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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 90942C43217 for ; Thu, 1 Dec 2022 09:37:36 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E801E6B0072; Thu, 1 Dec 2022 04:37:35 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id E09266B0073; Thu, 1 Dec 2022 04:37:35 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CA8FC6B0074; Thu, 1 Dec 2022 04:37:35 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id B7AD66B0072 for ; Thu, 1 Dec 2022 04:37:35 -0500 (EST) Received: from smtpin17.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 8736FA0CFF for ; Thu, 1 Dec 2022 09:37:35 +0000 (UTC) X-FDA: 80193234870.17.CD2F679 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by imf16.hostedemail.com (Postfix) with ESMTP id F32AE180015 for ; Thu, 1 Dec 2022 09:37:34 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id E08D1B81E5F; Thu, 1 Dec 2022 09:37:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 75389C43470; Thu, 1 Dec 2022 09:37:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1669887451; bh=BfOt5syWCVHNIGlCb5w84CIS4Di9VpSeQ2OX3cIcr0g=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=m/T9mQyWRqPURKZX3ywro3KQASCx/8OPjCwEnX3ONXn1gZnBx+Sf4nS2Tr/dDZE2x JyUxtPoL1HCM9kIie8EN+AD1YLaixfOtfzCR1TDv2XoJlmHA1wAEvGMZhzo+0m8Jmb /Z2h7e2XFK1uzrzHO/WpDhAwHo/7pP05AeWgSl29p7Q2yjqRtzC8fb3wzrI6OJ1HkZ KB8ipJ01wFYCSsMZ0DfDAgXLPcPBCSfVY1M5fIW1FlzEpAGu+s5g2QcDyh2qR9Mg8x RYP0Su61tWvN/xP44ZIh2d1yEm7nm1xsw/TWgw2675xlSDvo4WotLTgBYleKetNWad mf5S8Ws3o/j6w== Date: Thu, 1 Dec 2022 11:37:10 +0200 From: Mike Rapoport To: "Kirill A. Shutemov" Cc: Borislav Petkov , "Kirill A. Shutemov" , Andy Lutomirski , Sean Christopherson , Andrew Morton , Joerg Roedel , Ard Biesheuvel , Andi Kleen , Kuppuswamy Sathyanarayanan , David Rientjes , Vlastimil Babka , Tom Lendacky , Thomas Gleixner , Peter Zijlstra , Paolo Bonzini , Ingo Molnar , Varad Gautam , Dario Faggioli , Dave Hansen , David Hildenbrand , marcelo.cerri@canonical.com, tim.gardner@canonical.com, khalid.elmously@canonical.com, philip.cox@canonical.com, x86@kernel.org, linux-mm@kvack.org, linux-coco@lists.linux.dev, linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, Mike Rapoport Subject: Re: [PATCHv7 08/14] x86/mm: Reserve unaccepted memory bitmap Message-ID: References: <20220614120231.48165-1-kirill.shutemov@linux.intel.com> <20220614120231.48165-9-kirill.shutemov@linux.intel.com> <20221130012840.sf4rvddzc4ev7bj5@box.shutemov.name> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221130012840.sf4rvddzc4ev7bj5@box.shutemov.name> ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1669887455; a=rsa-sha256; cv=none; b=pqe5ecRKebnuc4x6NdV9dNL1ZG7eB6AQiyiSr1FHFtY8w5+zTBvuCL49XzJvrVzDJvuloW nYhTGfLZA4XM7w5xoH1D7BA1imzKavsrDhyTXvNI+oTvdtdvLEPzg2Kvb1SymmJ8CidoqQ M9JZMKCN6zjMHM3BsqN3lpFO9GV4aUM= ARC-Authentication-Results: i=1; imf16.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b="m/T9mQyW"; spf=pass (imf16.hostedemail.com: domain of rppt@kernel.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=none) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1669887455; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=TsJhdxGFdBmZdr4Zzpno6DDl+0kGNBYt/DoLNx/2LK0=; b=KKX2kOvAGt11KvRWBf31DANEYv+Nzt3PbkP1jRxdmoXwYc3ovzaTcgdry9D3z1g5BqezJM UAJcLF+b1NebZqhdigXliWn8nLELCf5EPbKsAw6q3chbZIMp4bx14hfxLO9Tqm1FpvLkdS rxVICzRc+Hkb699CLkRivUHK9vGWHUI= X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: F32AE180015 X-Rspam-User: Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b="m/T9mQyW"; spf=pass (imf16.hostedemail.com: domain of rppt@kernel.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=none) header.from=kernel.org X-Stat-Signature: hjhnq8gxfbazhio9513cj6jsa9ub1rwe X-HE-Tag: 1669887454-127915 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Nov 30, 2022 at 04:28:40AM +0300, Kirill A. Shutemov wrote: > On Tue, Jul 26, 2022 at 11:07:14AM +0200, Borislav Petkov wrote: > > On Tue, Jun 14, 2022 at 03:02:25PM +0300, Kirill A. Shutemov wrote: > > > diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c > > > index f267205f2d5a..22d1fe48dcba 100644 > > > --- a/arch/x86/kernel/e820.c > > > +++ b/arch/x86/kernel/e820.c > > > @@ -1316,6 +1316,16 @@ void __init e820__memblock_setup(void) > > > int i; > > > u64 end; > > > > > > + /* Mark unaccepted memory bitmap reserved */ > > > + if (boot_params.unaccepted_memory) { > > > + unsigned long size; > > > + > > > + /* One bit per 2MB */ > > > + size = DIV_ROUND_UP(e820__end_of_ram_pfn() * PAGE_SIZE, > > > + PMD_SIZE * BITS_PER_BYTE); > > > + memblock_reserve(boot_params.unaccepted_memory, size); > > > + } > > > + > > > > Hmm, I don't like how this is dropped right in the middle of a unrelated > > function. > > > > You're adding arch/x86/mm/unaccepted_memory.c later. Why don't you put > > that chunk in a function there which is called by early_reserve_memory() > > which does exactly what you want - reserve memory early, before memblock > > allocations? > > early_reserve_memory() specifically called before e820__memory_setup() > (see comment in setup_arch()), so we don't have e820_table finalized and > we need it to get correct RAM size from e820__end_of_ram_pfn(). > > I guess we can hide the chunk in a function in unaccepted_memory.c and > call it from here, but it would require #ifdeffery in a header file as the > .c is only compiled for CONFIG_UNACCEPTED_MEMORY=y. > > Looks like an overkill to me, no? Agree. Can we just extend the comment to explain why we reserve the bitmap at e820__memblock_setup() rather than in early_reserve_memory(), pretty much with the explanation above? > -- > Kiryl Shutsemau / Kirill A. Shutemov -- Sincerely yours, Mike.