The RAPSIZE definition originally introduced in 9c07a7af5da:
"target/i386: Expose new feature bits in..." hard-coded the value
of the field to 0x8. While this value works for current CPUs, the
value may change in the future. Update the definition to be a bit-mask
instead of a hard-coded value for future-proofing.

The field is currently unused, so no functional change is intended.

Signed-off-by: Ben Cheatham <[email protected]>
---
 target/i386/cpu.h | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index e66333cd9c24..ff63baa9dd23 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -1214,10 +1214,11 @@ uint64_t x86_cpu_get_supported_feature_word(X86CPU 
*cpu, FeatureWord w);
 #define CPUID_8000_0021_EAX_SRSO_USER_KERNEL_NO          (1U << 30)
 
 /*
- * Return Address Predictor size. RapSize x 8 is the minimum number of
- * CALL instructions software needs to execute to flush the RAP.
+ * Return Address Predictor size. RapSize x Y is the minimum number of
+ * CALL instructions software needs to execute to flush the RAP, where
+ * Y is the value of CPUID_8000_0021.EBX[23:16].
  */
-#define CPUID_8000_0021_EBX_RAPSIZE    (8U << 16)
+#define CPUID_8000_0021_EBX_RAPSIZE    (0x00FF0000U)
 
 /* CPU is not vulnerable TSA SA-SQ attack */
 #define CPUID_8000_0021_ECX_TSA_SQ_NO  (1U << 1)
-- 
2.53.0


Reply via email to