diff options
| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2024-06-14 12:58:48 +0300 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2024-06-17 17:45:31 +0200 |
| commit | 1037e4c53e851682ff8d1ab656567a4d5a333c93 (patch) | |
| tree | c8cfc660389ba2363984fed17eca71638b866688 /include/linux | |
| parent | 24dd05da8c7995cb2016b8f4da631c557aa6b40d (diff) | |
cpu/hotplug: Add support for declaring CPU offlining not supported
The ACPI MADT mailbox wakeup method doesn't allow to offline a CPU after
it has been woken up.
Currently, offlining is prevented based on the confidential computing attribute
which is set for Intel TDX. But TDX is not the only possible user of the wake up
method. The MADT wakeup can be implemented outside of a confidential computing
environment. Offline support is a property of the wakeup method, not the CoCo
implementation.
Introduce cpu_hotplug_disable_offlining() that can be called to indicate that
CPU offlining should be disabled.
This function is going to replace CC_ATTR_HOTPLUG_DISABLED for ACPI MADT wakeup
method.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Tao Liu <ltao@redhat.com>
Link: https://lore.kernel.org/r/20240614095904.1345461-4-kirill.shutemov@linux.intel.com
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/cpuhplock.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/cpuhplock.h b/include/linux/cpuhplock.h index 431560bbd045..f7aa20f62b87 100644 --- a/include/linux/cpuhplock.h +++ b/include/linux/cpuhplock.h @@ -21,6 +21,7 @@ void cpus_read_lock(void); void cpus_read_unlock(void); int cpus_read_trylock(void); void lockdep_assert_cpus_held(void); +void cpu_hotplug_disable_offlining(void); void cpu_hotplug_disable(void); void cpu_hotplug_enable(void); void clear_tasks_mm_cpumask(int cpu); @@ -36,6 +37,7 @@ static inline void cpus_read_lock(void) { } static inline void cpus_read_unlock(void) { } static inline int cpus_read_trylock(void) { return true; } static inline void lockdep_assert_cpus_held(void) { } +static inline void cpu_hotplug_disable_offlining(void) { } static inline void cpu_hotplug_disable(void) { } static inline void cpu_hotplug_enable(void) { } static inline int remove_cpu(unsigned int cpu) { return -EPERM; } |