Another example is X86_FEATURE_SRBDS_CTRL which gets added only after
microcode update:
- --- cpuid.before 2023-01-21 14:54:15.652000747 +0100
- +++ cpuid.after 2023-01-21 14:54:26.632001024 +0100
- @@ -10,7 +10,7 @@ CPU:
- 0x00000004 0x04: eax=0x00000000 ebx=0x00000000 ecx=0x00000000 edx=0x00000000
- 0x00000005 0x00: eax=0x00000040 ebx=0x00000040 ecx=0x00000003 edx=0x11142120
- 0x00000006 0x00: eax=0x000027f7 ebx=0x00000002 ecx=0x00000001 edx=0x00000000
- - 0x00000007 0x00: eax=0x00000000 ebx=0x029c6fbf ecx=0x40000000 edx=0xbc002400
- + 0x00000007 0x00: eax=0x00000000 ebx=0x029c6fbf ecx=0x40000000 edx=0xbc002e00
+# --- cpuid.before 2023-01-21 14:54:15.652000747 +0100
+# +++ cpuid.after 2023-01-21 14:54:26.632001024 +0100
+# @@ -10,7 +10,7 @@ CPU:
+# 0x00000004 0x04: eax=0x00000000 ebx=0x00000000 ecx=0x00000000 edx=0x00000000
+# 0x00000005 0x00: eax=0x00000040 ebx=0x00000040 ecx=0x00000003 edx=0x11142120
+# 0x00000006 0x00: eax=0x000027f7 ebx=0x00000002 ecx=0x00000001 edx=0x00000000
+# - 0x00000007 0x00: eax=0x00000000 ebx=0x029c6fbf ecx=0x40000000 edx=0xbc002400
+# + 0x00000007 0x00: eax=0x00000000 ebx=0x029c6fbf ecx=0x40000000 edx=0xbc002e00
^^^
and which proves for a gazillionth time that late loading is a bad bad