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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 7D83AC10DCE for ; Wed, 18 Mar 2020 03:51:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 58C2520738 for ; Wed, 18 Mar 2020 03:51:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727193AbgCRDvM (ORCPT ); Tue, 17 Mar 2020 23:51:12 -0400 Received: from mga14.intel.com ([192.55.52.115]:57668 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726229AbgCRDvL (ORCPT ); Tue, 17 Mar 2020 23:51:11 -0400 IronPort-SDR: JiYt3whZZc5rWcXYQjE9lZ0QWtm+Lx4F1ybZGVxtr7O+lvkYsIwK7Mr5yLmjyIXlkER81tSf3q a4C7MRwCGRLw== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Mar 2020 20:51:11 -0700 IronPort-SDR: 9bUF4H9QQNe3a8MQitbBFyw8f9tSiDyCfhjvRRegxTcaEa61P4rY7aAkTgy9i/WeNGTaHtWTYI 3rVfHzAzi7vg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,566,1574150400"; d="scan'208";a="268215257" Received: from icx-2s.bj.intel.com ([10.240.192.138]) by fmsmga004.fm.intel.com with ESMTP; 17 Mar 2020 20:51:09 -0700 From: Luwei Kang To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: pbonzini@redhat.com, sean.j.christopherson@intel.com, vkuznets@redhat.com, wanpengli@tencent.com, jmattson@google.com, joro@8bytes.org, Luwei Kang Subject: [PATCH] KVM: VMX: Disable Intel PT before VM-entry Date: Wed, 18 Mar 2020 11:48:18 +0800 Message-Id: <1584503298-18731-1-git-send-email-luwei.kang@intel.com> X-Mailer: git-send-email 1.8.3.1 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 If the logical processor is operating with Intel PT enabled ( IA32_RTIT_CTL.TraceEn = 1) at the time of VM entry, the “load IA32_RTIT_CTL” VM-entry control must be 0(SDM 26.2.1.1). The first disabled the host Intel PT(Clear TraceEn) will make all the buffered packets are flushed out of the processor and it may cause an Intel PT PMI. The host Intel PT will be re-enabled in the host Intel PT PMI handler. handle_pmi_common() -> intel_pt_interrupt() -> pt_config_start() This patch will disable the Intel PT twice to make sure the Intel PT is disabled before VM-Entry. Signed-off-by: Luwei Kang --- arch/x86/kvm/vmx/vmx.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 26f8f31..d936a91 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -1095,6 +1095,8 @@ static inline void pt_save_msr(struct pt_ctx *ctx, u32 addr_range) static void pt_guest_enter(struct vcpu_vmx *vmx) { + u64 rtit_ctl; + if (pt_mode == PT_MODE_SYSTEM) return; @@ -1103,8 +1105,14 @@ static void pt_guest_enter(struct vcpu_vmx *vmx) * Save host state before VM entry. */ rdmsrl(MSR_IA32_RTIT_CTL, vmx->pt_desc.host.ctl); - if (vmx->pt_desc.guest.ctl & RTIT_CTL_TRACEEN) { + if (vmx->pt_desc.host.ctl & RTIT_CTL_TRACEEN) { wrmsrl(MSR_IA32_RTIT_CTL, 0); + rdmsrl(MSR_IA32_RTIT_CTL, rtit_ctl); + if (rtit_ctl) + wrmsrl(MSR_IA32_RTIT_CTL, 0); + } + + if (vmx->pt_desc.guest.ctl & RTIT_CTL_TRACEEN) { pt_save_msr(&vmx->pt_desc.host, vmx->pt_desc.addr_range); pt_load_msr(&vmx->pt_desc.guest, vmx->pt_desc.addr_range); } -- 1.8.3.1