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Thu, 21 Jan 2021 07:20:18 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 9701111C06C; Thu, 21 Jan 2021 07:20:18 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 1946B11C04A; Thu, 21 Jan 2021 07:20:18 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTP; Thu, 21 Jan 2021 07:20:18 +0000 (GMT) From: Halil Pasic To: Tony Krowiak , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Halil Pasic , stable@vger.kernel.org, Pierre Morel , Harald Freudenberger , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , mjrosato@linux.ibm.com, alex.williamson@redhat.com, kwankhede@nvidia.com, fiuczy@linux.ibm.com, frankja@linux.ibm.com, david@redhat.com Subject: [PATCH 1/1] s390/vfio-ap: No need to disable IRQ after queue reset Date: Thu, 21 Jan 2021 08:20:08 +0100 Message-Id: <20210121072008.76523-1-pasic@linux.ibm.com> X-Mailer: git-send-email 2.17.1 X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.343,18.0.737 definitions=2021-01-21_03:2021-01-20,2021-01-21 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 impostorscore=0 clxscore=1015 phishscore=0 mlxlogscore=999 malwarescore=0 suspectscore=0 lowpriorityscore=0 adultscore=0 mlxscore=0 bulkscore=0 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2101210035 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Tony Krowiak The queues assigned to a matrix mediated device are currently reset when: * The VFIO_DEVICE_RESET ioctl is invoked * The mdev fd is closed by userspace (QEMU) * The mdev is removed from sysfs. Immediately after the reset of a queue, a call is made to disable interrupts for the queue. This is entirely unnecessary because the reset of a queue disables interrupts, so this will be removed. Furthermore, vfio_ap_irq_disable() does an unconditional PQAP/AQIC which can result in a specification exception (when the corresponding facility is not available), so this is actually a bugfix. Signed-off-by: Tony Krowiak [pasic@linux.ibm.com: minor rework before merging] Reviewed-by: Halil Pasic Signed-off-by: Halil Pasic Fixes: ec89b55e3bce ("s390: ap: implement PAPQ AQIC interception in kernel") Cc: Reviewed-by: Cornelia Huck Acked-by: Christian Borntraeger --- Since it turned out disabling the interrupts via PQAP/AQIC is not only unnecesary but also buggy, we decided to put this patch, which used to be apart of the series https://lkml.org/lkml/2020/12/22/757 on the fast lane. If the backports turn out to be a bother, which I hope won't be the case not, I am happy to help with those. --- drivers/s390/crypto/vfio_ap_drv.c | 6 +- drivers/s390/crypto/vfio_ap_ops.c | 100 ++++++++++++++++---------- drivers/s390/crypto/vfio_ap_private.h | 12 ++-- 3 files changed, 69 insertions(+), 49 deletions(-) base-commit: 9791581c049c10929e97098374dd1716a81fefcc diff --git a/drivers/s390/crypto/vfio_ap_drv.c b/drivers/s390/crypto/vfio_ap_drv.c index be2520cc010b..7dc72cb718b0 100644 --- a/drivers/s390/crypto/vfio_ap_drv.c +++ b/drivers/s390/crypto/vfio_ap_drv.c @@ -71,15 +71,11 @@ static int vfio_ap_queue_dev_probe(struct ap_device *apdev) static void vfio_ap_queue_dev_remove(struct ap_device *apdev) { struct vfio_ap_queue *q; - int apid, apqi; mutex_lock(&matrix_dev->lock); q = dev_get_drvdata(&apdev->device); + vfio_ap_mdev_reset_queue(q, 1); dev_set_drvdata(&apdev->device, NULL); - apid = AP_QID_CARD(q->apqn); - apqi = AP_QID_QUEUE(q->apqn); - vfio_ap_mdev_reset_queue(apid, apqi, 1); - vfio_ap_irq_disable(q); kfree(q); mutex_unlock(&matrix_dev->lock); } diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c index e0bde8518745..7ceb6c433b3b 100644 --- a/drivers/s390/crypto/vfio_ap_ops.c +++ b/drivers/s390/crypto/vfio_ap_ops.c @@ -25,6 +25,7 @@ #define VFIO_AP_MDEV_NAME_HWVIRT "VFIO AP Passthrough Device" static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev); +static struct vfio_ap_queue *vfio_ap_find_queue(int apqn); static int match_apqn(struct device *dev, const void *data) { @@ -49,20 +50,15 @@ static struct vfio_ap_queue *vfio_ap_get_queue( int apqn) { struct vfio_ap_queue *q; - struct device *dev; if (!test_bit_inv(AP_QID_CARD(apqn), matrix_mdev->matrix.apm)) return NULL; if (!test_bit_inv(AP_QID_QUEUE(apqn), matrix_mdev->matrix.aqm)) return NULL; - dev = driver_find_device(&matrix_dev->vfio_ap_drv->driver, NULL, - &apqn, match_apqn); - if (!dev) - return NULL; - q = dev_get_drvdata(dev); - q->matrix_mdev = matrix_mdev; - put_device(dev); + q = vfio_ap_find_queue(apqn); + if (q) + q->matrix_mdev = matrix_mdev; return q; } @@ -119,13 +115,18 @@ static void vfio_ap_wait_for_irqclear(int apqn) */ static void vfio_ap_free_aqic_resources(struct vfio_ap_queue *q) { - if (q->saved_isc != VFIO_AP_ISC_INVALID && q->matrix_mdev) + if (!q) + return; + if (q->saved_isc != VFIO_AP_ISC_INVALID && + !WARN_ON(!(q->matrix_mdev && q->matrix_mdev->kvm))) { kvm_s390_gisc_unregister(q->matrix_mdev->kvm, q->saved_isc); - if (q->saved_pfn && q->matrix_mdev) + q->saved_isc = VFIO_AP_ISC_INVALID; + } + if (q->saved_pfn && !WARN_ON(!q->matrix_mdev)) { vfio_unpin_pages(mdev_dev(q->matrix_mdev->mdev), &q->saved_pfn, 1); - q->saved_pfn = 0; - q->saved_isc = VFIO_AP_ISC_INVALID; + q->saved_pfn = 0; + } } /** @@ -144,7 +145,7 @@ static void vfio_ap_free_aqic_resources(struct vfio_ap_queue *q) * Returns if ap_aqic function failed with invalid, deconfigured or * checkstopped AP. */ -struct ap_queue_status vfio_ap_irq_disable(struct vfio_ap_queue *q) +static struct ap_queue_status vfio_ap_irq_disable(struct vfio_ap_queue *q) { struct ap_qirq_ctrl aqic_gisa = {}; struct ap_queue_status status; @@ -1114,48 +1115,70 @@ 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_queue(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, +int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q, unsigned int retry) { struct ap_queue_status status; + int ret; int retry2 = 2; - int apqn = AP_MKQID(apid, apqi); - do { - status = ap_zapq(apqn); - switch (status.response_code) { - case AP_RESPONSE_NORMAL: - while (!status.queue_empty && retry2--) { - msleep(20); - status = ap_tapq(apqn, NULL); - } - WARN_ON_ONCE(retry2 <= 0); - return 0; - case AP_RESPONSE_RESET_IN_PROGRESS: - case AP_RESPONSE_BUSY: + if (!q) + return 0; + +retry_zapq: + status = ap_zapq(q->apqn); + switch (status.response_code) { + case AP_RESPONSE_NORMAL: + ret = 0; + break; + case AP_RESPONSE_RESET_IN_PROGRESS: + if (retry--) { msleep(20); - break; - default: - /* things are really broken, give up */ - return -EIO; + goto retry_zapq; } - } while (retry--); + ret = -EBUSY; + break; + case AP_RESPONSE_Q_NOT_AVAIL: + case AP_RESPONSE_DECONFIGURED: + case AP_RESPONSE_CHECKSTOPPED: + WARN_ON_ONCE(status.irq_enabled); + ret = -EBUSY; + goto free_resources; + default: + /* things are really broken, give up */ + WARN(true, "PQAP/ZAPQ completed with invalid rc (%x)\n", + status.response_code); + return -EIO; + } + + /* wait for the reset to take effect */ + while (retry2--) { + if (status.queue_empty && !status.irq_enabled) + break; + msleep(20); + status = ap_tapq(q->apqn, NULL); + } + WARN_ON_ONCE(retry2 <= 0); - return -EBUSY; +free_resources: + vfio_ap_free_aqic_resources(q); + + return ret; } static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev) @@ -1163,13 +1186,15 @@ static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev) int ret; int rc = 0; unsigned long apid, apqi; + struct vfio_ap_queue *q; struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev); for_each_set_bit_inv(apid, matrix_mdev->matrix.apm, matrix_mdev->matrix.apm_max + 1) { for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm, matrix_mdev->matrix.aqm_max + 1) { - ret = vfio_ap_mdev_reset_queue(apid, apqi, 1); + q = vfio_ap_find_queue(AP_MKQID(apid, apqi)); + ret = vfio_ap_mdev_reset_queue(q, 1); /* * Regardless whether a queue turns out to be busy, or * is not operational, we need to continue resetting @@ -1177,7 +1202,6 @@ static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev) */ if (ret) rc = ret; - vfio_ap_irq_disable_apqn(AP_MKQID(apid, apqi)); } } diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h index f46dde56b464..28e9d9989768 100644 --- a/drivers/s390/crypto/vfio_ap_private.h +++ b/drivers/s390/crypto/vfio_ap_private.h @@ -88,11 +88,6 @@ struct ap_matrix_mdev { struct mdev_device *mdev; }; -extern int vfio_ap_mdev_register(void); -extern void vfio_ap_mdev_unregister(void); -int vfio_ap_mdev_reset_queue(unsigned int apid, unsigned int apqi, - unsigned int retry); - struct vfio_ap_queue { struct ap_matrix_mdev *matrix_mdev; unsigned long saved_pfn; @@ -100,5 +95,10 @@ struct vfio_ap_queue { #define VFIO_AP_ISC_INVALID 0xff unsigned char saved_isc; }; -struct ap_queue_status vfio_ap_irq_disable(struct vfio_ap_queue *q); + +int vfio_ap_mdev_register(void); +void vfio_ap_mdev_unregister(void); +int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q, + unsigned int retry); + #endif /* _VFIO_AP_PRIVATE_H_ */