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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DD5E5C433F5 for ; Mon, 27 Sep 2021 09:35:03 +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 5CD7A61157 for ; Mon, 27 Sep 2021 09:35:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 5CD7A61157 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:60034 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mUn2M-00070C-JR for qemu-devel@archiver.kernel.org; Mon, 27 Sep 2021 05:35:02 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54454) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mUn1b-0006K1-SP for qemu-devel@nongnu.org; Mon, 27 Sep 2021 05:34:16 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:33397) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mUn1a-0005al-4M for qemu-devel@nongnu.org; Mon, 27 Sep 2021 05:34:15 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1632735253; 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:in-reply-to:in-reply-to: references:references; bh=pW02kIB53oVRV8zVAymvgVVqXsYw0Uz4Qnunb2t8fqg=; b=aL7bgvt3nQ+/sMoTMUcGQSq0HLHa/yHsSQ3h5aXF2Go2Rn+ecXgj0MY3eifbeaGqHfpXJr wS+j7qS8FI8PiestDnGBN3oshXb3qvzC5IW6W+dvDEPeosTH/nUCzR+7ZpKXMLjdfHeuVQ b3+MfzaA5OtM7Ax7lYXWytvW3NSHIvI= 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-187-zl0wnj7_PdilSFH72pC2YQ-1; Mon, 27 Sep 2021 05:34:05 -0400 X-MC-Unique: zl0wnj7_PdilSFH72pC2YQ-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 CA15418D6A2A; Mon, 27 Sep 2021 09:34:04 +0000 (UTC) Received: from redhat.com (unknown [10.39.194.156]) by smtp.corp.redhat.com (Postfix) with ESMTPS id CA8D95C261; Mon, 27 Sep 2021 09:33:45 +0000 (UTC) Date: Mon, 27 Sep 2021 10:33:42 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: "Michael S. Tsirkin" Subject: Re: [PULL 1/5] hw/pcie-root-port: Fix hotplug for PCI devices requiring IO Message-ID: References: <20210803205043.165034-1-mst@redhat.com> <20210803205043.165034-2-mst@redhat.com> MIME-Version: 1.0 In-Reply-To: <20210803205043.165034-2-mst@redhat.com> User-Agent: Mutt/2.0.7 (2021-05-04) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=berrange@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Received-SPF: pass client-ip=216.205.24.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 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_LOW=-0.7, 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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: Marcel Apfelbaum , Peter Maydell , qemu-devel@nongnu.org, Igor Mammedov Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue, Aug 03, 2021 at 04:52:03PM -0400, Michael S. Tsirkin wrote: > From: Marcel Apfelbaum > > Q35 has now ACPI hotplug enabled by default for PCI(e) devices. > As opposed to native PCIe hotplug, guests like Fedora 34 > will not assign IO range to pcie-root-ports not supporting > native hotplug, resulting into a regression. > > Reproduce by: > qemu-bin -M q35 -device pcie-root-port,id=p1 -monitor stdio > device_add e1000,bus=p1 > In the Guest OS the respective pcie-root-port will have the IO range > disabled. > > Fix it by setting the "reserve-io" hint capability of the > pcie-root-ports so the firmware will allocate the IO range instead. > > Acked-by: Igor Mammedov > Signed-off-by: Marcel Apfelbaum > Message-Id: <20210802090057.1709775-1-marcel@redhat.com> > Reviewed-by: Michael S. Tsirkin > Signed-off-by: Michael S. Tsirkin > --- > hw/pci-bridge/gen_pcie_root_port.c | 5 +++++ > 1 file changed, 5 insertions(+) This change, when combined with the switch to ACPI based hotplug by default, is responsible for a significant regression in QEMU 6.1.0 It is no longer possible to have more than 15 pcie-root-port devices added to a q35 VM in 6.1.0. Before this I've had as many as 80+ devices present before I stopped trying to add more. https://gitlab.com/qemu-project/qemu/-/issues/641 This regression is significant, because it has broken the out of the box default configuration that OpenStack uses for booting all VMs. They add 16 pcie-root-ports by defalt to allow empty slots for device hotplug under q35 [1]. > diff --git a/hw/pci-bridge/gen_pcie_root_port.c b/hw/pci-bridge/gen_pcie_root_port.c > index ec9907917e..20099a8ae3 100644 > --- a/hw/pci-bridge/gen_pcie_root_port.c > +++ b/hw/pci-bridge/gen_pcie_root_port.c > @@ -28,6 +28,7 @@ OBJECT_DECLARE_SIMPLE_TYPE(GenPCIERootPort, GEN_PCIE_ROOT_PORT) > (GEN_PCIE_ROOT_PORT_AER_OFFSET + PCI_ERR_SIZEOF) > > #define GEN_PCIE_ROOT_PORT_MSIX_NR_VECTOR 1 > +#define GEN_PCIE_ROOT_DEFAULT_IO_RANGE 4096 > > struct GenPCIERootPort { > /*< private >*/ > @@ -75,6 +76,7 @@ static bool gen_rp_test_migrate_msix(void *opaque, int version_id) > static void gen_rp_realize(DeviceState *dev, Error **errp) > { > PCIDevice *d = PCI_DEVICE(dev); > + PCIESlot *s = PCIE_SLOT(d); > GenPCIERootPort *grp = GEN_PCIE_ROOT_PORT(d); > PCIERootPortClass *rpc = PCIE_ROOT_PORT_GET_CLASS(d); > Error *local_err = NULL; > @@ -85,6 +87,9 @@ static void gen_rp_realize(DeviceState *dev, Error **errp) > return; > } > > + if (grp->res_reserve.io == -1 && s->hotplug && !s->native_hotplug) { > + grp->res_reserve.io = GEN_PCIE_ROOT_DEFAULT_IO_RANGE; > + } > int rc = pci_bridge_qemu_reserve_cap_init(d, 0, > grp->res_reserve, errp); > > -- > MST > > Regards, Daniel [1] https://github.com/openstack/tripleo-heat-templates/blob/7a6cd0640ec390a330f5699d8ed60f71b2a9f514/deployment/nova/nova-compute-container-puppet.yaml#L462-L472 -- |: 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 :|