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 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 CB11EC433F5 for ; Thu, 21 Oct 2021 15:11:40 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 4194460F57 for ; Thu, 21 Oct 2021 15:11:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 4194460F57 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id CB7064B126; Thu, 21 Oct 2021 11:11:39 -0400 (EDT) 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 DyQnT+sD2sAs; Thu, 21 Oct 2021 11:11:38 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id F31924B1AB; Thu, 21 Oct 2021 11:11:37 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 1FF214B161 for ; Thu, 21 Oct 2021 11:11:36 -0400 (EDT) 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 Qkdc7lkTCLlY for ; Thu, 21 Oct 2021 11:11:34 -0400 (EDT) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id D79F14B119 for ; Thu, 21 Oct 2021 11:11:34 -0400 (EDT) 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 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 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 Cc: kernel-team@android.com, Will Deacon , broonie@kernel.org 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 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 _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm 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 8EABFC433FE for ; Thu, 21 Oct 2021 15:14:27 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5F7EC60F46 for ; Thu, 21 Oct 2021 15:14:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 5F7EC60F46 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:Cc :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=nYJdQtP/JeKFqu9R4cm/8lA1d0oNj6fcGMfYowhApmc=; b=eiRjaQ17zFk0+d tUINfuqiD02XhFgYji0k3/xLSN8aVCxf378zrIhZ82It4ZIQ3VL/a/VQM1WxtpilNiVczfEfRMCgW o1ZwMoRiGo9jCGzHKGrmJvNlmXX7WAy6rYIiMo7DBxuXjbBxp2fndMjRlB+yJFaqUQDED674kOQPj 0x90EUUkAUnSwwbJ/9xmc7XLgqlybl/5xMpmzjSZuuc4EzmhknHEt5mTxMmo5TWiagjWNsUkHpIsm 42vB5P19I3rJb3D+vJFhHXUYBPiymtsT/pzg2CGH5W01p1visxW3W0dx+qUqwULr+uCENDKZkCUn5 YhG4EPRnzM1ZjjwxZ4cw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mdZkW-0080lc-9z; Thu, 21 Oct 2021 15:12:56 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mdZjB-008023-4t for linux-arm-kernel@lists.infradead.org; Thu, 21 Oct 2021 15:11:34 +0000 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 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211021_081133_275033_2831E59B X-CRM114-Status: GOOD ( 12.81 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.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 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel