linux-kernel - [PATCH v2 17/49] KVM: x86: Do reverse CPUID sanity checks in __feature

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Date: Fri, 17 May 2024 10:38:54 -0700
From: Sean Christopherson <seanjc@...gle.com>
To: Paolo Bonzini <pbonzini@...hat.com>, Sean Christopherson <seanjc@...gle.com>, 
	Vitaly Kuznetsov <vkuznets@...hat.com>
Cc: kvm@...r.kernel.org, linux-kernel@...r.kernel.org, 
	Hou Wenlong <houwenlong.hwl@...group.com>, Kechen Lu <kechenl@...dia.com>, 
	Oliver Upton <oliver.upton@...ux.dev>, Maxim Levitsky <mlevitsk@...hat.com>, 
	Binbin Wu <binbin.wu@...ux.intel.com>, Yang Weijiang <weijiang.yang@...el.com>, 
	Robert Hoo <robert.hoo.linux@...il.com>
Subject: [PATCH v2 17/49] KVM: x86: Do reverse CPUID sanity checks in __feature_leaf()

Do the compile-time sanity checks on reverse_cpuid in __feature_leaf() so
that higher level APIs don't need to "manually" perform the sanity checks.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/kvm/cpuid.h         | 3 ---
 arch/x86/kvm/reverse_cpuid.h | 6 ++++--
 2 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h
index 7eb3d7318fc4..d68b7d879820 100644
--- a/arch/x86/kvm/cpuid.h
+++ b/arch/x86/kvm/cpuid.h
@@ -198,7 +198,6 @@ static __always_inline void kvm_cpu_cap_clear(unsigned int x86_feature)
 {
 	unsigned int x86_leaf = __feature_leaf(x86_feature);
 
-	reverse_cpuid_check(x86_leaf);
 	kvm_cpu_caps[x86_leaf] &= ~__feature_bit(x86_feature);
 }
 
@@ -206,7 +205,6 @@ static __always_inline void kvm_cpu_cap_set(unsigned int x86_feature)
 {
 	unsigned int x86_leaf = __feature_leaf(x86_feature);
 
-	reverse_cpuid_check(x86_leaf);
 	kvm_cpu_caps[x86_leaf] |= __feature_bit(x86_feature);
 }
 
@@ -214,7 +212,6 @@ static __always_inline u32 kvm_cpu_cap_get(unsigned int x86_feature)
 {
 	unsigned int x86_leaf = __feature_leaf(x86_feature);
 
-	reverse_cpuid_check(x86_leaf);
 	return kvm_cpu_caps[x86_leaf] & __feature_bit(x86_feature);
 }
 
diff --git a/arch/x86/kvm/reverse_cpuid.h b/arch/x86/kvm/reverse_cpuid.h
index 2f4e155080ba..245f71c16272 100644
--- a/arch/x86/kvm/reverse_cpuid.h
+++ b/arch/x86/kvm/reverse_cpuid.h
@@ -136,7 +136,10 @@ static __always_inline u32 __feature_translate(int x86_feature)
 
 static __always_inline u32 __feature_leaf(int x86_feature)
 {
-	return __feature_translate(x86_feature) / 32;
+	u32 x86_leaf = __feature_translate(x86_feature) / 32;
+
+	reverse_cpuid_check(x86_leaf);
+	return x86_leaf;
 }
 
 /*
@@ -159,7 +162,6 @@ static __always_inline struct cpuid_reg x86_feature_cpuid(unsigned int x86_featu
 {
 	unsigned int x86_leaf = __feature_leaf(x86_feature);
 
-	reverse_cpuid_check(x86_leaf);
 	return reverse_cpuid[x86_leaf];
 }
 
-- 
2.45.0.215.g3402c0e53f-goog