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=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,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 80086C48BCD for ; Wed, 9 Jun 2021 23:43:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 69B58613F0 for ; Wed, 9 Jun 2021 23:43:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229792AbhFIXpM (ORCPT ); Wed, 9 Jun 2021 19:45:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48350 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229802AbhFIXo5 (ORCPT ); Wed, 9 Jun 2021 19:44:57 -0400 Received: from mail-qk1-x749.google.com (mail-qk1-x749.google.com [IPv6:2607:f8b0:4864:20::749]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1E1FDC061760 for ; Wed, 9 Jun 2021 16:42:49 -0700 (PDT) Received: by mail-qk1-x749.google.com with SMTP id n3-20020a378b030000b02903a624ca95adso18102969qkd.17 for ; Wed, 09 Jun 2021 16:42:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=reply-to:date:in-reply-to:message-id:mime-version:references :subject:from:to:cc; bh=LN0JaAN3T5+nq6SFVxphdupyoLpcoEoPHxPPBl9bv9U=; b=Tla+YY0L+7EOHZs/dedTljFCSPp26cpMfl30zgXQ+OLUmSM/PUJMr+izjPlZ5UJBMu ii9xWBIsKqjss/9j8fA5GoeSocniFYkln61UJap8MPcxp8XXdZNYdjT+DktrczynrTXk 4HvgjORzpc4CzCRf9zsyU+RFcAUMMJ+8LxkVAxs+a6CgiwkBddTyvEvlApbvbFofThvp rrt4mM3//Ck/2FGMMZAQwtCbbly+YjzzPuIH3ZlPjGVcZdM4CpmpO/ampQMKhX9XmR70 WQJyu/ntDcu4dKxhl0wNDj2ePL+0rNI1SIf02fEGC8Z+Zp/DNuvjBwXhnAk4lKc+eLDz zpvQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:reply-to:date:in-reply-to:message-id :mime-version:references:subject:from:to:cc; bh=LN0JaAN3T5+nq6SFVxphdupyoLpcoEoPHxPPBl9bv9U=; b=ljxYKHTKvQ8/uEKKG1rySy2IaJ15a3/FEVIdQR+pdxv/6qi/gcOUSzCKDrizF/R1LR kHmPS4ljERtWMno1lSUnBOL/zxEe9H0vT5Guk3ZqPwwZS0s0xYLrTbvac4zWeTwHtNDK Iw9TAOlZmzrDso+TvjpDERjxmNo3vltNtYlcPt7FbP1QGdK/982nlcyAE+D7HqgTUGAk hLk4n0Q+FoJMY74DdQnnP/RRT1ZuNQaHMIqxaagjpEVPlDuwtI5O1zXaqBC9GpynZ217 0y9HgVFXYe8oGQzQ91mK1pvtdQGwCq5ELtQC9ppRR3UyKQikXTrH3wrQD6XjSxEF8hwL rBVw== X-Gm-Message-State: AOAM531ASa5mVS2o6t4wB02XwjXQ+O83diRxugsd8NplEilCTcr0EAVG yL0CYYKN46jNbkaXE2UeFgvQdkVNJrM= X-Google-Smtp-Source: ABdhPJy1wdnajK8auCAaIPjf4hKWJO3bnez97krGV/zeyw/JEJzMfsrA/ZOHXieVRy2GU1OrEiucYXPEmVQ= X-Received: from seanjc798194.pdx.corp.google.com ([2620:15c:f:10:8daf:e5e:ae50:4f28]) (user=seanjc job=sendgmr) by 2002:ad4:4c0c:: with SMTP id bz12mr2346916qvb.21.1623282166720; Wed, 09 Jun 2021 16:42:46 -0700 (PDT) Reply-To: Sean Christopherson Date: Wed, 9 Jun 2021 16:42:22 -0700 In-Reply-To: <20210609234235.1244004-1-seanjc@google.com> Message-Id: <20210609234235.1244004-3-seanjc@google.com> Mime-Version: 1.0 References: <20210609234235.1244004-1-seanjc@google.com> X-Mailer: git-send-email 2.32.0.rc1.229.g3e70b5a671-goog Subject: [PATCH 02/15] KVM: nVMX: Ensure 64-bit shift when checking VMFUNC bitmap From: Sean Christopherson To: Paolo Bonzini Cc: Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Junaid Shahid , Maxim Levitsky , Lai Jiangshan Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Use BIT_ULL() instead of an open-coded shift to check whether or not a function is enabled in L1's VMFUNC bitmap. This is a benign bug as KVM supports only bit 0, and will fail VM-Enter if any other bits are set, i.e. bits 63:32 are guaranteed to be zero. Note, "function" is bounded by hardware as VMFUNC will #UD before taking a VM-Exit if the function is greater than 63. Before: if ((vmcs12->vm_function_control & (1 << function)) == 0) 0x000000000001a916 <+118>: mov $0x1,%eax 0x000000000001a91b <+123>: shl %cl,%eax 0x000000000001a91d <+125>: cltq 0x000000000001a91f <+127>: and 0x128(%rbx),%rax After: if (!(vmcs12->vm_function_control & BIT_ULL(function & 63))) 0x000000000001a955 <+117>: mov 0x128(%rbx),%rdx 0x000000000001a95c <+124>: bt %rax,%rdx Fixes: 27c42a1bb867 ("KVM: nVMX: Enable VMFUNC for the L1 hypervisor") Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/nested.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 1c243758dd2c..c3624109ffeb 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -5540,7 +5540,7 @@ static int handle_vmfunc(struct kvm_vcpu *vcpu) } vmcs12 = get_vmcs12(vcpu); - if ((vmcs12->vm_function_control & (1 << function)) == 0) + if (!(vmcs12->vm_function_control & BIT_ULL(function))) goto fail; switch (function) { -- 2.32.0.rc1.229.g3e70b5a671-goog