11787 Kernel needs to be built with retpolines
11788 Kernel needs to generally use RSB stuffing
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Reviewed by: John Levon <john.levon@joyent.com>

*** 545,554 ****
--- 545,562 ----
  #define IA32_PKG_THERM_INTTERUPT_TR1_IE         0x00008000
  #define IA32_PKG_THERM_INTTERUPT_TR2_VAL(x)     (((x) >> 16) & 0x7f)
  #define IA32_PKG_THERM_INTERRUPT_TR2_IE         0x00800000
  #define IA32_PKG_THERM_INTERRUPT_PL_NE          0x01000000
  
+ /*
+  * This MSR exists on families, 10h, 12h+ for AMD. This controls instruction
+  * decoding. Most notably, for the AMD variant of retpolines, we must improve
+  * the serializability of lfence for the lfence based method to work.
+  */
+ #define MSR_AMD_DECODE_CONFIG                   0xc0011029
+ #define AMD_DECODE_CONFIG_LFENCE_DISPATCH       0x02
+ 
  #define MCI_CTL_VALUE           0xffffffff
  
  #define MTRR_TYPE_UC            0
  #define MTRR_TYPE_WC            1
  #define MTRR_TYPE_WT            4
*** 976,986 ****
  #define INTC_MODEL_BROADWELL            0x3d
  #define INTC_MODEL_BROADELL_2           0x47
  #define INTC_MODEL_BROADWELL_XEON       0x4f
  #define INTC_MODEL_BROADWELL_XEON_D     0x56
  
! #define INCC_MODEL_SKYLAKE_MOBILE       0x4e
  #define INTC_MODEL_SKYLAKE_XEON         0x55
  #define INTC_MODEL_SKYLAKE_DESKTOP      0x5e
  
  #define INTC_MODEL_KABYLAKE_MOBILE      0x8e
  #define INTC_MODEL_KABYLAKE_DESKTOP     0x9e
--- 984,994 ----
  #define INTC_MODEL_BROADWELL            0x3d
  #define INTC_MODEL_BROADELL_2           0x47
  #define INTC_MODEL_BROADWELL_XEON       0x4f
  #define INTC_MODEL_BROADWELL_XEON_D     0x56
  
! #define INTC_MODEL_SKYLAKE_MOBILE       0x4e
  #define INTC_MODEL_SKYLAKE_XEON         0x55
  #define INTC_MODEL_SKYLAKE_DESKTOP      0x5e
  
  #define INTC_MODEL_KABYLAKE_MOBILE      0x8e
  #define INTC_MODEL_KABYLAKE_DESKTOP     0x9e
*** 1053,1078 ****
  
  extern uint_t pentiumpro_bug4046376;
  
  extern const char CyrixInstead[];
  
  extern void (*spec_uarch_flush)(void);
  
  #endif
  
  #if defined(_KERNEL)
  
  /*
-  * x86_md_clear is the main entry point that should be called to deal with
-  * clearing u-arch buffers. Implementations are below because they're
-  * implemented in ASM. They shouldn't be used.
-  */
- extern void (*x86_md_clear)(void);
- extern void x86_md_clear_noop(void);
- extern void x86_md_clear_verw(void);
- 
- /*
   * This structure is used to pass arguments and get return values back
   * from the CPUID instruction in __cpuid_insn() routine.
   */
  struct cpuid_regs {
          uint32_t        cp_eax;
--- 1061,1083 ----
  
  extern uint_t pentiumpro_bug4046376;
  
  extern const char CyrixInstead[];
  
+ /*
+  * These functions are all used to perform various side-channel mitigations.
+  * Please see uts/i86pc/os/cpuid.c for more information.
+  */
  extern void (*spec_uarch_flush)(void);
+ extern void x86_rsb_stuff(void);
+ extern void x86_md_clear(void);
  
  #endif
  
  #if defined(_KERNEL)
  
  /*
   * This structure is used to pass arguments and get return values back
   * from the CPUID instruction in __cpuid_insn() routine.
   */
  struct cpuid_regs {
          uint32_t        cp_eax;