Inconsistent console behavior during HVM direct boot

[Tamas K Lengyel <tamas@xxxxxxxxxxxxx>]

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