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=-17.7 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 7432CC433E1 for ; Mon, 22 Mar 2021 11:34:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3E63E619A1 for ; Mon, 22 Mar 2021 11:34:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230092AbhCVLdz (ORCPT ); Mon, 22 Mar 2021 07:33:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:40820 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229993AbhCVLd0 (ORCPT ); Mon, 22 Mar 2021 07:33:26 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id BC56061984; Mon, 22 Mar 2021 11:33:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1616412806; bh=6NU8CoeVuy+xBCKoKihnD9B6AGKpzEVVYiFH3UaLDyk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=hcbvPInN/ygnKoUF6quhfsskpgiEr0UaC3QmE06DLMyacDxFWj+MwPETGfaf9kYGu zDo7TsVsbSvfUWsGBeSSHa9NyS/b4HH7jpnn3sLEfg//A5Eu11MfxLgCgLccuEy8l9 HHFt9/qD3rDSNTFpTLaVB0DvvTqwAYO0/OH5HnZk97F8bkKwggzVb/95O5141sXFfJ ZsHoZoZBw546UT6xSQXDl3llEHxCXeuKrqtmzQP9SeREnlannavgbOwyGo22j6F608 mMAMYez9XflctPuRnTyskBuBxYBCX38k0pvKQVqVymzOsx6ApySA67mKOWOgLMYPBh 7lY6nKkCYnOXw== Date: Mon, 22 Mar 2021 11:33:20 +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, seanjc@google.com, mate.toth-pal@arm.com, linux-kernel@vger.kernel.org, robh+dt@kernel.org, linux-arm-kernel@lists.infradead.org, kernel-team@android.com, kvmarm@lists.cs.columbia.edu, tabba@google.com, ardb@kernel.org, mark.rutland@arm.com, dbrazdil@google.com Subject: Re: [PATCH v6 33/38] KVM: arm64: Introduce KVM_PGTABLE_S2_IDMAP stage 2 flag Message-ID: <20210322113320.GD10318@willie-the-truck> References: <20210319100146.1149909-1-qperret@google.com> <20210319100146.1149909-34-qperret@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210319100146.1149909-34-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 Fri, Mar 19, 2021 at 10:01:41AM +0000, Quentin Perret wrote: > Introduce a new stage 2 configuration flag to specify that all mappings > in a given page-table will be identity-mapped, as will be the case for > the host. This allows to introduce sanity checks in the map path and to > avoid programming errors. > > Suggested-by: Will Deacon > Signed-off-by: Quentin Perret > --- > arch/arm64/include/asm/kvm_pgtable.h | 2 ++ > arch/arm64/kvm/hyp/pgtable.c | 3 +++ > 2 files changed, 5 insertions(+) > > diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h > index 55452f4831d2..c3674c47d48c 100644 > --- a/arch/arm64/include/asm/kvm_pgtable.h > +++ b/arch/arm64/include/asm/kvm_pgtable.h > @@ -60,9 +60,11 @@ struct kvm_pgtable_mm_ops { > * enum kvm_pgtable_stage2_flags - Stage-2 page-table flags. > * @KVM_PGTABLE_S2_NOFWB: Don't enforce Normal-WB even if the CPUs have > * ARM64_HAS_STAGE2_FWB. > + * @KVM_PGTABLE_S2_IDMAP: Only use identity mappings. > */ > enum kvm_pgtable_stage2_flags { > KVM_PGTABLE_S2_NOFWB = BIT(0), > + KVM_PGTABLE_S2_IDMAP = BIT(1), > }; > > /** > diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c > index b22b4860630c..c37c1dc4feaf 100644 > --- a/arch/arm64/kvm/hyp/pgtable.c > +++ b/arch/arm64/kvm/hyp/pgtable.c > @@ -760,6 +760,9 @@ int kvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size, > .arg = &map_data, > }; > > + if (WARN_ON((pgt->flags & KVM_PGTABLE_S2_IDMAP) && (addr != phys))) > + return -EINVAL; Acked-by: Will Deacon Will