From patchwork Tue May 17 15:34:36 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kirill A. Shutemov" X-Patchwork-Id: 12852703 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 4CA7CC433EF for ; Tue, 17 May 2022 15:35:27 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 404478D0002; Tue, 17 May 2022 11:35:10 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 3B3928D0005; Tue, 17 May 2022 11:35:10 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0F5FB8D0002; Tue, 17 May 2022 11:35:10 -0400 (EDT) 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 E9C7C8D0003 for ; Tue, 17 May 2022 11:35:09 -0400 (EDT) Received: from smtpin09.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id CCDE131B7B for ; Tue, 17 May 2022 15:35:09 +0000 (UTC) X-FDA: 79475633538.09.7FF8AFC Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by imf20.hostedemail.com (Postfix) with ESMTP id 337AD1C0088 for ; Tue, 17 May 2022 15:34:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1652801709; x=1684337709; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=Vt7QSmHfxcGQwi2CPob9vBQysbMDXN+N63yj2aSmEdc=; b=V2xz1cs1yr2d8N9+Dh3u9I2bOLzkxtgkfVGX3sD9wr/6iHU2ISMRTknT K85Qrq7ffRnJYPrFkE5gVyK/j72iR9/JY9nlc4VvcG2+vnUtXgcCySkLf bKF6NluuxXbzAbWCS9VFtBTrnYNi9ZplBM/GSIh/i7ViLTGYjtQ4LU7bf agJEpgQQ8bS6SbpDmIhUYgPYdSTT4QmTkfLb/e9nTPiOMB4a52GdLFLty P/PEuvvTbHOwv3u/a3KN+BRNrLVGss1Z44jKCGxHRxAFz43vfn0HoAhsz XerdpuuiqZnJL60egdHcQ3C+3g+hx4dFBw9KAaJYoDGJHYxu/VjDVM92q w==; X-IronPort-AV: E=McAfee;i="6400,9594,10350"; a="357629672" X-IronPort-AV: E=Sophos;i="5.91,233,1647327600"; d="scan'208";a="357629672" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 May 2022 08:35:06 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.91,233,1647327600"; d="scan'208";a="741831016" Received: from black.fi.intel.com ([10.237.72.28]) by orsmga005.jf.intel.com with ESMTP; 17 May 2022 08:34:58 -0700 Received: by black.fi.intel.com (Postfix, from userid 1000) id 979578F9; Tue, 17 May 2022 18:34:50 +0300 (EEST) From: "Kirill A. Shutemov" To: Borislav Petkov , Andy Lutomirski , Sean Christopherson , Andrew Morton , Joerg Roedel , Ard Biesheuvel Cc: Andi Kleen , Kuppuswamy Sathyanarayanan , David Rientjes , Vlastimil Babka , Tom Lendacky , Thomas Gleixner , Peter Zijlstra , Paolo Bonzini , Ingo Molnar , Varad Gautam , Dario Faggioli , Dave Hansen , Mike Rapoport , 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, "Kirill A. Shutemov" , Mike Rapoport Subject: [PATCHv6 07/15] x86/mm: Reserve unaccepted memory bitmap Date: Tue, 17 May 2022 18:34:36 +0300 Message-Id: <20220517153444.11195-8-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220517153444.11195-1-kirill.shutemov@linux.intel.com> References: <20220517153444.11195-1-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 337AD1C0088 X-Stat-Signature: 4s6swuibowqwjr746w6c1ncc81w15zre X-Rspam-User: Authentication-Results: imf20.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=V2xz1cs1; spf=none (imf20.hostedemail.com: domain of kirill.shutemov@linux.intel.com has no SPF policy when checking 192.55.52.43) smtp.mailfrom=kirill.shutemov@linux.intel.com; dmarc=pass (policy=none) header.from=intel.com X-HE-Tag: 1652801696-952379 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: A given page of memory can only be accepted once. The kernel has to accept memory both in the early decompression stage and during normal runtime. A bitmap is used to communicate the acceptance state of each page between the decompression stage and normal runtime. boot_params is used to communicate location of the bitmap throughout the boot. The bitmap is allocated and initially populated in EFI stub. Decompression stage accepts pages required for kernel/initrd and marks these pages accordingly in the bitmap. The main kernel picks up the bitmap from the same boot_params and uses it to determine what has to be accepted on allocation. In the runtime kernel, reserve the bitmap's memory to ensure nothing overwrites it. The size of bitmap is determined with e820__end_of_ram_pfn() which relies on setup_e820() marking unaccepted memory as E820_TYPE_RAM. Signed-off-by: Kirill A. Shutemov Acked-by: Mike Rapoport --- arch/x86/kernel/e820.c | 10 ++++++++++ 1 file changed, 10 insertions(+) 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); + } + /* * The bootstrap memblock region count maximum is 128 entries * (INIT_MEMBLOCK_REGIONS), but EFI might pass us more E820 entries