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=-7.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 94429C433ED for ; Tue, 4 May 2021 12:13:03 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 4CEF3613AA for ; Tue, 4 May 2021 12:13:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4CEF3613AA Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.122230.230498 (Exim 4.92) (envelope-from ) id 1ldtv4-0002OE-Mw; Tue, 04 May 2021 12:12:54 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 122230.230498; Tue, 04 May 2021 12:12:54 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1ldtv4-0002O7-JN; Tue, 04 May 2021 12:12:54 +0000 Received: by outflank-mailman (input) for mailman id 122230; Tue, 04 May 2021 12:12:53 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1ldtv2-0002O2-Tm for xen-devel@lists.xenproject.org; Tue, 04 May 2021 12:12:52 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 332afec1-6c43-47ce-94f9-2da946c419d1; Tue, 04 May 2021 12:12:51 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 1B77BB2DC; Tue, 4 May 2021 12:12:51 +0000 (UTC) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 332afec1-6c43-47ce-94f9-2da946c419d1 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1620130371; h=from:from:reply-to: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=Etumk9WiYOFtAAaAsfCpzSWRkB+mKLAtUDQEeNVOb4A=; b=sO+iz23Thm2R9P14oMqplr62s963f6FfQGdcqcBDUjP/9pOufmbOKrMV4f6m2vmgH7PmUv SeBxCWhYSIXtLH6/NP72a2dX2mH0O+rQ9fO063dSDc2pegfF1eWM3ggu9ZC4eAOet7zgop EEUeJ/ms29/NllkTPYn6YKbEG/ZjgTY= Subject: Re: [PATCH v3 07/13] libs/guest: obtain a compatible cpu policy from two input ones To: =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= Cc: Andrew Cooper , Ian Jackson , Wei Liu , Anthony PERARD , xen-devel@lists.xenproject.org References: <20210430155211.3709-1-roger.pau@citrix.com> <20210430155211.3709-8-roger.pau@citrix.com> <838e358d-5707-0f34-c8fe-64e29f000a69@suse.com> From: Jan Beulich Message-ID: <0fa9652d-2b38-516d-a371-df90943d93a3@suse.com> Date: Tue, 4 May 2021 14:12:50 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit On 04.05.2021 13:56, Roger Pau Monné wrote: > On Mon, May 03, 2021 at 12:43:08PM +0200, Jan Beulich wrote: >> On 30.04.2021 17:52, Roger Pau Monne wrote: >>> +/* Only level featuresets so far. */ >> >> I have to admit that I don't think I see all the implications from >> this implementation restriction. All other leaves get dropped by >> the caller, but it's not clear to me what this means wrt what the >> guest is ultimately going to get to see. > > This aims to be based on what XenServer does, which I was told is to > level the featuresets. I think the caller of the function will have to > fill the part of the policy that cannot be leveled. It's likely new > helpers will be added to do that as required. > > One option would be to get the default policy for the guest and then > use xc_cpu_policy_update_cpuid to apply the leveled one. Could such further plans perhaps be outlined (to a degree at least) in the description? Jan