Re: IXGBE, IOMMU DMAR DRHD handling fault issue

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

On 15-Feb-18 8:53 PM, Ravi Kerur wrote:
> 
> 
> On Thu, Feb 15, 2018 at 10:27 AM, Ravi Kerur <rkerur@gmail.com 
> <mailto:rkerur@gmail.com>> wrote:
> 
> 
> 
>     On Thu, Feb 15, 2018 at 2:28 AM, Burakov, Anatoly
>     <anatoly.burakov@intel.com <mailto:anatoly.burakov@intel.com>> wrote:
> 
>         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 for your help. I cannot use PF with DPDK (vfio-pci), VF
>     interfaces disappear after it is bound to DPDK. If there is a way to
>     use PF and VF with DPDK let me know I can try it out. I am not sure
>     how to move forward on this, Is CPU/IXGBE PF driver playing a role?
>     Following are the versions I have
> 
>     lscpu
>     Architecture:          x86_64
>     CPU op-mode(s):        32-bit, 64-bit
>     Byte Order:            Little Endian
>     CPU(s):                56
>     On-line CPU(s) list:   0-27
>     Off-line CPU(s) list:  28-55
>     Thread(s) per core:    1
>     Core(s) per socket:    14
>     Socket(s):             2
>     NUMA node(s):          2
>     Vendor ID:             GenuineIntel
>     CPU family:            6
>     Model:                 63
>     Model name:            Intel(R) Xeon(R) CPU E5-2683 v3 @ 2.00GHz
>     Stepping:              2
>     CPU MHz:               2500.610
>     CPU max MHz:           3000.0000
>     CPU min MHz:           1200.0000
>     BogoMIPS:              4000.74
>     Virtualization:        VT-x
>     L1d cache:             32K
>     L1i cache:             32K
>     L2 cache:              256K
>     L3 cache:              35840K
>     NUMA node0 CPU(s):     0-13
>     NUMA node1 CPU(s):     14-27
> 
>     # ethtool -i enp4s0f0
>     driver: ixgbe
>     version: 5.3.3
>     firmware-version: 0x800007b8, 1.1018.0
>     bus-info: 0000:04:00.0
>     supports-statistics: yes
>     supports-test: yes
>     supports-eeprom-access: yes
>     supports-register-dump: yes
>     supports-priv-flags: yes
> 
>     Thanks,
>     Ravi
> 
> 
> 
> Debugging this I could co-relate doing interface link-up associated with 
> the dpdk inside the guest causes DMAR errors on host and an additional 
> vflr message.
> 
> [ 8135.861622] DMAR: DRHD: handling fault status reg 402
> [ 8135.861627] DMAR: [DMA Read] Request device [04:10.0] fault addr 
> 1b648a000 [fault reason 06] PTE Read access is not set
> [ 8136.588074] ixgbe 0000:04:00.0: Issuing VFLR with pending transactions
> [ 8136.588079] ixgbe 0000:04:00.0: Issuing VFLR for VF 0000:04:10.0
> 
> Looked at ixgbe driver code 'ixgbe_issue_vf_flr' is called from 
> 'ixgbe_check_for_bad_vf' or 'ixgbe_io_error_detected' functions. Is it 
> possible that dpdk pmd vf driver is missing some fixes/porting from 
> ixgbevf driver since this issue is not seen when ixgbevf kernel driver 
> is used?
> 

Could very well be. +CC ixgbe maintainers which might be of further help 
debugging this issue.

-- 
Thanks,
Anatoly