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 EBC12C433ED for ; Tue, 20 Apr 2021 12:33:07 +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 7AF4E613C1 for ; Tue, 20 Apr 2021 12:33:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7AF4E613C1 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.113603.216500 (Exim 4.92) (envelope-from ) id 1lYpYj-0007HG-0Q; Tue, 20 Apr 2021 12:32:53 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 113603.216500; Tue, 20 Apr 2021 12:32:52 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lYpYi-0007H9-Tk; Tue, 20 Apr 2021 12:32:52 +0000 Received: by outflank-mailman (input) for mailman id 113603; Tue, 20 Apr 2021 12:32:51 +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 1lYpYh-0007Gl-2G for xen-devel@lists.xenproject.org; Tue, 20 Apr 2021 12:32:51 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id fdb9ad0c-b35f-4107-8f88-7526e3f83690; Tue, 20 Apr 2021 12:32:50 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 4A8D4B2E2; Tue, 20 Apr 2021 12:32:49 +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: fdb9ad0c-b35f-4107-8f88-7526e3f83690 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=1618921969; 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=hzJ2zvxaFBZEyJ0VfIKGlqu6FRZCu862q22MyiJu+rw=; b=JzU43WafOKQqIbkeGqy8fYj5opIEFiQDgCN0Ezi7CTGeNay2XbC0OMdnVSb11SnvkDtYfc Hyfksasn3xJ83paWoW0eM30vSlj4rCySYmJll597Z7rU4z9fOMMu5irXpKSQK0P/Ff2+m5 dqBK2lY6EN2Ak3jdLUX75f375ijBAIY= Subject: Re: [PATCH v9 10/13] x86/smpboot: switch clone_mapping() to new APIs To: Hongyan Xia Cc: jgrall@amazon.com, Andrew Cooper , =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= , Wei Liu , xen-devel@lists.xenproject.org References: From: Jan Beulich Message-ID: Date: Tue, 20 Apr 2021 14:32:49 +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 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit On 06.04.2021 13:05, Hongyan Xia wrote: > @@ -742,51 +742,58 @@ static int clone_mapping(const void *ptr, root_pgentry_t *rpt) > } > } > > + UNMAP_DOMAIN_PAGE(pl1e); > + UNMAP_DOMAIN_PAGE(pl2e); > + UNMAP_DOMAIN_PAGE(pl3e); Just one minor remark: A pedantic(?) compiler might warn about the setting to NULL of pl3e here, when > if ( !(root_get_flags(rpt[root_table_offset(linear)]) & _PAGE_PRESENT) ) > { > - pl3e = alloc_xen_pagetable(); > + mfn_t l3mfn; > + > + pl3e = alloc_map_clear_xen_pt(&l3mfn); > rc = -ENOMEM; > if ( !pl3e ) > goto out; > - clear_page(pl3e); > l4e_write(&rpt[root_table_offset(linear)], > - l4e_from_paddr(__pa(pl3e), __PAGE_HYPERVISOR)); > + l4e_from_mfn(l3mfn, __PAGE_HYPERVISOR)); > } > else > - pl3e = l4e_to_l3e(rpt[root_table_offset(linear)]); > + pl3e = map_l3t_from_l4e(rpt[root_table_offset(linear)]); ... it is guaranteed to get initialized again before any further consumption. IOW strictly speaking the last of those three would want to be unmap_domain_page(), just like you have ... > @@ -802,6 +809,9 @@ static int clone_mapping(const void *ptr, root_pgentry_t *rpt) > > rc = 0; > out: > + unmap_domain_page(pl1e); > + unmap_domain_page(pl2e); > + unmap_domain_page(pl3e); > return rc; > } ... here. Jan