Re: [PATCH v2 4/4] iommu: Get DT/ACPI parsing into the proper probe path

[Joerg Roedel <joro@8bytes.org>]

Hi Robin,

On Fri, Feb 28, 2025 at 03:46:33PM +0000, Robin Murphy wrote:
> +	/*
> +	 * And if we do now see any replay calls, they would indicate someone
> +	 * misusing the dma_configure path outside bus code.
> +	 */
> +	if (dev->driver)
> +		dev_WARN(dev, "late IOMMU probe at driver bind, something fishy here!\n");

This warning triggers on my workstation (with an AMD IOMMU), any ideas?

 ------------[ cut here ]------------
 reg-dummy reg-dummy: late IOMMU probe at driver bind, something fishy here!
 WARNING: CPU: 0 PID: 1 at drivers/iommu/iommu.c:449 __iommu_probe_device+0x10b/0x510
 Modules linked in:

 CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.14.0-rc6-iommu-next+ #1 1d691d7aebf343bde741cf4c8610d78a2ea2d2d9
 Hardware name: System manufacturer System Product Name/PRIME X470-PRO, BIOS 5406 11/13/2019
 RIP: 0010:__iommu_probe_device+0x10b/0x510
 Code: 68 00 74 28 48 8b 6b 50 48 85 ed 75 03 48 8b 2b 48 89 df e8 87 71 06 00 48 89 ea 48 c7 c7 90 dd 2c 8b 48 89 c6 e8 35 83 77 ff <0f> 0b 49 8b bd a8 00 00 00 e8 77 ab 85 ff 84 c0 0f 84 ad 01 00 00
 RSP: 0018:ffffafba00047c58 EFLAGS: 00010282
 RAX: 0000000000000000 RBX: ffffa00481301c10 RCX: 0000000000000003
 RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000001
 RBP: ffffa00480ffaee0 R08: 0000000000000000 R09: ffffafba00047ae8
 R10: ffffa0135e93ffa8 R11: 0000000000000003 R12: ffffafba00047d18
 R13: ffffffff8adac1a0 R14: 0000000000000000 R15: ffffa004802c5800
 FS:  0000000000000000(0000) GS:ffffa0135ea00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: ffffa00baca01000 CR3: 000000082b838000 CR4: 00000000003506f0
 Call Trace:
  <TASK>
  ? __iommu_probe_device+0x10b/0x510
  ? __warn.cold+0x93/0xf7
  ? __iommu_probe_device+0x10b/0x510
  ? report_bug+0xff/0x140
  ? prb_read_valid+0x1b/0x30
  ? handle_bug+0x58/0x90
  ? exc_invalid_op+0x17/0x70
  ? asm_exc_invalid_op+0x1a/0x20
  ? __iommu_probe_device+0x10b/0x510
  ? __iommu_probe_device+0x10b/0x510
  ? __pfx_probe_iommu_group+0x10/0x10
  probe_iommu_group+0x28/0x50
  bus_for_each_dev+0x7e/0xd0
  iommu_device_register+0xee/0x260
  iommu_go_to_state+0xa2a/0x1970
  ? srso_return_thunk+0x5/0x5f
  ? blake2s_update+0x68/0x160
  ? __pfx_pci_iommu_init+0x10/0x10
  amd_iommu_init+0x14/0x50
  ? __pfx_pci_iommu_init+0x10/0x10
  pci_iommu_init+0x12/0x40
  do_one_initcall+0x46/0x300
  kernel_init_freeable+0x23d/0x2a0
  ? __pfx_kernel_init+0x10/0x10
  kernel_init+0x1a/0x140
  ret_from_fork+0x34/0x50
  ? __pfx_kernel_init+0x10/0x10
  ret_from_fork_asm+0x1a/0x30
  </TASK>
 ---[ end trace 0000000000000000 ]---