While direct booting a Linux kernel into an HVM VM no console output is received if serial="pty" is set in the VM config but the kernel command line specifies "console=hvc0". If "console=ttyS0" is specified then the console output is received as expected. Conversely, if the serial line is commented out in the VM config but hvc0 is set on the kernel command line then it also works. It's unclear whether this behavior is expected or not, after some discussion it sounds like all kernels ought to understand hvc0 irrespective of the serial="pty" line being set or not. Reporting this in case someone has more insight and/or inclination digging into this.
Cheers, Tamas
