[PATCH 1/2] x86/cpufeatures: Add AMD-specific IBRS bits

Takahiro Itazuri
2023-02-27T21:15:14Z

AMD processors have some AMD-specific IBRS related bits in CPUID
Fn8000_0008_EBX (ref: AMD64 Architecture Programmer's Manual, Volume 3:
General-Purpose and System Instructions).

Signed-off-by: Takahiro Itazuri <itazur@amazon.com>
---
arch/x86/include/asm/cpufeatures.h | 3 +++
1 file changed, 3 insertions(+)

diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 8f39c46197b8..cd7245507745 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -324,7 +324,10 @@
#define X86_FEATURE_AMD_IBPB (13*32+12) /* "" Indirect Branch Prediction Barrier */
#define X86_FEATURE_AMD_IBRS (13*32+14) /* "" Indirect Branch Restricted Speculation */
#define X86_FEATURE_AMD_STIBP (13*32+15) /* "" Single Thread Indirect Branch Predictors */
+#define X86_FEATURE_AMD_IBRS_ALWAYS_ON (13*32+16) /* "" Indirect Branch Restricted Speculation always-on preferred */
#define X86_FEATURE_AMD_STIBP_ALWAYS_ON (13*32+17) /* "" Single Thread Indirect Branch Predictors always-on preferred */
+#define X86_FEATURE_AMD_IBRS_PREFERRED (13*32+18) /* "" Indirect Branch Restricted Speculation preferred over software */
+#define X86_FEATURE_AMD_IBRS_SAME_MODE (13*32+19) /* "" Indirect Branch Restricted Speculation provides same mode protection */
#define X86_FEATURE_AMD_PPIN (13*32+23) /* Protected Processor Inventory Number */
#define X86_FEATURE_AMD_SSBD (13*32+24) /* "" Speculative Store Bypass Disable */
#define X86_FEATURE_VIRT_SSBD (13*32+25) /* Virtualized Speculative Store Bypass Disable */
--
2.38.0