Hi,
I noticed that a new version of the default/alternate driver patch(es)
seems to have made its way onto the s390/features branch. As I did not
see any posting of that patch, and it has interaction with vfio-ap,
I'll repost the patch here in full for convenience and add some
comments below. (At least, the documentation for vfio-ap will need an
update if it is rebased on top of this patch.)
One thing on top: What about control domains? The vfio-ap interface
allows to assign control domains as well. Do we want to be able to have
any control domain available to be used for sending control commands by
guests, or do we want to restrict usage of some control domains as well?
> commit fc303d54f83b22b0f2b40e85f8f3e56658d59bc9
> Author: Harald Freudenberger <freude@xxxxxxxxxxxxx>
> Date: Fri Jul 20 08:36:53 2018 +0200
>
> s390/zcrypt: AP bus support for alternate driver(s)
>
> The current AP bus, AP devices and AP device drivers implementation
> uses a clearly defined mapping for binding AP devices to AP device
> drivers. So for example a CEX6C queue will always be bound to the
> cex4queue device driver.
>
> The Linux Device Driver model has no sensitivity for more than one
> device driver eligible for one device type. If there exist more than
> one drivers matching to the device type, simple all drivers are tried
> consecutively. There is no way to determine and influence the probing
> order of the drivers.
>
> With KVM there is a need to provide additional device drivers matching
> to the very same type of AP devices. With a simple implementation the
> KVM drivers run in competition to the regular drivers. Whichever
> 'wins' a device depends on build order and implementation details
> within the common Linux Device Driver Model and is not
> deterministic. However, a userspace process could figure out which
> device should be bound to which driver and sort out the correct
> binding by manipulating attributes in the sysfs.
>
> If for security reasons a AP device must not get bound to the 'wrong'
> device driver the sorting out has to be done within the Linux kernel
> by the AP bus code. This patch modifies the behavior of the AP bus
> for probing drivers for devices in a way that two sets of drivers are
> usable. Two new bitmasks 'apmask' and 'aqmask' are used to mark a
> subset of the APQN range for 'usable by the ap bus and the default
> drivers' or 'not usable by the default drivers and thus available for
> alternate drivers like vfio-xxx'. So an APQN which is addressed by
> this masking only the default drivers will be probed. In contrary an
> APQN which is not addressed by the masks will never be probed and
> bound to default drivers but onny to alternate drivers.
s/onny/only/
(already in my original comments)
>
> Eventually the two masks give a way to divide the range of APQNs into
> two pools: one pool of APQNs used by the AP bus and the default
> drivers and thus via zcrypt drivers available to the userspace of the
> system. And another pool where no zcrypt drivers are bound to and
> which can be used by alternate drivers (like vfio-xxx) for their
> needs. This division is hot-plug save and makes sure a APQN assigned
> to an alternate driver is at no time somehow exploitable by the wrong
> party.
>
> The two masks are located in sysfs at /sys/bus/ap/apmask and
> /sys/bus/ap/aqmask. The mask syntax is exactly the same as the
> already existing mask attributes in the /sys/bus/ap directory (for
> example ap_usage_domain_mask and ap_control_domain_mask).
>
> By default all APQNs belong to the ap bus and the default drivers:
>
> cat /sys/bus/ap/apmask
> 0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
> cat /sys/bus/ap/aqmask
> 0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
>
> The masks can be changed at boot time with the kernel command line
> like this:
>
> ... ap.apmask=0xffff ap.aqmask=0x40
>
> This would give these two pools:
>
> default drivers pool: adapter 0 - 15, domain 1
> alternate drivers pool: adapter 0 - 15, all but domain 1
> adapter 16-255, all domains
>
> The sysfs attributes for this two masks are writeable and an
> administrator is able to reconfigure the assignements on the fly by
> writing new mask values into. With changing the mask(s) a revision of
> the existing queue to driver bindings is done. So all APQNs which are
> bound to the 'wrong' driver are reprobed via kernel function
> device_reprobe() and thus the new correct driver will be assigned with
> respect of the changed apmask and aqmask bits.
>
> The mask values are bitmaps in big endian order starting with bit 0.
> So adapter number 0 is the leftmost bit, mask is 0x8000... The sysfs
> attributes accept 2 different formats:
> - Absolute hex string starting with 0x like "0x12345678" does set
> the mask starting from left to right. If the given string is shorter
> than the mask it is padded with 0s on the right. If the string is
> longer than the mask an error comes back (EINVAL).
> - '+' or '-' followed by a numerical value. Valid examples are "+1",
> "-13", "+0x41", "-0xff" and even "+0" and "-0". Only the addressed
> bit in the mask is switched on ('+') or off ('-').
>
> This patch will also be the base for an upcoming extension to the
> zcrypt drivers to be able to provide additional zcrypt device nodes
> with filtering based on ap and aq masks.
>
> Signed-off-by: Harald Freudenberger <freude@xxxxxxxxxxxxx>
> Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
> Signed-off-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
>
> diff --git a/drivers/s390/crypto/ap_bus.c b/drivers/s390/crypto/ap_bus.c
> index bf27fc4d1335..b023e35786ec 100644
> --- a/drivers/s390/crypto/ap_bus.c
> +++ b/drivers/s390/crypto/ap_bus.c
> @@ -34,6 +34,7 @@
> #include <linux/crypto.h>
> #include <linux/mod_devicetable.h>
> #include <linux/debugfs.h>
> +#include <linux/ctype.h>
>
> #include "ap_bus.h"
> #include "ap_debug.h"
> @@ -51,11 +52,26 @@ static int ap_thread_flag = 0;
> module_param_named(poll_thread, ap_thread_flag, int, S_IRUSR|S_IRGRP);
> MODULE_PARM_DESC(poll_thread, "Turn on/off poll thread, default is 0 (off).");
>
> +static char *apm_str;
> +module_param_named(apmask, apm_str, charp, 0440);
> +MODULE_PARM_DESC(apmask, "AP bus adapter mask.");
> +
> +static char *aqm_str;
> +module_param_named(aqmask, aqm_str, charp, 0440);
> +MODULE_PARM_DESC(aqmask, "AP bus domain mask.");
> +
> static struct device *ap_root_device;
>
> DEFINE_SPINLOCK(ap_list_lock);
> LIST_HEAD(ap_card_list);
>
> +/* Default permissions (card and domain masking) */
> +static struct ap_perms {
> + DECLARE_BITMAP(apm, AP_DEVICES);
> + DECLARE_BITMAP(aqm, AP_DOMAINS);
> +} ap_perms;
> +static DEFINE_MUTEX(ap_perms_mutex);
> +
> static struct ap_config_info *ap_configuration;
> static bool initialised;
>
> @@ -666,11 +682,96 @@ static struct bus_type ap_bus_type = {
> .pm = &ap_bus_pm_ops,
> };
>
> +static int __ap_revice_reserved(struct device *dev, void *dummy)
This probably wants to be either "device" or "revise"...
> +{
> + int rc, card, queue, devres, drvres;
> +
> + if (is_queue_dev(dev)) {
> + card = AP_QID_CARD(to_ap_queue(dev)->qid);
> + queue = AP_QID_QUEUE(to_ap_queue(dev)->qid);
> + mutex_lock(&ap_perms_mutex);
> + devres = test_bit_inv(card, ap_perms.apm)
> + && test_bit_inv(queue, ap_perms.aqm);
> + mutex_unlock(&ap_perms_mutex);
> + drvres = to_ap_drv(dev->driver)->flags
> + & AP_DRIVER_FLAG_DEFAULT;
> + if (!!devres != !!drvres) {
> + AP_DBF(DBF_DEBUG, "reprobing queue=%02x.%04x\n",
> + card, queue);
> + rc = device_reprobe(dev);
> + }
> + }
> +
> + return 0;
> +}
> +
> +static void ap_bus_revise_bindings(void)
> +{
> + bus_for_each_dev(&ap_bus_type, NULL, NULL, __ap_revice_reserved);
> +}
> +
> +int ap_owned_by_def_drv(int card, int queue)
> +{
> + int rc = 0;
> +
> + if (card < 0 || card >= AP_DEVICES || queue < 0 || queue >= AP_DOMAINS)
> + return -EINVAL;
> +
> + mutex_lock(&ap_perms_mutex);
> +
> + if (test_bit_inv(card, ap_perms.apm)
> + && test_bit_inv(queue, ap_perms.aqm))
> + rc = 1;
> +
> + mutex_unlock(&ap_perms_mutex);
> +
> + return rc;
> +}
> +EXPORT_SYMBOL(ap_owned_by_def_drv);
> +
> +int ap_apqn_in_matrix_owned_by_def_drv(unsigned long *apm,
> + unsigned long *aqm)
> +{
> + int card, queue, rc = 0;
> +
> + mutex_lock(&ap_perms_mutex);
> +
> + for (card = 0; !rc && card < AP_DEVICES; card++)
> + if (test_bit_inv(card, apm) &&
> + test_bit_inv(card, ap_perms.apm))
> + for (queue = 0; !rc && queue < AP_DOMAINS; queue++)
> + if (test_bit_inv(queue, aqm) &&
> + test_bit_inv(queue, ap_perms.aqm))
> + rc = 1;
> +
> + mutex_unlock(&ap_perms_mutex);
> +
> + return rc;
> +}
> +EXPORT_SYMBOL(ap_apqn_in_matrix_owned_by_def_drv);
> +
> static int ap_device_probe(struct device *dev)
> {
> struct ap_device *ap_dev = to_ap_dev(dev);
> struct ap_driver *ap_drv = to_ap_drv(dev->driver);
> - int rc;
> + int card, queue, devres, drvres, rc;
> +
> + if (is_queue_dev(dev)) {
> + /*
> + * For apqns marked as reserved/used by ap bus and
> + * default drivers only drivers with a default flag
> + * will be called for probe this device.
> + */
> + card = AP_QID_CARD(to_ap_queue(dev)->qid);
> + queue = AP_QID_QUEUE(to_ap_queue(dev)->qid);
> + mutex_lock(&ap_perms_mutex);
> + devres = test_bit_inv(card, ap_perms.apm)
> + && test_bit_inv(queue, ap_perms.aqm);
> + mutex_unlock(&ap_perms_mutex);
> + drvres = ap_drv->flags & AP_DRIVER_FLAG_DEFAULT;
> + if (!!devres != !!drvres)
> + return -ENODEV;
> + }
I think the following comments from my original review still apply:
"It's a bit more than that, right? You also won't probe non-reserved
devices if the driver has the default flag set.
/*
* If the apqn is marked as reserved/used by ap bus and
* default drivers, only probe with drivers with the default
* flag set. If it is not marked, only probe with drivers
* with the default flag not set.
*/
[As an aside: Is 'default' a good name for the driver flag? To a casual
reader I think it implies that it is the default driver if no other
driver comes along. Call it maybe 'trusted' or something like that?]"
>
> /* Add queue/card to list of active queues/cards */
> spin_lock_bh(&ap_list_lock);
> @@ -753,6 +854,36 @@ EXPORT_SYMBOL(ap_bus_force_rescan);
> /*
> * AP bus attributes.
> */
> +
> +static int hex2bitmap(const char *str, unsigned long *bitmap, int bits)
> +{
> + int i, n, b;
> +
> + /* bits needs to be a multiple of 8 */
> + if (bits & 0x07)
> + return -EINVAL;
> +
> + memset(bitmap, 0, bits / 8);
> +
> + if (str[0] == '0' && str[1] == 'x')
> + str++;
> + if (*str == 'x')
> + str++;
> +
> + for (i = 0; isxdigit(*str) && i < bits; str++) {
> + b = hex_to_bin(*str);
> + for (n = 0; n < 4; n++)
> + if (b & (0x08 >> n))
> + set_bit_inv(i + n, bitmap);
> + i += 4;
> + }
> +
> + if (i < 4 || isxdigit(*str))
> + return -EINVAL;
> +
> + return 0;
> +}
> +
> static ssize_t ap_domain_show(struct bus_type *bus, char *buf)
> {
> return snprintf(buf, PAGE_SIZE, "%d\n", ap_domain_index);
> @@ -764,7 +895,8 @@ static ssize_t ap_domain_store(struct bus_type *bus,
> int domain;
>
> if (sscanf(buf, "%i\n", &domain) != 1 ||
> - domain < 0 || domain > ap_max_domain_id)
> + domain < 0 || domain > ap_max_domain_id ||
> + !test_bit_inv(domain, ap_perms.aqm))
> return -EINVAL;
> spin_lock_bh(&ap_domain_lock);
> ap_domain_index = domain;
> @@ -901,6 +1033,114 @@ static ssize_t ap_max_domain_id_show(struct bus_type *bus, char *buf)
>
> static BUS_ATTR(ap_max_domain_id, 0444, ap_max_domain_id_show, NULL);
>
> +static ssize_t ap_apmask_show(struct bus_type *bus, char *buf)
> +{
> + int rc;
> +
> + if (mutex_lock_interruptible(&ap_perms_mutex))
> + return -ERESTARTSYS;
> + rc = snprintf(buf, PAGE_SIZE,
> + "0x%016lx%016lx%016lx%016lx\n",
> + ap_perms.apm[0], ap_perms.apm[1],
> + ap_perms.apm[2], ap_perms.apm[3]);
> + mutex_unlock(&ap_perms_mutex);
> +
> + return rc;
> +}
> +
> +static ssize_t ap_apmask_store(struct bus_type *bus, const char *buf,
> + size_t count)
> +{
> + int i;
> +
> + if (*buf == '+' || *buf == '-') {
> + if (kstrtoint(buf, 0, &i))
> + return -EINVAL;
> + if (i <= -AP_DEVICES || i >= AP_DEVICES)
> + return -EINVAL;
> + if (mutex_lock_interruptible(&ap_perms_mutex))
> + return -ERESTARTSYS;
> + if (*buf == '-')
> + clear_bit_inv(-i, ap_perms.apm);
> + else
> + set_bit_inv(i, ap_perms.apm);
> + } else {
> + DECLARE_BITMAP(apm, AP_DEVICES);
> +
> + i = hex2bitmap(buf, apm, AP_DEVICES);
> + if (i)
> + return i;
> + if (mutex_lock_interruptible(&ap_perms_mutex))
> + return -ERESTARTSYS;
> + for (i = 0; i < AP_DEVICES; i++)
> + if (test_bit_inv(i, apm))
> + set_bit_inv(i, ap_perms.apm);
> + else
> + clear_bit_inv(i, ap_perms.apm);
> + }
> + mutex_unlock(&ap_perms_mutex);
> +
> + ap_bus_revise_bindings();
> +
> + return count;
> +}
> +
> +static BUS_ATTR(apmask, 0644, ap_apmask_show, ap_apmask_store);
> +
> +static ssize_t ap_aqmask_show(struct bus_type *bus, char *buf)
> +{
> + int rc;
> +
> + if (mutex_lock_interruptible(&ap_perms_mutex))
> + return -ERESTARTSYS;
> + rc = snprintf(buf, PAGE_SIZE,
> + "0x%016lx%016lx%016lx%016lx\n",
> + ap_perms.aqm[0], ap_perms.aqm[1],
> + ap_perms.aqm[2], ap_perms.aqm[3]);
> + mutex_unlock(&ap_perms_mutex);
> +
> + return rc;
> +}
> +
> +static ssize_t ap_aqmask_store(struct bus_type *bus, const char *buf,
> + size_t count)
> +{
> + int i;
> +
> + if (*buf == '+' || *buf == '-') {
> + if (kstrtoint(buf, 0, &i))
> + return -EINVAL;
> + if (i <= -AP_DEVICES || i >= AP_DEVICES)
> + return -EINVAL;
> + if (mutex_lock_interruptible(&ap_perms_mutex))
> + return -ERESTARTSYS;
> + if (*buf == '-')
> + clear_bit_inv(-i, ap_perms.aqm);
> + else
> + set_bit_inv(i, ap_perms.aqm);
> + } else {
> + DECLARE_BITMAP(aqm, AP_DEVICES);
> +
> + i = hex2bitmap(buf, aqm, AP_DEVICES);
> + if (i)
> + return i;
> + if (mutex_lock_interruptible(&ap_perms_mutex))
> + return -ERESTARTSYS;
> + for (i = 0; i < AP_DEVICES; i++)
> + if (test_bit_inv(i, aqm))
> + set_bit_inv(i, ap_perms.aqm);
> + else
> + clear_bit_inv(i, ap_perms.aqm);
> + }
> + mutex_unlock(&ap_perms_mutex);
> +
> + ap_bus_revise_bindings();
> +
> + return count;
> +}
There a two things that bother me a bit here:
- The sysfs interface accepts both the hex format and the +/- format,
but the module parameters only the hex format. Probably not a big
deal, but it looks a bit inconsistent.
- With the more end-user friendly +/- interface, you can always only
add/remove one domain/queue at once. For every change, it will walk
along the bus and do the reprobing, if needed. It would be more
effective if you could trigger all needed changes at once, without
being forced to resort to the hex interface for that.
> +
> +static BUS_ATTR(aqmask, 0644, ap_aqmask_show, ap_aqmask_store);
> +
> static struct bus_attribute *const ap_bus_attrs[] = {
> &bus_attr_ap_domain,
> &bus_attr_ap_control_domain_mask,
> @@ -910,6 +1150,8 @@ static struct bus_attribute *const ap_bus_attrs[] = {
> &bus_attr_ap_interrupts,
> &bus_attr_poll_timeout,
> &bus_attr_ap_max_domain_id,
> + &bus_attr_apmask,
> + &bus_attr_aqmask,
> NULL,
> };
>
> @@ -938,7 +1180,8 @@ static int ap_select_domain(void)
> best_domain = -1;
> max_count = 0;
> for (i = 0; i < AP_DOMAINS; i++) {
> - if (!ap_test_config_domain(i))
> + if (!ap_test_config_domain(i) ||
> + !test_bit_inv(i, ap_perms.aqm))
> continue;
> count = 0;
> for (j = 0; j < AP_DEVICES; j++) {
> @@ -1187,6 +1430,37 @@ static int __init ap_debug_init(void)
> return 0;
> }
>
> +static void __init ap_perms_init(void)
> +{
> + int i, rc;
> +
> + /* start with all resources useable */
> + memset(&ap_perms.apm, 0xFF, sizeof(ap_perms.apm));
> + memset(&ap_perms.aqm, 0xFF, sizeof(ap_perms.aqm));
> +
> + /* process kernel parameters apm and aqm if given */
> + if (apm_str) {
> + DECLARE_BITMAP(apm, AP_DEVICES);
> +
> + rc = hex2bitmap(apm_str, apm, AP_DEVICES);
> + if (rc == 0) {
> + for (i = 0; i < AP_DEVICES; i++)
> + if (!test_bit_inv(i, apm))
> + clear_bit_inv(i, ap_perms.apm);
> + }
> + }
> + if (aqm_str) {
> + DECLARE_BITMAP(aqm, AP_DOMAINS);
> +
> + rc = hex2bitmap(aqm_str, aqm, AP_DOMAINS);
> + if (rc == 0) {
> + for (i = 0; i < AP_DOMAINS; i++)
> + if (!test_bit_inv(i, aqm))
> + clear_bit_inv(i, ap_perms.aqm);
> + }
> + }
> +}
> +
> /**
> * ap_module_init(): The module initialization code.
> *
> @@ -1206,6 +1480,9 @@ static int __init ap_module_init(void)
> return -ENODEV;
> }
>
> + /* set up the AP permissions (ap and aq masks) */
> + ap_perms_init();
> +
> /* Get AP configuration data if available */
> ap_init_configuration();
>
> @@ -1214,7 +1491,9 @@ static int __init ap_module_init(void)
> ap_max_domain_id ? ap_max_domain_id : AP_DOMAINS - 1;
> else
> max_domain_id = 15;
> - if (ap_domain_index < -1 || ap_domain_index > max_domain_id) {
> + if (ap_domain_index < -1 || ap_domain_index > max_domain_id ||
> + (ap_domain_index >= 0 &&
> + !test_bit_inv(ap_domain_index, ap_perms.aqm))) {
> pr_warn("%d is not a valid cryptographic domain\n",
> ap_domain_index);
> ap_domain_index = -1;
> diff --git a/drivers/s390/crypto/ap_bus.h b/drivers/s390/crypto/ap_bus.h
> index 936541937e15..380612762134 100644
> --- a/drivers/s390/crypto/ap_bus.h
> +++ b/drivers/s390/crypto/ap_bus.h
> @@ -117,9 +117,18 @@ enum ap_wait {
> struct ap_device;
> struct ap_message;
>
> +/*
> + * The ap driver struct includes a flags field which holds some info for
> + * the ap bus about the driver. Currently only one flag is supported and
> + * used: The DEFAULT flag marks an ap driver as a default driver which is
> + * used together with the apmask and aqmask whitelisting of the ap bus.
> + */
> +#define AP_DRIVER_FLAG_DEFAULT 0x0001
> +
> struct ap_driver {
> struct device_driver driver;
> struct ap_device_id *ids;
> + unsigned int flags;
>
> int (*probe)(struct ap_device *);
> void (*remove)(struct ap_device *);
> @@ -248,4 +257,27 @@ void ap_queue_resume(struct ap_device *ap_dev);
> struct ap_card *ap_card_create(int id, int queue_depth, int raw_device_type,
> int comp_device_type, unsigned int functions);
>
> +/*
> + * check APQN for owned/reserved by ap bus and default driver(s).
> + * Checks if this APQN is or will be in use by the ap bus
> + * and the default set of drivers.
> + * If yes, returns 1, if not returns 0. On error a negative
> + * errno value is returned.
> + */
> +int ap_owned_by_def_drv(int card, int queue);
> +
> +/*
> + * check 'matrix' of APQNs for owned/reserved by ap bus and
> + * default driver(s).
> + * Checks if there is at least one APQN in the given 'matrix'
> + * marked as owned/reserved by the ap bus and default driver(s).
> + * If such an APQN is found the return value is 1, otherwise
> + * 0 is returned. On error a negative errno value is returned.
> + * The parameter apm is a bitmask which should be declared
> + * as DECLARE_BITMAP(apm, AP_DEVICES), the aqm parameter is
> + * similar, should be declared as DECLARE_BITMAP(aqm, AP_DOMAINS).
> + */
> +int ap_apqn_in_matrix_owned_by_def_drv(unsigned long *apm,
> + unsigned long *aqm);
> +
> #endif /* _AP_BUS_H_ */
> diff --git a/drivers/s390/crypto/zcrypt_cex2a.c b/drivers/s390/crypto/zcrypt_cex2a.c
> index e701194d3611..f4ae5fa30ec9 100644
> --- a/drivers/s390/crypto/zcrypt_cex2a.c
> +++ b/drivers/s390/crypto/zcrypt_cex2a.c
> @@ -145,6 +145,7 @@ static struct ap_driver zcrypt_cex2a_card_driver = {
> .probe = zcrypt_cex2a_card_probe,
> .remove = zcrypt_cex2a_card_remove,
> .ids = zcrypt_cex2a_card_ids,
> + .flags = AP_DRIVER_FLAG_DEFAULT,
> };
>
> /**
> @@ -208,6 +209,7 @@ static struct ap_driver zcrypt_cex2a_queue_driver = {
> .suspend = ap_queue_suspend,
> .resume = ap_queue_resume,
> .ids = zcrypt_cex2a_queue_ids,
> + .flags = AP_DRIVER_FLAG_DEFAULT,
> };
>
> int __init zcrypt_cex2a_init(void)
> diff --git a/drivers/s390/crypto/zcrypt_cex4.c b/drivers/s390/crypto/zcrypt_cex4.c
> index f305538334ad..35d58dbbc4da 100644
> --- a/drivers/s390/crypto/zcrypt_cex4.c
> +++ b/drivers/s390/crypto/zcrypt_cex4.c
> @@ -214,6 +214,7 @@ static struct ap_driver zcrypt_cex4_card_driver = {
> .probe = zcrypt_cex4_card_probe,
> .remove = zcrypt_cex4_card_remove,
> .ids = zcrypt_cex4_card_ids,
> + .flags = AP_DRIVER_FLAG_DEFAULT,
> };
>
> /**
> @@ -283,6 +284,7 @@ static struct ap_driver zcrypt_cex4_queue_driver = {
> .suspend = ap_queue_suspend,
> .resume = ap_queue_resume,
> .ids = zcrypt_cex4_queue_ids,
> + .flags = AP_DRIVER_FLAG_DEFAULT,
> };
>
> int __init zcrypt_cex4_init(void)
> diff --git a/drivers/s390/crypto/zcrypt_pcixcc.c b/drivers/s390/crypto/zcrypt_pcixcc.c
> index 159b0a0dd211..e5e14d723163 100644
> --- a/drivers/s390/crypto/zcrypt_pcixcc.c
> +++ b/drivers/s390/crypto/zcrypt_pcixcc.c
> @@ -223,6 +223,7 @@ static struct ap_driver zcrypt_pcixcc_card_driver = {
> .probe = zcrypt_pcixcc_card_probe,
> .remove = zcrypt_pcixcc_card_remove,
> .ids = zcrypt_pcixcc_card_ids,
> + .flags = AP_DRIVER_FLAG_DEFAULT,
> };
>
> /**
> @@ -286,6 +287,7 @@ static struct ap_driver zcrypt_pcixcc_queue_driver = {
> .suspend = ap_queue_suspend,
> .resume = ap_queue_resume,
> .ids = zcrypt_pcixcc_queue_ids,
> + .flags = AP_DRIVER_FLAG_DEFAULT,
> };
>
> int __init zcrypt_pcixcc_init(void)
