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=-9.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 17355C433DF for ; Tue, 4 Aug 2020 14:03:00 +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 E54652086A for ; Tue, 4 Aug 2020 14:02:59 +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="JT3do+Hr" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E54652086A 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 1k2xWH-0002gS-T9; Tue, 04 Aug 2020 14:02:21 +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 1k2xWG-0002gN-Bn for xen-devel@lists.xenproject.org; Tue, 04 Aug 2020 14:02:20 +0000 X-Inumbo-ID: 700f1ab7-786a-4b27-b03b-99a20e3dfb7c Received: from mail.xenproject.org (unknown [104.130.215.37]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 700f1ab7-786a-4b27-b03b-99a20e3dfb7c; Tue, 04 Aug 2020 14:02:19 +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=0xm34ZhZtkbjneIiksswdOIJjA+6W/un6UZlSsYeumU=; b=JT3do+Hri4H5cQNf7WCPxIcj9R +WN9eDi+alRjVABzYukw0nZEIVVYItwh6zkY6Et6EmBykTI2kQ1YX9Sd0cfaIzvyvwGcvSDuMoDhV MD0dAUIQSVBv6wUhr+fTbJNTNlwtQKQrEp1sxX47DfbmorBG3Ze+ueyjNfzyi9YYuPRA=; Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1k2xVw-0000C7-Qr; Tue, 04 Aug 2020 14:02:00 +0000 Received: from 54-240-197-225.amazon.com ([54.240.197.225] 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 1k2xVw-0004ro-Fr; Tue, 04 Aug 2020 14:02:00 +0000 Subject: Re: [RFC PATCH V1 04/12] xen/arm: Introduce arch specific bits for IOREQ/DM features To: paul@xen.org, 'Oleksandr Tyshchenko' , xen-devel@lists.xenproject.org References: <1596478888-23030-1-git-send-email-olekstysh@gmail.com> <1596478888-23030-5-git-send-email-olekstysh@gmail.com> <001101d66a33$bba44670$32ecd350$@xen.org> From: Julien Grall Message-ID: <6c4f7698-a015-91c7-83ec-203f63d48900@xen.org> Date: Tue, 4 Aug 2020 15:01:57 +0100 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <001101d66a33$bba44670$32ecd350$@xen.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit 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' , 'Wei Liu' , 'Andrew Cooper' , 'Ian Jackson' , 'George Dunlap' , 'Oleksandr Tyshchenko' , 'Julien Grall' , 'Jan Beulich' , 'Daniel De Graaf' , 'Volodymyr Babchuk' Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" Hi Paul, On 04/08/2020 08:49, Paul Durrant wrote: >> diff --git a/tools/libxc/xc_dom_arm.c b/tools/libxc/xc_dom_arm.c >> index 931404c..b5fc066 100644 >> --- a/tools/libxc/xc_dom_arm.c >> +++ b/tools/libxc/xc_dom_arm.c >> @@ -26,11 +26,19 @@ >> #include "xg_private.h" >> #include "xc_dom.h" >> >> -#define NR_MAGIC_PAGES 4 >> + >> #define CONSOLE_PFN_OFFSET 0 >> #define XENSTORE_PFN_OFFSET 1 >> #define MEMACCESS_PFN_OFFSET 2 >> #define VUART_PFN_OFFSET 3 >> +#define IOREQ_SERVER_PFN_OFFSET 4 >> + >> +#define NR_IOREQ_SERVER_PAGES 8 >> +#define NR_MAGIC_PAGES (4 + NR_IOREQ_SERVER_PAGES) >> + >> +#define GUEST_MAGIC_BASE_PFN (GUEST_MAGIC_BASE >> XC_PAGE_SHIFT) >> + >> +#define special_pfn(x) (GUEST_MAGIC_BASE_PFN + (x)) > > Why introduce 'magic pages' for Arm? It's quite a horrible hack that we have begun to do away with by adding resource mapping. This would require us to mandate at least Linux 4.17 in a domain that will run an IOREQ server. If we don't mandate this, the minimum version would be 4.10 where DM OP was introduced. Because of XSA-300, we could technically not safely run an IOREQ server with existing Linux. So it is probably OK to enforce the use of the acquire interface. Note that I haven't yet looked at the rest of the series. So I am not sure if there is more work necessary to enable it. Cheers, -- Julien Grall