Commit 6fc85bbb authored by Yi Liu's avatar Yi Liu Committed by Jason Gunthorpe
Browse files

iommufd: Balance veventq->num_events inc/dec 

iommufd_veventq_fops_read() decrements veventq->num_events when a vevent
is read out. However, the report path ony increments veventq->num_events
for normal events. To be balanced, make the read path decrement num_events
only for normal vevents.

Fixes: e36ba5ab ("iommufd: Add IOMMUFD_OBJ_VEVENTQ and IOMMUFD_CMD_VEVENTQ_ALLOC")
Link: https://patch.msgid.link/r/20250324120034.5940-3-yi.l.liu@intel.com


Signed-off-by: default avatarYi Liu <yi.l.liu@intel.com>
Reviewed-by: default avatarNicolin Chen <nicolinc@nvidia.com>
Tested-by: default avatarNicolin Chen <nicolinc@nvidia.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
parent 41464a46

drivers/iommu/iommufd/eventq.c

+2 −1
Original line number Diff line number Diff line
@@ -385,6 +385,7 @@ static ssize_t iommufd_veventq_fops_read(struct file *filep, char __user *buf, 
			break;

		}

		spin_lock(&eventq->lock);

		if (!vevent_for_lost_events_header(cur))

			veventq->num_events--;

		spin_unlock(&eventq->lock);

		done += cur->data_len;