From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) (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 CA88011CA1 for ; Sun, 7 May 2023 23:46:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1683503204; x=1715039204; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=XL6vN5u+KeCOGSvPKGIDg51xwwNZ7oq3J9d7SYKdrYE=; b=ZFSMtuNADWHD0HG6Qtep1d49dwkpGsDRTrWc0RDinGLyg8Z914BsWQIn uSIfezZJM6eOcfoO1G7CfeL3l7rfbJsIsAG+D+0sYLFInZZlrOFESXZcE WDtxSblFWy/derVQBTs0yztkPzet/OjAXa31nuwqy+M6SbJdQyEN5g9l4 lxR+OttDQ/095Rc+o8iI4PcihE+cIa2MrbvzkWx0u2bJrLIKZB/G4MCuH XTFRQoMvzCSI+2Ospa1zRBBduqx/6dgD3HdQrKeItMQhNd4Xim2tsARQc uuzX1U/iMYP+9n57n2aLE3PbMxNkwHYveZjH2grvhEtCW20O/zFqdVrSv Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10703"; a="349550285" X-IronPort-AV: E=Sophos;i="5.99,258,1677571200"; d="scan'208";a="349550285" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 May 2023 16:46:39 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10703"; a="701222810" X-IronPort-AV: E=Sophos;i="5.99,258,1677571200"; d="scan'208";a="701222810" Received: from dancaspi-mobl1.ger.corp.intel.com (HELO box.shutemov.name) ([10.252.61.73]) by fmsmga007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 May 2023 16:46:32 -0700 Received: by box.shutemov.name (Postfix, from userid 1000) id 47A4610D334; Mon, 8 May 2023 02:46:20 +0300 (+03) From: "Kirill A. Shutemov" To: Borislav Petkov , Andy Lutomirski , Dave Hansen , 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 , Dario Faggioli , Mike Rapoport , David Hildenbrand , Mel Gorman , marcelo.cerri@canonical.com, tim.gardner@canonical.com, khalid.elmously@canonical.com, philip.cox@canonical.com, aarcange@redhat.com, peterx@redhat.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: [PATCHv10 06/11] x86/mm: Reserve unaccepted memory bitmap Date: Mon, 8 May 2023 02:46:13 +0300 Message-Id: <20230507234618.18067-7-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20230507234618.18067-1-kirill.shutemov@linux.intel.com> References: <20230507234618.18067-1-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 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 | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index fb8cf953380d..483c36a28d2e 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -1316,6 +1316,23 @@ void __init e820__memblock_setup(void) int i; u64 end; + /* + * 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; + + /* 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 -- 2.39.3