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=-12.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 54B5EC433B4 for ; Wed, 14 Apr 2021 13:37:11 +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 17BED61107 for ; Wed, 14 Apr 2021 13:37:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 17BED61107 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.110627.211156 (Exim 4.92) (envelope-from ) id 1lWfhS-0003uP-8P; Wed, 14 Apr 2021 13:36:58 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 110627.211156; Wed, 14 Apr 2021 13:36:58 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lWfhS-0003uI-51; Wed, 14 Apr 2021 13:36:58 +0000 Received: by outflank-mailman (input) for mailman id 110627; Wed, 14 Apr 2021 13:36:57 +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 1lWfhR-0003uD-0g for xen-devel@lists.xenproject.org; Wed, 14 Apr 2021 13:36:57 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id f668348c-b336-42ee-8f8b-56c468d8ef25; Wed, 14 Apr 2021 13:36:55 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id F41D0AEF8; Wed, 14 Apr 2021 13:36:54 +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: f668348c-b336-42ee-8f8b-56c468d8ef25 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=1618407415; 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=QwXYZUsNAPlU3TCDm0e4/thm+p5NJtUWnxek+st3b+c=; b=Ecdi9v41zn6eORTjiQA4va6umg/ccuTTdDX/ulg6smpJDXS79wj/JEOyCdGg8wLEJUZEk7 xZ9WQeghiciM59Qbhh5RZPqQkFtZzc87Eqd3tsEoteO+1RzX+RJgzaqL3SzHUmFy49nUme pwvgAeOmGOAyqojdhxObxggvPpqr8j8= Subject: Re: [PATCH v2 14/21] libs/guest: introduce helper to check cpu policy compatibility To: Roger Pau Monne Cc: Andrew Cooper , Ian Jackson , Wei Liu , xen-devel@lists.xenproject.org References: <20210413140140.73690-1-roger.pau@citrix.com> <20210413140140.73690-15-roger.pau@citrix.com> From: Jan Beulich Message-ID: Date: Wed, 14 Apr 2021 15:36:54 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.9.1 MIME-Version: 1.0 In-Reply-To: <20210413140140.73690-15-roger.pau@citrix.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit On 13.04.2021 16:01, Roger Pau Monne wrote: > --- a/tools/libs/guest/xg_cpuid_x86.c > +++ b/tools/libs/guest/xg_cpuid_x86.c > @@ -925,3 +925,22 @@ int xc_cpu_policy_update_msrs(xc_interface *xch, xc_cpu_policy_t policy, > > return rc; > } > + > +bool xc_cpu_policy_is_compatible(xc_interface *xch, const xc_cpu_policy_t host, > + const xc_cpu_policy_t guest) > +{ > + struct cpu_policy_errors err = INIT_CPU_POLICY_ERRORS; > + struct cpu_policy h = { &host->cpuid, &host->msr }; > + struct cpu_policy g = { &guest->cpuid, &guest->msr }; > + int rc = x86_cpu_policies_are_compatible(&h, &g, &err); > + > + if ( !rc ) > + return true; > + > + if ( err.leaf != -1 ) > + ERROR("Leaf %#x subleaf %#x is not compatible", err.leaf, err.subleaf); > + if ( err.msr != -1 ) > + ERROR("MSR index %#x is not compatible", err.msr); Personally I'm against making assumptions like these ones about what (in this case) INIT_CPU_POLICY_ERRORS actually expands to (i.e. three times -1). I can see how alternatives to this are quickly going to get ugly, so I'll leave it to others to judge. Jan