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

Burakov, Anatoly anatoly.burakov at intel.com
Thu Feb 15 11:28:33 CET 2018


On 14-Feb-18 8:00 PM, Ravi Kerur wrote:
> 
> Earlier I was focusing only on DMAR errors and I might have said 'it 
> worked' when I didn't notice them on host when dpdk was started on 
> guest. When trying to send packets out of that interface from guest I 
> did see DMAR errors. I am attaching information you requested.  I have 
> enabled log-level=8 and files contain dpdk EAL/PMD logs as well.

Great, now we're on the same page.

> 
> Snippets below
> 
> on host, DMAR fault address from dmesg
> 
> [351576.998109] DMAR: DRHD: handling fault status reg 702
> [351576.998113] DMAR: [DMA Read] Request device [04:10.0] fault addr 
> 257617000 [fault reason 06] PTE Read access is not set
> 
> on guest (dump phys_mem_layout)
> 
> Segment 235: phys:0x257600000, len:2097152, virt:0x7fce87e00000, 
> socket_id:0, hugepage_sz:2097152, nchannel:0, nrank:0
> ...
> PMD: ixgbe_dev_rx_queue_setup(): sw_ring=0x7fce87e0f4c0 
> sw_sc_ring=0x7fce87e07380 hw_ring=0x7fce87e17600 dma_addr=0x257617600
> PMD: ixgbe_dev_rx_queue_setup(): sw_ring=0x7fce89c67d40 
> sw_sc_ring=0x7fce89c5fc00 hw_ring=0x7fce89c6fe80 dma_addr=0x25406fe80
> ...
> 

To me this looks like host (i.e. either QEMU or the PF driver) is trying 
to do DMA using guest-physical (and not host-physical). I'm not too 
well-versed in how QEMU works, but i'm pretty sure that's not supposed 
to happen.

Is PF also bound to DPDK, or are you using native Linux ixgbe driver?

-- 
Thanks,
Anatoly


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