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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 CDF92C2D0DB for ; Tue, 21 Jan 2020 14:59:25 +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 98120207E0 for ; Tue, 21 Jan 2020 14:59:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="is2PKhPq" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 98120207E0 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]:56286 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1itv00-0002NB-NR for qemu-devel@archiver.kernel.org; Tue, 21 Jan 2020 09:59:24 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:48734) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1itunS-0007A9-Bd for qemu-devel@nongnu.org; Tue, 21 Jan 2020 09:46:30 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1itunN-0002MD-5T for qemu-devel@nongnu.org; Tue, 21 Jan 2020 09:46:25 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:26327 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 1itunN-0002Lo-0c for qemu-devel@nongnu.org; Tue, 21 Jan 2020 09:46:21 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1579617980; 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=EKZR5X3HjbWGViyoSjvLKmBh9NccgSBeFyLOJOCTdaE=; b=is2PKhPq/03DUA9+KwidCDOolxyYhBVnpZk65kpm3V66wvYwan+Rf6S3HVO6NJmL9SmBNP 9bK2cra20fmNCqcZQ5TSsrE3qTS9DB75+9nS/wpvlArOZ+Fdexj3khG2qMfCI4B9RAE3G2 jGsSHRso4uuRtsbh4eXY+sV234BBbmg= 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-179-ro40hWbnPRC3WIiw2hoOGQ-1; Tue, 21 Jan 2020 09:46:16 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1948A1B18BF2; Tue, 21 Jan 2020 14:46:15 +0000 (UTC) Received: from gondolin (dhcp-192-195.str.redhat.com [10.33.192.195]) by smtp.corp.redhat.com (Postfix) with ESMTP id E264C5DA66; Tue, 21 Jan 2020 14:46:10 +0000 (UTC) Date: Tue, 21 Jan 2020 15:46:08 +0100 From: Cornelia Huck To: Matthew Rosato Subject: Re: [PATCH v3] target/s390x/kvm: Enable adapter interruption suppression again Message-ID: <20200121154608.0b043233.cohuck@redhat.com> In-Reply-To: <95fa3c7d-8879-1401-6847-c5fa82a0cd3c@linux.ibm.com> References: <20200120132441.11884-1-thuth@redhat.com> <20200120182747.5135fea8.cohuck@redhat.com> <95fa3c7d-8879-1401-6847-c5fa82a0cd3c@linux.ibm.com> Organization: Red Hat GmbH MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-MC-Unique: ro40hWbnPRC3WIiw2hoOGQ-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.120 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 , David Hildenbrand , qemu-devel@nongnu.org, Halil Pasic , Christian Borntraeger , qemu-s390x@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue, 21 Jan 2020 09:33:02 -0500 Matthew Rosato wrote: > On 1/20/20 12:27 PM, Cornelia Huck wrote: > > On Mon, 20 Jan 2020 14:24:41 +0100 > > 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. > >> > >> While at it, also add a more verbose comment why we need the *_allowed() > >> wrappers in s390-virtio-ccw.c. > >> > >> Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1756946 > >> Reviewed-by: David Hildenbrand > >> Signed-off-by: Thomas Huth > >> --- > >> v3: Moved "s390mc->kvm_ais_allowed = false" to the end of the function > >> > >> hw/s390x/s390-virtio-ccw.c | 20 +++++++++++++++++--- > >> include/hw/s390x/s390-virtio-ccw.h | 3 +++ > >> target/s390x/kvm.c | 9 ++++++--- > >> 3 files changed, 26 insertions(+), 6 deletions(-) > > > >> diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c > >> index 15260aeb9a..cf4fb4f2d9 100644 > >> --- a/target/s390x/kvm.c > >> +++ b/target/s390x/kvm.c > >> @@ -365,10 +365,13 @@ 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 try to enable this for > >> + * newer machine types if KVM_CAP_S390_AIS_MIGRATION is available. > >> */ > >> - /* kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0); */ > >> + if (kvm_ais_allowed() && > >> + kvm_check_extension(s, KVM_CAP_S390_AIS_MIGRATION)) { > > > > Hnm, we actually need a kernel irqchip with the kvm flic to get ais to > > work; else we'll fail with > > > > qemu-system-s390x: Failed to inject airq with AIS supported > > > > in the kernel_irqchip=off case, as we won't have an I/O adapter > > registered. > > > > Adding 'kvm_kernel_irqchip_required() &&' seems to do the trick; > > comments? > > > > In spirit, I agree with this idea. But, a quick test shows that putting > this check here results in ais=off for the 'none' machine case (libvirt > capabilities detection). I think we have to only look at > kvm_kernel_irqchip_required() when working with a real machine. Sigh, I think you're right again. We need to check for the 'none' machine here; but I can't think of a non-ugly way to do so... > > >> + kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0); > >> + } > >> > >> kvm_set_max_memslot_size(KVM_SLOT_MAX_BYTES); > >> return 0; > > > > >