[dpdk-dev] [EXT] Re: [PATCH] bus/pci: fix IOVA as VA mode selection

[Thomas Monjalon]

09/07/2019 17:02, Burakov, Anatoly:
> When IOMMU is fully enabled (iommu=on at boot time), igb_uio will simply 
> not work. VFIO will work, whichever address mode you use.
> 
> When IOMMU is in pass-through mode (iommu=pt at boot time), both igb_uio 
> and VFIO will work, although igb_uio will only support IOVA as PA mode. 
> Both modes will enable IOMMU, and both can run in IOVA as PA mode 
> without losing that protection.
> 
> It's only when IOMMU is off, igb_uio will not engage IOMMU, and VFIO 
> will only work in no-IOMMU mode (thus not engaging IOMMU either), and 
> only then you lack the IOMMU protection.

Could we try to make IOMMU status clear in DPDK logs?
Then we could check the kernel drivers loaded and give
a compatibility status for each of them as debug logs.