From patchwork Tue Jul 13 02:25:37 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zachary Amsden X-Patchwork-Id: 111628 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter.kernel.org (8.14.4/8.14.3) with ESMTP id o6D2Relq015169 for ; Tue, 13 Jul 2010 02:27:40 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756815Ab0GMC0Z (ORCPT ); Mon, 12 Jul 2010 22:26:25 -0400 Received: from mx1.redhat.com ([209.132.183.28]:32137 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754091Ab0GMC0V (ORCPT ); Mon, 12 Jul 2010 22:26:21 -0400 Received: from int-mx05.intmail.prod.int.phx2.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.18]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o6D2QK5K018474 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Mon, 12 Jul 2010 22:26:21 -0400 Received: from mysore (vpn-10-168.rdu.redhat.com [10.11.10.168]) by int-mx05.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o6D2Pfim026035; Mon, 12 Jul 2010 22:26:19 -0400 From: Zachary Amsden To: KVM , Avi Kivity , Marcelo Tosatti , Glauber Costa Cc: Linux-kernel , Zachary Amsden , Avi Kivity , Marcelo Tosatti , Glauber Costa Subject: [PATCH 17/18] Indicate reliable TSC in kvmclock Date: Mon, 12 Jul 2010 16:25:37 -1000 Message-Id: <1278987938-23873-18-git-send-email-zamsden@redhat.com> In-Reply-To: <1278987938-23873-1-git-send-email-zamsden@redhat.com> References: <1278987938-23873-1-git-send-email-zamsden@redhat.com> X-Scanned-By: MIMEDefang 2.67 on 10.5.11.18 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.3 (demeter.kernel.org [140.211.167.41]); Tue, 13 Jul 2010 02:27:41 +0000 (UTC) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index e73ddf6..b3cc186 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -55,6 +55,7 @@ #include #include #include +#include #define MAX_IO_MSRS 256 #define CR0_RESERVED_BITS \ @@ -902,6 +903,13 @@ static inline int kvm_tsc_changes_freq(void) return ret; } +static inline int kvm_tsc_reliable(void) +{ + return (boot_cpu_has(X86_FEATURE_CONSTANT_TSC) && + boot_cpu_has(X86_FEATURE_NONSTOP_TSC) && + !check_tsc_unstable()); +} + static inline u64 nsec_to_cycles(u64 nsec) { WARN_ON(preemptible()); @@ -1025,7 +1033,7 @@ static int kvm_write_guest_time(struct kvm_vcpu *v) vcpu->hv_clock.tsc_timestamp = tsc_timestamp; vcpu->hv_clock.system_time = kernel_ns + v->kvm->arch.kvmclock_offset; vcpu->last_kernel_ns = kernel_ns; - vcpu->hv_clock.flags = 0; + vcpu->hv_clock.flags = kvm_tsc_reliable() ? PVCLOCK_TSC_STABLE_BIT : 0; /* * The interface expects us to write an even number signaling that the