From: David Woodhouse <d...@amazon.co.uk> 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 <d...@amazon.co.uk>
---
We might {also,instead} explicitly set the hardirqs_enabled flag to
zero when bringing up an AP?
drivers/acpi/processor_idle.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 3a34a8c425fe..55437f5e0c3a 100644
--- a/drivers/acpi/processor_idle.c
+++ b/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
--
2.41.0
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