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=-12.0 required=3.0 tests=BAYES_00,INCLUDES_PATCH, MAILING_LIST_MULTI,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 E6808C433DB for ; Mon, 1 Feb 2021 11:56:54 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 4903D64EA4 for ; Mon, 1 Feb 2021 11:56:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4903D64EA4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id D67314B3E7; Mon, 1 Feb 2021 06:56:53 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id xTnSxfkqRfo4; Mon, 1 Feb 2021 06:56:52 -0500 (EST) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id D67E24B259; Mon, 1 Feb 2021 06:56:50 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 5ED374B20F for ; Mon, 1 Feb 2021 06:56:49 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 1r7kHja3T6bl for ; Mon, 1 Feb 2021 06:56:47 -0500 (EST) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id B646F4B1E4 for ; Mon, 1 Feb 2021 06:56:47 -0500 (EST) Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4C8F064DCC; Mon, 1 Feb 2021 11:56:46 +0000 (UTC) Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94) (envelope-from ) id 1l6Xoy-00BG09-28; Mon, 01 Feb 2021 11:56:44 +0000 From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org Subject: [PATCH v6 00/21] arm64: Early CPU feature override, and applications to VHE, BTI and PAuth Date: Mon, 1 Feb 2021 11:56:16 +0000 Message-Id: <20210201115637.3123740-1-maz@kernel.org> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, catalin.marinas@arm.com, will@kernel.org, mark.rutland@arm.com, dbrazdil@google.com, alexandru.elisei@arm.com, ardb@kernel.org, jingzhangos@google.com, pajay@qti.qualcomm.com, psodagud@codeaurora.org, sramana@codeaurora.org, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com, kernel-team@android.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Cc: Prasad Sodagudi , Srinivas Ramana , Catalin Marinas , Ajay Patil , kernel-team@android.com, Will Deacon , Ard Biesheuvel X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu It recently came to light that there is a need to be able to override some CPU features very early on, before the kernel is fully up and running. The reasons for this range from specific feature support (such as using Protected KVM on VHE HW, which is the main motivation for this work) to errata workaround (a feature is broken on a CPU and needs to be turned off, or rather not enabled). This series tries to offer a limited framework for this kind of problems, by allowing a set of options to be passed on the command-line and altering the feature set that the cpufeature subsystem exposes to the rest of the kernel. Note that this doesn't change anything for code that directly uses the CPU ID registers. The series completely changes the way a VHE-capable system boots, by *always* booting non-VHE first, and then upgrading to VHE when deemed capable. Although it sounds scary, this is actually simple to implement (and I wish I had done that five years ago). The "upgrade to VHE" path is then conditioned on the VHE feature not being disabled from the command-line. Said command-line parsing borrows a lot from the kaslr code, and subsequently allows the "nokaslr" option to be moved to the new infrastructure (though it all looks a bit... odd). Further patches now add support for disabling BTI and PAuth, the latter being based on an initial series by Srinivas Ramana[0]. There is some ongoing discussions about being able to disable MTE, but no clear resolution on that subject yet. This has been tested on multiple VHE and non-VHE systems. * From v5 [5]: - Turn most __initdata into __initconst - Ensure that all strings are part of the __initconst section. This is a bit ugly, but saves memory once up and running - Make overrides __ro_after_init - Change the command-line parsing so that the same feature can be overridden multiple times, with the expected left-to-right parsing order being respected - Handle all space-like characters as option delimiters - Collected Acks, RBs and TBs * From v4 [4]: - Documentation fixes - Moved the val/mask pair into a arm64_ftr_override structure, leading to simpler code - All arm64_ftr_reg now have a default override, which simplifies the code a bit further - Dropped some of the "const" attributes - Renamed init_shadow_regs() to init_feature_override() - Renamed struct reg_desc to struct ftr_set_desc - Refactored command-line parsing - Simplified handling of VHE being disabled on the cmdline - Turn EL1 S1 MMU off on switch to VHE - HVC_VHE_RESTART now returns an error code on failure - Added missing asmlinkage and dummy prototypes - Collected Acks and RBs from David, Catalin and Suzuki * From v3 [3]: - Fixed the VHE_RESTART stub (duh!) - Switched to using arm64_ftr_safe_value() instead of the user provided value - Per-feature override warning * From v2 [2]: - Simplify the VHE_RESTART stub - Fixed a number of spelling mistakes, and hopefully introduced a few more - Override features in __read_sysreg_by_encoding() - Allow both BTI and PAuth to be overridden on the command line - Rebased on -rc3 * From v1 [1]: - Fix SPE init on VHE when EL2 doesn't own SPE - Fix re-init when KASLR is used - Handle the resume path - Rebased to 5.11-rc2 [0] https://lore.kernel.org/r/1610152163-16554-1-git-send-email-sramana@codeaurora.org [1] https://lore.kernel.org/r/20201228104958.1848833-1-maz@kernel.org [2] https://lore.kernel.org/r/20210104135011.2063104-1-maz@kernel.org [3] https://lore.kernel.org/r/20210111132811.2455113-1-maz@kernel.org [4] https://lore.kernel.org/r/20210118094533.2874082-1-maz@kernel.org [5] https://lore.kernel.org/r/20210125105019.2946057-1-maz@kernel.org Marc Zyngier (20): arm64: Fix labels in el2_setup macros arm64: Fix outdated TCR setup comment arm64: Turn the MMU-on sequence into a macro arm64: Provide an 'upgrade to VHE' stub hypercall arm64: Initialise as nVHE before switching to VHE arm64: Move VHE-specific SPE setup to mutate_to_vhe() arm64: Simplify init_el2_state to be non-VHE only arm64: Move SCTLR_EL1 initialisation to EL-agnostic code arm64: cpufeature: Add global feature override facility arm64: cpufeature: Use IDreg override in __read_sysreg_by_encoding() arm64: Extract early FDT mapping from kaslr_early_init() arm64: cpufeature: Add an early command-line cpufeature override facility arm64: Allow ID_AA64MMFR1_EL1.VH to be overridden from the command line arm64: Honor VHE being disabled from the command-line arm64: Add an aliasing facility for the idreg override arm64: Make kvm-arm.mode={nvhe, protected} an alias of id_aa64mmfr1.vh=0 KVM: arm64: Document HVC_VHE_RESTART stub hypercall arm64: Move "nokaslr" over to the early cpufeature infrastructure arm64: cpufeatures: Allow disabling of BTI from the command-line arm64: cpufeatures: Allow disabling of Pointer Auth from the command-line Srinivas Ramana (1): arm64: Defer enabling pointer authentication on boot core .../admin-guide/kernel-parameters.txt | 9 + Documentation/virt/kvm/arm/hyp-abi.rst | 9 + arch/arm64/include/asm/assembler.h | 17 ++ arch/arm64/include/asm/cpufeature.h | 11 + arch/arm64/include/asm/el2_setup.h | 60 ++--- arch/arm64/include/asm/pointer_auth.h | 10 + arch/arm64/include/asm/setup.h | 11 + arch/arm64/include/asm/stackprotector.h | 1 + arch/arm64/include/asm/virt.h | 7 +- arch/arm64/kernel/Makefile | 2 +- arch/arm64/kernel/asm-offsets.c | 3 + arch/arm64/kernel/cpufeature.c | 73 +++++- arch/arm64/kernel/head.S | 75 +----- arch/arm64/kernel/hyp-stub.S | 133 +++++++++- arch/arm64/kernel/idreg-override.c | 230 ++++++++++++++++++ arch/arm64/kernel/kaslr.c | 43 +--- arch/arm64/kernel/setup.c | 15 ++ arch/arm64/kernel/sleep.S | 1 + arch/arm64/kvm/arm.c | 3 + arch/arm64/kvm/hyp/nvhe/hyp-init.S | 2 +- arch/arm64/mm/mmu.c | 2 +- arch/arm64/mm/proc.S | 16 +- 22 files changed, 563 insertions(+), 170 deletions(-) create mode 100644 arch/arm64/include/asm/setup.h create mode 100644 arch/arm64/kernel/idreg-override.c -- 2.29.2 _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm