From patchwork Tue Jul 13 16:09:48 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eduardo Habkost X-Patchwork-Id: 1504728 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=OJ0LidJA; dkim-atps=neutral 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 ozlabs.org (Postfix) with ESMTPS id 4GPQyx52KMz9sWX for ; Wed, 14 Jul 2021 02:27:37 +1000 (AEST) Received: from localhost ([::1]:40066 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m3LFu-0004gQ-A3 for incoming@patchwork.ozlabs.org; Tue, 13 Jul 2021 12:27:34 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:36746) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m3L83-0003pS-95 for qemu-devel@nongnu.org; Tue, 13 Jul 2021 12:19:28 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:34440) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m3L7z-0006yc-7V for qemu-devel@nongnu.org; Tue, 13 Jul 2021 12:19:26 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1626193162; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=QXdViAzEq38Sqbq/iRur/uisrvoTQffbtfxp63NLQtU=; b=OJ0LidJAaGqWOBb/OPQbpmFFE6lWB7JgyOtaZsc6oH9+xSnlbUvz/C9unhZpVAFWt63r4j vNAEbA1/u57Tto9T9ZzZrA0DygATnwFM+9kOgBkAq5aKVp2Riq2mpZKNLrR9K4pBdUvgYb JyWAojXPmWkt2GnFI+c7R1ATG+mjegA= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-228-APn_u8i4OvSt74SbhVdVfw-1; Tue, 13 Jul 2021 12:19:20 -0400 X-MC-Unique: APn_u8i4OvSt74SbhVdVfw-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 818291B2C984; Tue, 13 Jul 2021 16:19:19 +0000 (UTC) Received: from localhost (ovpn-113-28.rdu2.redhat.com [10.10.113.28]) by smtp.corp.redhat.com (Postfix) with ESMTP id 41FC619C44; Tue, 13 Jul 2021 16:19:19 +0000 (UTC) From: Eduardo Habkost To: qemu-devel@nongnu.org, Peter Maydell Subject: [PULL 02/11] i386: hardcode supported eVMCS version to '1' Date: Tue, 13 Jul 2021 12:09:48 -0400 Message-Id: <20210713160957.3269017-3-ehabkost@redhat.com> In-Reply-To: <20210713160957.3269017-1-ehabkost@redhat.com> References: <20210713160957.3269017-1-ehabkost@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Received-SPF: pass client-ip=170.10.133.124; envelope-from=ehabkost@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -15 X-Spam_score: -1.6 X-Spam_bar: - X-Spam_report: (-1.6 / 5.0 requ) DKIMWL_WL_HIGH=-0.7, 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 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Eduardo Habkost , kvm@vger.kernel.org, "Michael S. Tsirkin" , Marcelo Tosatti , Richard Henderson , Paolo Bonzini , Vitaly Kuznetsov Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Vitaly Kuznetsov Currently, the only eVMCS version, supported by KVM (and described in TLFS) is '1'. When Enlightened VMCS feature is enabled, QEMU takes the supported eVMCS version range (from KVM_CAP_HYPERV_ENLIGHTENED_VMCS enablement) and puts it to guest visible CPUIDs. When (and if) eVMCS ver.2 appears a problem on migration is expected: it doesn't seem to be possible to migrate from a host supporting eVMCS ver.2 to a host, which only support eVMCS ver.1. Hardcode eVMCS ver.1 as the result of 'hv-evmcs' enablement for now. Newer eVMCS versions will have to have their own enablement options (e.g. 'hv-evmcs=2'). Signed-off-by: Vitaly Kuznetsov Reviewed-by: Eduardo Habkost Message-Id: <20210608120817.1325125-4-vkuznets@redhat.com> Signed-off-by: Eduardo Habkost --- docs/hyperv.txt | 2 +- target/i386/kvm/kvm.c | 39 +++++++++++++++++++++++++++++++++++---- 2 files changed, 36 insertions(+), 5 deletions(-) diff --git a/docs/hyperv.txt b/docs/hyperv.txt index a51953daa83..000638a2fd3 100644 --- a/docs/hyperv.txt +++ b/docs/hyperv.txt @@ -170,7 +170,7 @@ Recommended: hv-frequencies 3.16. hv-evmcs =============== The enlightenment is nested specific, it targets Hyper-V on KVM guests. When -enabled, it provides Enlightened VMCS feature to the guest. The feature +enabled, it provides Enlightened VMCS version 1 feature to the guest. The feature implements paravirtualized protocol between L0 (KVM) and L1 (Hyper-V) hypervisors making L2 exits to the hypervisor faster. The feature is Intel-only. Note: some virtualization features (e.g. Posted Interrupts) are disabled when diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c index a85035492fb..02216b70311 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -1409,6 +1409,21 @@ static int hyperv_fill_cpuids(CPUState *cs, static Error *hv_passthrough_mig_blocker; static Error *hv_no_nonarch_cs_mig_blocker; +/* Checks that the exposed eVMCS version range is supported by KVM */ +static bool evmcs_version_supported(uint16_t evmcs_version, + uint16_t supported_evmcs_version) +{ + uint8_t min_version = evmcs_version & 0xff; + uint8_t max_version = evmcs_version >> 8; + uint8_t min_supported_version = supported_evmcs_version & 0xff; + uint8_t max_supported_version = supported_evmcs_version >> 8; + + return (min_version >= min_supported_version) && + (max_version <= max_supported_version); +} + +#define DEFAULT_EVMCS_VERSION ((1 << 8) | 1) + static int hyperv_init_vcpu(X86CPU *cpu) { CPUState *cs = CPU(cpu); @@ -1488,17 +1503,33 @@ static int hyperv_init_vcpu(X86CPU *cpu) } if (hyperv_feat_enabled(cpu, HYPERV_FEAT_EVMCS)) { - uint16_t evmcs_version; + uint16_t evmcs_version = DEFAULT_EVMCS_VERSION; + uint16_t supported_evmcs_version; ret = kvm_vcpu_enable_cap(cs, KVM_CAP_HYPERV_ENLIGHTENED_VMCS, 0, - (uintptr_t)&evmcs_version); + (uintptr_t)&supported_evmcs_version); + /* + * KVM is required to support EVMCS ver.1. as that's what 'hv-evmcs' + * option sets. Note: we hardcode the maximum supported eVMCS version + * to '1' as well so 'hv-evmcs' feature is migratable even when (and if) + * ver.2 is implemented. A new option (e.g. 'hv-evmcs=2') will then have + * to be added. + */ if (ret < 0) { - fprintf(stderr, "Hyper-V %s is not supported by kernel\n", - kvm_hyperv_properties[HYPERV_FEAT_EVMCS].desc); + error_report("Hyper-V %s is not supported by kernel", + kvm_hyperv_properties[HYPERV_FEAT_EVMCS].desc); return ret; } + if (!evmcs_version_supported(evmcs_version, supported_evmcs_version)) { + error_report("eVMCS version range [%d..%d] is not supported by " + "kernel (supported: [%d..%d])", evmcs_version & 0xff, + evmcs_version >> 8, supported_evmcs_version & 0xff, + supported_evmcs_version >> 8); + return -ENOTSUP; + } + cpu->hyperv_nested[0] = evmcs_version; }