This is a note to let you know that I've just added the patch titled
ACPI: processor_idle: use raw_safe_halt() in acpi_idle_play_dead()
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
acpi-processor_idle-use-raw_safe_halt-in-acpi_idle_play_dead.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 9bb69ba4c177dccaa1f5b5cbdf80b67813328348 Mon Sep 17 00:00:00 2001
From: David Woodhouse <dwmw@xxxxxxxxxxxx>
Date: Fri, 27 Oct 2023 19:36:51 +0100
Subject: ACPI: processor_idle: use raw_safe_halt() in acpi_idle_play_dead()
From: David Woodhouse <dwmw@xxxxxxxxxxxx>
commit 9bb69ba4c177dccaa1f5b5cbdf80b67813328348 upstream.
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 <dwmw@xxxxxxxxxxxx>
Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: 6.6+ <stable@xxxxxxxxxxxxxxx> # 6.6+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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
--
2.43.0
Patches currently in stable-queue which might be from dwmw@xxxxxxxxxxxx are
queue-6.6/pm-tools-fix-sleepgraph-syntax-error.patch
queue-6.6/acpi-processor_idle-use-raw_safe_halt-in-acpi_idle_play_dead.patch
