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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 61104C433FE for ; Mon, 10 Oct 2022 03:58:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230361AbiJJD6g (ORCPT ); Sun, 9 Oct 2022 23:58:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51056 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230092AbiJJD6f (ORCPT ); Sun, 9 Oct 2022 23:58:35 -0400 Received: from out0.migadu.com (out0.migadu.com [94.23.1.103]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 53AED4A105; Sun, 9 Oct 2022 20:58:33 -0700 (PDT) Date: Mon, 10 Oct 2022 03:58:25 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1665374311; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=wy3CjO6m956FMVfpB0zMg7+XC0RTalCctjYSru1fYVw=; b=oWVAWjcVpjNvfw3SFVK1hv9hT41eVbN7mHBpbGOxDtRXsg5GY1AFAAAkuJRwIAznZbxpU5 nc9ffUv45N30VWIHBvEDUPuQNvrtLIBLaFrl/OQ2zk9saqP75Oaalht3sM03S3i4iFLXvV LU80PITJOklUELxX1kHc62yxI2dgUWA= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Oliver Upton To: Ricardo Koller Cc: Marc Zyngier , James Morse , Alexandru Elisei , Suzuki K Poulose , Catalin Marinas , Will Deacon , Quentin Perret , Reiji Watanabe , David Matlack , Ben Gardon , Paolo Bonzini , Gavin Shan , Peter Xu , Sean Christopherson , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 02/14] KVM: arm64: Tear down unlinked stage-2 subtree after break-before-make Message-ID: References: <20220830194132.962932-1-oliver.upton@linux.dev> <20220830194132.962932-3-oliver.upton@linux.dev> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Hey Ricardo, On Tue, Sep 13, 2022 at 05:20:11PM -0700, Ricardo Koller wrote: [...] > > diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c > > index d8127c25424c..5c0c8028d71c 100644 > > --- a/arch/arm64/kvm/hyp/pgtable.c > > +++ b/arch/arm64/kvm/hyp/pgtable.c > > @@ -763,17 +763,21 @@ static int stage2_map_walker_try_leaf(u64 addr, u64 end, u32 level, > > return 0; > > } > > > > +static int stage2_map_walk_leaf(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, > > + struct stage2_map_data *data); > > + > > static int stage2_map_walk_table_pre(u64 addr, u64 end, u32 level, > > kvm_pte_t *ptep, > > struct stage2_map_data *data) > > { > > - if (data->anchor) > > - return 0; > > + struct kvm_pgtable_mm_ops *mm_ops = data->mm_ops; > > + kvm_pte_t *childp = kvm_pte_follow(*ptep, mm_ops); > > + struct kvm_pgtable *pgt = data->mmu->pgt; > > + int ret; > > > > if (!stage2_leaf_mapping_allowed(addr, end, level, data)) > > return 0; > > > > - data->childp = kvm_pte_follow(*ptep, data->mm_ops); > > kvm_clear_pte(ptep); > > > > /* > > @@ -782,8 +786,13 @@ static int stage2_map_walk_table_pre(u64 addr, u64 end, u32 level, > > * individually. > > */ > > kvm_call_hyp(__kvm_tlb_flush_vmid, data->mmu); > > - data->anchor = ptep; > > - return 0; > > + > > + ret = stage2_map_walk_leaf(addr, end, level, ptep, data); > > I think this always ends up calling stage2_map_walker_try_leaf() (at > least it should). In that case, I think it might be clearer to do so, as > the intention is to just install a block. Yikes, I missed this in v2. I do agree with your point, it reads a bit odd to call something that could reinstall a table. Picked up the fix for v3. Thanks! -- Best, Oliver