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=-4.0 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 78FFEC433E2 for ; Mon, 7 Sep 2020 10:52:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 36458206D4 for ; Mon, 7 Sep 2020 10:52:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="hROGf9MP" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728909AbgIGKwp (ORCPT ); Mon, 7 Sep 2020 06:52:45 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:43884 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728589AbgIGKwh (ORCPT ); Mon, 7 Sep 2020 06:52:37 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1599475955; 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=nZNYuBpQt9HKowq473qvyGL7V94PMK5k48wA1l6+SwU=; b=hROGf9MPYXNBlp3ui4i/gdPAobn6s3w5gsFSnf7k9q/ZTniCdPRPZ1GaE/nnPn31d3tah+ ejcz9Ab6CNEuYrw7ALfrUH5WG1DxyFkcuokOO7eTIilTVYqdkFVZ6d7lnKv71GftV0WvEV 8gSMA7g8AJHeb1VQA8qHbntKg3iYFe8= 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-330-Xf1A5T0CPRi6WJ5rYOHlzw-1; Mon, 07 Sep 2020 06:52:28 -0400 X-MC-Unique: Xf1A5T0CPRi6WJ5rYOHlzw-1 Received: by mail-wr1-f69.google.com with SMTP id k13so3999844wrw.16 for ; Mon, 07 Sep 2020 03:52:28 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=nZNYuBpQt9HKowq473qvyGL7V94PMK5k48wA1l6+SwU=; b=rXvRz7nHJDNbeV8nod4NzlnnWI1qO/SHm86z508BOoOtlV7VxlWPuYVJuDDlxMBmZ1 PbEfrXOD0L8on5UKMGlOkyXRmIscEGE8woREo2HI2oTdvRZwm74ZtQoMyGQ3MKZm2GHS H1oyz5TPIS3q/gHiraKVtiDwnmSSmf4QW7tXkqp3WEH2eSAy9WSopA3M2CCjyMa05Xo1 uJTdAkTl12kJPOkvtORYh0x+T8NOwkSnhcgcPfhd8luROQj4Ipv5FHDtho2egdUK+AIg 4k+GJiIrWQnJ/MiYJTOvoB7iOlXQv4mR76R0Sb5nIuSdFnVGv73QqTh6LpgpClD1IYZ0 LTAw== X-Gm-Message-State: AOAM530b1N46AuuCptoQEeiyOj/k+BSXENxP9zQg0ZpmmfO7ydWYloCr yp6V9ifeuNXEDxHlGkikbE7ceYd74180rxm7eHPWzA+hVh/YcjPalPKOimiyap0dZX4Hnbt9Znz NijRFmmQ0y69CJiM7DCQPt2Qg X-Received: by 2002:adf:e292:: with SMTP id v18mr2295013wri.256.1599475947654; Mon, 07 Sep 2020 03:52:27 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyG5yHsS/XQWDRSHn7G2xKTYdTMeb9QBkBBhYcA+QxqmG74U+oeLI7TfgtvmkrDWtQwwtMcjA== X-Received: by 2002:adf:e292:: with SMTP id v18mr2294999wri.256.1599475947455; Mon, 07 Sep 2020 03:52:27 -0700 (PDT) Received: from redhat.com ([192.117.173.58]) by smtp.gmail.com with ESMTPSA id a74sm28019641wme.11.2020.09.07.03.52.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 07 Sep 2020 03:52:25 -0700 (PDT) Date: Mon, 7 Sep 2020 06:52:17 -0400 From: "Michael S. Tsirkin" To: Gerd Hoffmann Cc: Sean Christopherson , Vitaly Kuznetsov , Peter Xu , kvm@vger.kernel.org, Paolo Bonzini , Wanpeng Li , Jim Mattson , 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: <20200907065054-mutt-send-email-mst@kernel.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> <20200904072905.vbkiq3h762fyzds6@sirius.home.kraxel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200904072905.vbkiq3h762fyzds6@sirius.home.kraxel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 04, 2020 at 09:29:05AM +0200, Gerd Hoffmann wrote: > Hi, > > > Unless I'm mistaken, microvm doesn't even support PCI, does it? > > Correct, no pci support right now. > > We could probably wire up ecam (arm/virt style) for pcie support, once > the acpi support for mictovm finally landed (we need acpi for that > because otherwise the kernel wouldn't find the pcie bus). > > Question is whenever there is a good reason to do so. Why would someone > prefer microvm with pcie support over q35? The usual reasons to use pcie apply to microvm just the same. E.g.: pass through of pcie devices? > > If all of the above is true, this can be handled by adding "pci=lastbus=0" > > as a guest kernel param to override its scanning of buses. And couldn't > > that be done by QEMU's microvm_fix_kernel_cmdline() to make it transparent > > to the end user? > > microvm_fix_kernel_cmdline() is a hack, not a solution. > > Beside that I doubt this has much of an effect on microvm because > it doesn't support pcie in the first place. > > take care, > Gerd