From patchwork Tue Oct 20 07:39:11 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Haozhong Zhang X-Patchwork-Id: 7443141 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id C89DDBEEA4 for ; Tue, 20 Oct 2015 07:53:02 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 00733207C8 for ; Tue, 20 Oct 2015 07:53:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2298B207B9 for ; Tue, 20 Oct 2015 07:53:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753218AbbJTHmK (ORCPT ); Tue, 20 Oct 2015 03:42:10 -0400 Received: from mga03.intel.com ([134.134.136.65]:20971 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753209AbbJTHmJ (ORCPT ); Tue, 20 Oct 2015 03:42:09 -0400 Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga103.jf.intel.com with ESMTP; 20 Oct 2015 00:42:08 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.17,706,1437462000"; d="scan'208";a="830657238" Received: from hzzhang-optiplex-9020.sh.intel.com (HELO localhost) ([10.239.12.28]) by orsmga002.jf.intel.com with ESMTP; 20 Oct 2015 00:42:05 -0700 From: Haozhong Zhang To: kvm@vger.kernel.org Cc: Gleb Natapov , Paolo Bonzini , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, Joerg Roedel , Wanpeng Li , Xiao Guangrong , mdontu@bitdefender.com, Kai Huang , Andy Lutomirski , linux-kernel@vger.kernel.org, Haozhong Zhang Subject: [PATCH v2 11/12] KVM: VMX: Use a scaled host TSC for guest readings of MSR_IA32_TSC Date: Tue, 20 Oct 2015 15:39:11 +0800 Message-Id: <1445326752-8926-12-git-send-email-haozhong.zhang@intel.com> X-Mailer: git-send-email 2.4.8 In-Reply-To: <1445326752-8926-1-git-send-email-haozhong.zhang@intel.com> References: <1445326752-8926-1-git-send-email-haozhong.zhang@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch makes kvm-intel to return a scaled host TSC plus the TSC offset when handling guest readings to MSR_IA32_TSC. Signed-off-by: Haozhong Zhang --- arch/x86/kvm/vmx.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index c241ff3..a02b59c 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2372,15 +2372,16 @@ static void setup_msrs(struct vcpu_vmx *vmx) /* * reads and returns guest's timestamp counter "register" - * guest_tsc = host_tsc + tsc_offset -- 21.3 + * guest_tsc = (host_tsc * tsc multiplier) >> 48 + tsc_offset + * -- Intel TSC Scaling for Virtualization White Paper, sec 1.3 */ -static u64 guest_read_tsc(void) +static u64 guest_read_tsc(struct kvm_vcpu *vcpu) { u64 host_tsc, tsc_offset; host_tsc = rdtsc(); tsc_offset = vmcs_read64(TSC_OFFSET); - return host_tsc + tsc_offset; + return kvm_scale_tsc(vcpu, host_tsc) + tsc_offset; } /* @@ -2772,7 +2773,7 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) case MSR_EFER: return kvm_get_msr_common(vcpu, msr_info); case MSR_IA32_TSC: - msr_info->data = guest_read_tsc(); + msr_info->data = guest_read_tsc(vcpu); break; case MSR_IA32_SYSENTER_CS: msr_info->data = vmcs_read32(GUEST_SYSENTER_CS);