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 30EA7C3815B for ; Mon, 20 Apr 2020 12:27:06 +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 F0027206F4 for ; Mon, 20 Apr 2020 12:27:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="AJeXBr5w" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F0027206F4 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]:34628 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jQVVx-00063L-5d for qemu-devel@archiver.kernel.org; Mon, 20 Apr 2020 08:27:05 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:47308 helo=eggs1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jQVVN-0005dH-V5 for qemu-devel@nongnu.org; Mon, 20 Apr 2020 08:26:30 -0400 Received: from Debian-exim by eggs1p.gnu.org with spam-scanned (Exim 4.90_1) (envelope-from ) id 1jQVVM-0004eU-Lb for qemu-devel@nongnu.org; Mon, 20 Apr 2020 08:26:29 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:27147 helo=us-smtp-delivery-1.mimecast.com) by eggs1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jQVVM-0004eF-9P for qemu-devel@nongnu.org; Mon, 20 Apr 2020 08:26:28 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1587385587; 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=IUM3uWxnumaI1UKP7AE2YiDCyzFdYkWFgc0vGoA3q/o=; b=AJeXBr5w/I7PB48hN2TXuXx98t7DbZx5uKXKjmhk4dFRO7/I9/WV8ZrjPBvPYhytJWTnoh 2t9MkhEnMEU5dv3+31UfODcWQIB8Y9/uhBpBrd6uxCOQIeorQynO/hl8gNHtFmgLg4ufKc s426F9ofF/BWqyyvU9Du3VFWdH6MSEM= 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-357-P0sJ6mRMNY-oCwHinaD5FA-1; Mon, 20 Apr 2020 08:26:23 -0400 X-MC-Unique: P0sJ6mRMNY-oCwHinaD5FA-1 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 15E25DB6A; Mon, 20 Apr 2020 12:26:22 +0000 (UTC) Received: from gondolin (ovpn-112-224.ams2.redhat.com [10.36.112.224]) by smtp.corp.redhat.com (Postfix) with ESMTP id AE65F129F87; Mon, 20 Apr 2020 12:26:20 +0000 (UTC) Date: Mon, 20 Apr 2020 14:26:17 +0200 From: Cornelia Huck To: Jared Rossi Subject: Re: [PATCH 1/1] vfio-ccw: Enable transparent CCW IPL from DASD Message-ID: <20200420142617.5e255265.cohuck@redhat.com> In-Reply-To: <20200417183838.11796-2-jrossi@linux.ibm.com> References: <20200417183838.11796-1-jrossi@linux.ibm.com> <20200417183838.11796-2-jrossi@linux.ibm.com> Organization: Red Hat GmbH MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=207.211.31.81; envelope-from=cohuck@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs1p.gnu.org: First seen = 2020/04/20 01:47:04 X-ACL-Warn: Detected OS = 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: Eric Farman , qemu-s390x@nongnu.org, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Fri, 17 Apr 2020 14:38:38 -0400 Jared Rossi wrote: > Remove the explicit prefetch check when using vfio-ccw devices. > This check is not needed as all Linux channel programs are intended > to use prefetch and will be executed in the same way regardless. As already commented on the Linux patch: Can we log something, so this is debuggable if this statement does not hold true in the future? > > Signed-off-by: Jared Rossi > --- > hw/vfio/ccw.c | 13 +++---------- > 1 file changed, 3 insertions(+), 10 deletions(-) > > diff --git a/hw/vfio/ccw.c b/hw/vfio/ccw.c > index 50cc2ec75c..e649377b68 100644 > --- a/hw/vfio/ccw.c > +++ b/hw/vfio/ccw.c > @@ -74,16 +74,9 @@ static IOInstEnding vfio_ccw_handle_request(SubchDev *sch) > struct ccw_io_region *region = vcdev->io_region; > int ret; > > - if (!(sch->orb.ctrl0 & ORB_CTRL0_MASK_PFCH)) { > - if (!(vcdev->force_orb_pfch)) { > - warn_once_pfch(vcdev, sch, "requires PFCH flag set"); > - sch_gen_unit_exception(sch); > - css_inject_io_interrupt(sch); > - return IOINST_CC_EXPECTED; > - } else { > - sch->orb.ctrl0 |= ORB_CTRL0_MASK_PFCH; > - warn_once_pfch(vcdev, sch, "PFCH flag forced"); > - } > + if (!(sch->orb.ctrl0 & ORB_CTRL0_MASK_PFCH) && vcdev->force_orb_pfch) { > + sch->orb.ctrl0 |= ORB_CTRL0_MASK_PFCH; > + warn_once_pfch(vcdev, sch, "PFCH flag forced"); > } What happens when you run it with an old kernel? I guess the I/O is only rejected later (after a trip into the kernel), but has that path ever been tested? > > QEMU_BUILD_BUG_ON(sizeof(region->orb_area) != sizeof(ORB));