Re: [PATCH v2] block/file-posix: Optimize for macOS

[Akihiko Odaki]

2021年3月9日(火) 0:17 Stefan Hajnoczi <stefanha@redhat.com>:
>
> The live migration compatibility issue is still present. Migrating to
> another host might not work if the block limits are different.
>
> Here is an idea for solving it:
>
> Modify include/hw/block/block.h:DEFINE_BLOCK_PROPERTIES_BASE() to
> support a new value called "host". The default behavior remains
> unchanged for live migration compatibility but now you can use "host" if
> you know it's okay but don't care about migration compatibility.
>
> The downside to this approach is that users must explicitly say
> something like --drive ...,opt_io_size=host. But it's still better than
> the situation we have today where user must manually enter values for
> their disk.
>
> Does this sound okay to everyone?
>
> Stefan

I wonder how that change affects other block drivers implementing
bdrv_probe_blocksizes. As far as I know, the values they report are
already used by default, which is contrary to the default not being
"host".

Regards,
Akihiko Odaki