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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 D7B69C32789 for ; Thu, 8 Nov 2018 09:14:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A794A20685 for ; Thu, 8 Nov 2018 09:14:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A794A20685 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726892AbeKHStY (ORCPT ); Thu, 8 Nov 2018 13:49:24 -0500 Received: from mx1.redhat.com ([209.132.183.28]:38636 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726133AbeKHStY (ORCPT ); Thu, 8 Nov 2018 13:49:24 -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 146DF30023A2; Thu, 8 Nov 2018 09:14:51 +0000 (UTC) Received: from gondolin (ovpn-117-143.ams2.redhat.com [10.36.117.143]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3C30917575; Thu, 8 Nov 2018 09:14:38 +0000 (UTC) Date: Thu, 8 Nov 2018 10:14:35 +0100 From: Cornelia Huck To: Pierre Morel Cc: borntraeger@de.ibm.com, alex.williamson@redhat.com, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, frankja@linux.ibm.com, akrowiak@linux.ibm.com, pasic@linux.ibm.com, david@redhat.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, freude@linux.ibm.com, mimu@linux.ibm.com Subject: Re: [PATCH v1 4/7] vfio: ap: AP Queue Interrupt Control VFIO ioctl calls Message-ID: <20181108101435.023e835d.cohuck@redhat.com> In-Reply-To: <97094e1c-f74c-7b90-8439-5177301d3189@linux.ibm.com> References: <1541009577-29656-1-git-send-email-pmorel@linux.ibm.com> <1541009577-29656-5-git-send-email-pmorel@linux.ibm.com> <20181107104624.36707cca.cohuck@redhat.com> <97094e1c-f74c-7b90-8439-5177301d3189@linux.ibm.com> Organization: Red Hat GmbH MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit 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 [10.5.110.47]); Thu, 08 Nov 2018 09:14:51 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 7 Nov 2018 23:23:40 +0100 Pierre Morel wrote: > On 07/11/2018 10:46, Cornelia Huck wrote: > > On Wed, 31 Oct 2018 19:12:54 +0100 > > Pierre Morel wrote: > > > >> This is the implementation of the VFIO ioctl calls to handle > >> the AQIC interception and use GISA to handle interrupts. > >> > >> Signed-off-by: Pierre Morel > >> --- > >> drivers/s390/crypto/vfio_ap_ops.c | 95 +++++++++++++++++++++++++++++++ > >> 1 file changed, 95 insertions(+) > >> > >> diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c > >> index 272ef427dcc0..f68102163bf4 100644 > >> --- a/drivers/s390/crypto/vfio_ap_ops.c > >> +++ b/drivers/s390/crypto/vfio_ap_ops.c > >> @@ -895,12 +895,107 @@ static int vfio_ap_mdev_get_device_info(unsigned long arg) > >> return copy_to_user((void __user *)arg, &info, minsz); > >> } > >> > >> +static int ap_ioctl_setirq(struct ap_matrix_mdev *matrix_mdev, > >> + struct vfio_ap_aqic *parm) > >> +{ > >> + struct aqic_gisa aqic_gisa = reg2aqic(0); > >> + struct kvm_s390_gisa *gisa = matrix_mdev->kvm->arch.gisa; > >> + struct ap_status ap_status = reg2status(0); > >> + unsigned long p; > >> + int ret = -1; > >> + int apqn; > >> + uint32_t gd; > >> + > >> + apqn = (int)(parm->cmd & 0xffff); > > > > It seems you always use cmd & 0xffff only. What if there is other stuff > > in the remaining bits of cmd? Do you plan to ignore it in any case, or > > should you actively check that there is nothing in it? > > > > I do not think that the ioctl interface should reflect the hardware > interface. > The ioctl interface ignores the remaining bits. > We ignore the FC because we obviously want to make a AQIC FC=3 > We ignore the T bit. > > But we receive the information from the intercepting software, i.e. QEMU > which should I think do the checks before using the ioctl interface. Yes, it should; but you still can't know whether it actually did... > > It seemed easier to me to pass the complete registers and to ignore some > bits in them. In case we get any change in the future > But we could also only pass the APQN I'd prefer to use a well-defined structure that explicitly handles the userspace<->kernel communication. Not that we start relying on implicit assumptions and then things break when userspace does something different...