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 824B0ECAAA1 for ; Fri, 28 Oct 2022 21:42:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229992AbiJ1Vmi (ORCPT ); Fri, 28 Oct 2022 17:42:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39304 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229886AbiJ1Vmg (ORCPT ); Fri, 28 Oct 2022 17:42:36 -0400 Received: from mail-pg1-x52d.google.com (mail-pg1-x52d.google.com [IPv6:2607:f8b0:4864:20::52d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 448BE23B692 for ; Fri, 28 Oct 2022 14:42:36 -0700 (PDT) Received: by mail-pg1-x52d.google.com with SMTP id r18so5894713pgr.12 for ; Fri, 28 Oct 2022 14:42:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=MNtHWFuVJo7RCDVkDfutNqtv/jry9OXULraTG7JwUdc=; b=Vc7KCJ7tTFt79LcDHbPh0VgyMSPC07KNz2pxxjI4QACmCoCZHD0ua0xGZDIQlZSP9q Xvx17CovdmJVekN1CASKbFPtZ7wS9qKTMJkxZNvRZOgopi2vNV/lCjCFzRYwjRQNRN4E 1vrUdkRAtfDUBCHQJkGi8SJuTBrP7uPwSuKeUpNO6XrywJw0Mwm+ZNkw6OSr3rnvYXM7 rRrKecp4EsrMWtUWNehpfv4FhzGrxpeTRTdUMxdMAWP1zj68k2mBfNQKSE+DJDtz03Ql Pq9+O7f8vAMVO7OBqeMTgnaWi05XT18EY9jt0QoBnz1EeBFraE2zgSr6CIlRmscuqs3m VHGA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=MNtHWFuVJo7RCDVkDfutNqtv/jry9OXULraTG7JwUdc=; b=NUrBdKwAUzM6jOPjOrqdWJF5IWqMrGQPQu8z4ByvoASwntRY7OaRbLZna6iV191PNO WQD0I9LVXsLp9pnygQikTj3s7Qo6Kfo3tG1oNonnUZvnktpChuhq79kWYm6oTybDKlSA JSJ9bcOdLYjs3q+Gq9ypHfa7XJ8FQszrz4NEfkPq4rHV1PO8aD6y4I2uZLseUg89lYlb gb17BV/rOeBMrSf2kiXx73+O2ClUOZZq0IIzJ61nGryGEu+tipyFSenApJSyyD6+fcLW h/ZHN9G7DTVRZg/iWrMqMC6Wy+c94gZJcWqck0/wSma3Fbky+WaRrV7okylbius5tWIE 1q2A== X-Gm-Message-State: ACrzQf2lspv8v57Fd5GH+hIlGzjQkTTF1S+An5A0jmC/QJiJPk9SLkyD StHam9ftHULH/AAGTM1fBvH7HA== X-Google-Smtp-Source: AMsMyM7t32R71Q+XQko8kyhpPUDEskRsXMrXf0innMx8jyiy6H5cYLFZwqNd4+0HGqYl48VEk880MQ== X-Received: by 2002:a63:d848:0:b0:46f:81cb:6d6c with SMTP id k8-20020a63d848000000b0046f81cb6d6cmr555562pgj.453.1666993355455; Fri, 28 Oct 2022 14:42:35 -0700 (PDT) Received: from google.com (7.104.168.34.bc.googleusercontent.com. [34.168.104.7]) by smtp.gmail.com with ESMTPSA id p123-20020a625b81000000b0056299fd2ba2sm3264250pfb.162.2022.10.28.14.42.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 28 Oct 2022 14:42:35 -0700 (PDT) Date: Fri, 28 Oct 2022 21:42:31 +0000 From: Sean Christopherson To: David Matlack Cc: Paolo Bonzini , kvm@vger.kernel.org Subject: Re: [PATCH 0/2] KVM: x86/mmu: Do not recover NX Huge Pages when dirty logging is enabled Message-ID: References: <20221027200316.2221027-1-dmatlack@google.com> <7314b8f3-0bda-e52d-1134-02387815a6f8@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Fri, Oct 28, 2022, David Matlack wrote: > On Fri, Oct 28, 2022 at 2:07 PM Sean Christopherson wrote: > > > > On Fri, Oct 28, 2022, David Matlack wrote: > > > I'll experiment with a more accurate solution. i.e. have the recovery > > > worker lookup the memslot for each SP and check if it has dirty > > > logging enabled. Maybe the increase in CPU usage won't be as bad as I > > > thought. > > > > If you end up grabbing the memslot, use kvm_mmu_max_mapping_level() instead of > > checking only dirty logging. The way KVM will avoid zapping shadow pages that > > could have been NX huge pages when they were created, but can no longer be NX huge > > pages due to something other than dirty logging, e.g. because the gfn is being > > shadow for nested TDP. > > kvm_mmu_max_mapping_level() doesn't check if dirty logging is enabled Gah, I forgot that kvm_mmu_hugepage_adjust() does a one-off check for dirty logging instead of the info being fed into slot->arch.lpage_info. Never mind.