Re: [dpdk-dev] Trouble with Tx on some i40 ports in KVM VM

[Andrew Theurer <atheurer@redhat.com>]

----- Original Message -----
> From: "Danny Zhou" <danny.zhou@intel.com>
> To: "Andrew Theurer" <atheurer@redhat.com>
> Cc: dev@dpdk.org
> Sent: Tuesday, June 9, 2015 6:38:49 PM
> Subject: RE: Trouble with Tx on some i40 ports in KVM VM
> 
> On your system, what is your iommu and intel_iommu kernel parameters?
> 
> Could you try to use uio_pci_generic for both PF on host and VF in guest
> after configuring "iommu=pt" on your system?

I use iommu=pt intel_iommu=on

To clarify, I am not using a VF in the VM.  I am only using PF's, assigning them to the VM.  The host needs vfio module for kvm to assign these to the VM.
I don't see how uio_pci_generic can be used in the host if the PF is being passed to the VM.

Thanks,

-Andrew
> 
> > -----Original Message-----
> > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Andrew Theurer
> > Sent: Wednesday, June 10, 2015 5:48 AM
> > To: dev@dpdk.org
> > Subject: [dpdk-dev] Trouble with Tx on some i40 ports in KVM VM
> > 
> > Hello.  I am having some trouble with getting various dpdk applications to
> > work when using in a KVM VM.  This happens
> > with the 2nd port on a dual port adapter.  What I have configured:
> > 
> > Haswell-ep host with KVM, 2 x i40e phys functions bound to vfio-pci, 2
> > functions assigned to KVM guest.  In the guest, the
> > i40 functions bound to uio_pci_generic, running testpmd with these options:
> > --nb-cores=2 --nb-ports=2 --portmask=3
> > --interactive --auto-start.
> > 
> > On another host directly connected to these adapters, I run pktgen on the 2
> > i40e ports.  If I Tx on port1, I get packets back
> > on port0.  If I Tx on port0, no packets come back on port0.  For some
> > reason Tx simply does not happen on that second
> > port.
> > 
> > I have tried this test where there is no KVM, just using host, and it works
> > as expected.  I have also tried this test with ixgbe
> > adapter in a KVM VM (I have both in same system), and it works as expected.
> > I have also tried just using a bridge in the VM
> > with i40e ports, with i40e module in use, and that also works as expected.
> > So, I don't think this has anything to do with the
> > adapters themselves, or cables, etc.  Something is not working when using
> > the KVM VM, I just don't know what it is.
> > 
> > Here is xstats from testpmd:
> > ###### NIC extended statistics for port 1
> > rx_packets: 134615456
> > tx_packets: 0
> > rx_bytes: 8615389184
> > tx_bytes: 0
> > tx_errors: 0
> > rx_missed_errors: 0
> > rx_crc_errors: 0
> > rx_bad_length_errors: 0
> > rx_errors: 0
> > alloc_rx_buff_failed: 0
> > fdir_match: 0
> > fdir_miss: 0
> > tx_flow_control_xon: 0
> > rx_flow_control_xon: 0
> > tx_flow_control_xoff: 0
> > rx_flow_control_xoff: 0
> > rx_queue_0_rx_packets: 0
> > rx_queue_0_rx_bytes: 0
> > tx_queue_0_tx_packets: 0
> > tx_queue_0_tx_bytes: 0
> > tx_queue_0_tx_errors: 0
> > 
> > I can't find any evidence of errors anywhere.  It's just not doing Tx at
> > all on that port.  I have also tried using ptkgen in the
> > VM, to manually send packets on that port, and again, no packets sent, but
> > no errors either.
> > 
> > Has anyone else tried 2 i40e ports in a KVM VM?  Any ideas what could be
> > going on here?
> > 
> > Thanks,
> > 
> > -Andrew
>