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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4CE6AC433EF for ; Thu, 21 Oct 2021 15:11:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 244D261260 for ; Thu, 21 Oct 2021 15:11:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231731AbhJUPNu (ORCPT ); Thu, 21 Oct 2021 11:13:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:38402 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231641AbhJUPNs (ORCPT ); Thu, 21 Oct 2021 11:13:48 -0400 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 5916A611C7; Thu, 21 Oct 2021 15:11:32 +0000 (UTC) Received: from sofa.misterjones.org ([185.219.108.64] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1mdZj8-000jKD-64; Thu, 21 Oct 2021 16:11:30 +0100 From: Marc Zyngier To: kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: James Morse , Suzuki K Poulose , Alexandru Elisei , Quentin Perret , Will Deacon , broonie@kernel.org, kernel-team@android.com Subject: [PATCH 0/4] KVM: arm64: Stop mapping current thread_info at EL2 Date: Thu, 21 Oct 2021 16:11:20 +0100 Message-Id: <20211021151124.3098113-1-maz@kernel.org> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, james.morse@arm.com, suzuki.poulose@arm.com, alexandru.elisei@arm.com, qperret@google.com, will@kernel.org, broonie@kernel.org, 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 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org It recently became apparent that we are mapping each vcpu thread's thread_info structure at EL2 for the sole purpose of checking on the TIF_FOREIGN_FPSTATE flag. Given that this looks like a slightly over-engineered way of sharing a single bit of information, let's move to a slightly more obvious implementation by maintaining a vcpu-private shadow flag that represents the same state. I also take this opportunity to add what looks like a missing, and nonetheless crucial piece of information to the FPSIMD code regarding the way KVM (ab)uses the TIF_FOREIGN_FPSTATE. Lightly tested on an A53 box with a bunch of paranoia instances running in both host and guests. Marc Zyngier (4): KVM: arm64: Reorder vcpu flag definitions KVM: arm64: Introduce flag shadowing TIF_FOREIGN_FPSTATE KVM: arm64: Stop mapping current thread_info at EL2 arm64/fpsimd: Document the use of TIF_FOREIGN_FPSTATE by KVM arch/arm64/include/asm/kvm_host.h | 28 ++++++++++++------------- arch/arm64/kernel/fpsimd.c | 5 ++++- arch/arm64/kvm/arm.c | 1 + arch/arm64/kvm/fpsimd.c | 20 ++++++++---------- arch/arm64/kvm/hyp/include/hyp/switch.h | 3 +-- arch/arm64/kvm/hyp/nvhe/switch.c | 1 - arch/arm64/kvm/hyp/vhe/switch.c | 1 - 7 files changed, 29 insertions(+), 30 deletions(-) -- 2.30.2