Re: [QUESTION] qemu: how to control the switch of floppy drive

[Markus Armbruster]

"Xu, Yanfei" <yanfei.xu@windriver.com> writes:

> Hi experts,
>
> How can I disable the floppy controller drive when I boot a VM by qemu-
> system-x86_64? I did not specify any arguments about floppy, but after
> the qemu boots up, linux always can detect floppy drive and then
> modprobe the matched floppy.ko.
>
> qemu version: v5.2
>
> command line:
>
> qemu-system-x86_64 -device virtio-net-
> pci,netdev=net0,mac=52:54:00:12:34:02 -netdev
> tap,id=net0,ifname=tap0,script=no,downscript=no -object rng-
> random,filename=/dev/urandom,id=rng0 -device virtio-rng-pci,rng=rng0
> -drive file=/path/to/images/qemux86-64
> /qemux86-64.ext4,if=virtio,format=raw -usb -device usb-tablet   -cpu
> core2duo -enable-kvm -m 512  -pidfile /path/to/pidfile_4167420 -m 512
> -snapshot -serial mon:vc -serial null  -kernel /path/to/qemux86-64
> /bzImage.bin -append 'root=/dev/vda rw  mem=512M
> ip=192.168.7.2::192.168.7.1:255.255.255.0 oprofile.timer=1
> printk.time=1'
>
> As I konw BIOS can control the switch of floppy controller on a real
> hardware, But how can I do it on qemu? And does the qemu enable that by
> default?

Machine types pc-i440fx-* provide a floppy controller.  An empty floppy
drive is connected by default.  Use -nodefaults to suppress it.

Machine types pc-q35-* provide a floppy controller only when you ask for
it, e.g. with -drive if=floppy.

Use -M to select the machine type.