From patchwork Tue Apr 5 07:29:30 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 557250 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 0F8DEC388F3 for ; Tue, 5 Apr 2022 10:30:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355505AbiDEKUK (ORCPT ); Tue, 5 Apr 2022 06:20:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59912 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345323AbiDEJW0 (ORCPT ); Tue, 5 Apr 2022 05:22:26 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8B69F443C6; Tue, 5 Apr 2022 02:10:33 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id EE5BD61576; Tue, 5 Apr 2022 09:10:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 05BE0C385A0; Tue, 5 Apr 2022 09:10:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649149832; bh=H/g05GSqYLVNe7009eSkpVEVcdTs0rLY9M5I/WTcBDs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zZo2WCKK6YexZBxkd6aceRG4LT5N3NIsrRZuzgbKO72rgJ4XlwuHXKA/SQTt60GVr xo0G2h1qt0PIxWuF/6+9yEBWhI/lPCFbV/KHeJCJzF7b6MWoP8PXM94NdgXC/ecPjI a0Of1IrkOTD6Kg9x1ah2735yQu5jl87m/aSHIsUA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sean Christopherson , Paolo Bonzini Subject: [PATCH 5.16 0857/1017] KVM: x86: Reinitialize context if host userspace toggles EFER.LME Date: Tue, 5 Apr 2022 09:29:30 +0200 Message-Id: <20220405070419.674290454@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220405070354.155796697@linuxfoundation.org> References: <20220405070354.155796697@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Paolo Bonzini commit d6174299365ddbbf491620c0b8c5ca1a6ef2eea5 upstream. While the guest runs, EFER.LME cannot change unless CR0.PG is clear, and therefore EFER.NX is the only bit that can affect the MMU role. However, set_efer accepts a host-initiated change to EFER.LME even with CR0.PG=1. In that case, the MMU has to be reset. Fixes: 11988499e62b ("KVM: x86: Skip EFER vs. guest CPUID checks for host-initiated writes") Cc: stable@vger.kernel.org Reviewed-by: Sean Christopherson Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/mmu.h | 1 + arch/x86/kvm/x86.c | 3 +-- 2 files changed, 2 insertions(+), 2 deletions(-) --- a/arch/x86/kvm/mmu.h +++ b/arch/x86/kvm/mmu.h @@ -48,6 +48,7 @@ X86_CR4_SMEP | X86_CR4_SMAP | X86_CR4_PKE) #define KVM_MMU_CR0_ROLE_BITS (X86_CR0_PG | X86_CR0_WP) +#define KVM_MMU_EFER_ROLE_BITS (EFER_LME | EFER_NX) static __always_inline u64 rsvd_bits(int s, int e) { --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1614,8 +1614,7 @@ static int set_efer(struct kvm_vcpu *vcp return r; } - /* Update reserved bits */ - if ((efer ^ old_efer) & EFER_NX) + if ((efer ^ old_efer) & KVM_MMU_EFER_ROLE_BITS) kvm_mmu_reset_context(vcpu); return 0;