From patchwork Mon Nov 30 12:18:44 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yanan Wang X-Patchwork-Id: 11940319 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=-13.2 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,URIBL_BLOCKED,USER_AGENT_GIT 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 B7CADC83012 for ; Mon, 30 Nov 2020 12:20:34 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 3344E2074A for ; Mon, 30 Nov 2020 12:20:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Pmna4qVN" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3344E2074A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.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=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:Subject:To:From: Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender :Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=kt2y7W2Cy1SfNPwxBG0UhxwQtU/oqQCB5YClsYo8bV0=; b=Pmna4qVNAkgDFjOb8bNaxgwoNx RACzk+LEi/2W+sQttX7+OSV27kWwSODQU6h34822c9/QMmH/sc6gEHwAaMnMQu41Fn18VWz1G1+MB Lt/QPfuaWxZa/vsQWytIZKAGAC19aeGXyZw0MN4BKeYBKKoMzbhVWVczyOnnCP39S75CP92W1zZht ZT48zTXXrniE8iDGDRzezT123XoL8hj0sMLhgy9Gu1zRrnm2NTklU6uZ9jhNA6EKFG+qE6ZiHKSMh 96hzZ/KrB3k/rfQSY4Bj5RIpbwgYhcUb34dE9p39k2XXxj0o10kgjvF+FyNZqk6RNEkPrMbp+B7EU hCHld2WA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kji9I-0005gB-85; Mon, 30 Nov 2020 12:19:20 +0000 Received: from szxga05-in.huawei.com ([45.249.212.191]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kji9C-0005el-O1 for linux-arm-kernel@lists.infradead.org; Mon, 30 Nov 2020 12:19:15 +0000 Received: from DGGEMS402-HUB.china.huawei.com (unknown [172.30.72.59]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4Cl45T3JkGzLxpr; Mon, 30 Nov 2020 20:18:37 +0800 (CST) Received: from DESKTOP-TMVL5KK.china.huawei.com (10.174.186.123) by DGGEMS402-HUB.china.huawei.com (10.3.19.202) with Microsoft SMTP Server id 14.3.487.0; Mon, 30 Nov 2020 20:19:00 +0800 From: Yanan Wang To: , , Marc Zyngier , Catalin Marinas , Will Deacon , James Morse , "Julien Thierry" , Suzuki K Poulose , Gavin Shan , Quentin Perret Subject: [RFC PATCH 0/3] Fix several bugs in KVM stage 2 translation Date: Mon, 30 Nov 2020 20:18:44 +0800 Message-ID: <20201130121847.91808-1-wangyanan55@huawei.com> X-Mailer: git-send-email 2.8.4.windows.1 MIME-Version: 1.0 X-Originating-IP: [10.174.186.123] X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201130_071915_045288_CAAABB26 X-CRM114-Status: GOOD ( 11.63 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: lushenming@huawei.com, jiangkunkun@huawei.com, Yanan Wang , yezengruan@huawei.com, wangjingyi11@huawei.com, yuzenghui@huawei.com, wanghaibin.wang@huawei.com, zhukeqian1@huawei.com Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Several problems about KVM stage 2 translation were found when testing based on the mainline code. The following is description of the problems and the corresponding patchs. When installing a new pte entry or updating an old valid entry in stage 2 translation, we use get_page()/put_page() to record page_count of the page-table pages. PATCH 1/3 aims to fix incorrect use of get_page()/put_page() in stage 2, which might make page-table pages unable to be freed when unmapping a range. When dirty logging of a guest with hugepages is finished, we should merge tables back into a block entry if adjustment of huge mapping is found necessary. In addition to installing the block entry, mapping of the lower-levels for the block should also be unmapped to avoid multiple TLB entries. PATCH 2/3 adds unmap operation when merge tables into a block entry. The rewrite of page-table code and fault handling add two different handlers for "just relaxing permissions" and "map by stage2 page-table walk", that's great improvement. Yet, in function user_mem_abort(), conditions where we choose the above two fault handlers are not strictly distinguished. This will causes guest errors such as infinite-loop (soft lockup will occur in result), because of calling the inappropriate fault handler. So, a solution that can strictly distinguish conditions is introduced in PATCH 3/3. Yanan Wang (3): KVM: arm64: Fix possible memory leak in kvm stage2 KVM: arm64: Fix handling of merging tables into a block entry KVM: arm64: Add usage of stage 2 fault lookup level in user_mem_abort() arch/arm64/include/asm/esr.h | 1 + arch/arm64/include/asm/kvm_emulate.h | 5 +++++ arch/arm64/kvm/hyp/pgtable.c | 22 +++++++++++++++++----- arch/arm64/kvm/mmu.c | 11 +++++++++-- 4 files changed, 32 insertions(+), 7 deletions(-)