From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6310733C2 for ; Tue, 5 Apr 2022 23:48:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1649202529; x=1680738529; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=/1nyzn7F+fmd6VP9tbO0wCXT9G8b1V0YmZnfceU20K8=; b=h25z0TFijo+4JF25FBPbtbcNki0j9n6BMT63r/GmHzTQjbPF9dcLRz8K QaMZ2QEOnAbRp6PGMXlZjkR1BoqZNQF7kU8tGS3PtyrEe0vlyg1DEVZs2 S4QxZNmCulyK85AlA8yKEWg4xKeQr3KpA633MdWy7h67jWvTby683/+bf dEVay/0XQOzRxTX8hRJnCDbUpHl0Q+LQGZqwlIIR36dxQoiUt42N4ddri 7vFBqdk/AZ9u23gY2BSFzNbBOT1J8JYkGARJb4n7drl2Br3VmkjFKslWl 1xZL8TYhTW07WRCjkMTpxjI5lM+lR/6feRx0FzmEkCVox5Ku3NqTbYZ2N w==; X-IronPort-AV: E=McAfee;i="6200,9189,10308"; a="240827987" X-IronPort-AV: E=Sophos;i="5.90,238,1643702400"; d="scan'208";a="240827987" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Apr 2022 16:48:48 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.90,238,1643702400"; d="scan'208";a="588141278" Received: from black.fi.intel.com ([10.237.72.28]) by orsmga001.jf.intel.com with ESMTP; 05 Apr 2022 16:48:41 -0700 Received: by black.fi.intel.com (Postfix, from userid 1000) id C1FE05AA; Wed, 6 Apr 2022 02:43:47 +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 , Brijesh Singh , Mike Rapoport , David Hildenbrand , 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: [PATCHv4 5/8] x86/mm: Reserve unaccepted memory bitmap Date: Wed, 6 Apr 2022 02:43:40 +0300 Message-Id: <20220405234343.74045-6-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220405234343.74045-1-kirill.shutemov@linux.intel.com> References: <20220405234343.74045-1-kirill.shutemov@linux.intel.com> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit A given page of memory can only be accepted once. The kernel has a need to accept memory both in the early decompression stage and during normal runtime. A bitmap used to communicate the acceptance state of each page between the decompression stage and normal runtime. This eliminates the possibility of attempting to double-accept a page. The bitmap is allocated in EFI stub, decompression stage updates the state of pages used for the kernel and initrd and hands the bitmap over to the main kernel image via boot_params. In the runtime kernel, reserve the bitmap's memory to ensure nothing overwrites it. 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 -- 2.35.1