From patchwork Mon Oct 28 09:40:13 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Aneesh Kumar K.V" X-Patchwork-Id: 13853288 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 409DFD13570 for ; Mon, 28 Oct 2024 11:00:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=JNFPbeDpfcWwNjFqfpFGb1I3h0sHk40o+FNyTY0hGXM=; b=RPhZoZiq54RFg3pi9It54BUXI2 /LO72Htwmxxk/3doP1VpNZxcVnmslsjIM4SphtyG3p4dj1PGDbbd3aPWj41kLYdQs8c9SosofvDIn yP0m3sVQDQwBLCy6EXxpCaipmc/QkKD31H126kWQMtu71V7Y0nyIFitcAmL08Dv22UAeZHCrWsnoO tJBeeJNGvLIOYerydun6KORX6kZTpbHr/1QRTUEbM+Tfndu8TcdXkC9EbHxf4OXSxPVIMXNCgp6pW dlKNs63PNUUyFa33ZPiz+pR++TK9fZ77VUQuS44//YcwQtnaW3roYIWebx0vZf18YVuEMohqElweN hiq/N9fA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1t5NTv-0000000AUe0-2GPa; Mon, 28 Oct 2024 11:00:19 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1t5MEx-0000000AGRm-34pT for linux-arm-kernel@lists.infradead.org; Mon, 28 Oct 2024 09:40:48 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 1B75D5C5A10; Mon, 28 Oct 2024 09:40:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 41EA3C4CEE3; Mon, 28 Oct 2024 09:40:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1730108446; bh=z1mUlgIUaANV/bPlzaFct/onP+Qou91QVjn4WHN+xBg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=makORikMMp9/UbWQJ3sLJYYmDweBYANAH51dd82Y2lkQOuR/iidUeUDNFZazncjP9 SXlxlDLkTEuXSuJxdvyV3ic8Z8x8fkCuv5P2eGaDWz96MXcgNl1bu+4ps234VH4hFz hojhDqOkIT0MHmmm27Yqe04+In8D8Unw308HCHt3aw71+SxoM2XbzPIpwKzBZYbNDO CkomdyrKrGxLm7fCWIb77ITglUOIe6z6qrVF/clVOowdB2jt3wT1XARtYa/+jYQ3uo UiBKwAvgSnrqo9SM5rouDqir2whDwApOP26Gxoxe6qY9Zh0LMW8iGZjivdTvPpcIfQ 7UQJd5K8abhYg== From: "Aneesh Kumar K.V (Arm)" To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev Cc: Suzuki K Poulose , Steven Price , Will Deacon , Catalin Marinas , Marc Zyngier , Mark Rutland , Oliver Upton , Joey Gouly , Zenghui Yu , "Aneesh Kumar K.V (Arm)" Subject: [PATCH 3/4] arm64: mte: update code comments Date: Mon, 28 Oct 2024 15:10:13 +0530 Message-ID: <20241028094014.2596619-4-aneesh.kumar@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20241028094014.2596619-1-aneesh.kumar@kernel.org> References: <20241028094014.2596619-1-aneesh.kumar@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241028_024047_835966_A7C67DA0 X-CRM114-Status: GOOD ( 15.07 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org commit d77e59a8fccd ("arm64: mte: Lock a page for MTE tag initialisation") updated the locking such the kernel now allows VM_SHARED mapping with MTE. Update the code comment to reflect this. Signed-off-by: Aneesh Kumar K.V (Arm) --- arch/arm64/kvm/mmu.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index a509b63bd4dd..b5824e93cee0 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -1390,11 +1390,8 @@ static int get_vma_page_shift(struct vm_area_struct *vma, unsigned long hva) * able to see the page's tags and therefore they must be initialised first. If * PG_mte_tagged is set, tags have already been initialised. * - * The race in the test/set of the PG_mte_tagged flag is handled by: - * - preventing VM_SHARED mappings in a memslot with MTE preventing two VMs - * racing to santise the same page - * - mmap_lock protects between a VM faulting a page in and the VMM performing - * an mprotect() to add VM_MTE + * The race in the test/set of the PG_mte_tagged flag is handled by + * using PG_mte_lock and PG_mte_tagged together. */ static void sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn, unsigned long size) @@ -1646,7 +1643,10 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, } if (!fault_is_perm && !device && kvm_has_mte(kvm)) { - /* Check the VMM hasn't introduced a new disallowed VMA */ + /* + * not a permission fault implies a translation fault which + * means mapping the page for the first time + */ if (mte_allowed) { sanitise_mte_tags(kvm, pfn, vma_pagesize); } else {