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=-0.9 required=3.0 tests=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 40FACC2D0DB for ; Mon, 20 Jan 2020 10:33:00 +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 0C0182073D for ; Mon, 20 Jan 2020 10:33:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="fNQU/Kz5" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0C0182073D 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]:33448 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1itUMc-0001vU-Mg for qemu-devel@archiver.kernel.org; Mon, 20 Jan 2020 05:32:58 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:36578) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1itUL4-0000po-NB for qemu-devel@nongnu.org; Mon, 20 Jan 2020 05:31:24 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1itUKz-0008KV-O8 for qemu-devel@nongnu.org; Mon, 20 Jan 2020 05:31:22 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:29297 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1itUKz-0008J6-K0 for qemu-devel@nongnu.org; Mon, 20 Jan 2020 05:31:17 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1579516277; 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=XBelWxvArASSPZtYigkQBYN0VtHAWrUo/XWfxW3mvEQ=; b=fNQU/Kz5H76dwARsvw1sbNeA5PDN4epINuLSezNSlfkK/h72v7JrRzceSUKCPAPi2CrqrC W3WL1oTdkSUAcRYgafSzQQBT4EnZ7dxjry4W4Wmmomz+fEMLrymsdniowAWKqyyPZiwa6o nxmFGOpNOBKwSr1kycQNI1Mj/KB7bZ4= 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-113-5kdIwiKGNAyvIl_RWCjz_g-1; Mon, 20 Jan 2020 05:31:11 -0500 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 8BBE6800D48; Mon, 20 Jan 2020 10:31:09 +0000 (UTC) Received: from kamzik.brq.redhat.com (unknown [10.43.2.160]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A3712860E5; Mon, 20 Jan 2020 10:31:06 +0000 (UTC) Date: Mon, 20 Jan 2020 11:31:04 +0100 From: Andrew Jones To: Peter Maydell Subject: Re: [RFC PATCH v2 5/5] target/arm/cpu: Add the kvm-no-adjvtime CPU property Message-ID: <20200120103104.quc4r6577c6rrpux@kamzik.brq.redhat.com> References: <20191212173320.11610-1-drjones@redhat.com> <20191212173320.11610-6-drjones@redhat.com> MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-MC-Unique: 5kdIwiKGNAyvIl_RWCjz_g-1 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: 207.211.31.120 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: bijan.mottahedeh@oracle.com, Marc Zyngier , Richard Henderson , QEMU Developers , qemu-arm , Heyi Guo , msys.mizuma@gmail.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, Dec 16, 2019 at 03:06:57PM +0000, Peter Maydell wrote: > Incidentally, if I understand things correctly, for TCG the > behaviour is (and has always been) that VM-stopped time is > not counted, because we run the emulated versions of these counters > off QEMU_CLOCK_VIRTUAL. So having the KVM default be the same as > the TCG default is nicely consistent. It's correct that the vtimer has always been this way for TCG. However TCG and KVM still won't be the same with the adjvtime patches. The reason is that TCG also bases the ptimer off QEMU_CLOCK_VIRTUAL. This means on TCG ptimer =3D=3D vtimer and both will lag a clocksource outside the VM. I'm not sure if TCG people want to change that to match KVM. If so, then I guess the ptimer should be based off=20 QEMU_CLOCK_REALTIME. Thanks, drew