Re: [Qemu-devel] [PATCH 0/3] Fix confused output for alias properties

[Paolo Bonzini <pbonzini@redhat.com>]

Il 16/09/2014 11:16, Markus Armbruster ha scritto:
>> I think both "str" and "link<block-backend>" actually are a small degradation
>> compared to "drive", and this is why I kept the legacy_name.  But overall I
>> think it's not really worth the layering violation that patches 2 and 3 are;
>> and it's definitely not stable material.
> 
> "str" is clearly a degradation for me.  I breaks usage like
> 
>     for i in `qemu -device help 2>&1 | sed -n 's/^name "\([^"]*\)".*/\1/p'`
>     do qemu -device $i,help 2>&1
>     done | grep =drive
> 
> Finds all block device models.  I've done such things many times.

Just replace "grep =drive" with "fgrep .drive".  Similarly:

  =chr     -> .chardev  (bonus: matches the command line option)
  =netdev  -> .netdev
  =vlan    -> .vlan
  =macaddr -> .mac

We probably agree that having "=drive" work sometimes, but not always,
is the worst of both worlds.  Still doesn't make it stable material, IMO.

> Agree on the uselessness of "on/off".
> 
> Agree on the uselessness of "blocksize" without a definition of the
> term.
> 
> "chr" and "netdev" are like "drive", and replacing them by "str" is a
> degradation in my book.

It is, but we're suprisingly consistent in the naming of such
special-typed properties.  So it's actually a good thing that
legacy_name provides redundant information.

> Help for enum-valued properties in the form of "prop=ENUM-NAME" is not
> really helpful without a definition of ENUM-NAME.  It's still useful for
> finding devices with this kind of property.

Yes, but here you wouldn't have 'str', you would have the corresponding
QAPI enum name.  This would be an improvement, though a minor one.

Paolo