This is how it's described in bhyve(8). Basically you need to configure one for each bhyve VM. Otherwise the VM won't boot. I'm not sure if there's an equivalent device in other Hypervisors. I've used KVM for quite some time and didn't need to configure anything similar

lpc         LPC PCI-ISA bridge with COM1 and COM2
            16550 serial ports and a boot ROM.
            The LPC bridge emulation can only be
            configured on bus 0.
Regards,
Ivan

On 08/10/2018 03:25 PM, Daniel P. Berrangé wrote:

On Fri, Aug 10, 2018 at 03:20:06PM +0300, Ivan Mishonov wrote:

The problem is that LPC is not defined as a device in the XML. Is there a
device type we can use for the LPC slot configuration similarly to disk, NIC
etc? I couldn't find one, but I'm not that familiar with the code so maybe
I'm missing something

What is the LPC ?

Regards,
Daniel