From nobody Mon Feb 9 09:16:26 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1502096501905434.5816495632422; Mon, 7 Aug 2017 02:01:41 -0700 (PDT) Received: from localhost ([::1]:36122 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1deduu-0004rZ-Ba for importer@patchew.org; Mon, 07 Aug 2017 05:01:40 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54414) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dedqm-0001RQ-AY for qemu-devel@nongnu.org; Mon, 07 Aug 2017 04:57:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dedqk-0007Gz-TZ for qemu-devel@nongnu.org; Mon, 07 Aug 2017 04:57:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57664) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dedqk-0007Ga-O7 for qemu-devel@nongnu.org; Mon, 07 Aug 2017 04:57:22 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id A6E53DB94C; Mon, 7 Aug 2017 08:57:21 +0000 (UTC) Received: from dhcp-1-107.brq.redhat.com (unknown [10.43.2.49]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2D21084724; Mon, 7 Aug 2017 08:57:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com A6E53DB94C Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=lprosek@redhat.com From: Ladi Prosek To: qemu-devel@nongnu.org, kvm@vger.kernel.org Date: Mon, 7 Aug 2017 10:57:03 +0200 Message-Id: <20170807085703.32267-5-lprosek@redhat.com> In-Reply-To: <20170807085703.32267-1-lprosek@redhat.com> References: <20170807085703.32267-1-lprosek@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Mon, 07 Aug 2017 08:57:21 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v2 4/4] i386/kvm: advertise Hyper-V frequency MSRs X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: pbonzini@redhat.com, mtosatti@redhat.com, rkrcmar@redhat.com, david@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" As of kernel commit eb82feea59d6 ("KVM: hyperv: support HV_X64_MSR_TSC_FREQ= UENCY and HV_X64_MSR_APIC_FREQUENCY"), KVM supports two new MSRs which are requir= ed for nested Hyper-V to read timestamps with RDTSC + TSC page. This commit makes QEMU advertise the MSRs with CPUID.40000003H:EAX[11] and CPUID.40000003H:EDX[8] as specified in the Hyper-V TLFS and experimentally verified on a Hyper-V host. The feature is enabled with the existing hv-tim= e CPU flag, and only if the TSC frequency is stable across migrations and known. Signed-off-by: Ladi Prosek Reviewed-by: David Hildenbrand --- target/i386/kvm.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/target/i386/kvm.c b/target/i386/kvm.c index 2dc01c9..739334a 100644 --- a/target/i386/kvm.c +++ b/target/i386/kvm.c @@ -89,6 +89,7 @@ static bool has_msr_hv_vpindex; static bool has_msr_hv_runtime; static bool has_msr_hv_synic; static bool has_msr_hv_stimer; +static bool has_msr_hv_frequencies; static bool has_msr_xss; =20 static bool has_msr_architectural_pmu; @@ -640,7 +641,13 @@ static int hyperv_handle_properties(CPUState *cs) if (cpu->hyperv_time) { env->features[FEAT_HYPERV_EAX] |=3D HV_X64_MSR_HYPERCALL_AVAILABLE; env->features[FEAT_HYPERV_EAX] |=3D HV_X64_MSR_TIME_REF_COUNT_AVAI= LABLE; - env->features[FEAT_HYPERV_EAX] |=3D 0x200; + env->features[FEAT_HYPERV_EAX] |=3D HV_X64_MSR_REFERENCE_TSC_AVAIL= ABLE; + + if (has_msr_hv_frequencies && tsc_is_stable_and_known(env)) { + env->features[FEAT_HYPERV_EAX] |=3D HV_X64_ACCESS_FREQUENCY_MS= RS; + env->features[FEAT_HYPERV_EDX] |=3D + HV_FEATURE_FREQUENCY_MSRS_AVAILABLE; + } } if (cpu->hyperv_crash && has_msr_hv_crash) { env->features[FEAT_HYPERV_EDX] |=3D HV_X64_GUEST_CRASH_MSR_AVAILAB= LE; @@ -1134,6 +1141,9 @@ static int kvm_get_supported_msrs(KVMState *s) case HV_X64_MSR_STIMER0_CONFIG: has_msr_hv_stimer =3D true; break; + case HV_X64_MSR_TSC_FREQUENCY: + has_msr_hv_frequencies =3D true; + break; } } } --=20 2.9.3