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=-17.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 CB54FC433E9 for ; Thu, 4 Mar 2021 14:10:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9372664F23 for ; Thu, 4 Mar 2021 14:10:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240445AbhCDOKg (ORCPT ); Thu, 4 Mar 2021 09:10:36 -0500 Received: from mail.kernel.org ([198.145.29.99]:36532 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241370AbhCDOKW (ORCPT ); Thu, 4 Mar 2021 09:10:22 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6EC5F64EDF; Thu, 4 Mar 2021 14:09:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1614866982; bh=6EzIY8mKBs6byT+yHKkgcBlOIVV0b78KDf87tIOxB00=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=UrLovbK0Yz6BuDjF+iBIgvC9apQ074oZiquUsRoxNP57gxQyf9vO1V7aqG39ne+DE lkGnQAkCi6sUhrxkNYWD3ADJEMIpD/BFXFX8cjv4F7wW66vLoLYqbOwqQ3nt36Pz5W n7o34V0bjYFFuma7ZsasQa21f3v2oxb0pC768CNiwtN8cKp3quhy6YOMrbPrL08Qjf +ATR9QY5jJSBoRKvFRwX9X8JeEjse7Ds20/btLeZ/dwbCA10Jc0qEG3FHmLJ+TUwU3 fKD0cE07a1LfyCT8184I4jX0lCy4g9thQJoKyNngaMrF9K71BYbQYVDLyvWoivjN0L HoCTbDrMG6cFA== Date: Thu, 4 Mar 2021 14:09:36 +0000 From: Will Deacon To: Quentin Perret Cc: catalin.marinas@arm.com, maz@kernel.org, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com, android-kvm@google.com, linux-kernel@vger.kernel.org, kernel-team@android.com, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, tabba@google.com, mark.rutland@arm.com, dbrazdil@google.com, mate.toth-pal@arm.com, seanjc@google.com, robh+dt@kernel.org Subject: Re: [PATCH v3 07/32] KVM: arm64: Introduce a BSS section for use at Hyp Message-ID: <20210304140935.GD21229@willie-the-truck> References: <20210302150002.3685113-1-qperret@google.com> <20210302150002.3685113-8-qperret@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210302150002.3685113-8-qperret@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 02, 2021 at 02:59:37PM +0000, Quentin Perret wrote: > Currently, the hyp code cannot make full use of a bss, as the kernel > section is mapped read-only. > > While this mapping could simply be changed to read-write, it would > intermingle even more the hyp and kernel state than they currently are. > Instead, introduce a __hyp_bss section, that uses reserved pages, and > create the appropriate RW hyp mappings during KVM init. > > Signed-off-by: Quentin Perret > --- > arch/arm64/include/asm/sections.h | 1 + > arch/arm64/kernel/vmlinux.lds.S | 52 ++++++++++++++++++++----------- > arch/arm64/kvm/arm.c | 14 ++++++++- > arch/arm64/kvm/hyp/nvhe/hyp.lds.S | 1 + > 4 files changed, 49 insertions(+), 19 deletions(-) Acked-by: Will Deacon Will