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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 58876C04EB9 for ; Mon, 3 Dec 2018 14:03:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 26D3E206B7 for ; Mon, 3 Dec 2018 14:03:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 26D3E206B7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726331AbeLCOEW (ORCPT ); Mon, 3 Dec 2018 09:04:22 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:38004 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725897AbeLCOEW (ORCPT ); Mon, 3 Dec 2018 09:04:22 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 499F61682; Mon, 3 Dec 2018 06:03:14 -0800 (PST) Received: from [10.1.196.93] (en101.cambridge.arm.com [10.1.196.93]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 9FA363F614; Mon, 3 Dec 2018 06:03:12 -0800 (PST) Subject: Re: [PATCH v9 3/8] KVM: arm/arm64: Introduce helpers to manipulate page table entries To: Anshuman Khandual , Punit Agrawal , kvmarm@lists.cs.columbia.edu Cc: marc.zyngier@arm.com, Catalin Marinas , will.deacon@arm.com, linux-kernel@vger.kernel.org, Russell King , punitagrawal@gmail.com, linux-arm-kernel@lists.infradead.org References: <20181031175745.18650-1-punit.agrawal@arm.com> <20181031175745.18650-4-punit.agrawal@arm.com> <396402d5-fddf-ab72-01c4-80dd1a0d4d44@arm.com> From: Suzuki K Poulose Message-ID: Date: Mon, 3 Dec 2018 14:03:11 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: <396402d5-fddf-ab72-01c4-80dd1a0d4d44@arm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Anshuman, On 03/12/2018 13:50, Anshuman Khandual wrote: > > > On 10/31/2018 11:27 PM, Punit Agrawal wrote: >> Introduce helpers to abstract architectural handling of the conversion >> of pfn to page table entries and marking a PMD page table entry as a >> block entry. > > Why is this necessary ? we would still need to access PMD, PUD as is > without any conversion. IOW KVM knows the breakdown of the page table > at various levels. Is this something required from generic KVM code ? The KVM MMU code is shared for arm32 and arm64. Hence we need arch specific helpers to hide how we deal with the levels. e.g, PUD never exists for arm32. > >> >> The helpers are introduced in preparation for supporting PUD hugepages >> at stage 2 - which are supported on arm64 but do not exist on arm. > > Some of these patches (including the earlier two) are good on it's > own. Do we have still mention in commit message about the incoming PUD > enablement as the reason for these cleanup patches ? > Cheers Suzuki