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=-12.2 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,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 01C02C433ED for ; Sat, 15 May 2021 08:54:56 +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 B802A613F1 for ; Sat, 15 May 2021 08:54:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B802A613F1 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.127693.240003 (Exim 4.92) (envelope-from ) id 1lhq4K-0001J6-GK; Sat, 15 May 2021 08:54:44 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 127693.240003; Sat, 15 May 2021 08:54:44 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lhq4K-0001Iz-DA; Sat, 15 May 2021 08:54:44 +0000 Received: by outflank-mailman (input) for mailman id 127693; Sat, 15 May 2021 08:54:42 +0000 Received: from mail.xenproject.org ([104.130.215.37]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lhq4I-0001It-TP for xen-devel@lists.xenproject.org; Sat, 15 May 2021 08:54:42 +0000 Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lhq4E-0003Mv-Jo; Sat, 15 May 2021 08:54:38 +0000 Received: from [54.239.6.185] (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 1lhq4E-000592-BD; Sat, 15 May 2021 08:54:38 +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=ATct03ZRjkatB2Crje2oNczGFYgbArRpdYy7QxMVz6s=; b=KtqeDFJ1LgSDjvVbt/3wglgi4H PaUCCAGx9OBoecuA9wFt5NGR+eELWoZvIlvIhS5BXxzZ8Iwh7bXXG1oRdfMH4MI+xMxv+z4oMkNXN zRy07/iK4BD7AbS+tUwD+ymCmlAnVtWHIBo8kipBPfEA9v1d9CTY2nb02LftbPGVyWZM=; Subject: Re: [PATCH RFCv2 12/15] xen/arm: add Persistent Map (PMAP) infrastructure To: Stefano Stabellini Cc: xen-devel@lists.xenproject.org, Wei.Chen@arm.com, Henry.Wang@arm.com, Penny.Zheng@arm.com, Bertrand.Marquis@arm.com, Wei Liu , Volodymyr Babchuk , Hongyan Xia , Julien Grall , Jan Beulich , Wei Liu , Andrew Cooper , =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= , Hongian Xia References: <20210425201318.15447-1-julien@xen.org> <20210425201318.15447-13-julien@xen.org> From: Julien Grall Message-ID: <46b2da6d-d0db-0016-079c-72e18991eb1e@xen.org> Date: Sat, 15 May 2021 09:54:34 +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 Stefano, On 15/05/2021 00:25, Stefano Stabellini wrote: > On Sun, 25 Apr 2021, Julien Grall wrote: >> From: Wei Liu >> +extern lpae_t xen_fixmap[LPAE_ENTRIES]; >> + >> +void *__init pmap_map(mfn_t mfn) >> +{ >> + unsigned long flags; >> + unsigned int idx; >> + vaddr_t linear; >> + unsigned int slot; >> + lpae_t *entry, pte; >> + >> + BUILD_BUG_ON(sizeof(inuse) * BITS_PER_LONG < NUM_FIX_PMAP); >> + >> + ASSERT(system_state < SYS_STATE_smp_boot); > > One small concern here is that we have been using SYS_STATE_early_boot > to switch implementation of things like xen_map_table. Between > SYS_STATE_early_boot and SYS_STATE_smp_boot there is SYS_STATE_boot. > > I guess I am wondering if instead of three potentially different mapping > functions (<= SYS_STATE_early_boot, < SYS_STATE_smp_boot, >= > SYS_STATE_smp_boot) we can get away with only two? This is more flexible than the existing method to map memory when state == SYS_STATE_early_boot. If you look at the next patch (#13), you will see that there will be only two method to map memory. [...] >> diff --git a/xen/include/asm-arm/pmap.h b/xen/include/asm-arm/pmap.h >> new file mode 100644 >> index 000000000000..8e1dce93f8e4 >> --- /dev/null >> +++ b/xen/include/asm-arm/pmap.h >> @@ -0,0 +1,10 @@ >> +#ifndef __ASM_PMAP_H__ >> +#define __ARM_PMAP_H__ > > ASM/ARM I will fix it. > > >> +/* Large enough for mapping 5 levels of page tables with some headroom */ >> +#define NUM_FIX_PMAP 8 >> + >> +void *pmap_map(mfn_t mfn); >> +void pmap_unmap(const void *p); > >> +#endif /* __ASM_PMAP_H__ */ Cheers, -- Julien Grall