Re: [PATCH 3/5] iommu/vt-d: Do deferred attachment in iommu_need_mapping()

[Jerry Snitselaar]

On Mon Feb 17 20, Joerg Roedel wrote:
> From: Joerg Roedel <jroedel@xxxxxxx>
>
> The attachment of deferred devices needs to happen before the check
> whether the device is identity mapped or not. Otherwise the check will
> return wrong results, cause warnings boot failures in kdump kernels, like
>
> 	WARNING: CPU: 0 PID: 318 at ../drivers/iommu/intel-iommu.c:592 domain_get_iommu+0x61/0x70
>
> 	[...]
>
> 	 Call Trace:
> 	  __intel_map_single+0x55/0x190
> 	  intel_alloc_coherent+0xac/0x110
> 	  dmam_alloc_attrs+0x50/0xa0
> 	  ahci_port_start+0xfb/0x1f0 [libahci]
> 	  ata_host_start.part.39+0x104/0x1e0 [libata]
>
> With the earlier check the kdump boot succeeds and a crashdump is written.
>
> Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>

Reviewed-by: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>