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 3B96BC433EF for ; Wed, 29 Sep 2021 21:48:45 +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 7E8A1613CE for ; Wed, 29 Sep 2021 21:48:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 7E8A1613CE 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]:32968 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mVhRT-0006QR-FS for qemu-devel@archiver.kernel.org; Wed, 29 Sep 2021 17:48:43 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:39184) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mVhQd-0005jq-RU for qemu-devel@nongnu.org; Wed, 29 Sep 2021 17:47:51 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:48820) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mVhQb-0007yU-Jt for qemu-devel@nongnu.org; Wed, 29 Sep 2021 17:47:51 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1632952068; 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=KKqDYCRD4NTy3l0Fo3kIln6rLAkCOl3T9ZXlVFyZ4sY=; b=OU3YMwKiljey+kQPWaXqaPgEin5tsZn0dS2A4nYjacvYTU9N68rvPe3QV9KY86gMEMpaCn Lum7urUay64IVu9Ocdg7puTY+4GqqcCPrpGuicb8LGs45bqc2t/fQRw8LmhBmmT1dnfk0z T1HL5O89FxMHaOHG9H0IBVEKjQJqCPk= Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-494-f0oC9C7kOTSkYKFAmiY6sQ-1; Wed, 29 Sep 2021 17:47:43 -0400 X-MC-Unique: f0oC9C7kOTSkYKFAmiY6sQ-1 Received: by mail-wr1-f69.google.com with SMTP id p4-20020adfe604000000b0016074dc4c46so1036573wrm.2 for ; Wed, 29 Sep 2021 14:47:43 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=KKqDYCRD4NTy3l0Fo3kIln6rLAkCOl3T9ZXlVFyZ4sY=; b=bkAgOaLnA7Qyyg51ZTGs1/UqhEZFAqvTGnX3mII3iHzIoV2T2RxGQ4yODFZHjQZUm5 I0PDjLDvEv1OUvFFIbWXImvui8DaZMzR0Xyt4REe9kHFM7Mo56t1QiDmMip3K+gyUl5f Qs+OSjNPs86Kvc5e8LmxJDjfsc7lBlFaKxNpndZnAfefKZ+IFvpezCLoOg48/nl05iIQ zthVb68x+6hrNYGdcRdVhQ2hiwVtf0UhVTVfRQzEzU8JNwmO6Nxy2s4Mg0+hrGOA5l/1 tH18UBtK6NAACv+YP3JbpB5v1MSpBmKjJzovxWgmCB9NbV4RNdhihw7NHGIULTvRp4mZ pwxg== X-Gm-Message-State: AOAM530UzvmceCpY28c3NHgp5KE//Q3U6BHphONzR9x1pKab/M+VV4YH nEFRj6UXS3VzQxvTspKTwovWPtL5adSx7DNocpxMB426zMwuq+AzriGLprgzSh+5NPMFL9K4q4n gkSem2IYH98oEY28= X-Received: by 2002:a5d:4d84:: with SMTP id b4mr2597922wru.258.1632952062746; Wed, 29 Sep 2021 14:47:42 -0700 (PDT) X-Google-Smtp-Source: ABdhPJze+uWP2P/L5gOP+aP7krXDfSPQF669QjQvb3Qp1DvN7WXuTfGdZbmS+mVXAvKBBowoArppxg== X-Received: by 2002:a5d:4d84:: with SMTP id b4mr2597845wru.258.1632952061498; Wed, 29 Sep 2021 14:47:41 -0700 (PDT) Received: from redhat.com ([2.55.134.220]) by smtp.gmail.com with ESMTPSA id r9sm1077392wru.2.2021.09.29.14.47.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 29 Sep 2021 14:47:39 -0700 (PDT) Date: Wed, 29 Sep 2021 17:47:37 -0400 From: "Michael S. Tsirkin" To: marcel@redhat.com Subject: Re: [PULL 1/5] hw/pcie-root-port: Fix hotplug for PCI devices requiring IO Message-ID: <20210929172519-mutt-send-email-mst@kernel.org> References: <20210803205043.165034-1-mst@redhat.com> <20210803205043.165034-2-mst@redhat.com> <20210927053932-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 In-Reply-To: Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=mst@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=170.10.133.124; envelope-from=mst@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: , Cc: Peter Maydell , Daniel =?iso-8859-1?Q?P=2E_Berrang=E9?= , qemu-devel@nongnu.org, Igor Mammedov Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, Sep 29, 2021 at 04:41:49PM +0300, Marcel Apfelbaum wrote: > Hi Michael, > > On Mon, Sep 27, 2021 at 12:49 PM Michael S. Tsirkin wrote: > > On Mon, Sep 27, 2021 at 10:33:42AM +0100, Daniel P. Berrangé wrote: > > 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]. > > > Indeed, oops. Thanks for the report! > > Going back and looking at seabios code, didn't we get confused? > Shouldn't we have reserved memory and not IO? > > > We need the IO space for the legacy PCI bridges, otherwise an empty PCI bridge > will become unusable. Maybe we should go back to using OSC then ... the issue is we can't then mix acpi and native hotplug for bridges. > > > I see: >             int resource_optional = pcie_cap && (type == > PCI_REGION_TYPE_IO); >             if (!sum && hotplug_support && !resource_optional) >                 sum = align; /* reserve min size for hot-plug */ > > > generally maybe we should just add an ACPI-hotplug capability and > teach seabios about it? > > > I suppose it is possible. > > Thanks, > Marcel >   > > > Marcel? > > > > 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 :| > >