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=-17.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 AA00AC64E8A for ; Mon, 30 Nov 2020 13:35:58 +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 2969320727 for ; Mon, 30 Nov 2020 13:35:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="SBU4vGIk"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="dLD0NeIK" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2969320727 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org 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:In-Reply-To:MIME-Version:References:Message-ID: Subject: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=fHknl9IvEfR0q/kects+FN/JksbHbyXE1RCICAichm0=; b=SBU4vGIkvBa4uu50f4B+G9YZ4 Qqh6stt5eRicS7n99oXHE+WTzXM8bDFmUm3MIKFY3OWmYv73xNH20fKrDqM8oRB/M1qUt2qPVvPnu Fn0+QYrXV9B1tkkqZC7MipJHeG3z+qROKhOVDr/cFxJ6VO+tgoAxImXFu9TfpC9XZzrH2AwYdh3w6 f/K5WR8tlVsWwYZt1UK1Ifhv3QuPDUcyG+zR2vMuSLMjWJ4Ys+POk1c4miPP5mF3HVc3oM4CbNXtF 2QlVfFW3n5mSW7coYxwrNXLwmNRyu6Pi6sTOK4y6JTb+GpzXKXmKy3olu+fffVs7r+VkuZLVEmuxE RhAZgulhQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kjjK4-0003Tm-ID; Mon, 30 Nov 2020 13:34:32 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kjjK1-0003TQ-2t for linux-arm-kernel@lists.infradead.org; Mon, 30 Nov 2020 13:34:30 +0000 Received: from willie-the-truck (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2BAD720870; Mon, 30 Nov 2020 13:34:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1606743268; bh=lc+QhqwU7aPlngAV30FSRSh9frD9YFy1xiMIDEc7/ek=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=dLD0NeIKHfj3LKCzVj4ECu0YXu14LGj4tF3/fVOTM020EOYxI1Txtk987QZoYlVBq kggtg2/rFgP3M0oiF3Zj5q0z1/RKvpA111kLJUdRbY2B9vFbDGWa8wOubYBO8JH0EC p7wl2iZz9g4ZGJibeuO6fdU1Hd90R0+G/2Ze8W6Y= Date: Mon, 30 Nov 2020 13:34:21 +0000 From: Will Deacon To: Yanan Wang Subject: Re: [RFC PATCH 2/3] KVM: arm64: Fix handling of merging tables into a block entry Message-ID: <20201130133421.GB24837@willie-the-truck> References: <20201130121847.91808-1-wangyanan55@huawei.com> <20201130121847.91808-3-wangyanan55@huawei.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20201130121847.91808-3-wangyanan55@huawei.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-20201130_083429_669054_425BFD48 X-CRM114-Status: GOOD ( 25.26 ) 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: jiangkunkun@huawei.com, Gavin Shan , Suzuki K Poulose , Marc Zyngier , wangjingyi11@huawei.com, Quentin Perret , lushenming@huawei.com, linux-kernel@vger.kernel.org, yezengruan@huawei.com, James Morse , linux-arm-kernel@lists.infradead.org, Catalin Marinas , yuzenghui@huawei.com, wanghaibin.wang@huawei.com, zhukeqian1@huawei.com, Julien Thierry 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 Mon, Nov 30, 2020 at 08:18:46PM +0800, Yanan Wang wrote: > In dirty logging case(logging_active == True), we need to collapse a block > entry into a table if necessary. After dirty logging is canceled, when merging > tables back into a block entry, we should not only free the non-huge page > tables but also unmap the non-huge mapping for the block. Without the unmap, > inconsistent TLB entries for the pages in the the block will be created. > > We could also use unmap_stage2_range API to unmap the non-huge mapping, > but this could potentially free the upper level page-table page which > will be useful later. > > Signed-off-by: Yanan Wang > --- > arch/arm64/kvm/hyp/pgtable.c | 15 +++++++++++++-- > 1 file changed, 13 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c > index 696b6aa83faf..fec8dc9f2baa 100644 > --- a/arch/arm64/kvm/hyp/pgtable.c > +++ b/arch/arm64/kvm/hyp/pgtable.c > @@ -500,6 +500,9 @@ static int stage2_map_walk_table_pre(u64 addr, u64 end, u32 level, > return 0; > } > > +static void stage2_flush_dcache(void *addr, u64 size); > +static bool stage2_pte_cacheable(kvm_pte_t pte); > + > static int stage2_map_walk_leaf(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, > struct stage2_map_data *data) > { > @@ -507,9 +510,17 @@ static int stage2_map_walk_leaf(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, > struct page *page = virt_to_page(ptep); > > if (data->anchor) { > - if (kvm_pte_valid(pte)) > + if (kvm_pte_valid(pte)) { > + kvm_set_invalid_pte(ptep); > + kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, data->mmu, > + addr, level); > put_page(page); This doesn't make sense to me: the page-table pages we're walking when the anchor is set are not accessible to the hardware walker because we unhooked the entire sub-table in stage2_map_walk_table_pre(), which has the necessary TLB invalidation. Are you seeing a problem in practice here? > + if (stage2_pte_cacheable(pte)) > + stage2_flush_dcache(kvm_pte_follow(pte), > + kvm_granule_size(level)); I don't understand the need for the flush either, as we're just coalescing existing entries into a larger block mapping. Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel