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=-7.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=no 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 E6059C388F9 for ; Tue, 27 Oct 2020 21:51:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A2CED22249 for ; Tue, 27 Oct 2020 21:51:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603835485; bh=O5D4goy0vhumRnvIluG5lcRDisgHq+OWV12M5HePYx4=; h=From:To:Cc:Subject:Date:List-ID:From; b=yhpSigGFBC0H3u8xlhkZ+e4FZVDWwuhoLBXGr9U5uI1qHNfwggvf39R5BT6HchfAY H+fPhKq8SucMCPkLpHIAQWPG7Vci+V6CZInxqGRJw3K40LjQhm9j537XcJs7bSD3ad zw455R5oQySrXYuqgTery9u7TBE4g2mXPFbmM0vQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2506025AbgJ0VvZ (ORCPT ); Tue, 27 Oct 2020 17:51:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:42980 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2505991AbgJ0VvY (ORCPT ); Tue, 27 Oct 2020 17:51:24 -0400 Received: from localhost.localdomain (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 500D4207E8; Tue, 27 Oct 2020 21:51:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603835484; bh=O5D4goy0vhumRnvIluG5lcRDisgHq+OWV12M5HePYx4=; h=From:To:Cc:Subject:Date:From; b=Gso25ailQocviYmbXrC14bnc56r2ElzaO1xHi3uSlPtTpocOBtrqkLfZ/VSQFGRXs fuVK0S8kL5jsKNwOOtNKEaqv12tqcxg74fpbTPGkHlQ/7Uxg8BAtrtPd7rIXuqiM/z KHulAmPCNlwCX3BgBjgi9UmtLPaU+nhMj7CeNry0= From: Will Deacon To: linux-arm-kernel@lists.infradead.org Cc: linux-arch@vger.kernel.org, Will Deacon , Catalin Marinas , Marc Zyngier , Greg Kroah-Hartman , Peter Zijlstra , Morten Rasmussen , Qais Yousef , Suren Baghdasaryan , kernel-team@android.com Subject: [PATCH 0/6] An alternative series for asymmetric AArch32 systems Date: Tue, 27 Oct 2020 21:51:12 +0000 Message-Id: <20201027215118.27003-1-will@kernel.org> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org Hi all, I was playing around with the asymmetric AArch32 RFCv2 from Qais: https://lore.kernel.org/r/20201021104611.2744565-1-qais.yousef@arm.com and ended up writing my own implementation this afternoon. I think it's smaller, simpler and easier to work with. In particular: * I got rid of the sysctl in favour of a plain cmdline parameter * I don't have a new CPU capability * I don't have a new thread flag * I expose a cpumask to userspace via sysfs to identify the 32-bit CPUs Anyway, I don't think we should merge this stuff (other than the first patch) until we've figured out what's going on in Android, but I wanted to get this out as something which we might be able to build on. Cheers, Will Cc: Catalin Marinas Cc: Marc Zyngier Cc: Greg Kroah-Hartman Cc: Peter Zijlstra Cc: Morten Rasmussen Cc: Qais Yousef Cc: Suren Baghdasaryan Cc: kernel-team@android.com --->8 Qais Yousef (1): KVM: arm64: Handle Asymmetric AArch32 systems Will Deacon (5): arm64: Allow mismatched 32-bit EL0 support KVM: arm64: Kill 32-bit vCPUs on systems with mismatched EL0 support arm64: Kill 32-bit applications scheduled on 64-bit-only CPUs arm64: Advertise CPUs capable of running 32-bit applcations in sysfs arm64: Hook up cmdline parameter to allow mismatched 32-bit EL0 .../ABI/testing/sysfs-devices-system-cpu | 8 ++ .../admin-guide/kernel-parameters.txt | 7 ++ arch/arm64/include/asm/cpufeature.h | 3 + arch/arm64/kernel/cpufeature.c | 80 ++++++++++++++++++- arch/arm64/kernel/process.c | 21 ++++- arch/arm64/kernel/signal.c | 26 ++++++ arch/arm64/kvm/arm.c | 27 +++++++ 7 files changed, 168 insertions(+), 4 deletions(-) -- 2.29.0.rc2.309.g374f81d7ae-goog