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 109FEC433F5 for ; Thu, 6 Jan 2022 22:57:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245316AbiAFW5n (ORCPT ); Thu, 6 Jan 2022 17:57:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60598 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245315AbiAFW5j (ORCPT ); Thu, 6 Jan 2022 17:57:39 -0500 Received: from mail-lf1-x12d.google.com (mail-lf1-x12d.google.com [IPv6:2a00:1450:4864:20::12d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 32966C061245 for ; Thu, 6 Jan 2022 14:57:39 -0800 (PST) Received: by mail-lf1-x12d.google.com with SMTP id r4so9060639lfe.7 for ; Thu, 06 Jan 2022 14:57:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=yzJHZd4Gd1bheV/asbmK4G/1FwWEzAUZrWzJArtbIz0=; b=Zki0siD3mjTCJ70qLU296CjxF52vQfJKI9PpJrTU7MY3UICyxWjAKdi4TJ4C/B7HPz tuOP9SU2M7i0h0K5hJZUGebEweMPff9dy5AUBCuFom56gcWfis/ZpECIa8KMs2O+6VW4 oGeIaqvyI+YI/EtIZpGppHj5db0VKmjSSISAmJiS3KCVF3LI8CWhSostoJBNt7sTMLFm +ChSBeu1Xuf8WOyHMvH82CJxotgrxF91bIZAYNhwZnZWGF7tvkXD+1/JhqPxN5oqy2GL mY7kxxfDMmb2wG09pCYOwX73yQHNuhnTztrLJ6ifluVCG0xp/PKOUYTgi0VgSGSGzq50 Bu7A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=yzJHZd4Gd1bheV/asbmK4G/1FwWEzAUZrWzJArtbIz0=; b=6kR004UrSmxIwEVw548vV8p9dVrS5EGkkg0oyHGOAbcmErs5CFYb2W6hlGJ2FI8VWx otExw8s3J/STXgEk2wRmZGr2No8mpJHLIs3WgCeSQyQOseWVUZstuTc9HPmgGatFKQkW JvDg5mve9K+qg9mytEfNmWCxD7bMGeO3WUVaBvGanr5TOyIo8yIygoq2lmeaNuBmDgiN 9+LlNboIuEf9EGFsdpmxI/oE58DwqlCU4NOjp/mBQ9ITiZOVakRvilT4yxDtsESN4eGd 1O/raHf1acmG2dHdr/Bzo6i8iLcxm9rSB+Jo3PPdbz0VBFpxiLHeDbLVwpRQAc+xZNcQ 6ceQ== X-Gm-Message-State: AOAM5308CXzDGBC3gCfA9YugAqg6lbSj4HiLRuvSC11gPmLw+rdFG8ct UTsfvnTkCHRGhUsUTRBIW27WVWAOrSev4X9Cyeiw3Q== X-Google-Smtp-Source: ABdhPJzh5R/BPz0CNdBZp9zlAFI0lnHCaa+83+UPJ0fPwq4JsnQcqrVtpZN/2GMbdMF6B1JV/2eiK9mfFtjYlXqO5PU= X-Received: by 2002:ac2:5388:: with SMTP id g8mr52790726lfh.64.1641509857221; Thu, 06 Jan 2022 14:57:37 -0800 (PST) MIME-Version: 1.0 References: <20211213225918.672507-1-dmatlack@google.com> <20211213225918.672507-7-dmatlack@google.com> In-Reply-To: From: David Matlack Date: Thu, 6 Jan 2022 14:57:10 -0800 Message-ID: Subject: Re: [PATCH v1 06/13] KVM: x86/mmu: Refactor tdp_mmu iterators to take kvm_mmu_page root To: Sean Christopherson Cc: Paolo Bonzini , kvm list , Ben Gardon , Joerg Roedel , Jim Mattson , Wanpeng Li , Vitaly Kuznetsov , Janis Schoetterl-Glausch , Junaid Shahid , Oliver Upton , Harish Barathvajasankar , Peter Xu , Peter Shier , "Nikunj A . Dadhania" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Thu, Jan 6, 2022 at 12:34 PM Sean Christopherson wrote: > > On Mon, Dec 13, 2021, David Matlack wrote: > > Instead of passing a pointer to the root page table and the root level > > separately, pass in a pointer to the kvm_mmu_page that backs the root. > > This reduces the number of arguments by 1, cutting down on line lengths. > > > > No functional change intended. > > > > Signed-off-by: David Matlack > > Reviewed-by: Ben Gardon > > --- > > arch/x86/kvm/mmu/tdp_iter.c | 5 ++++- > > arch/x86/kvm/mmu/tdp_iter.h | 10 +++++----- > > arch/x86/kvm/mmu/tdp_mmu.c | 14 +++++--------- > > 3 files changed, 14 insertions(+), 15 deletions(-) > > > > diff --git a/arch/x86/kvm/mmu/tdp_iter.c b/arch/x86/kvm/mmu/tdp_iter.c > > index b3ed302c1a35..92b3a075525a 100644 > > --- a/arch/x86/kvm/mmu/tdp_iter.c > > +++ b/arch/x86/kvm/mmu/tdp_iter.c > > @@ -39,9 +39,12 @@ void tdp_iter_restart(struct tdp_iter *iter) > > * Sets a TDP iterator to walk a pre-order traversal of the paging structure > > * rooted at root_pt, starting with the walk to translate next_last_level_gfn. > > */ > > -void tdp_iter_start(struct tdp_iter *iter, u64 *root_pt, int root_level, > > +void tdp_iter_start(struct tdp_iter *iter, struct kvm_mmu_page *root, > > int min_level, gfn_t next_last_level_gfn) > > { > > + u64 *root_pt = root->spt; > > + int root_level = root->role.level; > > Uber nit, arch/x86/ prefers reverse fir tree, though I've yet to get Paolo fully > on board :-) > > But looking at the usage of root_pt, even better would be > > void tdp_iter_start(struct tdp_iter *iter, struct kvm_mmu_page *root, > int min_level, gfn_t next_last_level_gfn) > { > int root_level = root->role.level; > > WARN_ON(root_level < 1); > WARN_ON(root_level > PT64_ROOT_MAX_LEVEL); > > iter->next_last_level_gfn = next_last_level_gfn; > iter->root_level = root_level; > iter->min_level = min_level; > iter->pt_path[iter->root_level - 1] = (tdp_ptep_t)root->spt; > iter->as_id = kvm_mmu_page_as_id(root); > > tdp_iter_restart(iter); > } > > to avoid the pointless sptep_to_sp() and eliminate the motivation for root_pt. Will do.