Re: [dm-devel] [PATCH v4 00/10] Add Copy offload support

Damien Le Moal
2022-05-02T12:14:54Z

On 2022/04/27 21:49, Nitesh Shetty wrote:
> O Wed, Apr 27, 2022 at 11:19:48AM +0900, Damien Le Moal wrote:
>> On 4/26/22 19:12, Nitesh Shetty wrote:
>>> The patch series covers the points discussed in November 2021 virtual call
>>> [LSF/MM/BFP TOPIC] Storage: Copy Offload[0].
>>> We have covered the Initial agreed requirements in this patchset.
>>> Patchset borrows Mikulas's token based approach for 2 bdev
>>> implementation.
>>>
>>> Overall series supports –
>>>
>>> 1. Driver
>>> - NVMe Copy command (single NS), including support in nvme-target (for
>>> block and file backend)
>>
>> It would also be nice to have copy offload emulation in null_blk for testing.
>>
>
> We can plan this in next phase of copy support, once this series settles down.

Why ? How do you expect people to test simply without null_blk ? Sutre, you said
QEMU can be used. But if copy offload is not upstream for QEMU either, there is
no easy way to test.

Adding that support to null_blk would not be hard at all.

--
Damien Le Moal
Western Digital Research