From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:15026 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728713AbfHMNXe (ORCPT ); Tue, 13 Aug 2019 09:23:34 -0400 Subject: Re: [PATCH] s390: vfio-ap: remove unnecessary calls to disable queue interrupts References: <1565642829-20157-1-git-send-email-akrowiak@linux.ibm.com> <20190813132957.7fafad2d.cohuck@redhat.com> From: Tony Krowiak Message-ID: <0d5b92ea-a16b-c38c-da15-0de150b28adf@linux.ibm.com> Date: Tue, 13 Aug 2019 09:23:20 -0400 MIME-Version: 1.0 In-Reply-To: <20190813132957.7fafad2d.cohuck@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-s390-owner@vger.kernel.org List-ID: To: Cornelia Huck Cc: linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, freude@linux.ibm.com, borntraeger@de.ibm.com, frankja@linux.ibm.com, david@redhat.com, mjrosato@linux.ibm.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, pmorel@linux.ibm.com, pasic@linux.ibm.com, alex.williamson@redhat.com, kwankhede@nvidia.com On 8/13/19 7:29 AM, Cornelia Huck wrote: > On Mon, 12 Aug 2019 16:47:09 -0400 > Tony Krowiak wrote: > >> When an AP queue is reset (zeroized), interrupts are disabled. The queue >> reset function currently tries to disable interrupts unnecessarily. This patch >> removes the unnecessary calls to disable interrupts after queue reset. >> >> Signed-off-by: Tony Krowiak >> --- >> drivers/s390/crypto/vfio_ap_ops.c | 13 +++++++++---- >> 1 file changed, 9 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c >> index 0604b49a4d32..407c2f0f25f9 100644 >> --- a/drivers/s390/crypto/vfio_ap_ops.c >> +++ b/drivers/s390/crypto/vfio_ap_ops.c >> @@ -1114,18 +1114,19 @@ static int vfio_ap_mdev_group_notifier(struct notifier_block *nb, >> return NOTIFY_OK; >> } >> >> -static void vfio_ap_irq_disable_apqn(int apqn) >> +static struct vfio_ap_queue *vfio_ap_find_qdev(int apqn) >> { >> struct device *dev; >> - struct vfio_ap_queue *q; >> + struct vfio_ap_queue *q = NULL; >> >> dev = driver_find_device(&matrix_dev->vfio_ap_drv->driver, NULL, >> &apqn, match_apqn); >> if (dev) { >> q = dev_get_drvdata(dev); >> - vfio_ap_irq_disable(q); >> put_device(dev); >> } >> + >> + return q; >> } >> >> int vfio_ap_mdev_reset_queue(unsigned int apid, unsigned int apqi, >> @@ -1164,6 +1165,7 @@ static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev) >> int rc = 0; >> unsigned long apid, apqi; >> struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev); >> + struct vfio_ap_queue *q; >> >> for_each_set_bit_inv(apid, matrix_mdev->matrix.apm, >> matrix_mdev->matrix.apm_max + 1) { >> @@ -1177,7 +1179,10 @@ static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev) >> */ >> if (ret) >> rc = ret; >> - vfio_ap_irq_disable_apqn(AP_MKQID(apid, apqi)); > > Might be useful to stick a comment in this function that resetting the > queue has also disabled the interrupts, as the architecture > documentation for that is not publicly available. Will do. > >> + >> + q = vfio_ap_find_qdev(AP_MKQID(apid, apqi)); >> + if (q) >> + vfio_ap_free_aqic_resources(q); >> } >> } >> > > Trusting your reading of the architecture, > Reviewed-by: Cornelia Huck >