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=-18.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_IN_DEF_DKIM_WL autolearn=ham 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 1C8DCC432BE for ; Wed, 25 Aug 2021 23:31:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EE032610A7 for ; Wed, 25 Aug 2021 23:31:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233792AbhHYXcQ (ORCPT ); Wed, 25 Aug 2021 19:32:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53092 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231535AbhHYXcP (ORCPT ); Wed, 25 Aug 2021 19:32:15 -0400 Received: from mail-pl1-x636.google.com (mail-pl1-x636.google.com [IPv6:2607:f8b0:4864:20::636]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 59365C061757 for ; Wed, 25 Aug 2021 16:31:29 -0700 (PDT) Received: by mail-pl1-x636.google.com with SMTP id q21so551551plq.3 for ; Wed, 25 Aug 2021 16:31:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=bgT/xeyKOXnNMIg+PdpIMek16t1MpqSR/AfuX+wgSrA=; b=gOsmZJmwz/1EotD/4o/+JOTvdKprAHG3QXqP2jWFxCkc65Jxlox1da9kyvbK/kw++V 5iI/gbkrqst0NPvnibea0EzhlDUs5ix+e9h35hL4a/ESj2hCHHXzjwpFAsMSg4+HLfkr YL0Zxzp/cZLuMp68sm9woEizpwi9sDAR1cVayIwrAPt3DDKxx/npH0YS1bSZ8DgzGJUi +cwe7Sjsr67qJLqTdy1agguGlgNKZAnwPmND4EiXsJyVI0/p8t26zYHUAuSaBm8SzQj2 mA1zXZGzUnXpknTG5xTs79zPPmjnkEgHY6itsAwcndriwvehWI3NlB1KYrSDMjE2YpvN yYXw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=bgT/xeyKOXnNMIg+PdpIMek16t1MpqSR/AfuX+wgSrA=; b=K59L+0b+NMJOJwGDV6yZM/mzFv+bPCvsVbVbRLLNeBRi7i3W/yx+aX2Uu948a02ep0 ZmRtMFRap5KIctX1p3yZ90NpfMTNkpQqq/wo2ghigCc+cuHfbN3BrkDz7EH1B9N4G3p9 eqIHn+1OEYPCQzJtt12K3Dy4xccJMUDNU/6O+j5doEU1JwOeH8qvRM0m+Q2A9t1G6kbh Tot3ej7R8BT1lMcP15MdXE1SgVsECewOC/SWUSfkwv0oKUC/6T3KkMFhwOk6djmikxCU dUG4zr5LceOGsbZED+YW5v9Wz6BYqxoEb2tqrJ2KAUSnbODjoF9YFBTUcACP2BZCNaP0 ErrQ== X-Gm-Message-State: AOAM531h6bjpuF2jzplCrIV1rr2tqfWJ/YURrhJS4sNibfSf/mAvL+Km 7o+x09BTNv2BOkIr5ZcHTZ8VikPD8+fSdQ== X-Google-Smtp-Source: ABdhPJw6SDAriO2g5V8ktvD46t9dMsDkD/rs6uDbktv6l47zN/mFXV+bDpC3wfJm5Q6WGnRJbeG9yA== X-Received: by 2002:a17:902:ab52:b0:12d:92b8:60c7 with SMTP id ij18-20020a170902ab5200b0012d92b860c7mr746208plb.44.1629934288610; Wed, 25 Aug 2021 16:31:28 -0700 (PDT) Received: from google.com (157.214.185.35.bc.googleusercontent.com. [35.185.214.157]) by smtp.gmail.com with ESMTPSA id n32sm879724pgl.69.2021.08.25.16.31.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 Aug 2021 16:31:27 -0700 (PDT) Date: Wed, 25 Aug 2021 23:31:24 +0000 From: Sean Christopherson To: David Matlack Cc: Paolo Bonzini , kvm@vger.kernel.org, Ben Gardon , Joerg Roedel , Jim Mattson , Wanpeng Li , Vitaly Kuznetsov Subject: Re: [PATCH] KVM: x86/mmu: Refactor slot null check in kvm_mmu_hugepage_adjust Message-ID: References: <20210824233407.1845924-1-dmatlack@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210824233407.1845924-1-dmatlack@google.com> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, Aug 24, 2021, David Matlack wrote: > The current code is correct but relies on is_error_noslot_pfn() to > ensure slot is not null. The only reason is_error_noslot_pfn() was > checked instead is because we did not have the slot before > commit 6574422f913e ("KVM: x86/mmu: Pass the memslot around via struct > kvm_page_fault") and looking up the memslot is expensive. > > Now that the slot is available, explicitly check if it's null and > get rid of the redundant is_error_noslot_pfn() check. > > Suggested-by: Sean Christopherson > Signed-off-by: David Matlack > --- Reviewed-by: Sean Christopherson