From patchwork Thu Jan 12 14:03:08 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Igor Mammedov X-Patchwork-Id: 13098236 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 61444C54EBC for ; Thu, 12 Jan 2023 15:31:42 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pFyBW-0002WG-JG; Thu, 12 Jan 2023 09:04:02 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pFyBK-0002HN-3K for qemu-devel@nongnu.org; Thu, 12 Jan 2023 09:03:50 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pFyBF-00060v-QS for qemu-devel@nongnu.org; Thu, 12 Jan 2023 09:03:49 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1673532225; h=from:from: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=Z13F7ZxPepmju0UlhSUBoJZaNYceLXa2mu0PfuDyxYI=; b=W2Ojg89WZr/cP540qFsrmUCu78lQyqk7C8W1/nNduMPPPHl1kO88dOT7uawlJ/0P29Iqtd mTuSZK0jxV6Y29LcyOXeMJXyMs93oLgZwXiNpkKZq+5q27mnjdayqhyR/IH9u0rchP9ZpJ D5wcHzNGaXxeklJdXBZ1bEuwynTjHpk= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-351--Yx9fLy1PyOk5Ge_T9sCNQ-1; Thu, 12 Jan 2023 09:03:43 -0500 X-MC-Unique: -Yx9fLy1PyOk5Ge_T9sCNQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 718E02807D7B; Thu, 12 Jan 2023 14:03:42 +0000 (UTC) Received: from dell-r430-03.lab.eng.brq2.redhat.com (dell-r430-03.lab.eng.brq2.redhat.com [10.37.153.18]) by smtp.corp.redhat.com (Postfix) with ESMTP id E06294085720; Thu, 12 Jan 2023 14:03:41 +0000 (UTC) From: Igor Mammedov To: qemu-devel@nongnu.org Cc: "Michael S. Tsirkin" , Ani Sinha Subject: [PATCH 36/40] pcihp: acpi: ignore coldplugged bridges when composing hotpluggable slots Date: Thu, 12 Jan 2023 15:03:08 +0100 Message-Id: <20230112140312.3096331-37-imammedo@redhat.com> In-Reply-To: <20230112140312.3096331-1-imammedo@redhat.com> References: <20230112140312.3096331-1-imammedo@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 Received-SPF: pass client-ip=170.10.129.124; envelope-from=imammedo@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org coldplugged bridges are not unpluggable, so there is no need to describe slots where they are plugged as hotpluggable. To that effect we have a condition that marks slot as non-hotpluggable if it's populated by coldplugged bridge and prevents generation _SUN/_EJ0 objects for it. That leaves dynamic _DSM method on such slot (which also depends on BSEL and pcihp hardware). This _DSM method provides only dynamic acpi-index support so far, which is not actually used/supported by linux kernel for bridges and it's doubtful there will be need for it at all. So it's rather pointless to generate acpi-index related AML for bridges and we can simplify hotplug slots generator a bit more by completely ignoring coldplugged bridges on hotplug path. Another point in favor of dropping dynamic _DSM support, is that we can replace it with static _DSM if necessary since a slot with bridge can't change during VM runtime and without any dependency on ACPI PCI hotplug at that. Later I plan to implement bridge specific static _DSM PCI Firmware Specification 3.2 4.6.5. _DSM for Ignoring PCI Boot Configurations part of spec, to fix longstanding issue with fixed IO/MEM resource assignment that often leads to hotplugged device being in-operational within the guest due limited IO/MEM windows programmed on bridge at boot time. Expected change when coldplugged bridge is ignored by hotplug code, should look like: - Scope (S18) - { - Name (ASUN, 0x03) - Method (_DSM, 4, Serialized) // _DSM: Device-Specific Method - { - Local0 = Package (0x02) - { - BSEL, - ASUN - } - Return (PDSM (Arg0, Arg1, Arg2, Arg3, Local0)) - } - } Signed-off-by: Igor Mammedov --- hw/i386/acpi-build.c | 16 ++++++---------- 1 file changed, 6 insertions(+), 10 deletions(-) diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c index a4f882dc72..50504578b9 100644 --- a/hw/i386/acpi-build.c +++ b/hw/i386/acpi-build.c @@ -411,8 +411,11 @@ static bool is_devfn_ignored_generic(const int devfn, const PCIBus *bus) static bool is_devfn_ignored_hotplug(const int devfn, const PCIBus *bus) { - if (bus->devices[devfn]) { - return is_devfn_ignored_generic(devfn, bus); + PCIDevice *pdev = bus->devices[devfn]; + if (pdev) { + return is_devfn_ignored_generic(devfn, bus) || + /* Cold plugged bridges aren't themselves hot-pluggable */ + (IS_PCI_BRIDGE(pdev) && !DEVICE(pdev)->hotplugged); } else { /* non populated slots */ /* * hotplug is supported only for non-multifunction device @@ -447,14 +450,7 @@ static void build_append_pcihp_slots(Aml *parent_scope, PCIBus *bus, } if (pdev) { - /* - * Cold plugged bridges aren't themselves hot-pluggable. - * Hotplugged bridges *are* hot-pluggable. - */ - bool cold_plugged_bridge = IS_PCI_BRIDGE(pdev) && - !DEVICE(pdev)->hotplugged; - hotpluggbale_slot = DEVICE_GET_CLASS(pdev)->hotpluggable && - !cold_plugged_bridge; + hotpluggbale_slot = DEVICE_GET_CLASS(pdev)->hotpluggable; dev = aml_scope("S%.02X", devfn); } else { dev = aml_device("S%.02X", devfn);