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 X-Spam-Level: X-Spam-Status: No, score=-11.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3EA70C433E7 for ; Fri, 9 Oct 2020 19:43:11 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id DDC0122282 for ; Fri, 9 Oct 2020 19:43:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DDC0122282 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 0E96E6B0062; Fri, 9 Oct 2020 15:43:09 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 06CCD6B0068; Fri, 9 Oct 2020 15:43:08 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E24816B006C; Fri, 9 Oct 2020 15:43:08 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0168.hostedemail.com [216.40.44.168]) by kanga.kvack.org (Postfix) with ESMTP id AA0426B0062 for ; Fri, 9 Oct 2020 15:43:08 -0400 (EDT) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 3F7E01EE6 for ; Fri, 9 Oct 2020 19:43:08 +0000 (UTC) X-FDA: 77353410456.17.land00_6009e8b271e3 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin17.hostedemail.com (Postfix) with ESMTP id 20777180D0181 for ; Fri, 9 Oct 2020 19:43:08 +0000 (UTC) X-HE-Tag: land00_6009e8b271e3 X-Filterd-Recvd-Size: 7570 Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by imf13.hostedemail.com (Postfix) with ESMTP for ; Fri, 9 Oct 2020 19:43:06 +0000 (UTC) IronPort-SDR: obZq796WNCOmb2hoFujojGQ+IdwNBtvojbyQlvlBOWObxMouvg3pyMbWZTj8suNa/UahRIWV+7 U1kTJWa8igHg== X-IronPort-AV: E=McAfee;i="6000,8403,9769"; a="165591336" X-IronPort-AV: E=Sophos;i="5.77,355,1596524400"; d="scan'208";a="165591336" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Oct 2020 12:43:04 -0700 IronPort-SDR: rMdjjxowOVNBlu7aeC3rxeSAfOjMt26FkSg07m7V85+JIoYQHT8XGRHWJYiXG8+tNUyd0OV/IV R48BN9FuohTw== X-IronPort-AV: E=Sophos;i="5.77,355,1596524400"; d="scan'208";a="462299345" Received: from iweiny-desk2.sc.intel.com (HELO localhost) ([10.3.52.147]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Oct 2020 12:43:03 -0700 From: ira.weiny@intel.com To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Andy Lutomirski , Peter Zijlstra Cc: Ira Weiny , x86@kernel.org, Dave Hansen , Dan Williams , Andrew Morton , Fenghua Yu , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org Subject: [PATCH RFC V3 0/9] PKS: Add Protection Keys Supervisor (PKS) support RFC v3 Date: Fri, 9 Oct 2020 12:42:49 -0700 Message-Id: <20201009194258.3207172-1-ira.weiny@intel.com> X-Mailer: git-send-email 2.28.0.rc0.12.gb6a658bd00c9 MIME-Version: 1.0 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: From: Ira Weiny This RFC series has been reviewed by Dave Hansen. Introduce a new page protection mechanism for supervisor pages, Protectio= n Key Supervisor (PKS). 2 use cases for PKS are being developed, trusted keys and PMEM. Trusted = keys is a newer use case which is still being explored. PMEM was submitted as= part of the RFC (v2) series[1]. However, since then it was found that some ca= llers of kmap() require a global implementation of PKS. Specifically some user= s of kmap() expect mappings to be available to all kernel threads. While glob= al use of PKS is rare it needs to be included for correctness. Unfortunately th= e kmap() updates required a large patch series to make the needed changes a= t the various kmap() call sites so that patch set has been split out. Because = the global PKS feature is only required for that use case it will be deferred= to that set as well.[2] This patch set is being submitted as a precursor to= both of the use cases. For an overview of the entire PKS ecosystem, a git tree including this se= ries and the 2 use cases can be found here: https://github.com/weiny2/linux-kernel/tree/pks-rfc-v3 PKS enables protections on 'domains' of supervisor pages to limit supervi= sor mode access to those pages beyond the normal paging protections. PKS wor= ks in a similar fashion to user space pkeys, PKU. As with PKU, supervisor pkey= s are checked in addition to normal paging protections and Access or Writes can= be disabled via a MSR update without TLB flushes when permissions change. A= lso like PKU, a page mapping is assigned to a domain by setting pkey bits in = the page table entry for that mapping. Access is controlled through a PKRS register which is updated via WRMSR/R= DMSR. XSAVE is not supported for the PKRS MSR. Therefore the implementation saves/restores the MSR across context switches and during exceptions. Ne= sted exceptions are supported by each exception getting a new PKS state. For consistent behavior with current paging protections, pkey 0 is reserv= ed and configured to allow full access via the pkey mechanism, thus preserving t= he default paging protections on mappings with the default pkey value of 0. Other keys, (1-15) are allocated by an allocator which prepares us for ke= y contention from day one. Kernel users should be prepared for the allocat= or to fail either because of key exhaustion or due to PKS not being supported o= n the arch and/or CPU instance. The following are key attributes of PKS. 1) Fast switching of permissions 1a) Prevents access without page table manipulations 1b) No TLB flushes required 2) Works on a per thread basis PKS is available with 4 and 5 level paging. Like PKRU it consumes 4 bits= from the PTE to store the pkey within the entry. [1] https://lore.kernel.org/lkml/20200717072056.73134-1-ira.weiny@intel.c= om/ [2] https://github.com/weiny2/linux-kernel/commit/f10abb0f0d7b4e14f03fc88= 90313a5830cde1e49 and a testing patch https://github.com/weiny2/linux-kernel/commit/2a8e0fc7654a7c69b243d62= 8f63b01ff26a5a797 Fenghua Yu (3): x86/fpu: Refactor arch_set_user_pkey_access() for PKS support x86/pks: Enable Protection Keys Supervisor (PKS) x86/pks: Add PKS kernel API Ira Weiny (6): x86/pkeys: Create pkeys_common.h x86/pks: Preserve the PKRS MSR on context switch x86/entry: Pass irqentry_state_t by reference x86/entry: Preserve PKRS MSR across exceptions x86/fault: Report the PKRS state on fault x86/pks: Add PKS test code Documentation/core-api/protection-keys.rst | 102 ++- arch/x86/Kconfig | 1 + arch/x86/entry/common.c | 57 +- arch/x86/include/asm/cpufeatures.h | 1 + arch/x86/include/asm/idtentry.h | 29 +- arch/x86/include/asm/msr-index.h | 1 + arch/x86/include/asm/pgtable.h | 13 +- arch/x86/include/asm/pgtable_types.h | 12 + arch/x86/include/asm/pkeys.h | 15 + arch/x86/include/asm/pkeys_common.h | 36 + arch/x86/include/asm/processor.h | 13 + arch/x86/include/uapi/asm/processor-flags.h | 2 + arch/x86/kernel/cpu/common.c | 17 + arch/x86/kernel/cpu/mce/core.c | 4 + arch/x86/kernel/fpu/xstate.c | 22 +- arch/x86/kernel/kvm.c | 4 +- arch/x86/kernel/nmi.c | 7 +- arch/x86/kernel/process.c | 21 + arch/x86/kernel/traps.c | 21 +- arch/x86/mm/fault.c | 86 ++- arch/x86/mm/pkeys.c | 188 +++++- include/linux/entry-common.h | 19 +- include/linux/pgtable.h | 4 + include/linux/pkeys.h | 23 +- kernel/entry/common.c | 28 +- lib/Kconfig.debug | 12 + lib/Makefile | 3 + lib/pks/Makefile | 3 + lib/pks/pks_test.c | 690 ++++++++++++++++++++ mm/Kconfig | 2 + tools/testing/selftests/x86/Makefile | 3 +- tools/testing/selftests/x86/test_pks.c | 65 ++ 32 files changed, 1376 insertions(+), 128 deletions(-) create mode 100644 arch/x86/include/asm/pkeys_common.h create mode 100644 lib/pks/Makefile create mode 100644 lib/pks/pks_test.c create mode 100644 tools/testing/selftests/x86/test_pks.c --=20 2.28.0.rc0.12.gb6a658bd00c9