Re: [Qemu-devel] [PATCH 2/3] virtio_net: Add support for "Data Path Switching" during Live Migration.

[Eric Blake <eblake@redhat.com>]

On 12/10/18 10:15 AM, Venu Busireddy wrote:
> Added two new events, FAILOVER_PLUG_PRIMARY and FAILOVER_UNPLUG_PRIMARY.
> The first is emitted when the guest negotiates the F_STANDBY feature
> bit. The second is emitted when the virtio_net driver is removed, either
> manually or as a result of guest reboot. Management stack can use these
> events to determine when to plug/unplug the VF device to/from the guest.
> 
> Also, the Virtual Functions will be automatically removed from the guest
> if the guest is rebooted. To properly identify the VFIO devices that
> must be removed, a new property named "x-failover-primary" is added to
> the vfio-pci devices. Only the vfio-pci devices that have this property
> enabled are removed from the guest upon reboot.
> 
> Signed-off-by: Venu Busireddy <venu.busireddy@oracle.com>
> ---

> +++ b/qapi/net.json
> @@ -683,3 +683,47 @@
>   ##
>   { 'event': 'NIC_RX_FILTER_CHANGED',
>     'data': { '*name': 'str', 'path': 'str' } }
> +
> +##
> +# @FAILOVER_PLUG_PRIMARY:
> +#
> +# Emitted when the guest successfully loads the driver after the STANDBY
> +# feature bit is negotiated.
> +#
> +# @device: Indicates the virtio_net device.
> +#
> +# @path: Indicates the device path.
> +#
> +# Since: 3.0

You've missed 3.0, and even 3.1.  This should be 4.0.

> +#
> +# Example:
> +#
> +# <- {"timestamp": {"seconds": 1432121972, "microseconds": 744001},
> +#     "event": "FAILOVER_PLUG_PRIMARY",
> +#     "data": {"device": "net0", "path": "/machine/peripheral/net0/virtio-backend"} }
> +#
> +##
> +{ 'event': 'FAILOVER_PLUG_PRIMARY',
> +  'data': {'*device': 'str', 'path': 'str'} }
> +
> +##
> +# @FAILOVER_UNPLUG_PRIMARY:
> +#
> +# Emitted when the guest resets the virtio_net driver.
> +# The reset can be the result of either unloading the driver or a reboot.
> +#
> +# @device: Indicates the virtio_net device.
> +#
> +# @path: Indicates the device path.
> +#
> +# Since: 3.0

and again


-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org