On Mon, Feb 03, 2020 at 11:16:03PM +0800, Xiaoyao Li wrote:
> get_split_lock_detect_state() will be used by KVM module to get sld_state.
>
> Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
> ---
> arch/x86/include/asm/cpu.h | 12 ++++++++++++
> arch/x86/kernel/cpu/intel.c | 12 ++++++------
> 2 files changed, 18 insertions(+), 6 deletions(-)
>
> diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h
> index ff6f3ca649b3..167d0539e0ad 100644
> --- a/arch/x86/include/asm/cpu.h
> +++ b/arch/x86/include/asm/cpu.h
> @@ -40,11 +40,23 @@ int mwait_usable(const struct cpuinfo_x86 *);
> unsigned int x86_family(unsigned int sig);
> unsigned int x86_model(unsigned int sig);
> unsigned int x86_stepping(unsigned int sig);
> +
> +enum split_lock_detect_state {
> + sld_off = 0,
> + sld_warn,
> + sld_fatal,
> +};
> +
> #ifdef CONFIG_CPU_SUP_INTEL
> +extern enum split_lock_detect_state get_split_lock_detect_state(void);
> 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(struct pt_regs *regs, long error_code);
> #else
> +static inline enum split_lock_detect_state get_split_lock_detect_state(void)
> +{
> + return sld_off;
> +}
> static inline void __init cpu_set_core_cap_bits(struct cpuinfo_x86 *c) {}
> static inline void switch_to_sld(unsigned long tifn) {}
> static inline bool handle_user_split_lock(struct pt_regs *regs, long error_code)
> diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
> index db3e745e5d47..a810cd022db5 100644
> --- a/arch/x86/kernel/cpu/intel.c
> +++ b/arch/x86/kernel/cpu/intel.c
> @@ -33,12 +33,6 @@
> #include <asm/apic.h>
> #endif
>
> -enum split_lock_detect_state {
> - sld_off = 0,
> - sld_warn,
> - sld_fatal,
> -};
> -
> /*
> * Default to sld_off because most systems do not support split lock detection
> * split_lock_setup() will switch this to sld_warn on systems that support
> @@ -968,6 +962,12 @@ cpu_dev_register(intel_cpu_dev);
> #undef pr_fmt
> #define pr_fmt(fmt) "x86/split lock detection: " fmt
>
> +enum split_lock_detect_state get_split_lock_detect_state(void)
> +{
> + return sld_state;
> +}
> +EXPORT_SYMBOL_GPL(get_split_lock_detect_state);
I'm pretty sure KVM doesn't need to differentiate between warn and fatal if
its #AC interceptor is routed through handle_user_split_lock(). I.e. this
can return a boolean without exporting the enum.
bool is_split_lock_detect_enabled(void)
{
return sld_state != sld_off;
}
> +
> static const struct {
> const char *option;
> enum split_lock_detect_state state;
> --
> 2.23.0
>
