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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 B9545C4332B for ; Thu, 19 Mar 2020 11:29:33 +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 7948A2070A for ; Thu, 19 Mar 2020 11:29:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="HI+2GN2G" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7948A2070A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:36384 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jEtMi-0002mk-IP for qemu-devel@archiver.kernel.org; Thu, 19 Mar 2020 07:29:32 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:39120) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jEtLv-0002MK-KP for qemu-devel@nongnu.org; Thu, 19 Mar 2020 07:28:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jEtLt-0006kq-VM for qemu-devel@nongnu.org; Thu, 19 Mar 2020 07:28:42 -0400 Received: from us-smtp-delivery-74.mimecast.com ([216.205.24.74]:37922) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1jEtLt-0006hy-RY for qemu-devel@nongnu.org; Thu, 19 Mar 2020 07:28:41 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1584617320; 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=AQ0dBvEC7x09HJTpK3HT9GXNWHXtXjsIyfPFLpkeFh0=; b=HI+2GN2GXJ8klNr9n5OPFI1UBp4Vnzeq2FbGHsCo7XtmDv/aL7vPdp3DgqVAqHybSFWPfF h0+OkZuA/hPRIPjvE38siddNZep8jNjwPLcGntPX997NiEexT2GYpJw6hPEk9a/4xG1ljv UjBIZqariGgGyqsKBQfJitHbxiPFHGU= 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-205-XuXdCecoNOKmHC_Ns4kfBw-1; Thu, 19 Mar 2020 07:28:37 -0400 X-MC-Unique: XuXdCecoNOKmHC_Ns4kfBw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 37957107ACC4; Thu, 19 Mar 2020 11:28:36 +0000 (UTC) Received: from sirius.home.kraxel.org (ovpn-112-49.ams2.redhat.com [10.36.112.49]) by smtp.corp.redhat.com (Postfix) with ESMTP id EBF475D9CD; Thu, 19 Mar 2020 11:28:30 +0000 (UTC) Received: by sirius.home.kraxel.org (Postfix, from userid 1000) id F2C7F3BD; Thu, 19 Mar 2020 12:28:29 +0100 (CET) Date: Thu, 19 Mar 2020 12:28:29 +0100 From: Gerd Hoffmann To: Paolo Bonzini Subject: Re: [PATCH 00/13] microvm: add acpi support Message-ID: <20200319112829.m4fls4ekqgj4ucia@sirius.home.kraxel.org> References: <20200319080117.7725-1-kraxel@redhat.com> <2ed586e7-d7a1-77b2-ecc6-01b6fb38d72e@redhat.com> <20200319093342.m6fppq4y2qoqefpa@sirius.home.kraxel.org> MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Content-Disposition: inline X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 216.205.24.74 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: Eduardo Habkost , Sergio Lopez , "Michael S. Tsirkin" , qemu-devel@nongnu.org, Igor Mammedov , Richard Henderson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Hi, > The main reason for not having ACPI was the time that it took to start; Yep, ACPI needs additional boot time. Shouldn't be a big difference though, microvm acpi only declares some devices and has small tables. Also no acpi methods, so no interpreter work. Maybe it is mostly the additional time needed to log the ACPI stuff to the serial console (didn't try yet to time boots with "quiet"). On the other hand you have effects like this: Without acpi the kernel checks whenever hardware is present: # dmesg | grep i8042 [ 0.334403] i8042: PNP: No PS/2 controller found. [ 0.334619] i8042: Probing ports directly. [ 1.370573] i8042: No controller found With acpi the kernel trusts the firmware and doesn't bother probing directly: # dmesg | grep i8042 [ 0.345500] i8042: PNP: No PS/2 controller found. cheers, Gerd