Re: [PATCH 11/11] x86/cpu: Make all all CPUID leaf names consistent

[Dave Hansen <dave.hansen@intel.com>]

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On 11/29/24 10:27, Borislav Petkov wrote:
> Well, enum cpuid_leafs as it is now is the *indices* into the cap flags array:
> 
> struct cpuinfo_x86 {
> 
> 	...
> 
> 	__u32           x86_capability[NCAPINTS + NBUGINTS];
> 
> And having a "CPUID_" prefixed thing and a "CPUID_LEAF_" prefixed other thing
> is going to cause confusion.
> 
> And renaming enum cpuid_leafs is going to cause a massive churn...

Wait a sec though:

$ git grep 'enum cpuid_leafs' arch/x86/
arch/x86/include/asm/cpufeature.h:enum cpuid_leafs
arch/x86/kvm/cpuid.c:static __always_inline void kvm_cpu_cap_mask(enum
cpuid_leafs leaf, u32 mask)

So there is only one direct reference to the type.

I think all it will take to rename the _type_ is something like the
attached. Also, I think the new name 'x86_capability_words' and variable
'cap_nr' make the KVM site a lot more readable.

Thoughts?

[-- Attachment #2: rename-cpuid_leafs.patch --]
[-- Type: text/x-patch, Size: 1369 bytes --]



---

 b/arch/x86/include/asm/cpufeature.h |    2 +-
 b/arch/x86/kvm/cpuid.c              |    8 ++++----
 2 files changed, 5 insertions(+), 5 deletions(-)

diff -puN arch/x86/include/asm/cpufeature.h~rename-cpuid_leafs arch/x86/include/asm/cpufeature.h
--- a/arch/x86/include/asm/cpufeature.h~rename-cpuid_leafs	2024-12-06 14:57:52.350793675 -0800
+++ b/arch/x86/include/asm/cpufeature.h	2024-12-06 14:58:43.464719842 -0800
@@ -10,7 +10,7 @@
 #include <linux/bitops.h>
 #include <asm/alternative.h>
 
-enum cpuid_leafs
+enum x86_capability_words
 {
 	CPUID_1_EDX		= 0,
 	CPUID_8000_0001_EDX,
diff -puN arch/x86/kvm/cpuid.c~rename-cpuid_leafs arch/x86/kvm/cpuid.c
--- a/arch/x86/kvm/cpuid.c~rename-cpuid_leafs	2024-12-06 14:58:45.084780924 -0800
+++ b/arch/x86/kvm/cpuid.c	2024-12-06 14:59:24.818279432 -0800
@@ -594,14 +594,14 @@ void kvm_cpu_cap_init_kvm_defined(enum k
 	__kvm_cpu_cap_mask(leaf);
 }
 
-static __always_inline void kvm_cpu_cap_mask(enum cpuid_leafs leaf, u32 mask)
+static __always_inline void kvm_cpu_cap_mask(enum x86_capability_words cap_nr, u32 mask)
 {
 	/* Use kvm_cpu_cap_init_kvm_defined for KVM-only leafs. */
-	BUILD_BUG_ON(leaf >= NCAPINTS);
+	BUILD_BUG_ON(cap_nr >= NCAPINTS);
 
-	kvm_cpu_caps[leaf] &= mask;
+	kvm_cpu_caps[cap_nr] &= mask;
 
-	__kvm_cpu_cap_mask(leaf);
+	__kvm_cpu_cap_mask(cap_nr);
 }
 
 void kvm_set_cpu_caps(void)
_