From patchwork Fri Oct 27 10:50:42 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Dave Martin X-Patchwork-Id: 831245 Return-Path: X-Original-To: incoming-imx@patchwork.ozlabs.org Delivered-To: patchwork-incoming-imx@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=lists.infradead.org (client-ip=65.50.211.133; helo=bombadil.infradead.org; envelope-from=linux-arm-kernel-bounces+incoming-imx=patchwork.ozlabs.org@lists.infradead.org; receiver=) Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="iZensqUQ"; dkim-atps=neutral Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3yNgqg3HlJz9rxj for ; Fri, 27 Oct 2017 21:59:27 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=4EAM9ygOPuoy4XAb63fNUhgVrXYCiEh/FTcsIqe6GW8=; b=iZensqUQQzLb1/ yVCekq+6xI6nno2srRn1BjW42kFWYN5gnmSPJ/7fVW0hNuo2ACfubDMegPjiok3dCf5cImsUABp2M YcapwCEAMkGITJP82/JBmUy6T2RhUUI0Td6R0qB2KpjQHNm09emHnSi18EmF7xDPyV5fgLRIpW8wu rJf4BaYA7xljux3whSJy9Llq41WpCHRSeBrUzHLE3bHyJvDHJwmxQHhdRnTFB6tmG2xAjTvSF35hm tuSP7Qn1NKF/Ku5wx9J13G7i9dbbLFIH82AdBwa0mJ2ooc5EDdASMCxm7KQiXE1EEsgb+L2p0BqIx CQNGsPfPV3rFa+Rb/7oA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1e82MD-0002Nl-Aj; Fri, 27 Oct 2017 10:59:21 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1e82El-0003rH-S2 for linux-arm-kernel@lists.infradead.org; Fri, 27 Oct 2017 10:51:44 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9A34715AD; Fri, 27 Oct 2017 03:51:19 -0700 (PDT) Received: from e103592.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 98C943F24A; Fri, 27 Oct 2017 03:51:16 -0700 (PDT) From: Dave Martin To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v4 00/28] ARM Scalable Vector Extension (SVE) Date: Fri, 27 Oct 2017 11:50:42 +0100 Message-Id: <1509101470-7881-1-git-send-email-Dave.Martin@arm.com> X-Mailer: git-send-email 2.1.4 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20171027_035139_958230_7BC4E473 X-CRM114-Status: GOOD ( 21.13 ) X-Spam-Score: -6.9 (------) X-Spam-Report: SpamAssassin version 3.4.1 on bombadil.infradead.org summary: Content analysis details: (-6.9 points) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at http://www.dnswl.org/, high trust [217.140.101.70 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record -0.0 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arch@vger.kernel.org, Mark Rutland , Okamoto Takayuki , libc-alpha@sourceware.org, Ard Biesheuvel , Szabolcs Nagy , Catalin Marinas , Will Deacon , Oleg Nesterov , Marc Zyngier , Alexander Viro , Alan Hayward , linux-api@vger.kernel.org, =?utf-8?q?Alex_Benn=C3=A9e?= , kvmarm@lists.cs.columbia.edu, Christoffer Dall , Michael Kerrisk Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+incoming-imx=patchwork.ozlabs.org@lists.infradead.org List-Id: linux-imx-kernel.lists.patchwork.ozlabs.org This series implements Linux kernel support for the ARM Scalable Vector Extension (SVE). [1] It supersedes the previous v3: see [3] for link. See the individual patches for details of changes. The patches apply on git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/core fa3eb71d96f5 ("arm64: asm-bug: Renumber macro local labels to avoid clashes") For reviewer convenience, a git tree is available. [4] To reduce spam, some people may not been copied on the entire series. For those who did not receive the whole series, it can be found in the linux-arm-kernel archive. [2] *Note* The final two patches (27-28) of the series are still RFC and not proposed for merging at present. Before committing to this ABI it would be good to get feedback on whether the approach makes sense and whether it suitable for other architectures. These two patches are not required by the rest of the series and can be revised or merged later. Support for use of SVE by KVM guests is not currently included. Instead, such use will be trapped and reflected to the guest as undefined instruction execution. SVE is hidden from the view of the CPU feature registers visible to guests, so that guests will not expect it to work. This series has been build- and boot-tested on the ARM FVP Base model with and without the SVE plugin, and on ARM Juno r0. Because there is no hardware with SVE support yet, testing of the SVE functionality has only been performed on the model. Additional testing is under way. Series summary: * Patches 1-5 contain some individual bits of preparatory spadework, which are indirectly related to SVE. Dave Martin (5): regset: Add support for dynamically sized regsets arm64: KVM: Hide unsupported AArch64 CPU features from guests arm64: efi: Add missing Kconfig dependency on KERNEL_MODE_NEON arm64: Port deprecated instruction emulation to new sysctl interface arm64: fpsimd: Simplify uses of {set,clear}_ti_thread_flag() Non-trivial changes among these are: * Patch 1: updates the regset core code to handle regsets whose size is not fixed at compile time. This avoids bloating coredumps even though the maximum theoretical SVE regset size is large. * Patch 2: extends KVM to modify the ARM architectural ID registers seen by guests, by trapping and emulating certain registers. For SVE this is a temporary measure, but it may be useful for other architecture extensions. This patch may also be built on in the future, since the only registers currently emulated are those required for hiding SVE. * Patches 6-10 add SVE-specific system register and structure layout definitions, and the low-level boot code and accessors needed for making use of SVE. Dave Martin (5): arm64/sve: System register and exception syndrome definitions arm64/sve: Low-level SVE architectural state manipulation functions arm64/sve: Kconfig update and conditional compilation support arm64/sve: Signal frame and context structure definition arm64/sve: Low-level CPU setup * Patches 11-13 implement the core context management facilities to provide each user task with its own SVE register context, signal handling facilities, and sane programmer's model interoperation between SVE and FPSIMD. Dave Martin (3): arm64/sve: Core task context handling arm64/sve: Support vector length resetting for new processes arm64/sve: Signal handling support * Patches 14 and 16 provide backend logic for detecting and making use of the different SVE vector lengths supported by the hardware. * Patch 15 moves around code in cpufeatures.c to fit. Dave Martin (3): arm64/sve: Backend logic for setting the vector length arm64: cpufeature: Move sys_caps_initialised declarations arm64/sve: Probe SVE capabilities and usable vector lengths * Patches 17-18 update the kernel-mode NEON / EFI FPSIMD frameworks to interoperate correctly with SVE. Dave Martin (2): arm64/sve: Preserve SVE registers around kernel-mode NEON use arm64/sve: Preserve SVE registers around EFI runtime service calls * Patches 19-21 implement the userspace frontend for managing SVE, comprising ptrace, some new arch-specific prctl() calls, and a new sysctl for init-time setup. Dave Martin (3): arm64/sve: ptrace and ELF coredump support arm64/sve: Add prctl controls for userspace vector length management arm64/sve: Add sysctl to set the default vector length for new processes * Patches 22-24 provide stub KVM extensions for using KVM only on the host, while denying guest access. (A future series will extend this with full support for SVE in guests.) Dave Martin (3): arm64/sve: KVM: Prevent guests from using SVE arm64/sve: KVM: Treat guest SVE use as undefined instruction execution arm64/sve: KVM: Hide SVE from CPU features exposed to guests And finally: * Patch 25 disengages the safety catch, enabling the kernel SVE runtime support and allowing userspace to use SVE. Dave Martin (1): arm64/sve: Detect SVE and activate runtime support * Patch 26 adds some basic documentation. Dave Martin (1): arm64/sve: Add documentation * Patches 27-28 (which may be considered RFC) propose a mechanism to report the maximum runtime signal frame size to userspace. Dave Martin (2): arm64: signal: Report signal frame size to userspace via auxv arm64/sve: signal: Include SVE when computing AT_MINSIGSTKSZ References: [1] ARM Scalable Vector Extension https://community.arm.com/groups/processors/blog/2016/08/22/technology-update-the-scalable-vector-extension-sve-for-the-armv8-a-architecture [2] linux-arm-kernel October 2017 Archives by thread http://lists.infradead.org/pipermail/linux-arm-kernel/2017-October/thread.html [3] [PATCH v3 00/28] ARM Scalable Vector Extension (SVE) http://lists.infradead.org/pipermail/linux-arm-kernel/2017-October/535717.html [4] For review and testing only -- **do not pull** (This branch has review changelogs which should not form part of the final commits.) http://linux-arm.org/git?p=linux-dm.git;a=shortlog;h=refs/heads/sve/v4 git://linux-arm.org/linux-dm.git sve/v4 Full series and diffstat: Dave Martin (28): regset: Add support for dynamically sized regsets arm64: KVM: Hide unsupported AArch64 CPU features from guests arm64: efi: Add missing Kconfig dependency on KERNEL_MODE_NEON arm64: Port deprecated instruction emulation to new sysctl interface arm64: fpsimd: Simplify uses of {set,clear}_ti_thread_flag() arm64/sve: System register and exception syndrome definitions arm64/sve: Low-level SVE architectural state manipulation functions arm64/sve: Kconfig update and conditional compilation support arm64/sve: Signal frame and context structure definition arm64/sve: Low-level CPU setup arm64/sve: Core task context handling arm64/sve: Support vector length resetting for new processes arm64/sve: Signal handling support arm64/sve: Backend logic for setting the vector length arm64: cpufeature: Move sys_caps_initialised declarations arm64/sve: Probe SVE capabilities and usable vector lengths arm64/sve: Preserve SVE registers around kernel-mode NEON use arm64/sve: Preserve SVE registers around EFI runtime service calls arm64/sve: ptrace and ELF coredump support arm64/sve: Add prctl controls for userspace vector length management arm64/sve: Add sysctl to set the default vector length for new processes arm64/sve: KVM: Prevent guests from using SVE arm64/sve: KVM: Treat guest SVE use as undefined instruction execution arm64/sve: KVM: Hide SVE from CPU features exposed to guests arm64/sve: Detect SVE and activate runtime support arm64/sve: Add documentation arm64: signal: Report signal frame size to userspace via auxv arm64/sve: signal: Include SVE when computing AT_MINSIGSTKSZ Documentation/arm64/cpu-feature-registers.txt | 6 +- Documentation/arm64/elf_hwcaps.txt | 4 + Documentation/arm64/sve.txt | 508 +++++++++++++++ arch/arm/include/asm/kvm_host.h | 3 + arch/arm64/Kconfig | 12 + arch/arm64/include/asm/cpu.h | 4 + arch/arm64/include/asm/cpucaps.h | 3 +- arch/arm64/include/asm/cpufeature.h | 42 ++ arch/arm64/include/asm/elf.h | 5 + arch/arm64/include/asm/esr.h | 3 +- arch/arm64/include/asm/fpsimd.h | 71 +- arch/arm64/include/asm/fpsimdmacros.h | 148 +++++ arch/arm64/include/asm/kvm_arm.h | 5 +- arch/arm64/include/asm/kvm_host.h | 11 + arch/arm64/include/asm/processor.h | 10 + arch/arm64/include/asm/sysreg.h | 24 + arch/arm64/include/asm/thread_info.h | 5 + arch/arm64/include/asm/traps.h | 2 + arch/arm64/include/uapi/asm/auxvec.h | 3 +- arch/arm64/include/uapi/asm/hwcap.h | 1 + arch/arm64/include/uapi/asm/ptrace.h | 138 ++++ arch/arm64/include/uapi/asm/sigcontext.h | 120 +++- arch/arm64/kernel/armv8_deprecated.c | 15 +- arch/arm64/kernel/cpufeature.c | 99 ++- arch/arm64/kernel/cpuinfo.c | 7 + arch/arm64/kernel/entry-fpsimd.S | 17 + arch/arm64/kernel/entry.S | 40 +- arch/arm64/kernel/fpsimd.c | 902 +++++++++++++++++++++++++- arch/arm64/kernel/head.S | 13 +- arch/arm64/kernel/process.c | 24 + arch/arm64/kernel/ptrace.c | 280 +++++++- arch/arm64/kernel/signal.c | 216 +++++- arch/arm64/kernel/signal32.c | 2 +- arch/arm64/kernel/traps.c | 7 +- arch/arm64/kvm/handle_exit.c | 8 + arch/arm64/kvm/hyp/switch.c | 12 +- arch/arm64/kvm/sys_regs.c | 292 +++++++-- fs/binfmt_elf.c | 6 +- include/linux/regset.h | 67 +- include/uapi/linux/elf.h | 1 + include/uapi/linux/prctl.h | 9 + kernel/sys.c | 12 + virt/kvm/arm/arm.c | 3 + 43 files changed, 3014 insertions(+), 146 deletions(-) create mode 100644 Documentation/arm64/sve.txt Reviewed-by: Catalin Marinas Reviewed-by: Alex Bennée