[PATCH v4 1/8] KVM: x86: Make APIC_VERSION capture only the magic 0x14UL.

[Jue Wang <juew@google.com>]

To implement Corrected Machine Check Interrupt (CMCI) as another
LVT vector, the APIC LVT logic needs to be able to handle an additional
LVT vector conditioned on whether MCG_CMCI_P is enabled on the vCPU,
this is because CMCI signaling can only be enabled when the CPU's
MCG_CMCI_P bit is set (Intel SDM, section 15.3.1.1).

This patch factors out the dependency on KVM_APIC_LVT_NUM from the
APIC_VERSION macro. In later patches, KVM_APIC_LVT_NUM will be replaced
with a helper kvm_apic_get_nr_lvt_entries that reports different LVT
number conditioned on whether MCG_CMCI_P is enabled on the vCPU.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Jue Wang <juew@google.com>
---
 arch/x86/kvm/lapic.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 66b0eb0bda94..a5caa77e279f 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -54,7 +54,7 @@
 #define PRIo64 "o"
 
 /* 14 is the version for Xeon and Pentium 8.4.8*/
-#define APIC_VERSION			(0x14UL | ((KVM_APIC_LVT_NUM - 1) << 16))
+#define APIC_VERSION			0x14UL
 #define LAPIC_MMIO_LENGTH		(1 << 12)
 /* followed define is not in apicdef.h */
 #define MAX_APIC_VECTOR			256
@@ -401,7 +401,7 @@ static inline int apic_lvt_nmi_mode(u32 lvt_val)
 void kvm_apic_set_version(struct kvm_vcpu *vcpu)
 {
 	struct kvm_lapic *apic = vcpu->arch.apic;
-	u32 v = APIC_VERSION;
+	u32 v = APIC_VERSION | ((KVM_APIC_LVT_NUM - 1) << 16);
 
 	if (!lapic_in_kernel(vcpu))
 		return;
-- 
2.36.1.124.g0e6072fb45-goog