From patchwork Mon Jan 27 12:20:15 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cornelia Huck X-Patchwork-Id: 11352583 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6FE9D1800 for ; Mon, 27 Jan 2020 12:27:45 +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 477DE206D4 for ; Mon, 27 Jan 2020 12:27:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="bwawL77E" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 477DE206D4 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+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:44192 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iw3UW-000473-Gm for patchwork-qemu-devel@patchwork.kernel.org; Mon, 27 Jan 2020 07:27:44 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:35468) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iw3OD-0000jM-Vp for qemu-devel@nongnu.org; Mon, 27 Jan 2020 07:21:15 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iw3OC-0006wR-Ir for qemu-devel@nongnu.org; Mon, 27 Jan 2020 07:21:13 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:51732 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iw3OC-0006wI-GU for qemu-devel@nongnu.org; Mon, 27 Jan 2020 07:21:12 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1580127672; 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=CGluW5iqejwG7DeKJme/BLxyORrWws2kTLRoEn1h2m8=; b=bwawL77Euj3vsue9e+wV+hfwPh/W0o70MURqEfb+qi5Lhy3ahWPhw0IVhK3a91hYMy3JnK leC5SQd/sxELrTyqXcUIJ3BGjEHg5NjDJy7GaJsZI2RmDQUjoocTt+PdE2lFt3T1n1izTn n/2zb8X32Yy3MV3ijX7k3vw3RBnDxbg= 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-119-H7m74h8tM6O3hkBp4JT3AA-1; Mon, 27 Jan 2020 07:21:08 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1D5441005514; Mon, 27 Jan 2020 12:21:07 +0000 (UTC) Received: from localhost (ovpn-116-220.ams2.redhat.com [10.36.116.220]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 61BC785735; Mon, 27 Jan 2020 12:21:04 +0000 (UTC) From: Cornelia Huck To: Peter Maydell Subject: [PULL 14/15] hw/s390x: Add a more verbose comment about get_machine_class() and the wrappers Date: Mon, 27 Jan 2020 13:20:15 +0100 Message-Id: <20200127122016.18752-15-cohuck@redhat.com> In-Reply-To: <20200127122016.18752-1-cohuck@redhat.com> References: <20200127122016.18752-1-cohuck@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-MC-Unique: H7m74h8tM6O3hkBp4JT3AA-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 207.211.31.120 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: Thomas Huth , qemu-s390x@nongnu.org, Cornelia Huck , qemu-devel@nongnu.org, David Hildenbrand Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" From: Thomas Huth While working on the "Enable adapter interruption suppression again" recently, I had to discover that the meaning of get_machine_class() and the related *_allowed() wrappers is not very obvious. Add a more verbose comment here to clarify how these should be used. Signed-off-by: Thomas Huth Message-Id: <20200123170256.12386-1-thuth@redhat.com> Reviewed-by: David Hildenbrand Signed-off-by: Cornelia Huck --- hw/s390x/s390-virtio-ccw.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c index e0e28139a263..e759eb5f83cf 100644 --- a/hw/s390x/s390-virtio-ccw.c +++ b/hw/s390x/s390-virtio-ccw.c @@ -505,6 +505,19 @@ static inline void machine_set_dea_key_wrap(Object *obj, bool value, static S390CcwMachineClass *current_mc; +/* + * Get the class of the s390-ccw-virtio machine that is currently in use. + * Note: libvirt is using the "none" machine to probe for the features of the + * host CPU, so in case this is called with the "none" machine, the function + * returns the TYPE_S390_CCW_MACHINE base class. In this base class, all the + * various "*_allowed" variables are enabled, so that the *_allowed() wrappers + * below return the correct default value for the "none" machine. + * + * Attention! Do *not* add additional new wrappers for CPU features (e.g. like + * the ri_allowed() wrapper) via this mechanism anymore. CPU features should + * be handled via the CPU models, i.e. checking with cpu_model_allowed() during + * CPU initialization and s390_has_feat() later should be sufficient. + */ static S390CcwMachineClass *get_machine_class(void) { if (unlikely(!current_mc)) { @@ -521,19 +534,16 @@ static S390CcwMachineClass *get_machine_class(void) bool ri_allowed(void) { - /* for "none" machine this results in true */ return get_machine_class()->ri_allowed; } bool cpu_model_allowed(void) { - /* for "none" machine this results in true */ return get_machine_class()->cpu_model_allowed; } bool hpage_1m_allowed(void) { - /* for "none" machine this results in true */ return get_machine_class()->hpage_1m_allowed; }