From patchwork Wed Jan 5 08:57:04 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vitaly Kuznetsov X-Patchwork-Id: 12704158 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id CEEE5C433F5 for ; Wed, 5 Jan 2022 09:01:57 +0000 (UTC) Received: from localhost ([::1]:42042 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1n52BA-0001o8-IF for qemu-devel@archiver.kernel.org; Wed, 05 Jan 2022 04:01:56 -0500 Received: from eggs.gnu.org ([209.51.188.92]:40408) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1n527h-00005s-VO for qemu-devel@nongnu.org; Wed, 05 Jan 2022 03:58:21 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:31919) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1n527e-00052A-S5 for qemu-devel@nongnu.org; Wed, 05 Jan 2022 03:58:20 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1641373095; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ZhPCOtb+4Hl3fi/XJXGATWF5e4ieMNjTya+qOj+THmY=; b=e+JbL0qTFd0gAWUgvxbRLl0N+W3zTrIWDeHHbzt7qCGloSu+gAGcBOPsyBHMtIzpbqwCev eTjNwvpSak59ADhs8ftFmaLkZcU72LuDeBCo3LiFbNLz/Xmgy8/pWQGcQ6oGVdp4nTlwYi j+UXsHTb/y5pEG0leOgelFr1cfVWCFI= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-171-m14mP5D0N0Cd-pzOwbs78A-1; Wed, 05 Jan 2022 03:57:11 -0500 X-MC-Unique: m14mP5D0N0Cd-pzOwbs78A-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id AF846190A7A0 for ; Wed, 5 Jan 2022 08:57:10 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.40.194.48]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7B47170D39; Wed, 5 Jan 2022 08:57:09 +0000 (UTC) From: Vitaly Kuznetsov To: qemu-devel@nongnu.org Subject: [PATCH 2/2] i386: Hyper-V Enlightened MSR bitmap feature Date: Wed, 5 Jan 2022 09:57:04 +0100 Message-Id: <20220105085704.1267530-3-vkuznets@redhat.com> In-Reply-To: <20220105085704.1267530-1-vkuznets@redhat.com> References: <20220105085704.1267530-1-vkuznets@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=vkuznets@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=170.10.133.124; envelope-from=vkuznets@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.372, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Paolo Bonzini , Marcelo Tosatti Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" The newly introduced enlightenment allow L0 (KVM) and L1 (Hyper-V) hypervisors to collaborate to avoid unnecessary updates to L2 MSR-Bitmap upon vmexits. Signed-off-by: Vitaly Kuznetsov --- docs/hyperv.txt | 10 ++++++++++ target/i386/cpu.c | 2 ++ target/i386/cpu.h | 1 + target/i386/kvm/hyperv-proto.h | 5 +++++ target/i386/kvm/kvm.c | 7 +++++++ 5 files changed, 25 insertions(+) diff --git a/docs/hyperv.txt b/docs/hyperv.txt index 0417c183a3b0..08429124a634 100644 --- a/docs/hyperv.txt +++ b/docs/hyperv.txt @@ -225,6 +225,16 @@ default (WS2016). Note: hv-version-id-* are not enlightenments and thus don't enable Hyper-V identification when specified without any other enlightenments. +3.21. hv-emsr-bitmap +===================== +The enlightenment is nested specific, it targets Hyper-V on KVM guests. When +enabled, it allows L0 (KVM) and L1 (Hyper-V) hypervisors to collaborate to +avoid unnecessary updates to L2 MSR-Bitmap upon vmexits. While the protocol is +supported for both VMX (Intel) and SVM (AMD), the VMX implementation requires +Enlightened VMCS ('hv-evmcs') feature to also be enabled. + +Recommended: hv-evmcs (Intel) + 4. Supplementary features ========================= diff --git a/target/i386/cpu.c b/target/i386/cpu.c index aa9e6368004c..f7405fdf4fa5 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -6839,6 +6839,8 @@ static Property x86_cpu_properties[] = { HYPERV_FEAT_STIMER_DIRECT, 0), DEFINE_PROP_BIT64("hv-avic", X86CPU, hyperv_features, HYPERV_FEAT_AVIC, 0), + DEFINE_PROP_BIT64("hv-emsr-bitmap", X86CPU, hyperv_features, + HYPERV_FEAT_MSR_BITMAP, 0), DEFINE_PROP_ON_OFF_AUTO("hv-no-nonarch-coresharing", X86CPU, hyperv_no_nonarch_cs, ON_OFF_AUTO_OFF), DEFINE_PROP_BOOL("hv-passthrough", X86CPU, hyperv_passthrough, false), diff --git a/target/i386/cpu.h b/target/i386/cpu.h index a1165215d972..04e3b38abf25 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -1060,6 +1060,7 @@ typedef uint64_t FeatureWordArray[FEATURE_WORDS]; #define HYPERV_FEAT_IPI 13 #define HYPERV_FEAT_STIMER_DIRECT 14 #define HYPERV_FEAT_AVIC 15 +#define HYPERV_FEAT_MSR_BITMAP 16 #ifndef HYPERV_SPINLOCK_NEVER_NOTIFY #define HYPERV_SPINLOCK_NEVER_NOTIFY 0xFFFFFFFF diff --git a/target/i386/kvm/hyperv-proto.h b/target/i386/kvm/hyperv-proto.h index 89f81afda7c6..38e25468122d 100644 --- a/target/i386/kvm/hyperv-proto.h +++ b/target/i386/kvm/hyperv-proto.h @@ -72,6 +72,11 @@ #define HV_ENLIGHTENED_VMCS_RECOMMENDED (1u << 14) #define HV_NO_NONARCH_CORESHARING (1u << 18) +/* + * HV_CPUID_NESTED_FEATURES.EAX bits + */ +#define HV_NESTED_MSR_BITMAP (1u << 19) + /* * Basic virtualized MSRs */ diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c index c8f4956a4e0e..2baa9609e181 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -933,6 +933,13 @@ static struct { .bits = HV_DEPRECATING_AEOI_RECOMMENDED} } }, + [HYPERV_FEAT_MSR_BITMAP] = { + .desc = "enlightened MSR-Bitmap (hv-emsr-bitmap)", + .flags = { + {.func = HV_CPUID_NESTED_FEATURES, .reg = R_EAX, + .bits = HV_NESTED_MSR_BITMAP} + } + }, }; static struct kvm_cpuid2 *try_get_hv_cpuid(CPUState *cs, int max,