Re: [Qemu-devel] [qemu-devel][RFC] Enable usb with default options

[Hans de Goede]

Hi,

Sorry for jumping in the middle of the thread, I missed the beginning
of this. Enabling USB by default, esp. emulating a USB mouse by default
is a *bad* idea. They way the periodic schedule of the various USB
controllers works means that emulating a USB device means a 1000 vm exits
per second extra, even when the vm is completely idle! USB powermanagement
can be used to negate this, but this is off in both Linux and Windows for
HID devices by default because there are too many broken HID devices.

Regards,

Hans