Re: [PATCH QEMU v25 00/17] Add migration support for VFIO devices

[Zenghui Yu]

On 2020/9/23 7:24, Kirti Wankhede wrote:

> Patch 4-9:
> - Generic migration functionality for VFIO device.
>   * This patch set adds functionality for PCI devices, but can be
>     extended to other VFIO devices.
>   * Added all the basic functions required for pre-copy, stop-and-copy and
>     resume phases of migration.
>   * Added state change notifier and from that notifier function, VFIO
>     device's state changed is conveyed to VFIO device driver.
>   * During save setup phase and resume/load setup phase, migration region
>     is queried and is used to read/write VFIO device data.
>   * .save_live_pending and .save_live_iterate are implemented to use QEMU's
>     functionality of iteration during pre-copy phase.
>   * In .save_live_complete_precopy, that is in stop-and-copy phase,
>     iteration to read data from VFIO device driver is implemented till pending
>     bytes returned by driver are not zero.

s/are not zero/are zero/ ?

[...]

> Live migration resume path:
>     Incomming migration calls .load_setup for each device
>     (RESTORE_VM, _ACTIVE, STOPPED)

The _RESUMING device state is missed here?

>                         |
>     For each device, .load_state is called for that device section data
>                         |
>     At the end, called .load_cleanup for each device and vCPUs are started.
>                         |
>         (RUNNING, _NONE, _RUNNING)


Thanks,
Zenghui