From mboxrd@z Thu Jan 1 00:00:00 1970 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=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 9810CC33CB1 for ; Thu, 16 Jan 2020 12:39:33 +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 63001206E6 for ; Thu, 16 Jan 2020 12:39:33 +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="OGtUaVa+" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 63001206E6 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]:41162 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1is4Qu-0000e1-Ai for qemu-devel@archiver.kernel.org; Thu, 16 Jan 2020 07:39:32 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:35647) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1is4Pk-0007HL-CD for qemu-devel@nongnu.org; Thu, 16 Jan 2020 07:38:24 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1is4Pg-0007aS-DZ for qemu-devel@nongnu.org; Thu, 16 Jan 2020 07:38:20 -0500 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:37527 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1is4Pg-0007aD-8s for qemu-devel@nongnu.org; Thu, 16 Jan 2020 07:38:16 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1579178295; 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:openpgp:openpgp; bh=JJJ6jnL+mJoICIYsUgaCIQ19xUFx5G+P4k8qCPdXh5Q=; b=OGtUaVa+G7++U6yz2eD35F4OITl5gMmJQypoSzs+nON9VA4xYTV5b+t5ZEMLiWi0fCvef3 5Lpj00ron2akpaXVAOKG9Aa0OYS3SJmjyUc7kKOJ3XRP0lLDgh2es7MHXWC4uhTqQfWXC2 bqLAygzbIKwWTTD4584oExRhiCKcZD8= 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-405-2JDAVfiDPGmvFBC0PJj-Hw-1; Thu, 16 Jan 2020 07:38:14 -0500 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id EB836107ACC7; Thu, 16 Jan 2020 12:38:12 +0000 (UTC) Received: from thuth.remote.csb (ovpn-204-105.brq.redhat.com [10.40.204.105]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4E65388894; Thu, 16 Jan 2020 12:38:08 +0000 (UTC) Subject: Re: [PATCH] target/s390x/kvm: Enable adapter interruption suppression again To: David Hildenbrand , Cornelia Huck , Christian Borntraeger , qemu-devel@nongnu.org References: <20200116122026.5804-1-thuth@redhat.com> <7c5da42a-2de0-d9e6-f838-f2b0757cbcaa@redhat.com> <6d489327-b37d-73ae-6706-03f1e4c6b495@redhat.com> From: Thomas Huth Openpgp: preference=signencrypt Message-ID: Date: Thu, 16 Jan 2020 13:38:06 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-MC-Unique: 2JDAVfiDPGmvFBC0PJj-Hw-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.81 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: Halil Pasic , qemu-s390x@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 16/01/2020 13.28, David Hildenbrand wrote: > On 16.01.20 13:26, Thomas Huth wrote: >> On 16/01/2020 13.23, David Hildenbrand wrote: >>> On 16.01.20 13:20, Thomas Huth wrote: >>>> The AIS feature has been disabled late in the v2.10 development >>>> cycle since there were some issues with migration (see commit >>>> 3f2d07b3b01ea61126b - "s390x/ais: for 2.10 stable: disable ais >>>> facility"). We originally wanted to enable it again for newer >>>> machine types, but apparently we forgot to do this so far. Let's >>>> do it for the new s390-ccw-virtio-5.0 machine now. >>>> >>>> Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1756946 >>>> Signed-off-by: Thomas Huth >>>> --- >>>> hw/s390x/s390-virtio-ccw.c | 4 ++++ >>>> include/hw/s390x/s390-virtio-ccw.h | 4 ++++ >>>> target/s390x/kvm.c | 11 ++++++++--- >>>> 3 files changed, 16 insertions(+), 3 deletions(-) >>>> >>>> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c >>>> index e7eadd14e8..6f43136396 100644 >>>> --- a/hw/s390x/s390-virtio-ccw.c >>>> +++ b/hw/s390x/s390-virtio-ccw.c >>>> @@ -456,6 +456,7 @@ static void ccw_machine_class_init(ObjectClass *oc, void *data) >>>> s390mc->cpu_model_allowed = true; >>>> s390mc->css_migration_enabled = true; >>>> s390mc->hpage_1m_allowed = true; >>>> + s390mc->kvm_ais_allowed = true; >>>> mc->init = ccw_init; >>>> mc->reset = s390_machine_reset; >>>> mc->hot_add_cpu = s390_hot_add_cpu; >>>> @@ -662,6 +663,9 @@ static void ccw_machine_4_2_instance_options(MachineState *machine) >>>> >>>> static void ccw_machine_4_2_class_options(MachineClass *mc) >>>> { >>>> + S390CcwMachineClass *s390mc = S390_MACHINE_CLASS(mc); >>>> + >>>> + s390mc->kvm_ais_allowed = false; >>>> ccw_machine_5_0_class_options(mc); >>>> compat_props_add(mc->compat_props, hw_compat_4_2, hw_compat_4_2_len); >>>> } >>>> diff --git a/include/hw/s390x/s390-virtio-ccw.h b/include/hw/s390x/s390-virtio-ccw.h >>>> index 8aa27199c9..f142d379c6 100644 >>>> --- a/include/hw/s390x/s390-virtio-ccw.h >>>> +++ b/include/hw/s390x/s390-virtio-ccw.h >>>> @@ -21,6 +21,9 @@ >>>> #define S390_MACHINE_CLASS(klass) \ >>>> OBJECT_CLASS_CHECK(S390CcwMachineClass, (klass), TYPE_S390_CCW_MACHINE) >>>> >>>> +#define S390_CCW_MACHINE_OBJ_GET_CLASS(obj) \ >>>> + OBJECT_GET_CLASS(S390CcwMachineClass, obj, TYPE_S390_CCW_MACHINE) >>>> + >>>> typedef struct S390CcwMachineState { >>>> /*< private >*/ >>>> MachineState parent_obj; >>>> @@ -40,6 +43,7 @@ typedef struct S390CcwMachineClass { >>>> bool cpu_model_allowed; >>>> bool css_migration_enabled; >>>> bool hpage_1m_allowed; >>>> + bool kvm_ais_allowed; >>>> } S390CcwMachineClass; >>>> >>>> /* runtime-instrumentation allowed by the machine */ >>>> diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c >>>> index 15260aeb9a..4c1c8c0208 100644 >>>> --- a/target/s390x/kvm.c >>>> +++ b/target/s390x/kvm.c >>>> @@ -329,6 +329,8 @@ static void ccw_machine_class_foreach(ObjectClass *oc, void *opaque) >>>> >>>> int kvm_arch_init(MachineState *ms, KVMState *s) >>>> { >>>> + S390CcwMachineClass *smc = S390_CCW_MACHINE_OBJ_GET_CLASS(ms); >>>> + >>>> object_class_foreach(ccw_machine_class_foreach, TYPE_S390_CCW_MACHINE, >>>> false, NULL); >>>> >>>> @@ -365,10 +367,13 @@ int kvm_arch_init(MachineState *ms, KVMState *s) >>>> /* >>>> * The migration interface for ais was introduced with kernel 4.13 >>>> * but the capability itself had been active since 4.12. As migration >>>> - * support is considered necessary let's disable ais in the 2.10 >>>> - * machine. >>>> + * support is considered necessary we only enable this for newer >>>> + * machine types and if KVM_CAP_S390_AIS_MIGRATION is available. >>>> */ >>>> - /* kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0); */ >>>> + if (smc->kvm_ais_allowed && >>>> + kvm_check_extension(s, KVM_CAP_S390_AIS_MIGRATION)) { >>>> + kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0); >>>> + } >>>> >>>> kvm_set_max_memslot_size(KVM_SLOT_MAX_BYTES); >>>> return 0; >>>> >>> >>> We have ri_allowed(), cpu_model_allowed(), hpage_1m_allowed(). >>> >>> Care to create a similar wrapper? >> >> Honestly, why do we need these wrappers at all? They look cumbersome to >> me. I'd rather remove them in case they are not urgently needed (so far >> I don't see the point... could someone enlighten me why we have them?). > > I assume to minimize the number of places you have to lookup the > machine/machine class. I don't think that any of these functions is performance critical, since they are only used during the initialization phase... But looking more closely, cpu_model_allowed() and hpage_1m_allowed() are used in functions where the current machine state / class is not directly available, so the wrappers indeed make sense there. We could remove the ri_allowed() wrapper, though, since this is also only used in kvm_arch_init() where the machine state is easily available. Thomas