[patch V2 02/37] x86/microcode: Hide the config knob

From: Thomas Gleixner
Date: Sat Aug 12 2023 - 16:00:24 EST


In reality CONFIG_MICROCODE is enabled in any reasonable configuration when
Intel or AMD support is enabled. Accomodate to reality.

Requested-by: Borislav Petkov <bp@xxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
arch/x86/Kconfig | 38 ---------------------------------
arch/x86/include/asm/microcode.h | 6 ++---
arch/x86/include/asm/microcode_amd.h | 2 -
arch/x86/include/asm/microcode_intel.h | 2 -
arch/x86/kernel/cpu/microcode/Makefile | 4 +--
5 files changed, 8 insertions(+), 44 deletions(-)

--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1308,44 +1308,8 @@ config X86_REBOOTFIXUPS
Say N otherwise.

config MICROCODE
- bool "CPU microcode loading support"
- default y
+ def_bool y
depends on CPU_SUP_AMD || CPU_SUP_INTEL
- help
- If you say Y here, you will be able to update the microcode on
- Intel and AMD processors. The Intel support is for the IA32 family,
- e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
- AMD support is for families 0x10 and later. You will obviously need
- the actual microcode binary data itself which is not shipped with
- the Linux kernel.
-
- The preferred method to load microcode from a detached initrd is described
- in Documentation/arch/x86/microcode.rst. For that you need to enable
- CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
- initrd for microcode blobs.
-
- In addition, you can build the microcode into the kernel. For that you
- need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
- config option.
-
-config MICROCODE_INTEL
- bool "Intel microcode loading support"
- depends on CPU_SUP_INTEL && MICROCODE
- default MICROCODE
- help
- This options enables microcode patch loading support for Intel
- processors.
-
- For the current Intel microcode data package go to
- <https://downloadcenter.intel.com> and search for
- 'Linux Processor Microcode Data File'.
-
-config MICROCODE_AMD
- bool "AMD microcode loading support"
- depends on CPU_SUP_AMD && MICROCODE
- help
- If you select this option, microcode patch loading support for AMD
- processors will be enabled.

config MICROCODE_LATE_LOADING
bool "Late microcode loading (DANGEROUS)"
--- a/arch/x86/include/asm/microcode.h
+++ b/arch/x86/include/asm/microcode.h
@@ -54,16 +54,16 @@ struct ucode_cpu_info {
extern struct ucode_cpu_info ucode_cpu_info[];
struct cpio_data find_microcode_in_initrd(const char *path, bool use_pa);

-#ifdef CONFIG_MICROCODE_INTEL
+#ifdef CONFIG_CPU_SUP_INTEL
extern struct microcode_ops * __init init_intel_microcode(void);
#else
static inline struct microcode_ops * __init init_intel_microcode(void)
{
return NULL;
}
-#endif /* CONFIG_MICROCODE_INTEL */
+#endif /* CONFIG_CPU_SUP_INTEL */

-#ifdef CONFIG_MICROCODE_AMD
+#ifdef CONFIG_CPU_SUP_AMD
extern struct microcode_ops * __init init_amd_microcode(void);
extern void __exit exit_amd_microcode(void);
#else
--- a/arch/x86/include/asm/microcode_amd.h
+++ b/arch/x86/include/asm/microcode_amd.h
@@ -43,7 +43,7 @@ struct microcode_amd {

#define PATCH_MAX_SIZE (3 * PAGE_SIZE)

-#ifdef CONFIG_MICROCODE_AMD
+#ifdef CONFIG_CPU_SUP_AMD
extern void load_ucode_amd_early(unsigned int cpuid_1_eax);
extern int __init save_microcode_in_initrd_amd(unsigned int family);
void reload_ucode_amd(unsigned int cpu);
--- a/arch/x86/include/asm/microcode_intel.h
+++ b/arch/x86/include/asm/microcode_intel.h
@@ -71,7 +71,7 @@ static inline u32 intel_get_microcode_re
return rev;
}

-#ifdef CONFIG_MICROCODE_INTEL
+#ifdef CONFIG_CPU_SUP_INTEL
extern void __init load_ucode_intel_bsp(void);
extern void load_ucode_intel_ap(void);
extern void show_ucode_info_early(void);
--- a/arch/x86/kernel/cpu/microcode/Makefile
+++ b/arch/x86/kernel/cpu/microcode/Makefile
@@ -1,5 +1,5 @@
# SPDX-License-Identifier: GPL-2.0-only
microcode-y := core.o
obj-$(CONFIG_MICROCODE) += microcode.o
-microcode-$(CONFIG_MICROCODE_INTEL) += intel.o
-microcode-$(CONFIG_MICROCODE_AMD) += amd.o
+microcode-$(CONFIG_CPU_SUP_INTEL) += intel.o
+microcode-$(CONFIG_CPU_SUP_AMD) += amd.o