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 D7058C433DB for ; Fri, 15 Jan 2021 15:37:49 +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 92641207D0 for ; Fri, 15 Jan 2021 15:37:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 92641207D0 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.68367.122404 (Exim 4.92) (envelope-from ) id 1l0RAQ-0003jg-8Y; Fri, 15 Jan 2021 15:37:38 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 68367.122404; Fri, 15 Jan 2021 15:37:38 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1l0RAQ-0003jZ-4x; Fri, 15 Jan 2021 15:37:38 +0000 Received: by outflank-mailman (input) for mailman id 68367; Fri, 15 Jan 2021 15:37:37 +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 1l0RAP-0003jS-1P for xen-devel@lists.xenproject.org; Fri, 15 Jan 2021 15:37:37 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 88571682-daa0-4f92-8018-8dec871f9303; Fri, 15 Jan 2021 15:37:35 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id DA5D6AB7F; Fri, 15 Jan 2021 15:37:34 +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: 88571682-daa0-4f92-8018-8dec871f9303 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=1610725055; 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=REnWrUBueavpg+9/VqKKVvS0FRT4Alih8VwDlXO4qY8=; b=EQ4HOegeU95f16M/4YlJfWNXKePBG2BC4ZDG2s6E772nvc8208ZgfygXZo+y5G3a6s3p67 CbyjXo9Qk1VytzbWjF4Wby8+T7rUDkjji7HSiLaYwVxDWoIeaQFSdfcuvNjzm1SiMqcUeJ 8UjPS0ke6Hg0CsW2VvdoLwUtraX8qNA= Subject: Re: [PATCH v3 5/7] xen/memory: Improve compat XENMEM_acquire_resource handling To: Andrew Cooper Cc: George Dunlap , Ian Jackson , Stefano Stabellini , Wei Liu , Julien Grall , Paul Durrant , =?UTF-8?Q?Micha=c5=82_Leszczy=c5=84ski?= , Hubert Jasudowicz , Tamas K Lengyel , Xen-devel References: <20210112194841.1537-1-andrew.cooper3@citrix.com> <20210112194841.1537-6-andrew.cooper3@citrix.com> From: Jan Beulich Message-ID: Date: Fri, 15 Jan 2021 16:37:34 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.1 MIME-Version: 1.0 In-Reply-To: <20210112194841.1537-6-andrew.cooper3@citrix.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit On 12.01.2021 20:48, Andrew Cooper wrote: > @@ -446,6 +430,31 @@ int compat_memory_op(unsigned int cmd, XEN_GUEST_HANDLE_PARAM(void) compat) > > #undef XLAT_mem_acquire_resource_HNDL_frame_list > > + if ( xen_frame_list && cmp.mar.nr_frames ) > + { > + /* > + * frame_list is an input for translated guests, and an output > + * for untranslated guests. Only copy in for translated guests. > + */ > + if ( paging_mode_translate(currd) ) > + { > + compat_pfn_t *compat_frame_list = (void *)xen_frame_list; > + > + if ( !compat_handle_okay(cmp.mar.frame_list, > + cmp.mar.nr_frames) || > + __copy_from_compat_offset( > + compat_frame_list, cmp.mar.frame_list, > + 0, cmp.mar.nr_frames) ) > + return -EFAULT; > + > + /* > + * Iterate backwards over compat_frame_list[] expanding > + * compat_pfn_t to xen_pfn_t in place. > + */ > + for ( int x = cmp.mar.nr_frames - 1; x >= 0; --x ) > + xen_frame_list[x] = compat_frame_list[x]; Just as a nit, without requiring you to adjust (but with the request to consider adjusting) - x getting used as array index would generally suggest it wants to be an unsigned type (despite me guessing the compiler ought to be able to avoid an explicit sign-extension for the actual memory accesses): for ( unsigned int x = cmp.mar.nr_frames; x--; ) xen_frame_list[x] = compat_frame_list[x]; Jan