[PATCH v2 1/7] kvm: x86: Extract kvm_apic_base_update_cpuid() from kvm_update_cpuid_runtime()

[Robert Hoo <robert.hu@xxxxxxxxxxxxxxx>]

And let kvm_lapic_set_base() call kvm_apic_base_update_cpuid() instead of
whole kvm_update_cpuid_runtime().

Signed-off-by: Robert Hoo <robert.hu@xxxxxxxxxxxxxxx>
---
 arch/x86/kvm/cpuid.c | 14 ++++++++++++++
 arch/x86/kvm/cpuid.h |  1 +
 arch/x86/kvm/lapic.c |  2 +-
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 3fd6eec..b6dd4ee 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -73,6 +73,20 @@ static int kvm_check_cpuid(struct kvm_vcpu *vcpu)
 	return 0;
 }
 
+static inline void guest_cpuid_change(struct kvm_vcpu *vcpu, u32 function,
+					    u32 index, unsigned int feature, bool set)
+{
+	struct kvm_cpuid_entry2 *e =  kvm_find_cpuid_entry(vcpu, function, index);
+
+	if (e)
+		cpuid_entry_change(e, feature, set);
+}
+
+void kvm_apic_base_update_cpuid(struct kvm_vcpu *vcpu, bool set)
+{
+	guest_cpuid_change(vcpu, 1, 0, X86_FEATURE_APIC, set);
+}
+
 void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu)
 {
 	struct kvm_cpuid_entry2 *best;
diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h
index 3a923ae..ef4cb9c 100644
--- a/arch/x86/kvm/cpuid.h
+++ b/arch/x86/kvm/cpuid.h
@@ -9,6 +9,7 @@
 extern u32 kvm_cpu_caps[NCAPINTS] __read_mostly;
 void kvm_set_cpu_caps(void);
 
+void kvm_apic_base_update_cpuid(struct kvm_vcpu *vcpu, bool set);
 void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu);
 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
 					      u32 function, u32 index);
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 5ccbee7..5221b89 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -2231,7 +2231,7 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value)
 	vcpu->arch.apic_base = value;
 
 	if ((old_value ^ value) & MSR_IA32_APICBASE_ENABLE)
-		kvm_update_cpuid_runtime(vcpu);
+		kvm_apic_base_update_cpuid(vcpu, !!(value & MSR_IA32_APICBASE_ENABLE));
 
 	if (!apic)
 		return;
-- 
1.8.3.1