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=-9.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 B7D48C433E2 for ; Fri, 10 Jul 2020 14:12:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 83A7820836 for ; Fri, 10 Jul 2020 14:12:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="ZtoQ3/RD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728318AbgGJOMe (ORCPT ); Fri, 10 Jul 2020 10:12:34 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:48681 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728315AbgGJOMc (ORCPT ); Fri, 10 Jul 2020 10:12:32 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1594390351; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=VOceSolOcCnL8nnokzwJbOsFELxGoSPw4yCTbFrccdo=; b=ZtoQ3/RDbk5wHOsAs++BNJ07CzUsOucQbYMniUd8mg+l+Leu073he+xbnHhq0ocgEdnXo8 jbEfRcgIvQ7aCKG0xWfrhuCfP8EhemmRYHh2jK9inhFlabY+K4wmAOaE2TwMb989yPbBmo fTG03GX+++cVUpeLvUb8sy1wDQ8dRto= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-404-Ur86T0lJPLSe1nDsqltjyA-1; Fri, 10 Jul 2020 10:12:27 -0400 X-MC-Unique: Ur86T0lJPLSe1nDsqltjyA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 569CB1083; Fri, 10 Jul 2020 14:12:26 +0000 (UTC) Received: from vitty.brq.redhat.com (unknown [10.40.195.35]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2992374F52; Fri, 10 Jul 2020 14:12:23 +0000 (UTC) From: Vitaly Kuznetsov To: kvm@vger.kernel.org, Paolo Bonzini Cc: Sean Christopherson , Wanpeng Li , Jim Mattson , Junaid Shahid , linux-kernel@vger.kernel.org Subject: [PATCH v4 9/9] KVM: x86: drop superfluous mmu_check_root() from fast_pgd_switch() Date: Fri, 10 Jul 2020 16:11:57 +0200 Message-Id: <20200710141157.1640173-10-vkuznets@redhat.com> In-Reply-To: <20200710141157.1640173-1-vkuznets@redhat.com> References: <20200710141157.1640173-1-vkuznets@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The mmu_check_root() check in fast_pgd_switch() seems to be superfluous: when GPA is outside of the visible range cached_root_available() will fail for non-direct roots (as we can't have a matching one on the list) and we don't seem to care for direct ones. Also, raising #TF immediately when a non-existent GFN is written to CR3 doesn't seem to mach architectural behavior. Drop the check. Signed-off-by: Vitaly Kuznetsov --- arch/x86/kvm/mmu/mmu.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 13ec3c30eda2..50a923696bf1 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -4277,8 +4277,7 @@ static bool fast_pgd_switch(struct kvm_vcpu *vcpu, gpa_t new_pgd, */ if (mmu->shadow_root_level >= PT64_ROOT_4LEVEL && mmu->root_level >= PT64_ROOT_4LEVEL) - return !mmu_check_root(vcpu, new_pgd >> PAGE_SHIFT) && - cached_root_available(vcpu, new_pgd, new_role); + return cached_root_available(vcpu, new_pgd, new_role); return false; } -- 2.25.4