[PATCH v4 2/8] KVM: x86: Fill apic_lvt_mask with enums / explicit entries.

[Jue Wang <juew@google.com>]

To implement Corrected Machine Check Interrupt (CMCI) as an additional
LVT vector, the apic_lvt_mask array needs to handle LVT_CMCI
transparently when LVT_CMCI is added.

This patch defines a lapic_lvt_entry enum and use its elements as
explicit indices to the apic_lvt_mask array, naturally extensible to
support an additional LVT_CMCI enum hence apic_lvt_mask element in the
future.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Jue Wang <juew@google.com>
---
 arch/x86/kvm/lapic.c | 19 ++++++++++---------
 arch/x86/kvm/lapic.h | 12 +++++++++++-
 2 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index a5caa77e279f..73f5cd248a63 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -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 | ((KVM_APIC_LVT_NUM - 1) << 16);
+	u32 v = APIC_VERSION | ((KVM_APIC_MAX_NR_LVT_ENTRIES - 1) << 16);
 
 	if (!lapic_in_kernel(vcpu))
 		return;
@@ -419,12 +419,13 @@ void kvm_apic_set_version(struct kvm_vcpu *vcpu)
 	kvm_lapic_set_reg(apic, APIC_LVR, v);
 }
 
-static const unsigned int apic_lvt_mask[KVM_APIC_LVT_NUM] = {
-	LVT_MASK ,      /* part LVTT mask, timer mode mask added at runtime */
-	LVT_MASK | APIC_MODE_MASK,	/* LVTTHMR */
-	LVT_MASK | APIC_MODE_MASK,	/* LVTPC */
-	LINT_MASK, LINT_MASK,	/* LVT0-1 */
-	LVT_MASK		/* LVTERR */
+static const unsigned int apic_lvt_mask[KVM_APIC_MAX_NR_LVT_ENTRIES] = {
+	[LVT_TIMER] = LVT_MASK,      /* timer mode mask added at runtime */
+	[LVT_THERMAL_MONITOR] = LVT_MASK | APIC_MODE_MASK,
+	[LVT_PERFORMANCE_COUNTER] = LVT_MASK | APIC_MODE_MASK,
+	[LVT_LINT0] = LINT_MASK,
+	[LVT_LINT1] = LINT_MASK,
+	[LVT_ERROR] = LVT_MASK
 };
 
 static int find_highest_vector(void *bitmap)
@@ -2084,7 +2085,7 @@ static int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val)
 			int i;
 			u32 lvt_val;
 
-			for (i = 0; i < KVM_APIC_LVT_NUM; i++) {
+			for (i = 0; i < KVM_APIC_MAX_NR_LVT_ENTRIES; i++) {
 				lvt_val = kvm_lapic_get_reg(apic,
 						       APIC_LVTT + 0x10 * i);
 				kvm_lapic_set_reg(apic, APIC_LVTT + 0x10 * i,
@@ -2383,7 +2384,7 @@ void kvm_lapic_reset(struct kvm_vcpu *vcpu, bool init_event)
 		kvm_apic_set_xapic_id(apic, vcpu->vcpu_id);
 	kvm_apic_set_version(apic->vcpu);
 
-	for (i = 0; i < KVM_APIC_LVT_NUM; i++)
+	for (i = 0; i < KVM_APIC_MAX_NR_LVT_ENTRIES; i++)
 		kvm_lapic_set_reg(apic, APIC_LVTT + 0x10 * i, APIC_LVT_MASKED);
 	apic_update_lvtt(apic);
 	if (kvm_vcpu_is_reset_bsp(vcpu) &&
diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
index 4e4f8a22754f..4990793c2034 100644
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -10,7 +10,6 @@
 
 #define KVM_APIC_INIT		0
 #define KVM_APIC_SIPI		1
-#define KVM_APIC_LVT_NUM	6
 
 #define APIC_SHORT_MASK			0xc0000
 #define APIC_DEST_NOSHORT		0x0
@@ -29,6 +28,17 @@ enum lapic_mode {
 	LAPIC_MODE_X2APIC = MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE,
 };
 
+enum lapic_lvt_entry {
+	LVT_TIMER,
+	LVT_THERMAL_MONITOR,
+	LVT_PERFORMANCE_COUNTER,
+	LVT_LINT0,
+	LVT_LINT1,
+	LVT_ERROR,
+
+	KVM_APIC_MAX_NR_LVT_ENTRIES,
+};
+
 struct kvm_timer {
 	struct hrtimer timer;
 	s64 period; 				/* unit: ns */
-- 
2.36.1.124.g0e6072fb45-goog