From patchwork Mon Jan 14 14:34:32 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eduardo Habkost X-Patchwork-Id: 1024615 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) 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; dmarc=fail (p=none dis=none) header.from=redhat.com Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 43dbpM3QXpz9s4s for ; Tue, 15 Jan 2019 01:44:27 +1100 (AEDT) Received: from localhost ([127.0.0.1]:43122 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gj3TV-0000mZ-Aq for incoming@patchwork.ozlabs.org; Mon, 14 Jan 2019 09:44:25 -0500 Received: from eggs.gnu.org ([209.51.188.92]:57020) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gj3KM-0000kd-Tx for qemu-devel@nongnu.org; Mon, 14 Jan 2019 09:34:59 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gj3KL-0005ki-19 for qemu-devel@nongnu.org; Mon, 14 Jan 2019 09:34:58 -0500 Received: from mx1.redhat.com ([209.132.183.28]:55560) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gj3KK-0005kH-RS for qemu-devel@nongnu.org; Mon, 14 Jan 2019 09:34:56 -0500 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 8CE79C0587CE; Mon, 14 Jan 2019 14:34:55 +0000 (UTC) Received: from localhost (ovpn-116-76.gru2.redhat.com [10.97.116.76]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1C9685D73F; Mon, 14 Jan 2019 14:34:51 +0000 (UTC) From: Eduardo Habkost To: Peter Maydell , qemu-devel@nongnu.org Date: Mon, 14 Jan 2019 12:34:32 -0200 Message-Id: <20190114143432.4771-6-ehabkost@redhat.com> In-Reply-To: <20190114143432.4771-1-ehabkost@redhat.com> References: <20190114143432.4771-1-ehabkost@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Mon, 14 Jan 2019 14:34:55 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 5/5] i386/kvm: add a comment explaining why .feat_names are commented out for Hyper-V feature bits X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 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 , Paolo Bonzini , Vitaly Kuznetsov , Richard Henderson Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Vitaly Kuznetsov Hyper-V .feat_names are, unlike hardware features, commented out and it is not obvious why we do that. Document the current status quo. Signed-off-by: Vitaly Kuznetsov Message-Id: <20181221141604.16935-1-vkuznets@redhat.com> Signed-off-by: Eduardo Habkost --- target/i386/cpu.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 3ece83696e..2f5412592d 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -929,6 +929,13 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = { */ .no_autoenable_flags = ~0U, }, + /* + * .feat_names are commented out for Hyper-V enlightenments because we + * don't want to have two different ways for enabling them on QEMU command + * line. Some features (e.g. "hyperv_time", "hyperv_vapic", ...) require + * enabling several feature bits simultaneously, exposing these bits + * individually may just confuse guests. + */ [FEAT_HYPERV_EAX] = { .type = CPUID_FEATURE_WORD, .feat_names = {