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=-18.2 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=unavailable 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 BD7FFC4320E for ; Tue, 27 Jul 2021 18:10:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9ED2E60F57 for ; Tue, 27 Jul 2021 18:10:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231362AbhG0SKv (ORCPT ); Tue, 27 Jul 2021 14:10:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:54016 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229453AbhG0SKu (ORCPT ); Tue, 27 Jul 2021 14:10:50 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6349760F4F; Tue, 27 Jul 2021 18:10:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1627409450; bh=1idsSsOLd6j5B3mlucoHIl85eXG29dW6Ac2vbhUO3Bs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=EoFDUbpRaPCpop/dEtf4WAzlFiaUP3CjPo5T53gFnwUy4wbJ3B+0hT3gzFVMjsnrB gLndl4KBOIAQZyvL0c0pZSAOT1BEAhGFCmvzU3sAIoChqIerKeR98fF/2S2rQCDG5k phec+IZQs88i19ZKdLrLG/MT0rWFQp6Gr6SN/pSGHk77wCP1zP2QUcyqX54Z5C8OfW 7/tAQFHm9Px4MW92GtYwlqwqMSfND8kFmfuzSsZaLwaZe6xug/nkg39LP9h2p2l4sP 4rLd4bMxC2v7t5Scn4P2rhF4xDAP0+ukEt9wsgzbZmQbttMuWmezJZhFtCFQUOrOxx UFuCQq1bIr3ww== Date: Tue, 27 Jul 2021 19:10:45 +0100 From: Will Deacon To: Marc Zyngier Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, qperret@google.com, dbrazdil@google.com, Srivatsa Vaddagiri , Shanker R Donthineni , James Morse , Suzuki K Poulose , Alexandru Elisei , kernel-team@android.com Subject: Re: [PATCH 02/16] KVM: arm64: Don't issue CMOs when the physical address is invalid Message-ID: <20210727181044.GB19173@willie-the-truck> References: <20210715163159.1480168-1-maz@kernel.org> <20210715163159.1480168-3-maz@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210715163159.1480168-3-maz@kernel.org> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 15, 2021 at 05:31:45PM +0100, Marc Zyngier wrote: > Make sure we don't issue CMOs when mapping something that > is not a memory address in the S2 page tables. > > Signed-off-by: Marc Zyngier > --- > arch/arm64/kvm/hyp/pgtable.c | 16 ++++++++++------ > 1 file changed, 10 insertions(+), 6 deletions(-) > > diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c > index 05321f4165e3..a5874ebd0354 100644 > --- a/arch/arm64/kvm/hyp/pgtable.c > +++ b/arch/arm64/kvm/hyp/pgtable.c > @@ -619,12 +619,16 @@ static int stage2_map_walker_try_leaf(u64 addr, u64 end, u32 level, > } > > /* Perform CMOs before installation of the guest stage-2 PTE */ > - if (mm_ops->dcache_clean_inval_poc && stage2_pte_cacheable(pgt, new)) > - mm_ops->dcache_clean_inval_poc(kvm_pte_follow(new, mm_ops), > - granule); > - > - if (mm_ops->icache_inval_pou && stage2_pte_executable(new)) > - mm_ops->icache_inval_pou(kvm_pte_follow(new, mm_ops), granule); > + if (kvm_phys_is_valid(phys)) { > + if (mm_ops->dcache_clean_inval_poc && > + stage2_pte_cacheable(pgt, new)) > + mm_ops->dcache_clean_inval_poc(kvm_pte_follow(new, > + mm_ops), > + granule); > + if (mm_ops->icache_inval_pou && stage2_pte_executable(new)) > + mm_ops->icache_inval_pou(kvm_pte_follow(new, mm_ops), > + granule); > + } Given that this check corresponds to checking the validity of 'new', I wonder whether we'd be better off pushing the validity checks down into stage2_pte_{cacheable,executable}()? I.e. have stage2_pte_cacheable() return false if !kvm_pte_valid() Will