From patchwork Thu Jun 3 11:48:29 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vitaly Kuznetsov X-Patchwork-Id: 12297025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EDEB3C47097 for ; Thu, 3 Jun 2021 11:53:16 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id BAD4E613E3 for ; Thu, 3 Jun 2021 11:53:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BAD4E613E3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:34556 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1loluV-0007jD-T6 for qemu-devel@archiver.kernel.org; Thu, 03 Jun 2021 07:53:15 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:50488) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lolqD-0004s1-Ky for qemu-devel@nongnu.org; Thu, 03 Jun 2021 07:48:49 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:43125) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lolqB-00022o-Qx for qemu-devel@nongnu.org; Thu, 03 Jun 2021 07:48:49 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1622720927; 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=xL+X0F0Ai06zrlvOnlOoPjnfjRWpxoxzgv6QaQOdKBQ=; b=ZZIOUTj4+M67KAdJXQTtw5pzR9LrLmhTLgu1QI7RaY/THQfScqt6RTV8+h/z7cC0+Ri37k /29A7qkTvlRZrROulXrnhJu7U4l+RIr5IaCfCw3l9W2IMPe78q1/jojt4roCYLW7GQvXFl 2nwdC04t2a66gyJGvvY02ng/9EFGWrw= 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-256-H5CnCdZuO1uEuLd3EkXWeQ-1; Thu, 03 Jun 2021 07:48:45 -0400 X-MC-Unique: H5CnCdZuO1uEuLd3EkXWeQ-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 136DC8015F5 for ; Thu, 3 Jun 2021 11:48:45 +0000 (UTC) Received: from vitty.brq.redhat.com (unknown [10.40.194.97]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7D6EF17A75; Thu, 3 Jun 2021 11:48:43 +0000 (UTC) From: Vitaly Kuznetsov To: qemu-devel@nongnu.org, Eduardo Habkost Subject: [PATCH v7 3/9] i386: hardcode supported eVMCS version to '1' Date: Thu, 3 Jun 2021 13:48:29 +0200 Message-Id: <20210603114835.847451-4-vkuznets@redhat.com> In-Reply-To: <20210603114835.847451-1-vkuznets@redhat.com> References: <20210603114835.847451-1-vkuznets@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 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=-0.37, 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: Paolo Bonzini , Marcelo Tosatti , Igor Mammedov Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" 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 --- docs/hyperv.txt | 2 +- target/i386/kvm/kvm.c | 16 +++++++++++----- 2 files changed, 12 insertions(+), 6 deletions(-) diff --git a/docs/hyperv.txt b/docs/hyperv.txt index a51953daa833..000638a2fd38 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 c676ee8b38a7..d57eede5dc81 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -1490,13 +1490,19 @@ static int hyperv_init_vcpu(X86CPU *cpu) ret = kvm_vcpu_enable_cap(cs, KVM_CAP_HYPERV_ENLIGHTENED_VMCS, 0, (uintptr_t)&evmcs_version); - if (ret < 0) { - fprintf(stderr, "Hyper-V %s is not supported by kernel\n", - kvm_hyperv_properties[HYPERV_FEAT_EVMCS].desc); + /* + * 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 || (uint8_t)evmcs_version > 1) { + error_report("Hyper-V %s verson 1 is not supported by kernel", + kvm_hyperv_properties[HYPERV_FEAT_EVMCS].desc); return ret; } - - cpu->hyperv_nested[0] = evmcs_version; + cpu->hyperv_nested[0] = (1 << 8) | 1; } return 0;