Re: [dpdk-dev] IXGBE, IOMMU DMAR DRHD handling fault issue

["Burakov, Anatoly" <anatoly.burakov@intel.com>]

On 12-Feb-18 10:00 PM, Ravi Kerur wrote:
> 
>         Let me just give you what has been tested and working/nonworking
>         scenarios. Some of your questions might get answered as well.
>         Test bed is very simple with 2 VF's created under IXGBE PF on
>         host with one VF interface added to ovs-bridge on host and
>         another VF interface given to guest. Test connectivity between
>         VF's via ping.
> 
>         Host and guest -- Kernel 4.9
>         Host -- Qemu 2.11.50 (tried both released 2.11 and tip of the
>         git (2.11.50))
>         DPDK -- 17.05.1 on host and guest
>         Host and guest -- booted with GRUB intel_iommu=on (which enables
>         IOMMU). Have tried with "iommu=on and intel_iommu=on" as well,
>         but iommu=on is not needed when intel_iommu=on is set.
> 
>         Test-scenario-1: Host -- ixgbe_vf driver, Guest ixgbe_vf driver
>         ping works
>         Test-scenario-2: Host -- DPDK vfio-pci driver, Guest ixgbe_vf
>         driver ping works
>         Test-scenario-3: Host -- DPDK vfio-pci driver, Guest DPDK
>         vfio-pci driver, DMAR errors seen on host, ping doesn't work
> 
> 
>     OK, that makes it clearer, thanks. Does the third scenario work in
>     other DPDK versions?
> 
> 
> No. Tried 16.11 same issue on guest and works fine on host.
> 
> 
So now we've moved from "this worked on 16.11" to "this never worked".

It would be good to see output of rte_dump_physmem_layout() on both host 
and guest, and check which address triggers the DMAR error (i.e. if the 
physical address is present in mappings for either DPDK process).

-- 
Thanks,
Anatoly