From patchwork Wed May 25 11:59:45 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vitaly Kuznetsov X-Patchwork-Id: 12861080 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 A0C72C433EF for ; Wed, 25 May 2022 12:06:16 +0000 (UTC) Received: from localhost ([::1]:51842 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ntpmJ-0007yY-DE for qemu-devel@archiver.kernel.org; Wed, 25 May 2022 08:06:15 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:35938) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ntpgF-0004x4-BY for qemu-devel@nongnu.org; Wed, 25 May 2022 07:59:59 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:56517) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ntpgD-0000ja-NL for qemu-devel@nongnu.org; Wed, 25 May 2022 07:59:59 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1653479995; 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=CiMvOyIxBm73NtAT8j9CPiFE0748/R4EBpiDYPB7Iks=; b=Tj/DgV3Mr38zlhr2q06C5OqCTc+kOUGNIyskxHJH9SK/VgNWuQy4fF63wEdBl+sZ+1mmjM RUjr8vJdI4cSPUj8gPBl5I5DFbJW3N/j3777+YtjH8E2iHdIPSWb1yNWfpVCt+AwcjTATc btUrZWRZhoXzmCzdEDOoDLSsO/pErRg= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-532-c1xGTiakP6GE9TgufFkYVg-1; Wed, 25 May 2022 07:59:54 -0400 X-MC-Unique: c1xGTiakP6GE9TgufFkYVg-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 7061729DD995 for ; Wed, 25 May 2022 11:59:54 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.40.194.186]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4D7C140CF8EF; Wed, 25 May 2022 11:59:53 +0000 (UTC) From: Vitaly Kuznetsov To: qemu-devel@nongnu.org, Paolo Bonzini Cc: Marcelo Tosatti Subject: [PATCH v4 2/6] i386: Hyper-V Enlightened MSR bitmap feature Date: Wed, 25 May 2022 13:59:45 +0200 Message-Id: <20220525115949.1294004-3-vkuznets@redhat.com> In-Reply-To: <20220525115949.1294004-1-vkuznets@redhat.com> References: <20220525115949.1294004-1-vkuznets@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.11.54.1 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: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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: , 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 | 9 +++++++++ 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, 24 insertions(+) diff --git a/docs/hyperv.txt b/docs/hyperv.txt index 33588a03961f..5d85569b9941 100644 --- a/docs/hyperv.txt +++ b/docs/hyperv.txt @@ -239,6 +239,15 @@ This enlightenment requires a VMBus device (-device vmbus-bridge,irq=15) and the follow enlightenments to work: hv-relaxed,hv_time,hv-vapic,hv-vpindex,hv-synic,hv-runtime,hv-stimer +3.22. 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 35c3475e6c90..5aabf0c12e8d 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -6960,6 +6960,8 @@ 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_BIT64("hv-syndbg", X86CPU, hyperv_features, diff --git a/target/i386/cpu.h b/target/i386/cpu.h index 2e918daf6bef..c7882857366d 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -1106,6 +1106,7 @@ uint64_t x86_cpu_get_supported_feature_word(FeatureWord w, #define HYPERV_FEAT_STIMER_DIRECT 14 #define HYPERV_FEAT_AVIC 15 #define HYPERV_FEAT_SYNDBG 16 +#define HYPERV_FEAT_MSR_BITMAP 17 #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 e40e59411c83..cea18dbc0e23 100644 --- a/target/i386/kvm/hyperv-proto.h +++ b/target/i386/kvm/hyperv-proto.h @@ -86,6 +86,11 @@ */ #define HV_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING (1u << 1) +/* + * 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 93bfefa4a79e..82d1f0275c42 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -973,6 +973,13 @@ static struct { .dependencies = BIT(HYPERV_FEAT_SYNIC) | BIT(HYPERV_FEAT_RELAXED) }, #endif + [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,