqdedCod0= 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-481-mOcV9FeWPJaVFOKfE3mbDw-1; Mon, 24 Feb 2020 07:36:14 -0500 X-MC-Unique: mOcV9FeWPJaVFOKfE3mbDw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 970D718A6EC0; Mon, 24 Feb 2020 12:36:12 +0000 (UTC) Received: from redhat.com (unknown [10.42.16.105]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 8A2A95C3FA; Mon, 24 Feb 2020 12:36:08 +0000 (UTC) Date: Mon, 24 Feb 2020 12:36:06 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: miaoyubo Subject: Re: [RFC 2/2] pci-expender-bus:Add pcie-root-port to pxb-pcie under arm. Message-ID: <20200224123606.GM635661@redhat.com> References: <20200213074952.544-1-miaoyubo@huawei.com> <20200213074952.544-3-miaoyubo@huawei.com> <20200213135145.GN594756@redhat.com> <3fc86f5a6aaf4c6f81dad4f25fcafda0@huawei.com> <20200214102451.GA613610@redhat.com> <8f977fbdd8e346ef911ebfe71dbb1514@huawei.com> MIME-Version: 1.0 In-Reply-To: <8f977fbdd8e346ef911ebfe71dbb1514@huawei.com> User-Agent: Mutt/1.13.3 (2020-01-12) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.81 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: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: "peter.maydell@linaro.org" , "mst@redhat.com" , "qemu-devel@nongnu.org" , Xiexiangyou , "shannon.zhaosl@gmail.com" , "imammedo@redhat.com" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Sat, Feb 15, 2020 at 08:59:28AM +0000, miaoyubo wrote: >=20 > > -----Original Message----- > > From: Daniel P. Berrang=C3=A9 [mailto:berrange@redhat.com] > > Sent: Friday, February 14, 2020 6:25 PM > > To: miaoyubo > > Cc: peter.maydell@linaro.org; shannon.zhaosl@gmail.com; > > imammedo@redhat.com; qemu-devel@nongnu.org; Xiexiangyou > > ; mst@redhat.com > > Subject: Re: [RFC 2/2] pci-expender-bus:Add pcie-root-port to pxb-pcie = under > > arm. > >=20 > > On Fri, Feb 14, 2020 at 07:25:43AM +0000, miaoyubo wrote: > > > > > > > -----Original Message----- > > > > From: Daniel P. Berrang=C3=A9 [mailto:berrange@redhat.com] > > > > Sent: Thursday, February 13, 2020 9:52 PM > > > > To: miaoyubo > > > > Cc: peter.maydell@linaro.org; shannon.zhaosl@gmail.com; > > > > imammedo@redhat.com; qemu-devel@nongnu.org; Xiexiangyou > > > > ; mst@redhat.com > > > > Subject: Re: [RFC 2/2] pci-expender-bus:Add pcie-root-port to > > > > pxb-pcie under arm. > > > > > > > > On Thu, Feb 13, 2020 at 03:49:52PM +0800, Yubo Miao wrote: > > > > > From: miaoyubo > > > > > > > > > > Since devices could not directly plugged into pxb-pcie, under arm= , > > > > > one pcie-root port is plugged into pxb-pcie. Due to the bus for > > > > > each pxb-pcie is defined as 2 in acpi dsdt tables(one for > > > > > pxb-pcie, one for pcie-root-port), only one device could be plugg= ed into > > one pxb-pcie. > > > > > > > > What is the cause of this arm specific requirement for pxb-pcie and > > > > more importantly can be fix it so that we don't need this patch ? > > > > I think it is highly undesirable to have such a per-arch difference > > > > in configuration of the pxb-pcie device. It means any mgmt app whic= h > > > > already supports pxb-pcie will be broken and need to special case a= rm. > > > > > > > > > > Thanks for your reply, Without this patch, the pxb-pcie is also > > > useable, however, one extra pcie-root-port or pci-bridge or something > > > else need to be defined by mgmt. app. This patch will could be abando= ned. > >=20 > > That's not really answering my question. IIUC, this pxb-pcie device wor= ks fine > > on x86_64, and I want to know why it doesn't work on arm ? > > Requiring different setups by the mgmt apps is not at all nice because = it will > > inevitably lead to broken arm setups. x86_64 gets far more testing & us= age, > > developers won't realize arm is different. > >=20 > > >=20 > Thanks for replying. Currently, on x86_64, pxb-pcie devices is presented > in acpi tables but on arm, It is not, only one main host bridge is > presented for arm in acpi dsdt tables. That's why pxb-pcie works on > x86_64 but doesn't work on arm. The patch 1/2 do the work to present > and allocate resources for pxb-pcie in arm. Yes, this first patch makes sense > For x86_64, if one device is going to be plugged into pxb-pcie, one > extra pcie-root-port or pci-bridge have to be defined and plugged on > pxb-pcie, then the device is plugged on the pcie-root-port or pci-bridge. > This patch 2/2 just auto defined one pcie-root-port for arm. If this > patch abandoned, the usage of pxb-pcie would be the same with x86_64, > therefore, to keep the same step for x86 and arm, this patch 2/2 could > be abandonded. Yes, I think abandoning this patch 2 is best. Applications that know how to use pxb-pcie on x86_64, will already do the right thing on arm too, once your first patch is merged. Regards, Daniel --=20 |: https://berrange.com -o- https://www.flickr.com/photos/dberrange= :| |: https://libvirt.org -o- https://fstop138.berrange.com= :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange= :|