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=-11.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,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 1494CC64E90 for ; Mon, 30 Nov 2020 12:20:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B99EC2074A for ; Mon, 30 Nov 2020 12:20:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726388AbgK3MUH (ORCPT ); Mon, 30 Nov 2020 07:20:07 -0500 Received: from szxga05-in.huawei.com ([45.249.212.191]:9073 "EHLO szxga05-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726137AbgK3MUG (ORCPT ); Mon, 30 Nov 2020 07:20:06 -0500 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 CC: , , , , , , , Yanan Wang 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 Content-Type: text/plain X-Originating-IP: [10.174.186.123] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.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(-) -- 2.19.1