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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, 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 96425C433E0 for ; Wed, 17 Jun 2020 14:38:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7AFE620888 for ; Wed, 17 Jun 2020 14:38:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726976AbgFQOiT (ORCPT ); Wed, 17 Jun 2020 10:38:19 -0400 Received: from foss.arm.com ([217.140.110.172]:59000 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726708AbgFQOiS (ORCPT ); Wed, 17 Jun 2020 10:38:18 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 4EA4531B; Wed, 17 Jun 2020 07:38:18 -0700 (PDT) Received: from gaia (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 9D2CA3F73C; Wed, 17 Jun 2020 07:38:16 -0700 (PDT) Date: Wed, 17 Jun 2020 15:38:10 +0100 From: Catalin Marinas To: Steven Price Cc: Marc Zyngier , Will Deacon , James Morse , Julien Thierry , Suzuki K Poulose , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Dave Martin , Mark Rutland , Thomas Gleixner Subject: Re: [RFC PATCH 2/2] arm64: kvm: Introduce MTE VCPU feature Message-ID: <20200617143809.GF5388@gaia> References: <20200617123844.29960-1-steven.price@arm.com> <20200617123844.29960-3-steven.price@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200617123844.29960-3-steven.price@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 17, 2020 at 01:38:44PM +0100, Steven Price wrote: > diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c > index e3b9ee268823..040a7fffaa93 100644 > --- a/virt/kvm/arm/mmu.c > +++ b/virt/kvm/arm/mmu.c > @@ -1783,6 +1783,17 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, > vma_pagesize = PMD_SIZE; > } > > + if (system_supports_mte() && kvm->arch.vcpu_has_mte) { > + /* > + * VM will be able to see the page's tags, so we must ensure > + * they have been initialised. > + */ > + struct page *page = pfn_to_page(pfn); > + > + if (!test_and_set_bit(PG_mte_tagged, &page->flags)) > + mte_clear_page_tags(page_address(page), page_size(page)); > + } Are all the guest pages always mapped via a Stage 2 fault? It may be better if we did that via kvm_set_spte_hva(). -- Catalin