diff options
| author | David Woodhouse <dwmw@amazon.co.uk> | 2022-03-11 19:20:17 +0000 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2022-03-16 19:29:32 +0100 |
| commit | f6c46b1d62f8ffbf2cf6eb43ab0d277bd3f7e948 (patch) | |
| tree | 0cde7c4c4268fa79333c5def36eecc6cb3dbf3a3 /drivers/acpi | |
| parent | a759de6991b35ad437adba32b5f0cb2fd9e75929 (diff) | |
PM: hibernate: Honour ACPI hardware signature by default for virtual guests
The ACPI specification says that OSPM should refuse to restore from
hibernate if the hardware signature changes, and should boot from
scratch. However, real BIOSes often vary the hardware signature in cases
where we *do* want to resume from hibernate, so Linux doesn't follow the
spec by default.
However, in a virtual environment there's no reason for the VMM to vary
the hardware signature *unless* it wants to trigger a clean reboot as
defined by the ACPI spec. So enable the check by default if a hypervisor
is detected.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/sleep.c | 11 |
1 files changed, 3 insertions, 8 deletions
diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c index d4fbea91ab6b..74e54fd44b8e 100644 --- a/drivers/acpi/sleep.c +++ b/drivers/acpi/sleep.c @@ -869,12 +869,7 @@ static inline void acpi_sleep_syscore_init(void) {} #ifdef CONFIG_HIBERNATION static unsigned long s4_hardware_signature; static struct acpi_table_facs *facs; -static int sigcheck = -1; /* Default behaviour is just to warn */ - -void __init acpi_check_s4_hw_signature(int check) -{ - sigcheck = check; -} +int acpi_check_s4_hw_signature = -1; /* Default behaviour is just to warn */ static int acpi_hibernation_begin(pm_message_t stage) { @@ -999,7 +994,7 @@ static void acpi_sleep_hibernate_setup(void) hibernation_set_ops(old_suspend_ordering ? &acpi_hibernation_ops_old : &acpi_hibernation_ops); sleep_states[ACPI_STATE_S4] = 1; - if (!sigcheck) + if (!acpi_check_s4_hw_signature) return; acpi_get_table(ACPI_SIG_FACS, 1, (struct acpi_table_header **)&facs); @@ -1011,7 +1006,7 @@ static void acpi_sleep_hibernate_setup(void) */ s4_hardware_signature = facs->hardware_signature; - if (sigcheck > 0) { + if (acpi_check_s4_hw_signature > 0) { /* * If we're actually obeying the ACPI specification * then the signature is written out as part of the |