USB. Oracle VM VirtualBox emulates these types of USB host controllers: xHCI, EHCI, and OHCI. While xHCI handles all USB transfer speeds, some legacy guest OSes may not support xHCI. Note that for some legacy Windows guests, third party drivers must be installed for xHCI support.
Chipset: You can select which chipset will be presented to the virtual machine. PIIX3 is the default chipset for most guests. For some guest OSes such as Mac OS X, the PIIX3 chipset is not well supported. As a result, Oracle VM VirtualBox supports an emulation of the ICH9 chipset, which supports PCI express, three PCI buses, PCI-to-PCI bridges and Message Signaled Interrupts (MSI). This enables modern OSes to address more PCI devices and no longer requires IRQ sharing. Using the ICH9 chipset it is also possible to configure up to 36 network cards, compared to a maximum of eight network adapters with PIIX3. Note that ICH9 support is experimental and not recommended for guest OSes which do not require it.
On Windows hosts, a kernel mode device driver provides USB proxy support. It implements both a USB monitor, which enables Oracle VM VirtualBox to capture devices when they are plugged in, and a USB device driver to claim USB devices for a particular virtual machine. System reboots are not necessary after installing the driver. Also, you do not need to replug devices for Oracle VM VirtualBox to claim them. 2b1af7f3a8