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=-7.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 6C34CC433B4 for ; Fri, 2 Apr 2021 11:14:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 406C0610A0 for ; Fri, 2 Apr 2021 11:14:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235143AbhDBLO4 (ORCPT ); Fri, 2 Apr 2021 07:14:56 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:46940 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234919AbhDBLOz (ORCPT ); Fri, 2 Apr 2021 07:14:55 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1617362092; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=/fKJ2OSCFXizuU2U1MJ67BIOWCyNds4Q38dY2jX+k4E=; b=IuTrGx2H4s5+2boY/qSzwSUi70bWbbG7kBZSN2vQIJlTxSfpW9QhF2e33+CzSihH9Cla2q khTZPYErEx+FWFSKvMHUZZR5PpDBpUT2gO+CaWhgrlXoRtYzi0OR3urF1kL5tY36LEwLUS DZn290JgXSodiN1gdbv69H7ONV+xnDM= Received: from mail-wr1-f72.google.com (mail-wr1-f72.google.com [209.85.221.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-361-_gTvTO5ZPRunHnlNVaKVJg-1; Fri, 02 Apr 2021 07:14:51 -0400 X-MC-Unique: _gTvTO5ZPRunHnlNVaKVJg-1 Received: by mail-wr1-f72.google.com with SMTP id z17so4212824wrv.23 for ; Fri, 02 Apr 2021 04:14:51 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=/fKJ2OSCFXizuU2U1MJ67BIOWCyNds4Q38dY2jX+k4E=; b=QGBBFgarOkcX5GZAed6B3eZiLO1RmwUa2buZCix0sT1Aej2ONpDzFFCIrayeJLY1PP Gm6zxyOZ2ZLbE9WFx4wYQvTWVhkULil0u66trs9y932d9c3dstWgVG9+rLWrY9pBtzvX EglLFzf0iKFm/iIsL/worzJlltijv/ohYojS8Z7G/sz0LJnl8SSE5Ru1kzoLa9ITS4ba EvF/evHeei/CHopUjcBO0uBNYB0kqkoQRoMWPqE/RDsV6fzxavRfxRrLZPj3f4YW0uA6 ZB2N6tZSQX44bgw7cBLdagSZMs2Y6oVeJxF7sSRYbtJmTvOUKwQmrkk/ahCBuxOyVf93 4vTw== X-Gm-Message-State: AOAM530Y9aIT9BGw9HthZEknTZFOhqptEaWjpjqrhcKlxWzV/cgy3Qh2 87NcPOZNfJRHcHJ7GczlMfxHWgedXnJ7JQ3w2axZ41uRaFWl0fqsFOCEN7L2Izg52/5uy6R5TJv XhgKU6pAMUp0uEEStB6TT4PMr X-Received: by 2002:adf:fb05:: with SMTP id c5mr15230079wrr.302.1617362090123; Fri, 02 Apr 2021 04:14:50 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyDC2lEkIz55o7/8zmXTfl7KMf2+IvXa4U8NcK872E7p5nXNoS/a2umf8IXffQu2cm+oMqeRQ== X-Received: by 2002:adf:fb05:: with SMTP id c5mr15230063wrr.302.1617362089964; Fri, 02 Apr 2021 04:14:49 -0700 (PDT) Received: from ?IPv6:2001:b07:6468:f312:5e2c:eb9a:a8b6:fd3e? ([2001:b07:6468:f312:5e2c:eb9a:a8b6:fd3e]) by smtp.gmail.com with ESMTPSA id n1sm18076777wro.36.2021.04.02.04.14.48 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 02 Apr 2021 04:14:49 -0700 (PDT) Subject: Re: [PATCH v2 10/13] KVM: x86/mmu: Allow zapping collapsible SPTEs to use MMU read lock To: Ben Gardon , linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Peter Xu , Sean Christopherson , Peter Shier , Peter Feiner , Junaid Shahid , Jim Mattson , Yulei Zhang , Wanpeng Li , Vitaly Kuznetsov , Xiao Guangrong References: <20210401233736.638171-1-bgardon@google.com> <20210401233736.638171-11-bgardon@google.com> From: Paolo Bonzini Message-ID: <4140362f-92d5-5c5e-de8e-4e1e3a65b317@redhat.com> Date: Fri, 2 Apr 2021 13:14:47 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.0 MIME-Version: 1.0 In-Reply-To: <20210401233736.638171-11-bgardon@google.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/04/21 01:37, Ben Gardon wrote: > To speed the process of disabling dirty logging, change the TDP MMU > function which zaps collapsible SPTEs to run under the MMU read lock. Technically it only reduces the impact on the running VM; it doesn't speed it up right? Something like: To reduce the impact of disabling dirty logging, change the TDP MMU function which zaps collapsible SPTEs to run under the MMU read lock. This way, page faults on zapped SPTEs can proceed in parallel with kvm_mmu_zap_collapsible_sptes. Paolo