From 01396a374c3d31bc5f8b693026cfa9a657319624 Mon Sep 17 00:00:00 2001 From: Harald Freudenberger Date: Fri, 22 Feb 2019 17:24:11 +0100 Subject: s390/zcrypt: revisit ap device remove procedure Working with the vfio-ap driver let to some revisit of the way how an ap (queue) device is removed from the driver. With the current implementation all the cleanup was done before the driver even got notified about the removal. Now the ap queue removal is done in 3 steps: 1) A preparation step, all ap messages within the queue are flushed and so the driver does 'receive' them. Also a new state AP_STATE_REMOVE assigned to the queue makes sure there are no new messages queued in. 2) Now the driver's remove function is invoked and the driver should do the job of cleaning up it's internal administration lists or whatever. After 2) is done it is guaranteed, that the driver is not invoked any more. On the other hand the driver has to make sure that the APQN is not accessed any more after step 2 is complete. 3) Now the ap bus code does the job of total cleanup of the APQN. A reset with zero is triggered and the state of the queue goes to AP_STATE_UNBOUND. After step 3) is complete, the ap queue has no pending messages and the APQN is cleared and so there are no requests and replies lingering around in the firmware queue for this APQN. Also the interrupts are disabled. After these remove steps the ap queue device may be assigned to another driver. Stress testing this remove/probe procedure showed a problem with the correct module reference counting. The actual receive of an reply in the driver is done asynchronous with completions. So with a driver change on an ap queue the message flush triggers completions but the threads waiting for the completions may run at a time where the queue already has the new driver assigned. So the module_put() at receive time needs to be done on the driver module which queued the ap message. This change is also part of this patch. Signed-off-by: Harald Freudenberger Reviewed-by: Ingo Franzki Signed-off-by: Martin Schwidefsky --- drivers/s390/crypto/ap_bus.c | 9 ++++++++- drivers/s390/crypto/ap_bus.h | 2 ++ drivers/s390/crypto/ap_queue.c | 26 +++++++++++++++++++++----- drivers/s390/crypto/zcrypt_api.c | 30 ++++++++++++++++++------------ 4 files changed, 49 insertions(+), 18 deletions(-) (limited to 'drivers') diff --git a/drivers/s390/crypto/ap_bus.c b/drivers/s390/crypto/ap_bus.c index e15816ff1265..033a1acabf48 100644 --- a/drivers/s390/crypto/ap_bus.c +++ b/drivers/s390/crypto/ap_bus.c @@ -810,11 +810,18 @@ static int ap_device_remove(struct device *dev) struct ap_device *ap_dev = to_ap_dev(dev); struct ap_driver *ap_drv = ap_dev->drv; + /* prepare ap queue device removal */ if (is_queue_dev(dev)) - ap_queue_remove(to_ap_queue(dev)); + ap_queue_prepare_remove(to_ap_queue(dev)); + + /* driver's chance to clean up gracefully */ if (ap_drv->remove) ap_drv->remove(ap_dev); + /* now do the ap queue device remove */ + if (is_queue_dev(dev)) + ap_queue_remove(to_ap_queue(dev)); + /* Remove queue/card from list of active queues/cards */ spin_lock_bh(&ap_list_lock); if (is_card_dev(dev)) diff --git a/drivers/s390/crypto/ap_bus.h b/drivers/s390/crypto/ap_bus.h index d0059eae5d94..15a98a673c5c 100644 --- a/drivers/s390/crypto/ap_bus.h +++ b/drivers/s390/crypto/ap_bus.h @@ -91,6 +91,7 @@ enum ap_state { AP_STATE_WORKING, AP_STATE_QUEUE_FULL, AP_STATE_SUSPEND_WAIT, + AP_STATE_REMOVE, /* about to be removed from driver */ AP_STATE_UNBOUND, /* momentary not bound to a driver */ AP_STATE_BORKED, /* broken */ NR_AP_STATES @@ -252,6 +253,7 @@ void ap_bus_force_rescan(void); void ap_queue_init_reply(struct ap_queue *aq, struct ap_message *ap_msg); struct ap_queue *ap_queue_create(ap_qid_t qid, int device_type); +void ap_queue_prepare_remove(struct ap_queue *aq); void ap_queue_remove(struct ap_queue *aq); void ap_queue_suspend(struct ap_device *ap_dev); void ap_queue_resume(struct ap_device *ap_dev); diff --git a/drivers/s390/crypto/ap_queue.c b/drivers/s390/crypto/ap_queue.c index ba261210c6da..6a340f2c3556 100644 --- a/drivers/s390/crypto/ap_queue.c +++ b/drivers/s390/crypto/ap_queue.c @@ -420,6 +420,10 @@ static ap_func_t *ap_jumptable[NR_AP_STATES][NR_AP_EVENTS] = { [AP_EVENT_POLL] = ap_sm_suspend_read, [AP_EVENT_TIMEOUT] = ap_sm_nop, }, + [AP_STATE_REMOVE] = { + [AP_EVENT_POLL] = ap_sm_nop, + [AP_EVENT_TIMEOUT] = ap_sm_nop, + }, [AP_STATE_UNBOUND] = { [AP_EVENT_POLL] = ap_sm_nop, [AP_EVENT_TIMEOUT] = ap_sm_nop, @@ -740,18 +744,31 @@ void ap_flush_queue(struct ap_queue *aq) } EXPORT_SYMBOL(ap_flush_queue); -void ap_queue_remove(struct ap_queue *aq) +void ap_queue_prepare_remove(struct ap_queue *aq) { - ap_flush_queue(aq); + spin_lock_bh(&aq->lock); + /* flush queue */ + __ap_flush_queue(aq); + /* set REMOVE state to prevent new messages are queued in */ + aq->state = AP_STATE_REMOVE; del_timer_sync(&aq->timeout); + spin_unlock_bh(&aq->lock); +} - /* reset with zero, also clears irq registration */ +void ap_queue_remove(struct ap_queue *aq) +{ + /* + * all messages have been flushed and the state is + * AP_STATE_REMOVE. Now reset with zero which also + * clears the irq registration and move the state + * to AP_STATE_UNBOUND to signal that this queue + * is not used by any driver currently. + */ spin_lock_bh(&aq->lock); ap_zapq(aq->qid); aq->state = AP_STATE_UNBOUND; spin_unlock_bh(&aq->lock); } -EXPORT_SYMBOL(ap_queue_remove); void ap_queue_reinit_state(struct ap_queue *aq) { @@ -760,4 +777,3 @@ void ap_queue_reinit_state(struct ap_queue *aq) ap_wait(ap_sm_event(aq, AP_EVENT_POLL)); spin_unlock_bh(&aq->lock); } -EXPORT_SYMBOL(ap_queue_reinit_state); diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c index eb93c2d27d0a..689c2af7026a 100644 --- a/drivers/s390/crypto/zcrypt_api.c +++ b/drivers/s390/crypto/zcrypt_api.c @@ -586,6 +586,7 @@ static inline bool zcrypt_check_queue(struct ap_perms *perms, int queue) static inline struct zcrypt_queue *zcrypt_pick_queue(struct zcrypt_card *zc, struct zcrypt_queue *zq, + struct module **pmod, unsigned int weight) { if (!zq || !try_module_get(zq->queue->ap_dev.drv->driver.owner)) @@ -595,15 +596,15 @@ static inline struct zcrypt_queue *zcrypt_pick_queue(struct zcrypt_card *zc, atomic_add(weight, &zc->load); atomic_add(weight, &zq->load); zq->request_count++; + *pmod = zq->queue->ap_dev.drv->driver.owner; return zq; } static inline void zcrypt_drop_queue(struct zcrypt_card *zc, struct zcrypt_queue *zq, + struct module *mod, unsigned int weight) { - struct module *mod = zq->queue->ap_dev.drv->driver.owner; - zq->request_count--; atomic_sub(weight, &zc->load); atomic_sub(weight, &zq->load); @@ -653,6 +654,7 @@ static long zcrypt_rsa_modexpo(struct ap_perms *perms, unsigned int weight, pref_weight; unsigned int func_code; int qid = 0, rc = -ENODEV; + struct module *mod; trace_s390_zcrypt_req(mex, TP_ICARSAMODEXPO); @@ -706,7 +708,7 @@ static long zcrypt_rsa_modexpo(struct ap_perms *perms, pref_weight = weight; } } - pref_zq = zcrypt_pick_queue(pref_zc, pref_zq, weight); + pref_zq = zcrypt_pick_queue(pref_zc, pref_zq, &mod, weight); spin_unlock(&zcrypt_list_lock); if (!pref_zq) { @@ -718,7 +720,7 @@ static long zcrypt_rsa_modexpo(struct ap_perms *perms, rc = pref_zq->ops->rsa_modexpo(pref_zq, mex); spin_lock(&zcrypt_list_lock); - zcrypt_drop_queue(pref_zc, pref_zq, weight); + zcrypt_drop_queue(pref_zc, pref_zq, mod, weight); spin_unlock(&zcrypt_list_lock); out: @@ -735,6 +737,7 @@ static long zcrypt_rsa_crt(struct ap_perms *perms, unsigned int weight, pref_weight; unsigned int func_code; int qid = 0, rc = -ENODEV; + struct module *mod; trace_s390_zcrypt_req(crt, TP_ICARSACRT); @@ -788,7 +791,7 @@ static long zcrypt_rsa_crt(struct ap_perms *perms, pref_weight = weight; } } - pref_zq = zcrypt_pick_queue(pref_zc, pref_zq, weight); + pref_zq = zcrypt_pick_queue(pref_zc, pref_zq, &mod, weight); spin_unlock(&zcrypt_list_lock); if (!pref_zq) { @@ -800,7 +803,7 @@ static long zcrypt_rsa_crt(struct ap_perms *perms, rc = pref_zq->ops->rsa_modexpo_crt(pref_zq, crt); spin_lock(&zcrypt_list_lock); - zcrypt_drop_queue(pref_zc, pref_zq, weight); + zcrypt_drop_queue(pref_zc, pref_zq, mod, weight); spin_unlock(&zcrypt_list_lock); out: @@ -819,6 +822,7 @@ static long _zcrypt_send_cprb(struct ap_perms *perms, unsigned int func_code; unsigned short *domain; int qid = 0, rc = -ENODEV; + struct module *mod; trace_s390_zcrypt_req(xcRB, TB_ZSECSENDCPRB); @@ -865,7 +869,7 @@ static long _zcrypt_send_cprb(struct ap_perms *perms, pref_weight = weight; } } - pref_zq = zcrypt_pick_queue(pref_zc, pref_zq, weight); + pref_zq = zcrypt_pick_queue(pref_zc, pref_zq, &mod, weight); spin_unlock(&zcrypt_list_lock); if (!pref_zq) { @@ -881,7 +885,7 @@ static long _zcrypt_send_cprb(struct ap_perms *perms, rc = pref_zq->ops->send_cprb(pref_zq, xcRB, &ap_msg); spin_lock(&zcrypt_list_lock); - zcrypt_drop_queue(pref_zc, pref_zq, weight); + zcrypt_drop_queue(pref_zc, pref_zq, mod, weight); spin_unlock(&zcrypt_list_lock); out: @@ -932,6 +936,7 @@ static long zcrypt_send_ep11_cprb(struct ap_perms *perms, unsigned int func_code; struct ap_message ap_msg; int qid = 0, rc = -ENODEV; + struct module *mod; trace_s390_zcrypt_req(xcrb, TP_ZSENDEP11CPRB); @@ -1000,7 +1005,7 @@ static long zcrypt_send_ep11_cprb(struct ap_perms *perms, pref_weight = weight; } } - pref_zq = zcrypt_pick_queue(pref_zc, pref_zq, weight); + pref_zq = zcrypt_pick_queue(pref_zc, pref_zq, &mod, weight); spin_unlock(&zcrypt_list_lock); if (!pref_zq) { @@ -1012,7 +1017,7 @@ static long zcrypt_send_ep11_cprb(struct ap_perms *perms, rc = pref_zq->ops->send_ep11_cprb(pref_zq, xcrb, &ap_msg); spin_lock(&zcrypt_list_lock); - zcrypt_drop_queue(pref_zc, pref_zq, weight); + zcrypt_drop_queue(pref_zc, pref_zq, mod, weight); spin_unlock(&zcrypt_list_lock); out_free: @@ -1033,6 +1038,7 @@ static long zcrypt_rng(char *buffer) struct ap_message ap_msg; unsigned int domain; int qid = 0, rc = -ENODEV; + struct module *mod; trace_s390_zcrypt_req(buffer, TP_HWRNGCPRB); @@ -1064,7 +1070,7 @@ static long zcrypt_rng(char *buffer) pref_weight = weight; } } - pref_zq = zcrypt_pick_queue(pref_zc, pref_zq, weight); + pref_zq = zcrypt_pick_queue(pref_zc, pref_zq, &mod, weight); spin_unlock(&zcrypt_list_lock); if (!pref_zq) { @@ -1076,7 +1082,7 @@ static long zcrypt_rng(char *buffer) rc = pref_zq->ops->rng(pref_zq, buffer, &ap_msg); spin_lock(&zcrypt_list_lock); - zcrypt_drop_queue(pref_zc, pref_zq, weight); + zcrypt_drop_queue(pref_zc, pref_zq, mod, weight); spin_unlock(&zcrypt_list_lock); out: -- cgit v1.2.3-59-g8ed1b From 50b7f1b7236bab08ebbbecf90521e84b068d7a17 Mon Sep 17 00:00:00 2001 From: Cornelia Huck Date: Mon, 11 Mar 2019 10:59:53 +0100 Subject: vfio: ccw: only free cp on final interrupt When we get an interrupt for a channel program, it is not necessarily the final interrupt; for example, the issuing guest may request an intermediate interrupt by specifying the program-controlled-interrupt flag on a ccw. We must not switch the state to idle if the interrupt is not yet final; even more importantly, we must not free the translated channel program if the interrupt is not yet final, or the host can crash during cp rewind. Fixes: e5f84dbaea59 ("vfio: ccw: return I/O results asynchronously") Cc: stable@vger.kernel.org # v4.12+ Reviewed-by: Eric Farman Signed-off-by: Cornelia Huck --- drivers/s390/cio/vfio_ccw_drv.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c index a10cec0e86eb..0b3b9de45c60 100644 --- a/drivers/s390/cio/vfio_ccw_drv.c +++ b/drivers/s390/cio/vfio_ccw_drv.c @@ -72,20 +72,24 @@ static void vfio_ccw_sch_io_todo(struct work_struct *work) { struct vfio_ccw_private *private; struct irb *irb; + bool is_final; private = container_of(work, struct vfio_ccw_private, io_work); irb = &private->irb; + is_final = !(scsw_actl(&irb->scsw) & + (SCSW_ACTL_DEVACT | SCSW_ACTL_SCHACT)); if (scsw_is_solicited(&irb->scsw)) { cp_update_scsw(&private->cp, &irb->scsw); - cp_free(&private->cp); + if (is_final) + cp_free(&private->cp); } memcpy(private->io_region->irb_area, irb, sizeof(*irb)); if (private->io_trigger) eventfd_signal(private->io_trigger, 1); - if (private->mdev) + if (private->mdev && is_final) private->state = VFIO_CCW_STATE_IDLE; } -- cgit v1.2.3-59-g8ed1b From 0d9c038feff6f834ad9e5d88b66715235ab23ff3 Mon Sep 17 00:00:00 2001 From: Tony Krowiak Date: Mon, 18 Feb 2019 12:01:35 -0500 Subject: zcrypt: handle AP Info notification from CHSC SEI command The current AP bus implementation periodically polls the AP configuration to detect changes. When the AP configuration is dynamically changed via the SE or an SCLP instruction, the changes will not be reflected to sysfs until the next time the AP configuration is polled. The CHSC architecture provides a Store Event Information (SEI) command to make notification of an AP configuration change. This patch introduces a handler to process notification from the CHSC SEI command by immediately kicking off an AP bus scan-after-event. Signed-off-by: Tony Krowiak Reviewed-by: Halil Pasic Reviewed-by: Sebastian Ott Reviewed-by: Harald Freudenberger Reviewed-by: Cornelia Huck Signed-off-by: Sebastian Ott Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/ap.h | 11 +++++++++++ drivers/s390/cio/chsc.c | 13 +++++++++++++ drivers/s390/crypto/ap_bus.c | 10 ++++++++++ 3 files changed, 34 insertions(+) (limited to 'drivers') diff --git a/arch/s390/include/asm/ap.h b/arch/s390/include/asm/ap.h index 1a6a7092d942..e94a0a28b5eb 100644 --- a/arch/s390/include/asm/ap.h +++ b/arch/s390/include/asm/ap.h @@ -360,4 +360,15 @@ static inline struct ap_queue_status ap_dqap(ap_qid_t qid, return reg1; } +/* + * Interface to tell the AP bus code that a configuration + * change has happened. The bus code should at least do + * an ap bus resource rescan. + */ +#if IS_ENABLED(CONFIG_ZCRYPT) +void ap_bus_cfg_chg(void); +#else +static inline void ap_bus_cfg_chg(void){}; +#endif + #endif /* _ASM_S390_AP_H_ */ diff --git a/drivers/s390/cio/chsc.c b/drivers/s390/cio/chsc.c index a0baee25134c..eaf4699be2c5 100644 --- a/drivers/s390/cio/chsc.c +++ b/drivers/s390/cio/chsc.c @@ -24,6 +24,7 @@ #include #include #include +#include #include "css.h" #include "cio.h" @@ -586,6 +587,15 @@ static void chsc_process_sei_scm_avail(struct chsc_sei_nt0_area *sei_area) " failed (rc=%d).\n", ret); } +static void chsc_process_sei_ap_cfg_chg(struct chsc_sei_nt0_area *sei_area) +{ + CIO_CRW_EVENT(3, "chsc: ap config changed\n"); + if (sei_area->rs != 5) + return; + + ap_bus_cfg_chg(); +} + static void chsc_process_sei_nt2(struct chsc_sei_nt2_area *sei_area) { switch (sei_area->cc) { @@ -612,6 +622,9 @@ static void chsc_process_sei_nt0(struct chsc_sei_nt0_area *sei_area) case 2: /* i/o resource accessibility */ chsc_process_sei_res_acc(sei_area); break; + case 3: /* ap config changed */ + chsc_process_sei_ap_cfg_chg(sei_area); + break; case 7: /* channel-path-availability information */ chsc_process_sei_chp_avail(sei_area); break; diff --git a/drivers/s390/crypto/ap_bus.c b/drivers/s390/crypto/ap_bus.c index 033a1acabf48..1546389d71db 100644 --- a/drivers/s390/crypto/ap_bus.c +++ b/drivers/s390/crypto/ap_bus.c @@ -867,6 +867,16 @@ void ap_bus_force_rescan(void) } EXPORT_SYMBOL(ap_bus_force_rescan); +/* +* A config change has happened, force an ap bus rescan. +*/ +void ap_bus_cfg_chg(void) +{ + AP_DBF(DBF_INFO, "%s config change, forcing bus rescan\n", __func__); + + ap_bus_force_rescan(); +} + /* * hex2bitmap() - parse hex mask string and set bitmap. * Valid strings are "0x012345678" with at least one valid hex number. -- cgit v1.2.3-59-g8ed1b