Messages in this thread |  | | From | "Tian, Kevin" <> | | Subject | RE: [PATCH 1/1] iommu/vt-d: Fix WARN_ON in iommu probe path | | Date | Thu, 11 Apr 2024 06:53:39 +0000 |
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> From: Baolu Lu <baolu.lu@linux.intel.com> > Sent: Thursday, April 11, 2024 10:48 AM > > On 4/7/24 9:14 AM, Lu Baolu wrote: > > Commit 1a75cc710b95 ("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: 1a75cc710b95 ("iommu/vt-d: Use rbtree to track iommu probed > devices") > > Signed-off-by: Lu Baolu<baolu.lu@linux.intel.com> > > --- > > drivers/iommu/intel/iommu.c | 11 +++++++---- > > 1 file changed, 7 insertions(+), 4 deletions(-) > > This patch closes a boot bug described here. > > Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/10689 > > I will queue it for v6.9-rc if no objection. >
let's do it. the issue which I raised is rare and can be tackled when it arises.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
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