Re: [Qemu-devel] [PATCH] Do not emulate a floppy drive when -nodefaults

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, May 14, 2015 at 02:02:04PM +0200, Markus Armbruster wrote:
> Correct.
> 
> Here's how I think it should be done:
> 
> * Create a machine option to control the FDC
> 
>   This is a machine-specific option.  It should only exist for machine
>   types that have an optional FDC.
> 
>   Default must be "on" for old machine types.  Default may be "off" for
>   new machine types.
> 
>   It should certainly be off for pc-q35-2.4 and newer.  Real Q35 boards
>   commonly don't have an FDC (depends on the Super I/O chip used).
> 
>   We may want to keep it off for pc-i440fx-2.4 and newer.  I doubt
>   there's a real i440FX without an FDC, but our virtual i440FX is quite
>   unlike a real one in other ways already.

I think making it off by default is a bad idea, it will break
command-line users.


> * Create the FDC only if the option is "on".
> 
> * Optional: make -drive if=floppy,... auto-enable it

Every time we do such auto hacks, we regret this later.
Just do what we are told, fail if=floppy if disabled.

>   I wouldn't bother doing the same for -global isa-fdc.driveA=... and
>   such.
> 
> Stefano, if you're willing to tackle this, go right ahead!