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Subject[PATCH v2 23/49] KVM: x86: Handle kernel- and KVM-defined CPUID words in a single helper
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Merge kvm_cpu_cap_init() and kvm_cpu_cap_init_kvm_defined() into a single
helper. The only advantage of separating the two was to make it somewhat
obvious that KVM directly initializes the KVM-defined words, whereas using
a common helper will allow for hardening both kernel- and KVM-defined
CPUID words without needing copy+paste.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/cpuid.c | 44 +++++++++++++++-----------------------------
1 file changed, 15 insertions(+), 29 deletions(-)

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index f2bd2f5c4ea3..8efffd48cdf1 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -622,37 +622,23 @@ static __always_inline u32 raw_cpuid_get(struct cpuid_reg cpuid)
return *__cpuid_entry_get_reg(&entry, cpuid.reg);
}

-/* Mask kvm_cpu_caps for @leaf with the raw CPUID capabilities of this CPU. */
-static __always_inline void __kvm_cpu_cap_mask(unsigned int leaf)
+static __always_inline void kvm_cpu_cap_init(u32 leaf, u32 mask)
{
const struct cpuid_reg cpuid = x86_feature_cpuid(leaf * 32);

- reverse_cpuid_check(leaf);
+ /*
+ * For kernel-defined leafs, mask the boot CPU's pre-populated value.
+ * For KVM-defined leafs, explicitly set the leaf, as KVM is the one
+ * and only authority.
+ */
+ if (leaf < NCAPINTS)
+ kvm_cpu_caps[leaf] &= mask;
+ else
+ kvm_cpu_caps[leaf] = mask;

kvm_cpu_caps[leaf] &= raw_cpuid_get(cpuid);
}

-static __always_inline
-void kvm_cpu_cap_init_kvm_defined(enum kvm_only_cpuid_leafs leaf, u32 mask)
-{
- /* Use kvm_cpu_cap_init for leafs that aren't KVM-only. */
- BUILD_BUG_ON(leaf < NCAPINTS);
-
- kvm_cpu_caps[leaf] = mask;
-
- __kvm_cpu_cap_mask(leaf);
-}
-
-static __always_inline void kvm_cpu_cap_init(enum cpuid_leafs leaf, u32 mask)
-{
- /* Use kvm_cpu_cap_init_kvm_defined for KVM-only leafs. */
- BUILD_BUG_ON(leaf >= NCAPINTS);
-
- kvm_cpu_caps[leaf] &= mask;
-
- __kvm_cpu_cap_mask(leaf);
-}
-
void kvm_set_cpu_caps(void)
{
memset(kvm_cpu_caps, 0, sizeof(kvm_cpu_caps));
@@ -740,12 +726,12 @@ void kvm_set_cpu_caps(void)
F(AMX_FP16) | F(AVX_IFMA) | F(LAM)
);

- kvm_cpu_cap_init_kvm_defined(CPUID_7_1_EDX,
+ kvm_cpu_cap_init(CPUID_7_1_EDX,
F(AVX_VNNI_INT8) | F(AVX_NE_CONVERT) | F(PREFETCHITI) |
F(AMX_COMPLEX)
);

- kvm_cpu_cap_init_kvm_defined(CPUID_7_2_EDX,
+ kvm_cpu_cap_init(CPUID_7_2_EDX,
F(INTEL_PSFD) | F(IPRED_CTRL) | F(RRSBA_CTRL) | F(DDPD_U) |
F(BHI_CTRL) | F(MCDT_NO)
);
@@ -755,7 +741,7 @@ void kvm_set_cpu_caps(void)
X86_64_F(XFD)
);

- kvm_cpu_cap_init_kvm_defined(CPUID_12_EAX,
+ kvm_cpu_cap_init(CPUID_12_EAX,
SF(SGX1) | SF(SGX2) | SF(SGX_EDECCSSA)
);

@@ -781,7 +767,7 @@ void kvm_set_cpu_caps(void)
if (!tdp_enabled && IS_ENABLED(CONFIG_X86_64))
kvm_cpu_cap_set(X86_FEATURE_GBPAGES);

- kvm_cpu_cap_init_kvm_defined(CPUID_8000_0007_EDX,
+ kvm_cpu_cap_init(CPUID_8000_0007_EDX,
SF(CONSTANT_TSC)
);

@@ -835,7 +821,7 @@ void kvm_set_cpu_caps(void)
kvm_cpu_cap_check_and_set(X86_FEATURE_IBPB_BRTYPE);
kvm_cpu_cap_check_and_set(X86_FEATURE_SRSO_NO);

- kvm_cpu_cap_init_kvm_defined(CPUID_8000_0022_EAX,
+ kvm_cpu_cap_init(CPUID_8000_0022_EAX,
F(PERFMON_V2)
);

--
2.45.0.215.g3402c0e53f-goog

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