When releasing the vfio-ccw mdev, we currently do not release
any existing channel program and it's pinned pages. This can
lead to the following warning:
[1038876.561565] WARNING: CPU: 2 PID: 144727 at drivers/vfio/vfio_iommu_type1.c:1494 vfio_sanity_check_pfn_list+0x40/0x70 [vfio_iommu_type1]
....
1038876.561921] Call Trace:
[1038876.561935] ([<00000009897fb870>] 0x9897fb870)
[1038876.561949] [<000003ff8013bf62>] vfio_iommu_type1_detach_group+0xda/0x2f0 [vfio_iommu_type1]
[1038876.561965] [<000003ff8007b634>] __vfio_group_unset_container+0x64/0x190 [vfio]
[1038876.561978] [<000003ff8007b87e>] vfio_group_put_external_user+0x26/0x38 [vfio]
[1038876.562024] [<000003ff806fc608>] kvm_vfio_group_put_external_user+0x40/0x60 [kvm]
[1038876.562045] [<000003ff806fcb9e>] kvm_vfio_destroy+0x5e/0xd0 [kvm]
[1038876.562065] [<000003ff806f63fc>] kvm_put_kvm+0x2a4/0x3d0 [kvm]
[1038876.562083] [<000003ff806f655e>] kvm_vm_release+0x36/0x48 [kvm]
[1038876.562098] [<00000000003c2dc4>] __fput+0x144/0x228
[1038876.562113] [<000000000016ee82>] task_work_run+0x8a/0xd8
[1038876.562125] [<000000000014c7a8>] do_exit+0x5d8/0xd90
[1038876.562140] [<000000000014d084>] do_group_exit+0xc4/0xc8
[1038876.562155] [<000000000015c046>] get_signal+0x9ae/0xa68
[1038876.562169] [<0000000000108d66>] do_signal+0x66/0x768
[1038876.562185] [<0000000000b9e37e>] system_call+0x1ea/0x2d8
[1038876.562195] 2 locks held by qemu-system-s39/144727:
[1038876.562205] #0: 00000000537abaf9 (&container->group_lock){++++}, at: __vfio_group_unset_container+0x3c/0x190 [vfio]
[1038876.562230] #1: 00000000670008b5 (&iommu->lock){+.+.}, at: vfio_iommu_type1_detach_group+0x36/0x2f0 [vfio_iommu_type1]
[1038876.562250] Last Breaking-Event-Address:
[1038876.562262] [<000003ff8013aa24>] vfio_sanity_check_pfn_list+0x3c/0x70 [vfio_iommu_type1]
[1038876.562272] irq event stamp: 4236481
[1038876.562287] hardirqs last enabled at (4236489): [<00000000001cee7a>] console_unlock+0x6d2/0x740
[1038876.562299] hardirqs last disabled at (4236496): [<00000000001ce87e>] console_unlock+0xd6/0x740
[1038876.562311] softirqs last enabled at (4234162): [<0000000000b9fa1e>] __do_softirq+0x556/0x598
[1038876.562325] softirqs last disabled at (4234153): [<000000000014e4cc>] irq_exit+0xac/0x108
[1038876.562337] ---[ end trace 6c96d467b1c3ca06 ]---
Similarly we do not free the channel program when we are removing
the vfio-ccw device. Let's fix this by resetting the device and freeing
the channel program and pinned pages in both the release and remove
path.
Signed-off-by: Farhan Ali <alifm@xxxxxxxxxxxxx>
---
drivers/s390/cio/vfio_ccw_ops.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index ec2f796c..763c350 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -138,6 +138,7 @@ static int vfio_ccw_mdev_remove(struct mdev_device *mdev)
/* The state will be NOT_OPER on error. */
}
+ cp_free(&private->cp);
private->mdev = NULL;
atomic_inc(&private->avail);
@@ -171,6 +172,14 @@ static void vfio_ccw_mdev_release(struct mdev_device *mdev)
dev_get_drvdata(mdev_parent_dev(mdev));
int i;
+ if ((private->state != VFIO_CCW_STATE_NOT_OPER) &&
+ (private->state != VFIO_CCW_STATE_STANDBY)) {
+ if (!vfio_ccw_mdev_reset(mdev))
+ private->state = VFIO_CCW_STATE_STANDBY;
+ /* The state will be NOT_OPER on error. */
+ }
+
+ cp_free(&private->cp);
vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
&private->nb);
--
2.7.4
