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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT 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 A20CBC6786C for ; Fri, 14 Dec 2018 12:06:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6576821486 for ; Fri, 14 Dec 2018 12:06:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1544789172; bh=CNc93kexL0wvXYlx1b4oHvkLU56jpPfC+KwzFsAJIfs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=EPoptM2ab/F9N0DsIR4VVckbQwfcRkk4csubrQonpLnreSYgHCaW0ebEGVPoBOgNO VQWtXE+pAczxBrNsHrf6wJTw3qP42cfjTO0tdqakHUI5B0OkM/lcTdARJUYs8a2RFq sVRuWNBfSsEF1fqf83R7FATAcxJCl6H4A772NZfc= DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6576821486 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730035AbeLNMGL (ORCPT ); Fri, 14 Dec 2018 07:06:11 -0500 Received: from mail.kernel.org ([198.145.29.99]:51082 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730055AbeLNMGH (ORCPT ); Fri, 14 Dec 2018 07:06:07 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3EDA02148E; Fri, 14 Dec 2018 12:06:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1544789166; bh=CNc93kexL0wvXYlx1b4oHvkLU56jpPfC+KwzFsAJIfs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xOCfHGqhHYN71l0XNsbUzFYgWE5jrVr97eZGG9Wy35yJlG5ICMz4DgnyBK73Z4zLb mLAo/P7Qnnn6x3h/jQQ1QNjHS323wcPZvFcPQ5kgx5Q3huQXKFcunxd0/kIVG0h3sd D1ZDpkXs7qhf96GifAz1eiLrreP9zikIyq14mk6U= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eyal Moscovici , Mihai Carabas , Liam Merwick , Jim Mattson , Liran Alon , Paolo Bonzini , Sasha Levin Subject: [PATCH 4.19 097/142] KVM: VMX: Update shared MSRs to be saved/restored on MSR_EFER.LMA changes Date: Fri, 14 Dec 2018 12:59:42 +0100 Message-Id: <20181214115750.936421427@linuxfoundation.org> X-Mailer: git-send-email 2.20.0 In-Reply-To: <20181214115747.053633987@linuxfoundation.org> References: <20181214115747.053633987@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit f48b4711dd6e1cf282f9dfd159c14a305909c97c ] When guest transitions from/to long-mode by modifying MSR_EFER.LMA, the list of shared MSRs to be saved/restored on guest<->host transitions is updated (See vmx_set_efer() call to setup_msrs()). On every entry to guest, vcpu_enter_guest() calls vmx_prepare_switch_to_guest(). This function should also take care of setting the shared MSRs to be saved/restored. However, the function does nothing in case we are already running with loaded guest state (vmx->loaded_cpu_state != NULL). This means that even when guest modifies MSR_EFER.LMA which results in updating the list of shared MSRs, it isn't being taken into account by vmx_prepare_switch_to_guest() because it happens while we are running with loaded guest state. To fix above mentioned issue, add a flag to mark that the list of shared MSRs has been updated and modify vmx_prepare_switch_to_guest() to set shared MSRs when running with host state *OR* list of shared MSRs has been updated. Note that this issue was mistakenly introduced by commit 678e315e78a7 ("KVM: vmx: add dedicated utility to access guest's kernel_gs_base") because previously vmx_set_efer() always called vmx_load_host_state() which resulted in vmx_prepare_switch_to_guest() to set shared MSRs. Fixes: 678e315e78a7 ("KVM: vmx: add dedicated utility to access guest's kernel_gs_base") Reported-by: Eyal Moscovici Reviewed-by: Mihai Carabas Reviewed-by: Liam Merwick Reviewed-by: Jim Mattson Signed-off-by: Liran Alon Signed-off-by: Paolo Bonzini Signed-off-by: Sasha Levin --- arch/x86/kvm/vmx.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index e55f7a90d4b2..b1aef90aab91 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -962,6 +962,7 @@ struct vcpu_vmx { struct shared_msr_entry *guest_msrs; int nmsrs; int save_nmsrs; + bool guest_msrs_dirty; unsigned long host_idt_base; #ifdef CONFIG_X86_64 u64 msr_host_kernel_gs_base; @@ -2874,6 +2875,20 @@ static void vmx_prepare_switch_to_guest(struct kvm_vcpu *vcpu) vmx->req_immediate_exit = false; + /* + * Note that guest MSRs to be saved/restored can also be changed + * when guest state is loaded. This happens when guest transitions + * to/from long-mode by setting MSR_EFER.LMA. + */ + if (!vmx->loaded_cpu_state || vmx->guest_msrs_dirty) { + vmx->guest_msrs_dirty = false; + for (i = 0; i < vmx->save_nmsrs; ++i) + kvm_set_shared_msr(vmx->guest_msrs[i].index, + vmx->guest_msrs[i].data, + vmx->guest_msrs[i].mask); + + } + if (vmx->loaded_cpu_state) return; @@ -2934,11 +2949,6 @@ static void vmx_prepare_switch_to_guest(struct kvm_vcpu *vcpu) vmcs_writel(HOST_GS_BASE, gs_base); host_state->gs_base = gs_base; } - - for (i = 0; i < vmx->save_nmsrs; ++i) - kvm_set_shared_msr(vmx->guest_msrs[i].index, - vmx->guest_msrs[i].data, - vmx->guest_msrs[i].mask); } static void vmx_prepare_switch_to_host(struct vcpu_vmx *vmx) @@ -3418,6 +3428,7 @@ static void setup_msrs(struct vcpu_vmx *vmx) move_msr_up(vmx, index, save_nmsrs++); vmx->save_nmsrs = save_nmsrs; + vmx->guest_msrs_dirty = true; if (cpu_has_vmx_msr_bitmap()) vmx_update_msr_bitmap(&vmx->vcpu); -- 2.19.1