ACPI: processor_idle: use raw_safe_halt() in acpi_idle_play_dead()

Xen HVM guests were observed taking triple-faults when attempting to
online a previously offlined vCPU.

Investigation showed that the fault was coming from a failing call
to lockdep_assert_irqs_disabled(), in load_current_idt() which was
too early in the CPU bringup to actually catch the exception and
report the failure cleanly.

This was a false positive, caused by acpi_idle_play_dead() setting
the per-cpu hardirqs_enabled flag by calling safe_halt(). Switch it
to use raw_safe_halt() instead, which doesn't do so.

Signed-off-by: David Woodhouse <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Cc: 6.6+ <[email protected]> # 6.6+
Signed-off-by: Rafael J. Wysocki <[email protected]>

drivers/acpi/processor_idle.c

@@ -592,7 +592,7 @@ static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
  while (1) {
 
  if (cx->entry_method == ACPI_CSTATE_HALT)
- safe_halt();
+ raw_safe_halt();
  else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
  io_idle(cx->address);
  } else