From nobody Fri Nov 7 02:00:46 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1545401940325112.69289854878855; Fri, 21 Dec 2018 06:19:00 -0800 (PST) Received: from localhost ([::1]:45971 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gaLdi-0001be-R9 for importer@patchew.org; Fri, 21 Dec 2018 09:18:58 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46767) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gaLb4-0008Lk-IJ for qemu-devel@nongnu.org; Fri, 21 Dec 2018 09:16:15 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gaLb0-00007N-Bx for qemu-devel@nongnu.org; Fri, 21 Dec 2018 09:16:14 -0500 Received: from mx1.redhat.com ([209.132.183.28]:60714) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gaLb0-00006y-0D for qemu-devel@nongnu.org; Fri, 21 Dec 2018 09:16:10 -0500 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 1519BA12FB; Fri, 21 Dec 2018 14:16:09 +0000 (UTC) Received: from vitty.brq.redhat.com (unknown [10.43.2.155]) by smtp.corp.redhat.com (Postfix) with ESMTP id 90145177E0; Fri, 21 Dec 2018 14:16:05 +0000 (UTC) From: Vitaly Kuznetsov To: Eduardo Habkost Date: Fri, 21 Dec 2018 15:16:04 +0100 Message-Id: <20181221141604.16935-1-vkuznets@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Fri, 21 Dec 2018 14:16:09 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH] 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: Paolo Bonzini , Marcelo Tosatti , Roman Kagan , qemu-devel@nongnu.org, Richard Henderson Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" 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 --- target/i386/cpu.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 677a3bd5fb..18a486c5a0 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -929,6 +929,13 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS= ] =3D { */ .no_autoenable_flags =3D ~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 com= mand + * line. Some features (e.g. "hyperv_time", "hyperv_vapic", ...) requi= re + * enabling several feature bits simultaneously, exposing these bits + * individually may just confuse guests. + */ [FEAT_HYPERV_EAX] =3D { .type =3D CPUID_FEATURE_WORD, .feat_names =3D { --=20 2.19.2