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 8DD29C43217 for ; Fri, 28 Jan 2022 20:59:09 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A24946B00F6; Fri, 28 Jan 2022 15:59:06 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 9D2686B00F7; Fri, 28 Jan 2022 15:59:06 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 873BC6B00FA; Fri, 28 Jan 2022 15:59:06 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0140.hostedemail.com [216.40.44.140]) by kanga.kvack.org (Postfix) with ESMTP id 779A16B00F7 for ; Fri, 28 Jan 2022 15:59:06 -0500 (EST) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 27F19181D75CA for ; Fri, 28 Jan 2022 20:59:06 +0000 (UTC) X-FDA: 79080910692.27.4581AD3 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by imf13.hostedemail.com (Postfix) with ESMTP id 0E95A2003E for ; Fri, 28 Jan 2022 20:59:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1643403545; x=1674939545; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=yBU3sLS+Lgz2kPgXMhsfbKdvUBXEv9uGAAkeVU4p2WI=; b=XFM+newj4UBzbnXeHIuMwmBZb9v55IGgGMesFRW98pIWGyk2Yf+0LSV6 y5/YJpME4iaqheZRZf7bg70JmHOfnWYgMo+9RBeEInsb3/LSAp1oh48V/ VY7rBoIyxg6YmgJfnDbk8xAV0TEU15Nhqstm7pe15Na4ZJGOjh2OK41o9 vxR8o7DqjGr1/kL4MR+BqoXKY8QD3ZVzwgzcqWM3Pwo7q/KQGofV7Zy16 j0PFwBPgVPbgRJYGIgiZ/cCrK3YBd0MPbxuXl/GK0HQdHUq33Sr4K2gDh kMr+YDy5sDegYWh2aVND86G/Ttvnml59holXqdGyQwCM8+OY+y3Th4qen Q==; X-IronPort-AV: E=McAfee;i="6200,9189,10241"; a="271658784" X-IronPort-AV: E=Sophos;i="5.88,324,1635231600"; d="scan'208";a="271658784" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Jan 2022 12:59:02 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.88,324,1635231600"; d="scan'208";a="564315491" Received: from black.fi.intel.com ([10.237.72.28]) by orsmga001.jf.intel.com with ESMTP; 28 Jan 2022 12:58:55 -0800 Received: by black.fi.intel.com (Postfix, from userid 1000) id 7CDD594; Fri, 28 Jan 2022 22:59:09 +0200 (EET) 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" Subject: [PATCHv3 0/7] Implement support for unaccepted memory Date: Fri, 28 Jan 2022 23:58:59 +0300 Message-Id: <20220128205906.27503-1-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 X-Rspam-User: nil X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 0E95A2003E X-Stat-Signature: ejj4k59rbcyx5k1dcyrdwbpdhcswfbh8 Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=XFM+newj; dmarc=pass (policy=none) header.from=intel.com; spf=none (imf13.hostedemail.com: domain of kirill.shutemov@linux.intel.com has no SPF policy when checking 192.55.52.88) smtp.mailfrom=kirill.shutemov@linux.intel.com X-HE-Tag: 1643403544-390710 Content-Transfer-Encoding: quoted-printable 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: UEFI Specification version 2.9 introduces the concept of memory acceptance: Some Virtual Machine platforms, such as Intel TDX or AMD SEV-SNP, requiring memory to be accepted before it can be used by the guest. Accepting happens via a protocol specific for the Virtual Machine platform. Accepting memory is costly and it makes VMM allocate memory for the accepted guest physical address range. It's better to postpone memory acceptance until memory is needed. It lowers boot time and reduces memory overhead. The kernel needs to know what memory has been accepted. Firmware communicates this information via memory map: a new memory type -- EFI_UNACCEPTED_MEMORY -- indicates such memory. Range-based tracking works fine for firmware, but it gets bulky for the kernel: e820 has to be modified on every page acceptance. It leads to table fragmentation, but there's a limited number of entries in the e820 table Another option is to mark such memory as usable in e820 and track if the range has been accepted in a bitmap. One bit in the bitmap represents 2MiB in the address space: one 4k page is enough to track 64GiB or physical address space. In the worst-case scenario -- a huge hole in the middle of the address space -- It needs 256MiB to handle 4PiB of the address space. Any unaccepted memory that is not aligned to 2M gets accepted upfront. The approach lowers boot time substantially. Boot to shell is ~2.5x faster for 4G TDX VM and ~4x faster for 64G. Patches 1-6/7 are generic and don't have any dependencies on TDX. They should serve AMD SEV needs as well. TDX-specific code isolated in the last patch. This patch requires the core TDX patchset which is currently under review. Kirill A. Shutemov (7): mm: Add support for unaccepted memory efi/x86: Get full memory map in allocate_e820() efi/x86: Implement support for unaccepted memory x86/boot/compressed: Handle unaccepted memory x86/mm: Reserve unaccepted memory bitmap x86/mm: Provide helpers for unaccepted memory x86/tdx: Unaccepted memory support Documentation/x86/zero-page.rst | 1 + arch/x86/Kconfig | 1 + arch/x86/boot/compressed/Makefile | 1 + arch/x86/boot/compressed/bitmap.c | 86 ++++++++++++++++++ arch/x86/boot/compressed/kaslr.c | 14 ++- arch/x86/boot/compressed/misc.c | 11 +++ arch/x86/boot/compressed/tdx.c | 27 ++++++ arch/x86/boot/compressed/unaccepted_memory.c | 75 ++++++++++++++++ arch/x86/include/asm/page.h | 5 ++ arch/x86/include/asm/shared/tdx.h | 21 +++++ arch/x86/include/asm/tdx.h | 19 ---- arch/x86/include/asm/unaccepted_memory.h | 17 ++++ arch/x86/include/uapi/asm/bootparam.h | 3 +- arch/x86/kernel/e820.c | 10 +++ arch/x86/kernel/tdx.c | 6 ++ arch/x86/mm/Makefile | 2 + arch/x86/mm/unaccepted_memory.c | 94 ++++++++++++++++++++ drivers/firmware/efi/Kconfig | 15 ++++ drivers/firmware/efi/efi.c | 1 + drivers/firmware/efi/libstub/x86-stub.c | 88 ++++++++++++++---- include/linux/efi.h | 3 +- include/linux/page-flags.h | 27 ++++++ mm/internal.h | 15 ++++ mm/memblock.c | 8 ++ mm/page_alloc.c | 23 ++++- 25 files changed, 534 insertions(+), 39 deletions(-) create mode 100644 arch/x86/boot/compressed/bitmap.c create mode 100644 arch/x86/boot/compressed/unaccepted_memory.c create mode 100644 arch/x86/include/asm/unaccepted_memory.h create mode 100644 arch/x86/mm/unaccepted_memory.c --=20 2.34.1