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 E28CAC433F5 for ; Thu, 3 Mar 2022 20:03:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233490AbiCCUEk (ORCPT ); Thu, 3 Mar 2022 15:04:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38240 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231293AbiCCUEi (ORCPT ); Thu, 3 Mar 2022 15:04:38 -0500 Received: from mail-pf1-x435.google.com (mail-pf1-x435.google.com [IPv6:2607:f8b0:4864:20::435]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B858D4B40D for ; Thu, 3 Mar 2022 12:03:52 -0800 (PST) Received: by mail-pf1-x435.google.com with SMTP id j1so1711224pfj.5 for ; Thu, 03 Mar 2022 12:03:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=Pi8iH0FAYkIoz6MeuCkLdqM2juK9qQBoN4Ks48wQ+iA=; b=kwAxKx2fJbB7ljjwDZJV2FM0kwSPs73r6pQ8wAnY/3kHs37v6JZsIrTXQN53Bt4skz yyqVxn6+X7N3wpZLLN8h9GKt32c6qIlcAPqIDKfo9dH5iB1eeQ6v22e/xOtcht6inFUJ B6F87BAaFpwNu1r6QBlFyBpzdbDDpoOM224IxSKT+Abshs68aZSvbBiNdoE0jevxiMAj 7rbmoLO/r5urHspdeg6T/wy63VhA3E3KCf0BgXYo3dI6ht7Ge1Q6QDHUgN+O+RgQCiv/ uDwKWtOFhUyDGdvaJccDbRAxzkpHF8jms3QQ+IAqDUnsN9OFu1H/B7iQO8Z/CgnwzUjM uhTw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=Pi8iH0FAYkIoz6MeuCkLdqM2juK9qQBoN4Ks48wQ+iA=; b=M/OFCkyB6gf3XaVkijrl8FPnqTP3DUKWiXgP6TO6EQgUnaM2E4hsAlIXkN2jzYdpVr R9AG5YSpxK87qFQnnka3tOh/xLms/dNbMalFOzG1DYWJJEIJUJnvlTWLO7mdHDP4jnJv n+7/PlCnpfH77qYlQsKUxEWv/AtKMZnTs1721Myr+/FXQ5Altp3cH54VNkMU3yvijxIt 2p2aDYSahD9ZXycrBSXOo3dCVzDuyg1AJ6is6JR1nJgpVifUvokPFxYF6mCedypcwRIm OUC2zFxKPFczvlDPFo6NVe8nSkCu0l9+znIyLLSCiOX8395en5CBBGOMBEBA6U1xP4et ABSw== X-Gm-Message-State: AOAM530GIK9e5mvsUXqGaSQAuULdwKrmwCWY6gcg4sKGxWcq09yv1Ds/ 1ywy0OO4ycWpTYwMKevhalisvw== X-Google-Smtp-Source: ABdhPJzWDDSu+QZHAmizrO5aMSiFU6NdT3KLIfTXE5v94X6e4+P4/7SuaoNqW/drd1Cpjh/dctSSSg== X-Received: by 2002:a63:d252:0:b0:363:271c:fe63 with SMTP id t18-20020a63d252000000b00363271cfe63mr31827445pgi.524.1646337831852; Thu, 03 Mar 2022 12:03:51 -0800 (PST) Received: from google.com (157.214.185.35.bc.googleusercontent.com. [35.185.214.157]) by smtp.gmail.com with ESMTPSA id m4-20020a17090a7f8400b001bef3fc3938sm2837806pjl.49.2022.03.03.12.03.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 03 Mar 2022 12:03:51 -0800 (PST) Date: Thu, 3 Mar 2022 20:03:47 +0000 From: Sean Christopherson To: Paolo Bonzini Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , David Hildenbrand , David Matlack , Ben Gardon , Mingwei Zhang Subject: Re: [PATCH v4 06/30] KVM: x86/mmu: only perform eager page splitting on valid roots Message-ID: References: <20220303193842.370645-1-pbonzini@redhat.com> <20220303193842.370645-7-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220303193842.370645-7-pbonzini@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 03, 2022, Paolo Bonzini wrote: > Eager page splitting is an optimization; it does not have to be performed on > invalid roots. It is also the only case in which a reader might acquire > a reference to an invalid root, so after this change we know that readers > will skip both dying and invalid roots. > > Signed-off-by: Paolo Bonzini > --- Reviewed-by: Sean Christopherson