From patchwork Tue Apr 19 14:48:00 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vitaly Kuznetsov X-Patchwork-Id: 12818718 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 62AA0C433EF for ; Tue, 19 Apr 2022 15:33:01 +0000 (UTC) Received: from localhost ([::1]:47424 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ngpqe-0006aK-J9 for qemu-devel@archiver.kernel.org; Tue, 19 Apr 2022 11:33:00 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:39788) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ngpfn-0002EH-Lz for qemu-devel@nongnu.org; Tue, 19 Apr 2022 11:21:47 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:45452) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ngp9F-0008BP-Uo for qemu-devel@nongnu.org; Tue, 19 Apr 2022 10:48:11 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1650379688; 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=uLuffatAT8VSGsl2+sdu35TWMeCNnPWh8yPZZ6BNRf4=; b=Dd7ufM5eTYsJiW6RRX88TvvTyNly2boEwiOlWWlHxpetpSuEjfO0/fiiSbx02FiV0V/C5j o8ArBN6VZ/wb8qM4pWZIsrfIYIz8ULmY3ZFikC6muK3Z9MR/YhRSap52B2p37qAdCMXRjr GdvJlp9vYr2KMgthd2jd5FGlFFQY9pM= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-219-l3ezPl0zPHyXgmeG57Hb7w-1; Tue, 19 Apr 2022 10:48:07 -0400 X-MC-Unique: l3ezPl0zPHyXgmeG57Hb7w-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 5BA7C824065 for ; Tue, 19 Apr 2022 14:48:07 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.40.194.114]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5C02440E80E0; Tue, 19 Apr 2022 14:48:06 +0000 (UTC) From: Vitaly Kuznetsov To: qemu-devel@nongnu.org, Paolo Bonzini Subject: [PATCH v3 2/5] i386: Hyper-V Enlightened MSR bitmap feature Date: Tue, 19 Apr 2022 16:48:00 +0200 Message-Id: <20220419144803.1698337-3-vkuznets@redhat.com> In-Reply-To: <20220419144803.1698337-1-vkuznets@redhat.com> References: <20220419144803.1698337-1-vkuznets@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.11.54.2 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=170.10.129.124; envelope-from=vkuznets@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -28 X-Spam_score: -2.9 X-Spam_bar: -- X-Spam_report: (-2.9 / 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_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, 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: , Cc: 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 cb6b5467d067..3f053919685f 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -6925,6 +6925,8 @@ 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 73dc387c52f5..9615c330315f 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -1084,6 +1084,7 @@ uint64_t x86_cpu_get_supported_feature_word(FeatureWord w, #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 ff79994faa87..4059b46b9449 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -966,6 +966,13 @@ 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,