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=-10.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,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 B2A86C433DB for ; Sat, 27 Mar 2021 15:25:09 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 4BF1661991 for ; Sat, 27 Mar 2021 15:25:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4BF1661991 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=tiIQlbLryXhpPz+fBodpCnO4BQx8qU0wHbRjCwDLnhQ=; b=lrQGzOIdBCYN2bn2/JVxP6pId aMKByokGWvxLEwt5zp30bMbKf/0ERBqhCMeaAiaB7rTETgNn1s7uwLeSoJxqdEiR6nbLdAYNN+Szu W7xIo/aW9GSdQdI6P72UNXdyaTFMey3ienvbHyY4MemvuzLPkGfbMt8nPU1GKg/SeE+NU74A7omKM rn5y9IRajBGBFLdA9dW9ir7MnExkZvvsIq54g4W2mQ1c0B/WafeadBsthuu8tMs2+FqEJ7OyRUqrZ fht+U3Y4mVSto95ehNBqhY6AxNeFwtp6hhByURmikCXg72+4IETIy3Zr6DSrnGq5Bz9MlJFkMUSxD smusz8+3w==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lQAmn-005Dkd-2p; Sat, 27 Mar 2021 15:23:37 +0000 Received: from mail.kernel.org ([198.145.29.99]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lQAmj-005DkG-Bn for linux-arm-kernel@lists.infradead.org; Sat, 27 Mar 2021 15:23:35 +0000 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 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 , qemu-devel@nongnu.org, Juan Quintela , "Dr. David Alan Gilbert" , Richard Henderson , Peter Maydell , Haibo Xu , Andrew Jones 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-Disposition: inline In-Reply-To: <20210312151902.17853-3-steven.price@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210327_152333_645840_54FF8DF1 X-CRM114-Status: GOOD ( 16.43 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel