diff options
Diffstat (limited to 'arch/x86/kernel/process.c')
| -rw-r--r-- | arch/x86/kernel/process.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 3ca198080ea9..bd6b85fac666 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -355,6 +355,7 @@ bool xen_set_default_idle(void) return ret; } #endif + void stop_this_cpu(void *dummy) { local_irq_disable(); @@ -365,8 +366,20 @@ void stop_this_cpu(void *dummy) disable_local_APIC(); mcheck_cpu_clear(this_cpu_ptr(&cpu_info)); - for (;;) - halt(); + for (;;) { + /* + * Use wbinvd followed by hlt to stop the processor. This + * provides support for kexec on a processor that supports + * SME. With kexec, going from SME inactive to SME active + * requires clearing cache entries so that addresses without + * the encryption bit set don't corrupt the same physical + * address that has the encryption bit set when caches are + * flushed. To achieve this a wbinvd is performed followed by + * a hlt. Even if the processor is not in the kexec/SME + * scenario this only adds a wbinvd to a halting processor. + */ + asm volatile("wbinvd; hlt" : : : "memory"); + } } /* |