[PATCH v3 4/8] x86/split_lock: Add and export split_lock_detect_enabled() and split_lock_detect_fatal()

[Xiaoyao Li <xiaoyao.li@xxxxxxxxx>]

These two functions will be used by KVM to check whether host's
sld_state.

Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
---
 arch/x86/include/asm/cpu.h  |  4 ++++
 arch/x86/kernel/cpu/intel.c | 12 ++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h
index 2b20829db450..f5172dbd3f01 100644
--- a/arch/x86/include/asm/cpu.h
+++ b/arch/x86/include/asm/cpu.h
@@ -46,6 +46,8 @@ unsigned int x86_stepping(unsigned int sig);
 extern void __init cpu_set_core_cap_bits(struct cpuinfo_x86 *c);
 extern void switch_to_sld(unsigned long tifn);
 extern bool handle_user_split_lock(unsigned long ip);
+extern bool split_lock_detect_enabled(void);
+extern bool split_lock_detect_fatal(void);
 #else
 static inline void __init cpu_set_core_cap_bits(struct cpuinfo_x86 *c) {}
 static inline void switch_to_sld(unsigned long tifn) {}
@@ -53,5 +55,7 @@ static inline bool handle_user_split_lock(unsigned long ip)
 {
 	return false;
 }
+static inline bool split_lock_detect_enabled(void) { return false; }
+static inline bool split_lock_detect_fatal(void) { return false; }
 #endif
 #endif /* _ASM_X86_CPU_H */
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index ff27d026cb4a..b67b46ea66df 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -1131,3 +1131,15 @@ void __init cpu_set_core_cap_bits(struct cpuinfo_x86 *c)
 	if (ia32_core_caps & MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT)
 		split_lock_setup();
 }
+
+bool split_lock_detect_enabled(void)
+{
+	return sld_state != sld_off;
+}
+EXPORT_SYMBOL_GPL(split_lock_detect_enabled);
+
+bool split_lock_detect_fatal(void)
+{
+	return sld_state == sld_fatal;
+}
+EXPORT_SYMBOL_GPL(split_lock_detect_fatal);
-- 
2.23.0