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=-17.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 8A1E9C433ED for ; Thu, 29 Apr 2021 13:10:27 +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 2833861405 for ; Thu, 29 Apr 2021 13:10:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2833861405 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.119987.226860 (Exim 4.92) (envelope-from ) id 1lc6Qk-00015I-Ld; Thu, 29 Apr 2021 13:10:10 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 119987.226860; Thu, 29 Apr 2021 13:10:10 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lc6Qk-00015B-I2; Thu, 29 Apr 2021 13:10:10 +0000 Received: by outflank-mailman (input) for mailman id 119987; Thu, 29 Apr 2021 13:10:09 +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 1lc6Qj-000154-Hm for xen-devel@lists.xenproject.org; Thu, 29 Apr 2021 13:10:09 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 57ebc86c-7861-4f11-baf3-d3c0bd0e841c; Thu, 29 Apr 2021 13:10:08 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 44ED5B12E; Thu, 29 Apr 2021 13:10:07 +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: 57ebc86c-7861-4f11-baf3-d3c0bd0e841c 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=1619701807; 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; bh=3k+xAgvQZtJpxfl3IYt7nqtMgLjyZZ2LoR7FStHB82k=; b=Le3PWrken0cEVs2Q+FgPVAceMIZKGAfJutSJh62jPcpFRqw1p7HNreE7n9VVm9AXctIL83 qTjsgFFIG85JrQDfasiLZyIpI6Kd061rNo9E2qQx284XO4bb0QuWOD3nWjOr3o2ne5DvIb ekpDDjz9GTg9jZx6G3L1ddDgkhYLACs= To: "xen-devel@lists.xenproject.org" Cc: Andrew Cooper , George Dunlap , Ian Jackson , Julien Grall , Stefano Stabellini , Wei Liu , Luca Fancellu From: Jan Beulich Subject: [PATCH] public/gnttab: relax v2 recommendation Message-ID: Date: Thu, 29 Apr 2021 15:10:06 +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 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit With there being a way to disable v2 support, telling new guests to use v2 exclusively is not a good suggestion. Signed-off-by: Jan Beulich --- a/xen/include/public/grant_table.h +++ b/xen/include/public/grant_table.h @@ -121,8 +121,10 @@ typedef uint32_t grant_ref_t; */ /* - * Version 1 of the grant table entry structure is maintained purely - * for backwards compatibility. New guests should use version 2. + * Version 1 of the grant table entry structure is maintained largely for + * backwards compatibility. New guests are recommended to support using + * version 2 to overcome version 1 limitations, but to be able to fall back + * to version 1. */ #if __XEN_INTERFACE_VERSION__ < 0x0003020a #define grant_entry_v1 grant_entry