From nobody Mon Feb 9 09:33:18 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 1501838587404460.0540634617264; Fri, 4 Aug 2017 02:23:07 -0700 (PDT) Received: from localhost ([::1]:49598 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ddYoz-0001Ot-MM for importer@patchew.org; Fri, 04 Aug 2017 05:23:05 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59010) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ddYnl-0000iO-6s for qemu-devel@nongnu.org; Fri, 04 Aug 2017 05:21:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ddYni-0008Jr-1l for qemu-devel@nongnu.org; Fri, 04 Aug 2017 05:21:49 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51202) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ddYnh-0008Ip-Rg for qemu-devel@nongnu.org; Fri, 04 Aug 2017 05:21:45 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2791D4A6E8; Fri, 4 Aug 2017 09:14:13 +0000 (UTC) Received: from dhcp-1-107.brq.redhat.com (ovpn-204-166.brq.redhat.com [10.40.204.166]) by smtp.corp.redhat.com (Postfix) with ESMTP id 89A6952FBC; Fri, 4 Aug 2017 09:14:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 2791D4A6E8 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: Fri, 4 Aug 2017 11:14:03 +0200 Message-Id: <20170804091403.13478-4-lprosek@redhat.com> In-Reply-To: <20170804091403.13478-1-lprosek@redhat.com> References: <20170804091403.13478-1-lprosek@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Fri, 04 Aug 2017 09:14:13 +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 3/3] 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 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 migration and known. Signed-off-by: Ladi Prosek --- target/i386/kvm.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/target/i386/kvm.c b/target/i386/kvm.c index 77b6373..7e484a7 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; @@ -631,7 +632,17 @@ 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 clock must be stable and known for this feature. */ + && ((env->features[FEAT_8000_0007_EDX] & CPUID_APM_INVTSC) + || env->user_tsc_khz !=3D 0) + && env->tsc_khz !=3D 0) { + + 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; @@ -1127,6 +1138,9 @@ 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 } --=20 2.9.3