Re: [dpdk-users] Peformance troubleshouting of TCP/IP stack over DPDK.

[Vincent Li <vincent.mc.li@gmail.com>]

On Thu, 21 May 2020, Pavel Vajarov wrote:

>       I am curious how you get F-Stack working with KVM VM with SR-IOV. The
>       author of F-Stack mentioned F-Stack not tested working for KVM VM. I had
>       an issue report here: https://github.com/F-Stack/f-stack/issues/489
> 
> 
> Hi there,
> 
> I asked our admin who setup the KVM for the tests.
> He said that this parameter has been given to the QEMU:
>  -device vfio-pci,host=af:00.2,id=hostdev0,bus=pci.0,addr=0x9
> 
> This is how the device configuration looks in the XML:
> <hostdev mode='subsystem' type='pci' managed='yes'>
>       <driver name='vfio'/>
>       <source>
>         <address domain='0x0000' bus='0xaf' slot='0x00' function='0x2'/>
>       </source>
>       <alias name='hostdev0'/>
>       <address type='pci' domain='0x0000' bus='0x00' slot='0x09' function='0x0'/>
>     </hostdev>
> 
> Here is how the things are seen from the guest machine:
> 00:03.0 Ethernet controller: Red Hat, Inc. Virtio network device    <----- This device is used for SSH access to the server
> 00:09.0 Ethernet controller: Intel Corporation Ethernet Controller X710 for 10GbE SFP+ (rev 02)   <------ This is the 10Gpbs card used for the tests.

this seems to be passing the PF to guest, not SR-IOV VF. I am wondering 
what happens if you use SR-IOV and pass VF to guest, you may run into same 
issue as I did.

> 
> Network devices using DPDK-compatible driver
> ============================================
> 0000:00:09.0 'Ethernet Controller X710 for 10GbE SFP+ 1572' drv=igb_uio unused=i40e
> 
> Network devices using kernel driver
> ===================================
> 0000:00:03.0 'Virtio network device 1000' if=ens3 drv=virtio-pci unused=igb_uio *Active*
> 
> Hope that helps.
> 
> Regards,
> Pavel.
> 
>