Re: [Qemu-devel] [PATCH v1 0/4] Add feature to start QEMU without vhost-user backend

[Tetsuya Mukawa]

On 2015/06/15 23:08, Stefan Hajnoczi wrote:
> On Fri, May 29, 2015 at 01:42:26PM +0900, Tetsuya Mukawa wrote:
>>    - Change user interface to be able to specify each feature by name.
> I disagree with this change, the uint64_t backend_features option was
> better because:
>
> The text options will just result in a very long command-line that is
> hard to read for humans.  Instead of checking a bit in a single hex
> number, you have to scan over long comma-separated text options which
> can be in any arbitrary order to find the feature bit you were looking
> for.
>
> This option needs to be scripted or generated by a management tool
> anyway since it depends on the vhost-user backend program that is being
> paired with QEMU.  The number of human users constructing these option
> is extremely low - if they use it they'll copy-paste it from their
> vhost-user program's documentation so the contents don't matter much
> (shorter is better though).
>
> The text options must be updated when new feature bits are added to
> virtio-net.
>
> For these reasons I find the numeric backend_features option better.

Thanks for comments.
I guess it's reasonable, so I will revert it in next patches.

Regards,
Tetsuya