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=-10.3 required=3.0 tests=BAYES_00, 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 1A061C433C1 for ; Sat, 27 Mar 2021 15:24:54 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 6F92561991 for ; Sat, 27 Mar 2021 15:24:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6F92561991 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:46202 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lQAo0-00032d-Bp for qemu-devel@archiver.kernel.org; Sat, 27 Mar 2021 11:24:52 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:42778) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lQAml-0002We-Nk for qemu-devel@nongnu.org; Sat, 27 Mar 2021 11:23:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:35580) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lQAmi-00086T-24 for qemu-devel@nongnu.org; Sat, 27 Mar 2021 11:23:34 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5CA1861941; Sat, 27 Mar 2021 15:23:27 +0000 (UTC) Date: Sat, 27 Mar 2021 15:23:24 +0000 From: Catalin Marinas To: Steven Price Subject: Re: [PATCH v10 2/6] arm64: kvm: Introduce MTE VM feature Message-ID: <20210327152324.GA28167@arm.com> References: <20210312151902.17853-1-steven.price@arm.com> <20210312151902.17853-3-steven.price@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210312151902.17853-3-steven.price@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) Received-SPF: pass client-ip=198.145.29.99; envelope-from=cmarinas@kernel.org; helo=mail.kernel.org X-Spam_score_int: -66 X-Spam_score: -6.7 X-Spam_bar: ------ X-Spam_report: (-6.7 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.25, RCVD_IN_DNSWL_HI=-5, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Peter Maydell , "Dr. David Alan Gilbert" , Andrew Jones , Haibo Xu , Suzuki K Poulose , qemu-devel@nongnu.org, Marc Zyngier , Juan Quintela , Richard Henderson , linux-kernel@vger.kernel.org, Dave Martin , James Morse , linux-arm-kernel@lists.infradead.org, Thomas Gleixner , Will Deacon , kvmarm@lists.cs.columbia.edu, Julien Thierry Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Fri, Mar 12, 2021 at 03:18:58PM +0000, Steven Price wrote: > diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c > index 77cb2d28f2a4..b31b7a821f90 100644 > --- a/arch/arm64/kvm/mmu.c > +++ b/arch/arm64/kvm/mmu.c > @@ -879,6 +879,22 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, > if (vma_pagesize == PAGE_SIZE && !force_pte) > vma_pagesize = transparent_hugepage_adjust(memslot, hva, > &pfn, &fault_ipa); > + > + if (fault_status != FSC_PERM && kvm_has_mte(kvm) && pfn_valid(pfn)) { This pfn_valid() check may be problematic. Following commit eeb0753ba27b ("arm64/mm: Fix pfn_valid() for ZONE_DEVICE based memory"), it returns true for ZONE_DEVICE memory but such memory is allowed not to support MTE. I now wonder if we can get a MAP_ANONYMOUS mapping of ZONE_DEVICE pfn even without virtualisation. > + /* > + * VM will be able to see the page's tags, so we must ensure > + * they have been initialised. if PG_mte_tagged is set, tags > + * have already been initialised. > + */ > + struct page *page = pfn_to_page(pfn); > + unsigned long i, nr_pages = vma_pagesize >> PAGE_SHIFT; > + > + for (i = 0; i < nr_pages; i++, page++) { > + if (!test_and_set_bit(PG_mte_tagged, &page->flags)) > + mte_clear_page_tags(page_address(page)); > + } > + } > + > if (writable) > prot |= KVM_PGTABLE_PROT_W; > -- Catalin