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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 E9708C433DF for ; Fri, 3 Jul 2020 07:58:49 +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 A17D2206BE for ; Fri, 3 Jul 2020 07:58:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=xen.org header.i=@xen.org header.b="WDzZ2nhG" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A17D2206BE Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=xen.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jrGaJ-0007Wv-OB; Fri, 03 Jul 2020 07:58:11 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jrGaI-0007Wq-Ke for xen-devel@lists.xenproject.org; Fri, 03 Jul 2020 07:58:10 +0000 X-Inumbo-ID: efdd61e8-bd02-11ea-bca7-bc764e2007e4 Received: from mail.xenproject.org (unknown [104.130.215.37]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id efdd61e8-bd02-11ea-bca7-bc764e2007e4; Fri, 03 Jul 2020 07:58:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=xen.org; s=20200302mail; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: MIME-Version:Date:Message-ID:From:References:Cc:To:Subject:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=y831c3SyaYAviC2e5WYtZjpRaHUueP+RBPpzoR37b8I=; b=WDzZ2nhG96liyYN8lPXOKggYBH LGwv7KLXO8TN7b3HAHwMm7rzCqFHs9UUFlDR7g1BA1yrzHMcbPEZ3+8are/MLK5gNx4mDD2pmMTrC Txk4e/fSTlK1PeZzUgbMweCxrBGl64FFob0VJYwZSZ5ifb53utXixLggvElw3uHlCcbU=; Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jrGaC-00012e-RV; Fri, 03 Jul 2020 07:58:04 +0000 Received: from 54-240-197-234.amazon.com ([54.240.197.234] helo=a483e7b01a66.ant.amazon.com) by xenbits.xenproject.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1jrGaC-0005im-Ij; Fri, 03 Jul 2020 07:58:04 +0000 Subject: Re: [PATCH v4 02/10] x86/vmx: add IPT cpu feature To: =?UTF-8?Q?Micha=c5=82_Leszczy=c5=84ski?= References: <3fa0c3e7-9243-b1bb-d6ad-a3bd21437782@xen.org> <0e02a9b5-ba7a-43a2-3369-a4410f216ddb@suse.com> <9a3f4d58-e5ad-c7a1-6c5f-42aa92101ca1@xen.org> <7f915146-6566-e5a7-14d2-cb2319838562@xen.org> <7ac383c2-0264-cc75-a85b-13c1fdfb0bd6@suse.com> <187614050.18497785.1593721708078.JavaMail.zimbra@cert.pl> From: Julien Grall Message-ID: <2e01fca9-efcd-7d09-355f-29245bbc8721@xen.org> Date: Fri, 3 Jul 2020 08:58:01 +0100 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <187614050.18497785.1593721708078.JavaMail.zimbra@cert.pl> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 8bit X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Kevin Tian , Stefano Stabellini , tamas lengyel , Jan Beulich , Wei Liu , Andrew Cooper , Ian Jackson , George Dunlap , Jun Nakajima , xen-devel@lists.xenproject.org, luwei kang , =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" Hi, On 02/07/2020 21:28, Michał Leszczyński wrote: > ----- 2 lip 2020 o 16:31, Julien Grall julien@xen.org napisał(a): > >> On 02/07/2020 15:17, Jan Beulich wrote: >>> On 02.07.2020 16:14, Julien Grall wrote: >>>> On 02/07/2020 14:30, Jan Beulich wrote: >>>>> On 02.07.2020 11:57, Julien Grall wrote: >>>>>> On 02/07/2020 10:18, Jan Beulich wrote: >>>>>>> On 02.07.2020 10:54, Julien Grall wrote: >>>>>>>> On 02/07/2020 09:50, Jan Beulich wrote: >>>>>>>>> On 02.07.2020 10:42, Julien Grall wrote: >>>>>>>>>> On 02/07/2020 09:29, Jan Beulich wrote: >>>>>> Another way to do it, would be the toolstack to do the mapping. At which >>>>>> point, you still need an hypercall to do the mapping (probably the >>>>>> hypercall acquire). >>>>> >>>>> There may not be any mapping to do in such a contrived, fixed-range >>>>> environment. This scenario was specifically to demonstrate that the >>>>> way the mapping gets done may be arch-specific (here: a no-op) >>>>> despite the allocation not being so. >>>> You are arguing on extreme cases which I don't think is really helpful >>>> here. Yes if you want to map at a fixed address in a guest you may not >>>> need the acquire hypercall. But in most of the other cases (see has for >>>> the tools) you will need it. >>>> >>>> So what's the problem with requesting to have the acquire hypercall >>>> implemented in common code? >>> >>> Didn't we start out by you asking that there be as little common code >>> as possible for the time being? >> >> Well as I said I am not in favor of having the allocation in common >> code, but if you want to keep it then you also want to implement >> map/unmap in the common code ([1], [2]). >> >>> I have no issue with putting the >>> acquire implementation there ... >> This was definitely not clear given how you argued with extreme cases... >> >> Cheers, >> >> [1] <9a3f4d58-e5ad-c7a1-6c5f-42aa92101ca1@xen.org> >> [2] >> >> -- >> Julien Grall > > > Guys, > > could you express your final decision on this topic? Can you move the acquire implementation from x86 to common code? Cheers, -- Julien Grall