• Lu Baolu's avatar
    iommu/vt-d: Fix WARN_ON in iommu probe path · 89436f4f
    Lu Baolu authored
    Commit 1a75cc71 ("iommu/vt-d: Use rbtree to track iommu probed
    devices") adds all devices probed by the iommu driver in a rbtree
    indexed by the source ID of each device. It assumes that each device
    has a unique source ID. This assumption is incorrect and the VT-d
    spec doesn't state this requirement either.
    
    The reason for using a rbtree to track devices is to look up the device
    with PCI bus and devfunc in the paths of handling ATS invalidation time
    out error and the PRI I/O page faults. Both are PCI ATS feature related.
    
    Only track the devices that have PCI ATS capabilities in the rbtree to
    avoid unnecessary WARN_ON in the iommu probe path. Otherwise, on some
    platforms below kernel splat will be displayed and the iommu probe results
    in failure.
    
     WARNING: CPU: 3 PID: 166 at drivers/iommu/intel/iommu.c:158 intel_iommu_probe_device+0x319/0xd90
     Call Trace:
      <TASK>
      ? __warn+0x7e/0x180
      ? intel_iommu_probe_device+0x319/0xd90
      ? report_bug+0x1f8/0x200
      ? handle_bug+0x3c/0x70
      ? exc_invalid_op+0x18/0x70
      ? asm_exc_invalid_op+0x1a/0x20
      ? intel_iommu_probe_device+0x319/0xd90
      ? debug_mutex_init+0x37/0x50
      __iommu_probe_device+0xf2/0x4f0
      iommu_probe_device+0x22/0x70
      iommu_bus_notifier+0x1e/0x40
      notifier_call_chain+0x46/0x150
      blocking_notifier_call_chain+0x42/0x60
      bus_notify+0x2f/0x50
      device_add+0x5ed/0x7e0
      platform_device_add+0xf5/0x240
      mfd_add_devices+0x3f9/0x500
      ? preempt_count_add+0x4c/0xa0
      ? up_write+0xa2/0x1b0
      ? __debugfs_create_file+0xe3/0x150
      intel_lpss_probe+0x49f/0x5b0
      ? pci_conf1_write+0xa3/0xf0
      intel_lpss_pci_probe+0xcf/0x110 [intel_lpss_pci]
      pci_device_probe+0x95/0x120
      really_probe+0xd9/0x370
      ? __pfx___driver_attach+0x10/0x10
      __driver_probe_device+0x73/0x150
      driver_probe_device+0x19/0xa0
      __driver_attach+0xb6/0x180
      ? __pfx___driver_attach+0x10/0x10
      bus_for_each_dev+0x77/0xd0
      bus_add_driver+0x114/0x210
      driver_register+0x5b/0x110
      ? __pfx_intel_lpss_pci_driver_init+0x10/0x10 [intel_lpss_pci]
      do_one_initcall+0x57/0x2b0
      ? kmalloc_trace+0x21e/0x280
      ? do_init_module+0x1e/0x210
      do_init_module+0x5f/0x210
      load_module+0x1d37/0x1fc0
      ? init_module_from_file+0x86/0xd0
      init_module_from_file+0x86/0xd0
      idempotent_init_module+0x17c/0x230
      __x64_sys_finit_module+0x56/0xb0
      do_syscall_64+0x6e/0x140
      entry_SYSCALL_64_after_hwframe+0x71/0x79
    
    Fixes: 1a75cc71 ("iommu/vt-d: Use rbtree to track iommu probed devices")
    Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/10689Signed-off-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
    Link: https://lore.kernel.org/r/20240407011429.136282-1-baolu.lu@linux.intel.comReviewed-by: default avatarKevin Tian <kevin.tian@intel.com>
    Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
    89436f4f
iommu.c 134 KB