Implementations without hypervisor/LPAR support are permitted by the
architecture, but should have MSR[HV] forced to be 1 at all times, not
0, and should implement various instructions and registers that are
only accessible in hypervisor mode.
This commit implements MSR[HV] as a constant 1 bit and adds the hrfid
instruction, which behaves exactly the same as rfid except that it
reads HSRR0/1 instead of SRR0/1. We already have HSRR0/1 and HSPRG0/1
implemented.
When HV=1, Linux expects external interrupts to arrive as hypervisor
interrupts, so this adds support for hypervisor interrupts (i.e.,
those that set HSRR0/1) and makes the external interrupt be a
hypervisor interrupt. (If we had an LPCR register, the LPES bit would
control this, but we don't.) The xics test is updated to read HSRR0/1
after an external interrupt.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Paul Mackerras