From: Cornelia Huck <cohuck@redhat.com>
To: Martin Schwidefsky <schwidefsky@de.ibm.com>,
Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Farhan Ali <alifm@linux.ibm.com>,
Eric Farman <farman@linux.ibm.com>,
Halil Pasic <pasic@linux.ibm.com>,
linux-s390@vger.kernel.org, kvm@vger.kernel.org,
Cornelia Huck <cohuck@redhat.com>
Subject: [PULL 8/9] vfio-ccw: Release any channel program when releasing/removing vfio-ccw mdev
Date: Thu, 25 Apr 2019 11:15:58 +0200 [thread overview]
Message-ID: <20190425091559.15490-9-cohuck@redhat.com> (raw)
In-Reply-To: <20190425091559.15490-1-cohuck@redhat.com>
From: Farhan Ali <alifm@linux.ibm.com>
When releasing the vfio-ccw mdev, we currently do not release
any existing channel program and its 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 the release path. For the remove
path we can just quiesce the device, since in the remove path the mediated
device is going away for good and so we don't need to do a full reset.
Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Message-Id: <ae9f20dc8873f2027f7b3c5d2aaa0bdfe06850b8.1554756534.git.alifm@linux.ibm.com>
Acked-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
---
drivers/s390/cio/vfio_ccw_ops.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index 3e2802a4a43d..5eb61116ca6f 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -134,11 +134,12 @@ static int vfio_ccw_mdev_remove(struct mdev_device *mdev)
if ((private->state != VFIO_CCW_STATE_NOT_OPER) &&
(private->state != VFIO_CCW_STATE_STANDBY)) {
- if (!vfio_ccw_mdev_reset(mdev))
+ if (!vfio_ccw_sch_quiesce(private->sch))
private->state = VFIO_CCW_STATE_STANDBY;
/* The state will be NOT_OPER on error. */
}
+ cp_free(&private->cp);
private->mdev = NULL;
atomic_inc(&private->avail);
@@ -172,6 +173,14 @@ 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);
--
2.17.2
next prev parent reply other threads:[~2019-04-25 9:15 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-25 9:15 [PULL 0/9] vfio-ccw patches for 5.2 Cornelia Huck
2019-04-25 9:15 ` [PULL 1/9] vfio-ccw: make it safe to access channel programs Cornelia Huck
2019-04-25 9:15 ` [PULL 2/9] vfio-ccw: rework ssch state handling Cornelia Huck
2019-04-25 9:15 ` [PULL 3/9] vfio-ccw: protect the I/O region Cornelia Huck
2019-04-25 9:15 ` [PULL 4/9] vfio-ccw: add capabilities chain Cornelia Huck
2019-04-25 9:15 ` [PULL 5/9] s390/cio: export hsch to modules Cornelia Huck
2019-04-25 9:15 ` [PULL 6/9] vfio-ccw: add handling for async channel instructions Cornelia Huck
2019-04-25 9:15 ` [PULL 7/9] vfio-ccw: Do not call flush_workqueue while holding the spinlock Cornelia Huck
2019-04-25 9:15 ` Cornelia Huck [this message]
2019-04-25 9:15 ` [PULL 9/9] vfio-ccw: Prevent quiesce function going into an infinite loop Cornelia Huck
2019-04-25 11:47 ` [PULL 0/9] vfio-ccw patches for 5.2 Martin Schwidefsky
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