Re: [dpdk-dev] Regarding VM live migration with SRIOV

[Prashant Upadhyaya <prashant.upadhyaya@aricent.com>]

Hi Stephen,

The rte_eal_pci_probe is typically called at the startup.

Now let's say a DPDK application is running with a PCI device (doing tx and rx) and I remove that PCI device underneath (hot plugout)
So how does the application now know that the device is gone ?

Is it that rte_eal_pci_probe should be called periodically from, let's say, the slow control path of the DPDK application ?

Regards
-Prashant


-----Original Message-----
From: Stephen Hemminger [mailto:stephen@networkplumber.org]
Sent: Wednesday, November 27, 2013 10:16 AM
To: Prashant Upadhyaya
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] Regarding VM live migration with SRIOV

On Wed, 27 Nov 2013 10:09:09 +0530
Prashant Upadhyaya <prashant.upadhyaya@aricent.com> wrote:

> Hi,
>
> Let me be more specific.
> Does DPDK support hot plugin/plugout of PCI devices ?
> What typically needs to be done if this is to be achieved inside an application.
>
> Typically, the NIC PF or VF appears to the DPDK application as a PCI device which is probed at startup.
> Now what happens if I insert a new VF dynamically and want to use it
> inside the DPDK application (while it is already running), how should
> this typically be done ? [hotplugin] And what happens if the DPDK
> application is in control of a PCI device and that PCI device is
> suddenly removed ? How can the application detect this and stop doing
> data transfer on this and sort of unload it ? [hotplugout]
>
> If the above can be coded inside the DPDK app, then we can think of live VM migration with SRIOV -- just hotplugin and plugout the VF's.
>
> Regards
> -Prashant
>

The current implementation does look like it supports hotplug.
All devices are discovered during rte_eal_pci_probe.





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