| From d44d4a5b2317e23df1f1f61706ac684b7521e228 Mon Sep 17 00:00:00 2001 |
| From: Farhan Ali <alifm@linux.ibm.com> |
| Date: Mon, 8 Apr 2019 17:05:33 -0400 |
| Subject: vfio-ccw: Release any channel program when releasing/removing |
| vfio-ccw mdev |
| |
| [ Upstream commit b49bdc8602b7c9c7a977758bee4125683f73e59f ] |
| |
| 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> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| 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 f673e106c0415..dc5ff47de3fee 100644 |
| --- a/drivers/s390/cio/vfio_ccw_ops.c |
| +++ b/drivers/s390/cio/vfio_ccw_ops.c |
| @@ -130,11 +130,12 @@ 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); |
| |
| @@ -158,6 +159,14 @@ static void vfio_ccw_mdev_release(struct mdev_device *mdev) |
| struct vfio_ccw_private *private = |
| dev_get_drvdata(mdev_parent_dev(mdev)); |
| |
| + 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); |
| } |
| -- |
| 2.20.1 |
| |