From patchwork Thu Oct 21 15:23:28 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anthony Krowiak X-Patchwork-Id: 12575577 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5B28AC433EF for ; Thu, 21 Oct 2021 15:24:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4424F60C49 for ; Thu, 21 Oct 2021 15:24:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232238AbhJUP0p (ORCPT ); Thu, 21 Oct 2021 11:26:45 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:12928 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S232034AbhJUP0e (ORCPT ); Thu, 21 Oct 2021 11:26:34 -0400 Received: from pps.filterd (m0098413.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 19LEBLXr023564; 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Thu, 21 Oct 2021 15:24:11 +0000 (GMT) Received: from cpe-172-100-181-211.stny.res.rr.com.com (unknown [9.160.98.118]) by b03ledav005.gho.boulder.ibm.com (Postfix) with ESMTP; Thu, 21 Oct 2021 15:24:11 +0000 (GMT) From: Tony Krowiak To: linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: jjherne@linux.ibm.com, freude@linux.ibm.com, borntraeger@de.ibm.com, cohuck@redhat.com, mjrosato@linux.ibm.com, pasic@linux.ibm.com, alex.williamson@redhat.com, kwankhede@nvidia.com, fiuczy@linux.ibm.com, Tony Krowiak Subject: [PATCH v17 11/15] s390/ap: driver callback to indicate resource in use Date: Thu, 21 Oct 2021 11:23:28 -0400 Message-Id: <20211021152332.70455-12-akrowiak@linux.ibm.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211021152332.70455-1-akrowiak@linux.ibm.com> References: <20211021152332.70455-1-akrowiak@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: 5neirPk4Jwhm43LmxkvkSj0h1mWiPfWD X-Proofpoint-GUID: oh7ImjwGjbpPLJY3htkky9vkN_RZpaQs X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.182.1,Aquarius:18.0.790,Hydra:6.0.425,FMLib:17.0.607.475 definitions=2021-10-21_04,2021-10-21_02,2020-04-07_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 bulkscore=0 clxscore=1015 priorityscore=1501 suspectscore=0 phishscore=0 lowpriorityscore=0 malwarescore=0 spamscore=0 adultscore=0 mlxlogscore=999 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2109230001 definitions=main-2110210079 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Introduces a new driver callback to prevent a root user from re-assigning the APQN of a queue that is in use by a non-default host device driver to a default host device driver and vice versa. The callback will be invoked whenever a change to the AP bus's sysfs apmask or aqmask attributes would result in one or more APQNs being re-assigned. If the callback responds in the affirmative for any driver queried, the change to the apmask or aqmask will be rejected with a device busy error. For this patch, only non-default drivers will be queried. Currently, there is only one non-default driver, the vfio_ap device driver. The vfio_ap device driver facilitates pass-through of an AP queue to a guest. The idea here is that a guest may be administered by a different sysadmin than the host and we don't want AP resources to unexpectedly disappear from a guest's AP configuration (i.e., adapters and domains assigned to the matrix mdev). This will enforce the proper procedure for removing AP resources intended for guest usage which is to first unassign them from the matrix mdev, then unbind them from the vfio_ap device driver. Signed-off-by: Tony Krowiak Reviewed-by: Harald Freudenberger Reviewed-by: Halil Pasic --- drivers/s390/crypto/ap_bus.c | 160 ++++++++++++++++++++++++++++++++--- drivers/s390/crypto/ap_bus.h | 4 + 2 files changed, 154 insertions(+), 10 deletions(-) diff --git a/drivers/s390/crypto/ap_bus.c b/drivers/s390/crypto/ap_bus.c index d9b804943d19..15886610f61a 100644 --- a/drivers/s390/crypto/ap_bus.c +++ b/drivers/s390/crypto/ap_bus.c @@ -36,6 +36,7 @@ #include #include #include +#include #include "ap_bus.h" #include "ap_debug.h" @@ -1060,6 +1061,23 @@ static int modify_bitmap(const char *str, unsigned long *bitmap, int bits) return 0; } +static int ap_parse_bitmap_str(const char *str, unsigned long *bitmap, int bits, + unsigned long *newmap) +{ + unsigned long size; + int rc; + + size = BITS_TO_LONGS(bits) * sizeof(unsigned long); + if (*str == '+' || *str == '-') { + memcpy(newmap, bitmap, size); + rc = modify_bitmap(str, newmap, bits); + } else { + memset(newmap, 0, size); + rc = hex2bitmap(str, newmap, bits); + } + return rc; +} + int ap_parse_mask_str(const char *str, unsigned long *bitmap, int bits, struct mutex *lock) @@ -1079,14 +1097,7 @@ int ap_parse_mask_str(const char *str, kfree(newmap); return -ERESTARTSYS; } - - if (*str == '+' || *str == '-') { - memcpy(newmap, bitmap, size); - rc = modify_bitmap(str, newmap, bits); - } else { - memset(newmap, 0, size); - rc = hex2bitmap(str, newmap, bits); - } + rc = ap_parse_bitmap_str(str, bitmap, bits, newmap); if (rc == 0) memcpy(bitmap, newmap, size); mutex_unlock(lock); @@ -1278,12 +1289,76 @@ static ssize_t apmask_show(struct bus_type *bus, char *buf) return rc; } +static int __verify_card_reservations(struct device_driver *drv, void *data) +{ + int rc = 0; + struct ap_driver *ap_drv = to_ap_drv(drv); + unsigned long *newapm = (unsigned long *)data; + + /* + * No need to verify whether the driver is using the queues if it is the + * default driver. + */ + if (ap_drv->flags & AP_DRIVER_FLAG_DEFAULT) + return 0; + + /* + * increase the driver's module refcounter to be sure it is not + * going away when we invoke the callback function. + */ + if (!try_module_get(drv->owner)) + return 0; + + if (ap_drv->in_use) { + rc = ap_drv->in_use(newapm, ap_perms.aqm); + if (rc) + rc = -EBUSY; + } + + /* release the driver's module */ + module_put(drv->owner); + + return rc; +} + +static int apmask_commit(unsigned long *newapm) +{ + int rc; + unsigned long reserved[BITS_TO_LONGS(AP_DEVICES)]; + + /* + * Check if any bits in the apmask have been set which will + * result in queues being removed from non-default drivers + */ + if (bitmap_andnot(reserved, newapm, ap_perms.apm, AP_DEVICES)) { + rc = bus_for_each_drv(&ap_bus_type, NULL, reserved, + __verify_card_reservations); + if (rc) + return rc; + } + + memcpy(ap_perms.apm, newapm, APMASKSIZE); + + return 0; +} + static ssize_t apmask_store(struct bus_type *bus, const char *buf, size_t count) { int rc; + DECLARE_BITMAP(newapm, AP_DEVICES); - rc = ap_parse_mask_str(buf, ap_perms.apm, AP_DEVICES, &ap_perms_mutex); + if (mutex_lock_interruptible(&ap_perms_mutex)) + return -ERESTARTSYS; + + rc = ap_parse_bitmap_str(buf, ap_perms.apm, AP_DEVICES, newapm); + if (rc) + goto done; + + rc = apmask_commit(newapm); + +done: + mutex_unlock(&ap_perms_mutex); if (rc) return rc; @@ -1309,12 +1384,77 @@ static ssize_t aqmask_show(struct bus_type *bus, char *buf) return rc; } +static int __verify_queue_reservations(struct device_driver *drv, void *data) +{ + int rc = 0; + struct ap_driver *ap_drv = to_ap_drv(drv); + unsigned long *newaqm = (unsigned long *)data; + + /* + * If the reserved bits do not identify queues reserved for use by the + * non-default driver, there is no need to verify the driver is using + * the queues. + */ + if (ap_drv->flags & AP_DRIVER_FLAG_DEFAULT) + return 0; + + /* + * increase the driver's module refcounter to be sure it is not + * going away when we invoke the callback function. + */ + if (!try_module_get(drv->owner)) + return 0; + + if (ap_drv->in_use) { + rc = ap_drv->in_use(ap_perms.apm, newaqm); + if (rc) + return -EBUSY; + } + + /* release the driver's module */ + module_put(drv->owner); + + return rc; +} + +static int aqmask_commit(unsigned long *newaqm) +{ + int rc; + unsigned long reserved[BITS_TO_LONGS(AP_DOMAINS)]; + + /* + * Check if any bits in the aqmask have been set which will + * result in queues being removed from non-default drivers + */ + if (bitmap_andnot(reserved, newaqm, ap_perms.aqm, AP_DOMAINS)) { + rc = bus_for_each_drv(&ap_bus_type, NULL, reserved, + __verify_queue_reservations); + if (rc) + return rc; + } + + memcpy(ap_perms.aqm, newaqm, AQMASKSIZE); + + return 0; +} + static ssize_t aqmask_store(struct bus_type *bus, const char *buf, size_t count) { int rc; + DECLARE_BITMAP(newaqm, AP_DOMAINS); + + if (mutex_lock_interruptible(&ap_perms_mutex)) + return -ERESTARTSYS; + + rc = ap_parse_bitmap_str(buf, ap_perms.aqm, AP_DOMAINS, newaqm); + if (rc) + goto done; + + rc = aqmask_commit(newaqm); - rc = ap_parse_mask_str(buf, ap_perms.aqm, AP_DOMAINS, &ap_perms_mutex); +done: + mutex_unlock(&ap_perms_mutex); if (rc) return rc; diff --git a/drivers/s390/crypto/ap_bus.h b/drivers/s390/crypto/ap_bus.h index 95b577754b35..67c1bef60ad5 100644 --- a/drivers/s390/crypto/ap_bus.h +++ b/drivers/s390/crypto/ap_bus.h @@ -142,6 +142,7 @@ struct ap_driver { int (*probe)(struct ap_device *); void (*remove)(struct ap_device *); + int (*in_use)(unsigned long *apm, unsigned long *aqm); }; #define to_ap_drv(x) container_of((x), struct ap_driver, driver) @@ -289,6 +290,9 @@ void ap_queue_init_state(struct ap_queue *aq); struct ap_card *ap_card_create(int id, int queue_depth, int raw_type, int comp_type, unsigned int functions, int ml); +#define APMASKSIZE (BITS_TO_LONGS(AP_DEVICES) * sizeof(unsigned long)) +#define AQMASKSIZE (BITS_TO_LONGS(AP_DOMAINS) * sizeof(unsigned long)) + struct ap_perms { unsigned long ioctlm[BITS_TO_LONGS(AP_IOCTLS)]; unsigned long apm[BITS_TO_LONGS(AP_DEVICES)];