From patchwork Mon Apr 25 03:39:22 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: 12825224 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 42661C433EF for ; Mon, 25 Apr 2022 03:39:45 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id AE1F56B00AA; Sun, 24 Apr 2022 23:39:44 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A92016B00AB; Sun, 24 Apr 2022 23:39:44 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 931F66B00AC; Sun, 24 Apr 2022 23:39:44 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.28]) by kanga.kvack.org (Postfix) with ESMTP id 7F9CE6B00AA for ; Sun, 24 Apr 2022 23:39:44 -0400 (EDT) Received: from smtpin04.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 54901273D0 for ; Mon, 25 Apr 2022 03:39:44 +0000 (UTC) X-FDA: 79393997088.04.D1BB663 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by imf23.hostedemail.com (Postfix) with ESMTP id 17F33140036 for ; Mon, 25 Apr 2022 03:39:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1650857983; x=1682393983; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=YE2m7vjbBEAvaTYRxGOmnaa0fOqIRylP+ci0sDothHE=; b=bFYgahDVWvX3yfkytQagBLHGK1z9edE0OH3skRU3qR7A07tLifiEUBmq 1QKX2GD9a7YMXjx4jGho90bCuiHScA/l1JE+ongXgQVfhq/Ff4UqiEVeD omF7bP6+/bre8EvSgUvvb1tQid8T5ylemLStaHUtGW4gPU6+eI7+rBGCj DtLI1+kkLTC2L0Lw9mgF/Jtb+1sjIhw+QWS8LVXyA8qLcpiNKvmrIKSOS VBxZOI+soOPkeWtqMJ3cEDQUeixvB8pl8HFFqAGLnd9xxAWBmJigRTcYD vFZnjTUrBj0mDdhPaWNmEVhPm9TB+SluNcOTlQGMttUZrmjQXbq9hjZrX Q==; X-IronPort-AV: E=McAfee;i="6400,9594,10327"; a="262727662" X-IronPort-AV: E=Sophos;i="5.90,287,1643702400"; d="scan'208";a="262727662" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Apr 2022 20:39:41 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.90,287,1643702400"; d="scan'208";a="563911364" Received: from black.fi.intel.com ([10.237.72.28]) by fmsmga007.fm.intel.com with ESMTP; 24 Apr 2022 20:39:35 -0700 Received: by black.fi.intel.com (Postfix, from userid 1000) id 7E6D1120; Mon, 25 Apr 2022 06:39:35 +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" Subject: [PATCHv5 00/12] mm, x86/cc: Implement support for unaccepted memory Date: Mon, 25 Apr 2022 06:39:22 +0300 Message-Id: <20220425033934.68551-1-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.35.1 MIME-Version: 1.0 X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 17F33140036 X-Stat-Signature: ad4orfny77bbx7cdnfy661hjpc1zzdfg X-Rspam-User: Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=bFYgahDV; spf=none (imf23.hostedemail.com: domain of kirill.shutemov@linux.intel.com has no SPF policy when checking 192.55.52.93) smtp.mailfrom=kirill.shutemov@linux.intel.com; dmarc=pass (policy=none) header.from=intel.com X-HE-Tag: 1650857978-80356 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. TDX-specific code isolated from the core of unaccepted memory support. It supposed to help to plug-in different implementation of unaccepted memory such as SEV-SNP. The tree can be found here: https://github.com/intel/tdx.git guest-unaccepted-memory v5: - Updates comments and commit messages; + Explain options for unaccepted memory handling; - Expose amount of unaccepted memory in /proc/meminfo - Adjust check in page_expected_state(); - Fix error code handling in allocate_e820(); - Centralize __pa()/__va() definitions in the boot stub; - Avoid includes from the main kernel in the boot stub; - Use an existing hole in boot_param for unaccepted_memory, instead of adding to the end of the structure; - Extract allocate_unaccepted_memory() form allocate_e820(); - Complain if there's unaccepted memory, but kernel does not support it; - Fix vmstat counter; - Split up few preparatory patches; - Random readability adjustments; v4: - PageBuddyUnaccepted() -> PageUnaccepted; - Use separate page_type, not shared with offline; - Rework interface between core-mm and arch code; - Adjust commit messages; - Ack from Mike; Kirill A. Shutemov (12): x86/boot/: Centralize __pa()/__va() definitions mm: Add support for unaccepted memory efi/x86: Get full memory map in allocate_e820() x86/boot: Add infrastructure required for unaccepted memory support 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: Make _tdx_hypercall() and __tdx_module_call() available in boot stub x86/tdx: Unaccepted memory support mm/vmstat: Add counter for memory accepting x86/mm: Report unaccepted memory in /proc/meminfo Documentation/x86/zero-page.rst | 1 + arch/x86/Kconfig | 1 + arch/x86/boot/bitops.h | 40 ++++++++ arch/x86/boot/compressed/Makefile | 1 + arch/x86/boot/compressed/align.h | 14 +++ arch/x86/boot/compressed/bitmap.c | 43 +++++++++ arch/x86/boot/compressed/bitmap.h | 49 ++++++++++ arch/x86/boot/compressed/bits.h | 36 ++++++++ arch/x86/boot/compressed/compiler.h | 9 ++ arch/x86/boot/compressed/find.c | 54 +++++++++++ arch/x86/boot/compressed/find.h | 80 ++++++++++++++++ arch/x86/boot/compressed/ident_map_64.c | 8 -- arch/x86/boot/compressed/kaslr.c | 14 ++- arch/x86/boot/compressed/math.h | 37 ++++++++ arch/x86/boot/compressed/mem.c | 111 +++++++++++++++++++++++ arch/x86/boot/compressed/minmax.h | 61 +++++++++++++ arch/x86/boot/compressed/misc.c | 9 ++ arch/x86/boot/compressed/misc.h | 9 ++ arch/x86/boot/compressed/sev.c | 2 - arch/x86/boot/compressed/tdx.c | 85 +++++++++++++++++ arch/x86/coco/tdx/tdx.c | 57 +++++------- arch/x86/include/asm/page.h | 3 + arch/x86/include/asm/set_memory.h | 2 + arch/x86/include/asm/shared/tdx.h | 47 ++++++++++ arch/x86/include/asm/tdx.h | 19 ---- arch/x86/include/asm/unaccepted_memory.h | 25 +++++ arch/x86/include/uapi/asm/bootparam.h | 2 +- arch/x86/kernel/e820.c | 10 ++ arch/x86/mm/Makefile | 2 + arch/x86/mm/init.c | 8 ++ arch/x86/mm/pat/set_memory.c | 2 +- arch/x86/mm/unaccepted_memory.c | 98 ++++++++++++++++++++ drivers/firmware/efi/Kconfig | 15 +++ drivers/firmware/efi/efi.c | 1 + drivers/firmware/efi/libstub/x86-stub.c | 97 +++++++++++++++++--- include/linux/efi.h | 3 +- include/linux/page-flags.h | 31 +++++++ include/linux/vm_event_item.h | 3 + mm/internal.h | 11 +++ mm/memblock.c | 9 ++ mm/page_alloc.c | 77 +++++++++++++++- mm/vmstat.c | 3 + 42 files changed, 1103 insertions(+), 86 deletions(-) create mode 100644 arch/x86/boot/compressed/align.h create mode 100644 arch/x86/boot/compressed/bitmap.c create mode 100644 arch/x86/boot/compressed/bitmap.h create mode 100644 arch/x86/boot/compressed/bits.h create mode 100644 arch/x86/boot/compressed/compiler.h create mode 100644 arch/x86/boot/compressed/find.c create mode 100644 arch/x86/boot/compressed/find.h create mode 100644 arch/x86/boot/compressed/math.h create mode 100644 arch/x86/boot/compressed/mem.c create mode 100644 arch/x86/boot/compressed/minmax.h create mode 100644 arch/x86/include/asm/unaccepted_memory.h create mode 100644 arch/x86/mm/unaccepted_memory.c