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>

@@ -545,10 +545,18 @@
 #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

@@ -976,11 +984,11 @@
 #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_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

@@ -1053,26 +1061,23 @@
 
 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)
 
 /*
- * 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;