x86/fred: Add Kconfig option for FRED (CONFIG_X86_FRED)

Add the configuration option CONFIG_X86_FRED to enable FRED.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Shan Kang <shan.kang@intel.com>
Link: https://lore.kernel.org/r/20231205105030.8698-6-xin3.li@intel.com

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 5edec175b9bfc92dfac8832fc3600b843407828b..854ab38a359a2fed14ac69fc600f64303ed6b8c1 100644 (file)
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -496,6 +496,15 @@ config X86_CPU_RESCTRL
 
          Say N if unsure.
 
+config X86_FRED
+       bool "Flexible Return and Event Delivery"
+       depends on X86_64
+       help
+         When enabled, try to use Flexible Return and Event Delivery
+         instead of the legacy SYSCALL/SYSENTER/IDT architecture for
+         ring transitions and exception/interrupt handling if the
+         system supports.
+
 if X86_32
 config X86_BIGSMP
        bool "Support for big SMP systems with more than 8 CPUs"