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

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

On Thu, May 14, 2015 at 06:38:24AM +0200, Stefan Weil wrote:
> Am 13.05.2015 um 20:15 schrieb Stefano Stabellini:
> >On Wed, 13 May 2015, Daniel P. Berrange wrote:
> >>On Wed, May 13, 2015 at 06:29:46PM +0100, Stefano Stabellini wrote:
> >>>Do not emulate a floppy drive if no drives are supposed to be present.
> >>>
> >>>This fixes the behavior of -nodefaults, that should remove the floppy
> >>>drive (see docs/qdev-device-use.txt:Default Devices), but actually
> >>>doesn't.
> >>Technically that doc is just refering to the disablement of the
> >>primary floppy drive, as opposed to the floppy controller. The
> >>floppy controller itself is really a built-in device that is
> >>defined as part of the machine type, along with the various other
> >>platform devices hanging off the PIIX and ISA brige.
> >I think you are right, this patch is a bit too harsh in fixing the
> >problem: I just wanted to properly disable drive emulation, because from
> >my tests the guest thinks that one drive is present even when is not.
> 
> A short test on some of my physical machines shows that most
> of them don't have a floppy disk controller at all (dmesg | grep FDC).
> 
> Only some older machines still have one.
> 
> Therefore I think that QEMU must also be able to offer a virtual
> machine without an FDC, maybe as the default for the next
> version of QEMU.
> 
> Stefan

Making it the default in QEMU might break a bunch of existing setups,
but IMO it's very reasonable to add such a property, and teach libvirt
to set it automatically.

-- 
MST