diff options
| author | David Woodhouse <dwmw@amazon.co.uk> | 2022-03-11 22:20:17 +0300 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2022-03-16 21:29:32 +0300 |
| commit | f6c46b1d62f8ffbf2cf6eb43ab0d277bd3f7e948 (patch) | |
| tree | 0cde7c4c4268fa79333c5def36eecc6cb3dbf3a3 /arch | |
| parent | a759de6991b35ad437adba32b5f0cb2fd9e75929 (diff) | |
| download | linux-f6c46b1d62f8ffbf2cf6eb43ab0d277bd3f7e948.tar.xz | |
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 'arch')
| -rw-r--r-- | arch/x86/kernel/acpi/sleep.c | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c index 1e97f944b47d..3b7f4cdbf2e0 100644 --- a/arch/x86/kernel/acpi/sleep.c +++ b/arch/x86/kernel/acpi/sleep.c @@ -15,6 +15,7 @@ #include <asm/desc.h> #include <asm/cacheflush.h> #include <asm/realmode.h> +#include <asm/hypervisor.h> #include <linux/ftrace.h> #include "../../realmode/rm/wakeup.h" @@ -140,9 +141,9 @@ static int __init acpi_sleep_setup(char *str) acpi_realmode_flags |= 4; #ifdef CONFIG_HIBERNATION if (strncmp(str, "s4_hwsig", 8) == 0) - acpi_check_s4_hw_signature(1); + acpi_check_s4_hw_signature = 1; if (strncmp(str, "s4_nohwsig", 10) == 0) - acpi_check_s4_hw_signature(0); + acpi_check_s4_hw_signature = 0; #endif if (strncmp(str, "nonvs", 5) == 0) acpi_nvs_nosave(); @@ -160,3 +161,21 @@ static int __init acpi_sleep_setup(char *str) } __setup("acpi_sleep=", acpi_sleep_setup); + +#if defined(CONFIG_HIBERNATION) && defined(CONFIG_HYPERVISOR_GUEST) +static int __init init_s4_sigcheck(void) +{ + /* + * If running on a hypervisor, honour the ACPI specification + * by default and trigger a clean reboot when the hardware + * signature in FACS is changed after hibernation. + */ + if (acpi_check_s4_hw_signature == -1 && + !hypervisor_is_type(X86_HYPER_NATIVE)) + acpi_check_s4_hw_signature = 1; + + return 0; +} +/* This must happen before acpi_init() which is a subsys initcall */ +arch_initcall(init_s4_sigcheck); +#endif |