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=-6.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 2AB61C43464 for ; Fri, 18 Sep 2020 08:49:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C89B120C56 for ; Fri, 18 Sep 2020 08:49:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Oe4Z2/gh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726698AbgIRItZ (ORCPT ); Fri, 18 Sep 2020 04:49:25 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:33943 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726683AbgIRItW (ORCPT ); Fri, 18 Sep 2020 04:49:22 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1600418960; 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: in-reply-to:in-reply-to:references:references; bh=/QfTiUWUoHzQknijYTUbsX5+5g78epx3oQpvxWAg6QE=; b=Oe4Z2/ghXJJNOX3iOuktbP1VjdZSLHeMCOFY3Y5LuBIf7sezFIKWji8pBop9zMRZhfvU9E mOf290Ih5aZalxhfV24p2sGwCviwOxtcJZbH3YuEJz2b8iyRFeaQ4+jOc1UeRy2x1X408S VaZkluVITKGUQb3/XHGIh6cMs80qcPQ= 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-206-De-04fBRN2mwIgOqXJGzFA-1; Fri, 18 Sep 2020 04:49:15 -0400 X-MC-Unique: De-04fBRN2mwIgOqXJGzFA-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 2C7C71084C92; Fri, 18 Sep 2020 08:49:14 +0000 (UTC) Received: from sirius.home.kraxel.org (ovpn-112-85.ams2.redhat.com [10.36.112.85]) by smtp.corp.redhat.com (Postfix) with ESMTP id 55F311002D68; Fri, 18 Sep 2020 08:49:07 +0000 (UTC) Received: by sirius.home.kraxel.org (Postfix, from userid 1000) id 721CD16E16; Fri, 18 Sep 2020 10:49:06 +0200 (CEST) Date: Fri, 18 Sep 2020 10:49:06 +0200 From: Gerd Hoffmann To: Sean Christopherson Cc: Vitaly Kuznetsov , Peter Xu , kvm@vger.kernel.org, Paolo Bonzini , Wanpeng Li , Jim Mattson , Michael Tsirkin , Julia Suvorova , Andy Lutomirski , Andrew Jones , linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 0/3] KVM: x86: KVM_MEM_PCI_HOLE memory Message-ID: <20200918084906.ja5elzh5zli47mg3@sirius.home.kraxel.org> References: <20200807141232.402895-1-vkuznets@redhat.com> <20200825212526.GC8235@xz-x1> <87eenlwoaa.fsf@vitty.brq.redhat.com> <20200901200021.GB3053@xz-x1> <877dtcpn9z.fsf@vitty.brq.redhat.com> <20200904061210.GA22435@sjchrist-ice> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200904061210.GA22435@sjchrist-ice> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, > I see a similar ~8k PCI hole reads with a -kernel boot w/ OVMF. All but 60 > of those are from pcibios_fixup_peer_bridges(), and all are from the kernel. pcibios_fixup_peer_bridges() looks at pcibios_last_bus, and that in turn seems to be set according to the mmconfig size (in arch/x86/pci/mmconfig-shared.c). So, maybe we just need to declare a smaller mmconfig window in the acpi tables, depending on the number of pci busses actually used ... > If all of the above is true, this can be handled by adding "pci=lastbus=0" ... so we don't need manual quirks like this? take care, Gerd