Re: [PATCH 1/3] vfio/migration: Report only stop-copy size in vfio_state_pending_exact()

["Cédric Le Goater" <clg@redhat.com>]

On 10/25/24 17:18, Michael Tokarev wrote:
> 20.10.2024 16:01, Avihai Horon:
>> vfio_state_pending_exact() is used to update migration core how much
>> device data is left for the device migration. Currently, the sum of
>> pre-copy and stop-copy sizes of the VFIO device are reported.
>>
>> The pre-copy size is obtained via the VFIO_MIG_GET_PRECOPY_INFO ioctl,
>> which returns the amount of device data available to be transferred
>> while the device is in the PRE_COPY states.
>>
>> The stop-copy size is obtained via the VFIO_DEVICE_FEATURE_MIG_DATA_SIZE
>> ioctl, which returns the total amount of device data left to be
>> transferred in order to complete the device migration.
>>
>> According to the above, current implementation is wrong -- it reports
>> extra overlapping data because pre-copy size is already contained in
>> stop-copy size. Fix it by reporting only stop-copy size.
>>
>> Fixes: eda7362af959 ("vfio/migration: Add VFIO migration pre-copy support")
>> Signed-off-by: Avihai Horon <avihaih@nvidia.com>
> 
> This smells like a qemu-stable material (for 8.1+).

I am in favor.

Thanks,

C.