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=-7.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 5D0EAC433B4 for ; Tue, 18 May 2021 10:10:10 +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 1B783611AD for ; Tue, 18 May 2021 10:10:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1B783611AD 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 list by lists.xenproject.org with outflank-mailman.129022.242189 (Exim 4.92) (envelope-from ) id 1liwfl-0003ki-5T; Tue, 18 May 2021 10:09:57 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 129022.242189; Tue, 18 May 2021 10:09:57 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1liwfl-0003kb-2R; Tue, 18 May 2021 10:09:57 +0000 Received: by outflank-mailman (input) for mailman id 129022; Tue, 18 May 2021 10:09:56 +0000 Received: from mail.xenproject.org ([104.130.215.37]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1liwfk-0003kV-OD for xen-devel@lists.xenproject.org; Tue, 18 May 2021 10:09:56 +0000 Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1liwfk-0008T6-Il; Tue, 18 May 2021 10:09:56 +0000 Received: from [54.239.6.186] (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 1liwfk-0008Nc-Cq; Tue, 18 May 2021 10:09:56 +0000 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" 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; bh=+WmblekLkivM2UjT70d4R92sZ3gx7s/ukyceI63fapA=; b=nGkc9rkqZriuRn6A93VKLLDWAc WmkeoiJQtBGeC+qTSUgPx1DnBwF8FBYm3zxyRFsgn0NH2/k9KmauMKFK3m7AzpOU20KyI2tVHVXlY PgDVcihPapKYuvI2Gkd87KBqHdWP9/FfLbeBrrxd4Un+7q8oSuguVv6tlxSqKUU4+R78=; Subject: Re: [PATCH 05/10] xen/arm: introduce alloc_staticmem_pages To: Jan Beulich , Penny Zheng Cc: Bertrand.Marquis@arm.com, Wei.Chen@arm.com, nd@arm.com, xen-devel@lists.xenproject.org, sstabellini@kernel.org References: <20210518052113.725808-1-penny.zheng@arm.com> <20210518052113.725808-6-penny.zheng@arm.com> From: Julien Grall Message-ID: <7f36351e-fa08-ea74-cbc2-049ced7aac4e@xen.org> Date: Tue, 18 May 2021 11:09:54 +0100 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Hi Jan, On 18/05/2021 08:24, Jan Beulich wrote: > On 18.05.2021 07:21, Penny Zheng wrote: >> + * to PGC_state_inuse. >> + */ >> + pg[i].count_info = (pg[i].count_info & PGC_reserved) | PGC_state_inuse; >> + /* Initialise fields which have other uses for free pages. */ >> + pg[i].u.inuse.type_info = 0; >> + page_set_owner(&pg[i], NULL); >> + >> + /* >> + * Ensure cache and RAM are consistent for platforms where the >> + * guest can control its own visibility of/through the cache. >> + */ >> + flush_page_to_ram(mfn_x(page_to_mfn(&pg[i])), >> + !(memflags & MEMF_no_icache_flush)); >> + } >> + >> + if ( need_tlbflush ) >> + filtered_flush_tlb_mask(tlbflush_timestamp); > > With reserved pages dedicated to a specific domain, in how far is it > possible that stale mappings from a prior use can still be around, > making such TLB flushing necessary? I would rather not make the assumption. I can see future where we just want to allocate memory from a static pool that may be shared with multiple domains. Cheers, -- Julien Grall