Starting with commit fa212a97f3a3 ("iommu/vt-d: Probe DMA-capable ACPI name space devices"), we now probe DMA-capable ACPI name space devices. On Dell XPS 13 9343, which has an Intel LPSS platform device INTL9C60 enumerated via ACPI, this change leads to the following warning:
------------[ cut here ]------------ WARNING: CPU: 1 PID: 1 at pci_device_group+0x11a/0x130 CPU: 1 PID: 1 Comm: swapper/0 Tainted: G T 5.5.0-rc3+ #22 Hardware name: Dell Inc. XPS 13 9343/0310JH, BIOS A20 06/06/2019 RIP: 0010:pci_device_group+0x11a/0x130 Code: f0 ff ff 48 85 c0 49 89 c4 75 c4 48 8d 74 24 10 48 89 ef e8 48 ef ff ff 48 85 c0 49 89 c4 75 af e8 db f7 ff ff 49 89 c4 eb a5 <0f> 0b 49 c7 c4 ea ff ff ff eb 9a e8 96 1e c7 ff 66 0f 1f 44 00 00 RSP: 0000:ffffc0d6c0043cb0 EFLAGS: 00010202 RAX: 0000000000000000 RBX: ffffa3d1d43dd810 RCX: 0000000000000000 RDX: ffffa3d1d4fecf80 RSI: ffffa3d12943dcc0 RDI: ffffa3d1d43dd810 RBP: ffffa3d1d43dd810 R08: 0000000000000000 R09: ffffa3d1d4c04a80 R10: ffffa3d1d4c00880 R11: ffffa3d1d44ba000 R12: 0000000000000000 R13: ffffa3d1d4383b80 R14: ffffa3d1d4c090d0 R15: ffffa3d1d4324530 FS: 0000000000000000(0000) GS:ffffa3d1d6700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000000460a001 CR4: 00000000003606e0 Call Trace: ? iommu_group_get_for_dev+0x81/0x1f0 ? intel_iommu_add_device+0x61/0x170 ? iommu_probe_device+0x43/0xd0 ? intel_iommu_init+0x1fa2/0x2235 ? pci_iommu_init+0x52/0xe7 ? e820__memblock_setup+0x15c/0x15c ? do_one_initcall+0xcc/0x27e ? kernel_init_freeable+0x169/0x259 ? rest_init+0x95/0x95 ? kernel_init+0x5/0xeb ? ret_from_fork+0x35/0x40 ---[ end trace 28473e7abc25b92c ]--- DMAR: ACPI name space devices didn't probe correctly The bug results from the fact that while we now enumerate ACPI devices, we aren't able to handle any non-PCI device when generating the device group. Fix the issue by implementing an Intel-specific callback that returns `pci_device_group` only if the device is a PCI device. Otherwise, it will return a generic device group. Fixes: fa212a97f3a3 ("iommu/vt-d: Probe DMA-capable ACPI name space devices") Signed-off-by: Patrick Steinhardt <p...@pks.im> --- I've recently spotted above warning in v5.5-rc3. The attached fix is rather intended as a discussion starter -- it's quite likely to be wrong as I ain't got much of a clue about the IOMMU subsystem. drivers/iommu/intel-iommu.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 42966611a192..e3696a754fd1 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -5972,6 +5972,13 @@ static bool intel_iommu_is_attach_deferred(struct iommu_domain *domain, return dev->archdata.iommu == DEFER_DEVICE_DOMAIN_INFO; } +static struct iommu_group *intel_iommu_device_group(struct device *dev) +{ + if (dev_is_pci(dev)) + return pci_device_group(dev); + return generic_device_group(dev); +} + const struct iommu_ops intel_iommu_ops = { .capable = intel_iommu_capable, .domain_alloc = intel_iommu_domain_alloc, @@ -5989,7 +5996,7 @@ const struct iommu_ops intel_iommu_ops = { .get_resv_regions = intel_iommu_get_resv_regions, .put_resv_regions = intel_iommu_put_resv_regions, .apply_resv_region = intel_iommu_apply_resv_region, - .device_group = pci_device_group, + .device_group = intel_iommu_device_group, .dev_has_feat = intel_iommu_dev_has_feat, .dev_feat_enabled = intel_iommu_dev_feat_enabled, .dev_enable_feat = intel_iommu_dev_enable_feat, -- 2.24.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu