[PATCH] drm/i915/gvt: correct cleanup sequence in intel_gvt_clean_device

[hang.yuan at linux.intel.com]

From: Hang Yuan <hang.yuan at linux.intel.com>

Free vgpu resource first and then gvt resource to fix oops like below
during unbinding Intel gfx device.

BUG: unable to handle kernel NULL pointer dereference at       00000000000000a8
  PGD 80000003c9d2c067 P4D 80000003c9d2c067 PUD 3c817c067 P      MD 0
  Oops: 0002 [#1] SMP PTI
  RIP: 0010:down_write+0x1b/0x40
Call Trace:
  debugfs_remove_recursive+0x46/0x1a0
  intel_gvt_debugfs_remove_vgpu+0x15/0x30 [i915]
  intel_gvt_destroy_vgpu+0x2d/0xf0 [i915]
  intel_vgpu_remove+0x2c/0x30 [kvmgt]
  mdev_device_remove_ops+0x23/0x50 [mdev]
  mdev_device_remove+0xdb/0x190 [mdev]
  mdev_device_remove+0x190/0x190 [mdev]
  device_for_each_child+0x47/0x90
  mdev_unregister_device+0xd5/0x120 [mdev]
  intel_gvt_clean_device+0x91/0x120 [i915]
  i915_driver_unload+0x9d/0x120 [i915]
  i915_pci_remove+0x15/0x20 [i915]
  pci_device_remove+0x3b/0xc0
  device_release_driver_internal+0x157/0x230
  unbind_store+0xfc/0x150
  kernfs_fop_write+0x10f/0x180
  __vfs_write+0x36/0x180
  ? common_file_perm+0x41/0x130
  ? _cond_resched+0x16/0x40
  vfs_write+0xb3/0x1a0
  ksys_write+0x52/0xc0
  do_syscall_64+0x55/0x100
  entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: unable to handle kernel NULL pointer dereference at 0      000000000000038
  PGD 8000000405bce067 P4D 8000000405bce067 PUD 405bcd067 PM      D 0
  Oops: 0000 [#1] SMP PTI
  RIP: 0010:hrtimer_active+0x5/0x40
Call Trace:
  hrtimer_try_to_cancel+0x25/0x120
  ? tbs_sched_clean_vgpu+0x1f/0x50 [i915]
  hrtimer_cancel+0x15/0x20
  intel_gvt_destroy_vgpu+0x4c/0xf0 [i915]
  intel_vgpu_remove+0x2c/0x30 [kvmgt]
  mdev_device_remove_ops+0x23/0x50 [mdev]
  mdev_device_remove+0xdb/0x190 [mdev]
  ? mdev_device_remove+0x190/0x190 [mdev]
  device_for_each_child+0x47/0x90
  mdev_unregister_device+0xd5/0x120 [mdev]
  intel_gvt_clean_device+0x89/0x120 [i915]
  i915_driver_unload+0x9d/0x120 [i915]
  i915_pci_remove+0x15/0x20 [i915]
  pci_device_remove+0x3b/0xc0
  device_release_driver_internal+0x157/0x230
  unbind_store+0xfc/0x150
  kernfs_fop_write+0x10f/0x180
  __vfs_write+0x36/0x180
  ? common_file_perm+0x41/0x130
  ? _cond_resched+0x16/0x40
  vfs_write+0xb3/0x1a0
  ksys_write+0x52/0xc0
  do_syscall_64+0x55/0x100
  entry_SYSCALL_64_after_hwframe+0x44/0xa9

Signed-off-by: Hang Yuan <hang.yuan at linux.intel.com>
---
 drivers/gpu/drm/i915/gvt/gvt.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/gvt/gvt.c b/drivers/gpu/drm/i915/gvt/gvt.c
index 4e65266..b96c6c7 100644
--- a/drivers/gpu/drm/i915/gvt/gvt.c
+++ b/drivers/gpu/drm/i915/gvt/gvt.c
@@ -315,6 +315,11 @@ void intel_gvt_clean_device(struct drm_i915_private *dev_priv)
 	if (WARN_ON(!gvt))
 		return;
 
+	intel_gvt_destroy_idle_vgpu(gvt->idle_vgpu);
+	intel_gvt_hypervisor_host_exit(&dev_priv->drm.pdev->dev, gvt);
+	intel_gvt_cleanup_vgpu_type_groups(gvt);
+	intel_gvt_clean_vgpu_types(gvt);
+
 	intel_gvt_debugfs_clean(gvt);
 	clean_service_thread(gvt);
 	intel_gvt_clean_cmd_parser(gvt);
@@ -322,17 +327,10 @@ void intel_gvt_clean_device(struct drm_i915_private *dev_priv)
 	intel_gvt_clean_workload_scheduler(gvt);
 	intel_gvt_clean_gtt(gvt);
 	intel_gvt_clean_irq(gvt);
-	intel_gvt_clean_mmio_info(gvt);
 	intel_gvt_free_firmware(gvt);
-
-	intel_gvt_hypervisor_host_exit(&dev_priv->drm.pdev->dev, gvt);
-	intel_gvt_cleanup_vgpu_type_groups(gvt);
-	intel_gvt_clean_vgpu_types(gvt);
-
+	intel_gvt_clean_mmio_info(gvt);
 	idr_destroy(&gvt->vgpu_idr);
 
-	intel_gvt_destroy_idle_vgpu(gvt->idle_vgpu);
-
 	kfree(dev_priv->gvt);
 	dev_priv->gvt = NULL;
 }
-- 
2.7.4