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=-8.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 71D30C433DF for ; Tue, 21 Jul 2020 10:38:52 +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 45AA620714 for ; Tue, 21 Jul 2020 10:38:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 45AA620714 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 1jxpfV-0005NP-IK; Tue, 21 Jul 2020 10:38:41 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jxpfU-0005NJ-Ad for xen-devel@lists.xenproject.org; Tue, 21 Jul 2020 10:38:40 +0000 X-Inumbo-ID: 56b014ee-cb3e-11ea-84fe-bc764e2007e4 Received: from mail-wm1-f66.google.com (unknown [209.85.128.66]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 56b014ee-cb3e-11ea-84fe-bc764e2007e4; Tue, 21 Jul 2020 10:38:39 +0000 (UTC) Received: by mail-wm1-f66.google.com with SMTP id q15so2317465wmj.2 for ; Tue, 21 Jul 2020 03:38:39 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to:user-agent; bh=eixWLu67VU8LUPqETPCzqjgNnJL3BeZahrEuSfq3FmU=; b=GoySYz8zStWZ3l62G8wY3LD3N83fXRwBPLQuG7zODDV7TviHXydO7aLEAYntBIUDeL VasJWTw96iDBwInHKLYWItd7bIH/meu0ur2q+Ol5BW6DP/72RHAarv1eOeONxXuKYhsY vi04/R6HOA/o/9dE/qCz7b2huQgTd8MSrJigh70XMJ5OGqzDPl0mkMddO2Gn9QnN2ABm J3lsT0UrXz6iaL1IF/cLiIzz1XXmurvbD8bsyhfCDKP9QE/lXRZYOthOBl5cEa+SEt9D jHBzuIwWhku3LCoBAfagSGPOWmUBZyVn0JY/um1gnHlmQyvEtEC2U20hDOazaDLrGCr9 0iHw== X-Gm-Message-State: AOAM531Qy5O5uTKKjo+Df5j+ASSv9ZpM/td+k45JzEfWj61+fuq8KoJR djp99nYvNnNhkiFEFGYX1yE= X-Google-Smtp-Source: ABdhPJxiFTII/CEwGTG5E+eqNo78WE3VAW1b0Gbu84hSLPspMcYZYPBjHvgSZ0UvzcuHxiPiKcP67g== X-Received: by 2002:a7b:ce97:: with SMTP id q23mr3492831wmj.89.1595327918759; Tue, 21 Jul 2020 03:38:38 -0700 (PDT) Received: from liuwe-devbox-debian-v2 ([51.145.34.42]) by smtp.gmail.com with ESMTPSA id x9sm2890366wmk.45.2020.07.21.03.38.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 21 Jul 2020 03:38:38 -0700 (PDT) Date: Tue, 21 Jul 2020 10:38:36 +0000 From: Wei Liu To: Jan Beulich Subject: Re: [PATCH] compat: add a little bit of description to xlat.lst Message-ID: <20200721103836.ogdcvbcuknuxcf32@liuwe-devbox-debian-v2> References: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: NeoMutt/20180716 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: Stefano Stabellini , Julien Grall , Wei Liu , George Dunlap , Andrew Cooper , Ian Jackson , "xen-devel@lists.xenproject.org" , Roger Pau =?utf-8?B?TW9ubsOp?= Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" On Thu, Jul 16, 2020 at 02:21:33PM +0200, Jan Beulich wrote: > Requested-by: Roger Pau Monné > Signed-off-by: Jan Beulich Acked-by: Wei Liu This is much appreciated. > > --- a/xen/include/xlat.lst > +++ b/xen/include/xlat.lst > @@ -1,3 +1,22 @@ > +# There are a few fundamentally different strategies for handling compat > +# (sub-)hypercalls: > +# > +# 1) Wrap a translation layer around the native hypercall. Structures involved > +# in this model should use translation (xlat) macros generated by adding > +# !-prefixed lines here. > +# > +# 2) Compile the entire hypercall function a second time, arranging for the > +# compat structures to get used in place of the native ones. There are no xlat > +# macros involved here, all that's needed are correctly translated structures. > +# > +# 3) Adhoc translation, which may or may not involve adding entries here. > +# > +# 4) Any mixture of the above. > +# > +# In all models any structures re-used in their native form should have > +# ?-mark prefixed lines added here, with the resulting checking macros invoked > +# somewhere in the code handling the hypercall or its translation. > +# > # First column indicator: > # ! - needs translation > # ? - needs checking