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 66BB6C43217 for ; Thu, 1 Dec 2022 13:47:59 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id AB9246B0072; Thu, 1 Dec 2022 08:47:58 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A69E06B0073; Thu, 1 Dec 2022 08:47:58 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 933B86B0074; Thu, 1 Dec 2022 08:47:58 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 84D2B6B0072 for ; Thu, 1 Dec 2022 08:47:58 -0500 (EST) Received: from smtpin05.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 4A871AB2DF for ; Thu, 1 Dec 2022 13:47:58 +0000 (UTC) X-FDA: 80193865836.05.7D0D988 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by imf23.hostedemail.com (Postfix) with ESMTP id DE49414000C for ; Thu, 1 Dec 2022 13:47:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1669902476; x=1701438476; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=mTaZIIv3uUc9JYNMsjX+rfZMzd1G+Dsj8zGp0aHQgQI=; b=EnaOgte25qubhv2XEuGM5FKgJ1yCdOvew2AfNGfNbYv2R5TDYaZdJ5eW cLjpyszi7k+qPIN6/Ke/24WjEwna2zJyxYSy0zIoUFkNSnFQiDnkp5uB6 aav2M/Ba0SjIzTozhbo/WBGdYyTgFlWA8xfvM8ORIT8fJWlgmOKEkv9vw dJJhDiSQ/JjmlO3ePR86sYefTKgRog082LAKOkxtgbjB/1m9OKtcxYTUP 0dZt865uOrYXtETPEcgCLVP156LxltRN8wNNZg8EFhpobUmqq741/AskC T7ToeuU+TLHPPCo0BZPLf8Srot4CelvouilNvXkKcpmvf9fiiOVRNHkr/ w==; X-IronPort-AV: E=McAfee;i="6500,9779,10548"; a="314385101" X-IronPort-AV: E=Sophos;i="5.96,209,1665471600"; d="scan'208";a="314385101" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Dec 2022 05:47:55 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10548"; a="677219981" X-IronPort-AV: E=Sophos;i="5.96,209,1665471600"; d="scan'208";a="677219981" Received: from ichepiga-mobl1.ger.corp.intel.com (HELO box.shutemov.name) ([10.252.55.59]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Dec 2022 05:47:47 -0800 Received: by box.shutemov.name (Postfix, from userid 1000) id CD4AA109781; Thu, 1 Dec 2022 16:47:44 +0300 (+03) Date: Thu, 1 Dec 2022 16:47:44 +0300 From: "Kirill A. Shutemov" To: Mike Rapoport Cc: "Kirill A. Shutemov" , Borislav Petkov , 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: <20221201134744.7p3lgw6buv4oqwyn@box.shutemov.name> 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: ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1669902477; a=rsa-sha256; cv=none; b=x/tbD8XBF+X4/iP5gHWa4OX0i69nzPRVsuvXm29w/W3mA0lW7r6XAU6rZCW6Nz7fDOho8o pBQOnqvasfo1clU0/3X8HltzpHQ3MYzyh3XEHrMKMaz8/VI/WmHXnu9A/jo/wjx+Vqbp2Y 5drfoLMSnv3GEr+9ho+uByF5Fp3djWE= ARC-Authentication-Results: i=1; imf23.hostedemail.com; dkim=none ("invalid DKIM record") header.d=intel.com header.s=Intel header.b=EnaOgte2; spf=none (imf23.hostedemail.com: domain of kirill.shutemov@linux.intel.com has no SPF policy when checking 192.55.52.120) smtp.mailfrom=kirill.shutemov@linux.intel.com; dmarc=fail reason="No valid SPF" header.from=intel.com (policy=none) ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1669902477; 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=3ir+sbtxZn186MBJE8wHDikI4IfhcWh8wZll3aE66X0=; b=ws5lj0WWBFPsTZ/U/eU1WGbBSie89EbOpeoFVDcsOkzFyvCaZk6wPkNT6VU43AuTyPMVKH XzytBmc6WLpJ0mCJQCReeZd+2yYRzoRQlV1f1kaP6H1AcvMw6dpQyIqZOCHwA0uz71ShNG +WeongXbB/rEHka8Ejo81CrA54fOAmE= X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: DE49414000C X-Rspam-User: Authentication-Results: imf23.hostedemail.com; dkim=none ("invalid DKIM record") header.d=intel.com header.s=Intel header.b=EnaOgte2; spf=none (imf23.hostedemail.com: domain of kirill.shutemov@linux.intel.com has no SPF policy when checking 192.55.52.120) smtp.mailfrom=kirill.shutemov@linux.intel.com; dmarc=fail reason="No valid SPF" header.from=intel.com (policy=none) X-Stat-Signature: q3d6w996k1xgrjuoc3ri97o6gewuyrwn X-HE-Tag: 1669902476-917078 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 Thu, Dec 01, 2022 at 11:37:10AM +0200, Mike Rapoport wrote: > 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? Okay, I will do this: diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index 49b5164a4cba..62068956bb76 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -1316,7 +1316,14 @@ void __init e820__memblock_setup(void) int i; u64 end; - /* Mark unaccepted memory bitmap reserved */ + /* + * Mark unaccepted memory bitmap reserved. + * + * This kind of reservation usually done from early_reserve_memory(), + * but early_reserve_memory() called before e820__memory_setup(), so + * e820_table is not finalized and e820__end_of_ram_pfn() cannot be + * used to get correct RAM size. + */ if (boot_params.unaccepted_memory) { unsigned long size; -- Kiryl Shutsemau / Kirill A. Shutemov