[PATCH openEuler-5.10-LTS 10/21] Revert "iommu: handle page response timeout"

From: Guo Mengqi guomengqi3@huawei.com

hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5EOOG CVE: NA

--------------------------------

This reverts commit da76349ca8776aa7f8b186010005fb563fb163bb. However, the iommu_fault_param and iommu_fault_event changes are reserved to avoid KABI change.

Signed-off-by: Guo Mengqi guomengqi3@huawei.com Reviewed-by: Weilong Chen chenweilong@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- drivers/iommu/iommu.c | 55 ------------------------------------------- include/linux/iommu.h | 4 ++-- 2 files changed, 2 insertions(+), 57 deletions(-)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 9116c93945d0..97953fa27630 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -1084,39 +1084,6 @@ int iommu_group_unregister_notifier(struct iommu_group *group, } EXPORT_SYMBOL_GPL(iommu_group_unregister_notifier);

-static void iommu_dev_fault_timer_fn(struct timer_list *t) -{ - struct iommu_fault_param *fparam = from_timer(fparam, t, timer); - struct iommu_fault_event *evt; - struct iommu_fault_page_request *prm; - - u64 now; - - now = get_jiffies_64(); - - /* The goal is to ensure driver or guest page fault handler(via vfio) - * send page response on time. Otherwise, limited queue resources - * may be occupied by some irresponsive guests or drivers. - * When per device pending fault list is not empty, we periodically checks - * if any anticipated page response time has expired. - * - * TODO: - * We could do the following if response time expires: - * 1. send page response code FAILURE to all pending PRQ - * 2. inform device driver or vfio - * 3. drain in-flight page requests and responses for this device - * 4. clear pending fault list such that driver can unregister fault - * handler(otherwise blocked when pending faults are present). - */ - list_for_each_entry(evt, &fparam->faults, list) { - prm = &evt->fault.prm; - if (time_after64(now, evt->expire)) - pr_err("Page response time expired!, pasid %d gid %d exp %llu now %llu\n", - prm->pasid, prm->grpid, evt->expire, now); - } - mod_timer(t, now + prq_timeout); -} - /** * iommu_register_device_fault_handler() - Register a device fault handler * @dev: the device @@ -1164,9 +1131,6 @@ int iommu_register_device_fault_handler(struct device *dev, mutex_init(&param->fault_param->lock); INIT_LIST_HEAD(&param->fault_param->faults);

- if (prq_timeout) - timer_setup(&param->fault_param->timer, iommu_dev_fault_timer_fn, - TIMER_DEFERRABLE); done_unlock: mutex_unlock(&param->lock);

@@ -1306,9 +1270,7 @@ int iommu_report_device_fault(struct device *dev, struct iommu_fault_event *evt) struct dev_iommu *param = dev->iommu; struct iommu_fault_event *evt_pending = NULL; struct iommu_fault_param *fparam; - struct timer_list *tmr; int ret = 0; - u64 exp;

if (!param || !evt || WARN_ON_ONCE(!iommu_fault_valid(&evt->fault))) return -EINVAL; @@ -1329,17 +1291,7 @@ int iommu_report_device_fault(struct device *dev, struct iommu_fault_event *evt) ret = -ENOMEM; goto done_unlock; } - /* Keep track of response expiration time */ - exp = get_jiffies_64() + prq_timeout; - evt_pending->expire = exp; mutex_lock(&fparam->lock); - if (list_empty(&fparam->faults)) { - /* First pending event, start timer */ - tmr = &fparam->timer; - WARN_ON(timer_pending(tmr)); - mod_timer(tmr, exp); - } - list_add_tail(&evt_pending->list, &fparam->faults); mutex_unlock(&fparam->lock); } @@ -1417,13 +1369,6 @@ int iommu_page_response(struct device *dev, break; }

- /* stop response timer if no more pending request */ - if (list_empty(&param->fault_param->faults) && - timer_pending(&param->fault_param->timer)) { - pr_debug("no pending PRQ, stop timer\n"); - del_timer(&param->fault_param->timer); - } - done_unlock: mutex_unlock(&param->fault_param->lock); return ret; diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 8baf5ed66a84..092384b71ab2 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -393,7 +393,7 @@ struct iommu_device { struct iommu_fault_event { struct iommu_fault fault; struct list_head list; - u64 expire; + _KABI_DEPRECATE(u64, expire); };

/** @@ -408,7 +408,7 @@ struct iommu_fault_param { iommu_dev_fault_handler_t handler; void *data; struct list_head faults; - struct timer_list timer; + _KABI_DEPRECATE(struct timer_list, timer); struct mutex lock; };