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=-6.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=ham 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 2892FCA9EA0 for ; Tue, 22 Oct 2019 17:18:46 +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 E8B4320679 for ; Tue, 22 Oct 2019 17:18:45 +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="Zw1RZe/i" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E8B4320679 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]:37266 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iMxnw-0003AY-Rk for qemu-devel@archiver.kernel.org; Tue, 22 Oct 2019 13:18:44 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:47804) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iMxmv-0002Au-O0 for qemu-devel@nongnu.org; Tue, 22 Oct 2019 13:17:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iMxms-00012s-Ug for qemu-devel@nongnu.org; Tue, 22 Oct 2019 13:17:40 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:33051 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 1iMxms-00011a-RE for qemu-devel@nongnu.org; Tue, 22 Oct 2019 13:17:38 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1571764658; 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=jagol9ei1YyfWIfvBSB06tLZyxTw2fLivQNbo1pTQRs=; b=Zw1RZe/igSCshUlLWOZJ6Nwc2AWSj7uEhOROamHuQ3fScFkhRTEqHPYO3OdaakSyJVHq12 oYXmTWtUsd65y+x6vW+bhEqx4YFiJ1RZvTydDyMqyx+NfIPdHwnBr6RIREi5GIOJcQw6ru M6412Wa2vwQii7cOswc06NSQJIGD9L0= 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-175-5Gp43HXtPtq6CmQoUrtuNw-1; Tue, 22 Oct 2019 13:17:34 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0D1E947B; Tue, 22 Oct 2019 17:17:34 +0000 (UTC) Received: from ptitpuce (ovpn-117-172.ams2.redhat.com [10.36.117.172]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B8BD4194B6; Tue, 22 Oct 2019 17:17:16 +0000 (UTC) References: <20191009132252.17860-1-imammedo@redhat.com> <20191009132252.17860-2-imammedo@redhat.com> User-agent: mu4e 1.3.2; emacs 26.2 From: Christophe de Dinechin To: qemu-devel@nongnu.org Subject: Re: [RFC 1/3] acpi: cpuhp: fix 'Command data' description is spec In-reply-to: Date: Tue, 22 Oct 2019 19:17:13 +0200 Message-ID: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-MC-Unique: 5Gp43HXtPtq6CmQoUrtuNw-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable 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: Eduardo Habkost , "Michael S. Tsirkin" , Gerd Hoffmann , Paolo Bonzini , Igor Mammedov , Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= , Richard Henderson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Laszlo Ersek writes: > On 10/10/19 15:31, Laszlo Ersek wrote: >> 2nd round: >> >> On 10/09/19 15:22, Igor Mammedov wrote: >>> QEMU returns 0, in case of erro or invalid value in 'Command field', >>> make spec match reality, i.e. >> >> AHA! so this is exactly where you meant to list the particular cases >> when "command data" reads as 0: >> - CPU >=3D max_cpus selected, >> - CPU with pending events asked for, but none found >> >>> Also fix returned value description in case 'Command field' =3D=3D 0x0= , >>> it's in not PXM but CPU selector value with pending event >>> >>> Signed-off-by: Igor Mammedov >>> --- >>> docs/specs/acpi_cpu_hotplug.txt | 5 +++-- >>> 1 file changed, 3 insertions(+), 2 deletions(-) >>> >>> diff --git a/docs/specs/acpi_cpu_hotplug.txt b/docs/specs/acpi_cpu_hotp= lug.txt >>> index ee219c8358..ac5903b2b1 100644 >>> --- a/docs/specs/acpi_cpu_hotplug.txt >>> +++ b/docs/specs/acpi_cpu_hotplug.txt >>> @@ -44,9 +44,10 @@ read access: >>> 3-7: reserved and should be ignored by OSPM >>> [0x5-0x7] reserved >>> [0x8] Command data: (DWORD access) >>> - in case of error or unsupported command reads is 0xFFFFFFFF >>> + in case of error or unsupported command reads is 0x0 >>> current 'Command field' value: >>> - 0: returns PXM value corresponding to device >>> + 0: returns CPU selector value corresponding to a CPU wit= h >>> + pending event. >>> >>> write access: >>> offset: >>> >> >> How about: >> >> [0x8] Command data: (DWORD access, little endian) >> If the "CPU selector" value last stored by the guest refers to >> an impossible CPU, then 0. >> Otherwise, if the "Command field" value last stored by the >> guest differs from 0, then 0. >> Otherwise, if there is at least one CPU with a pending event, >> then that CPU has been selected; the command data register >> returns that selector. >> Otherwise, 0. > > Hmmm not exactly. Let me try again. > > [0x8] Command data: (DWORD access, little endian) > If the "CPU selector" value last stored by the guest refers to > an impossible CPU, then 0. > Otherwise, if the "Command field" value last stored by the > guest differs from 0, then 0. > Otherwise, the currently selected CPU. How about phrasing it to put the more general case first, e.g. [0x8] Command data: (DWORD access, little endian) The currently selected CPU, unless: - The "CPU selector" value refers to an impossible CPU - The "Command field" value last stored by the guest differs from 0 In these last two cases, the value is 0. > > Thanks, > Laszlo -- Cheers, Christophe de Dinechin (IRC c3d)