[PATCH v1 3/4] KVM: arm64: Convert KVM_ARM_VCPU_* features into an enum

[Fuad Tabba <tabba@google.com>]

Instead of using compile time defines, convert the KVM_ARM_VCPU_*
features into an enum. Among other things, this reduces the
chances of missing to update KVM_ARM_VCPU_MAX_FEATURES.

Also rename KVM_VCPU_MAX_FEATURES and KVM_ARM_VCPU_VALID_FEATURES
to KVM_ARM_VCPU_MAX_FEATURES and KVM_ARM_VCPU_VALID_FEATURES in
order to match the features they're counting.

No functional change intended.

Signed-off-by: Fuad Tabba <tabba@google.com>
---
 arch/arm64/include/asm/kvm_host.h |  2 +-
 arch/arm64/include/uapi/asm/kvm.h | 25 ++++++++++++++-----------
 arch/arm64/kvm/arm.c              | 10 +++++-----
 3 files changed, 20 insertions(+), 17 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 85901afeb332..9b7bf4ba07a3 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -326,7 +326,7 @@ struct kvm_arch {
 	unsigned long flags;
 
 	/* VM-wide vCPU feature set */
-	DECLARE_BITMAP(vcpu_features, KVM_VCPU_MAX_FEATURES);
+	DECLARE_BITMAP(vcpu_features, KVM_ARM_VCPU_MAX_FEATURES);
 
 	/* MPIDR to vcpu index mapping, optional */
 	struct kvm_mpidr_data *mpidr_data;
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index 2d5fd0ed7dff..b6ebd79b8373 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -100,17 +100,20 @@ struct kvm_regs {
 #define KVM_VGIC_V3_REDIST_SIZE		(2 * SZ_64K)
 #define KVM_VGIC_V3_ITS_SIZE		(2 * SZ_64K)
 
-#define KVM_ARM_VCPU_POWER_OFF		0 /* CPU is started in OFF state */
-#define KVM_ARM_VCPU_EL1_32BIT		1 /* CPU running a 32bit VM */
-#define KVM_ARM_VCPU_PSCI_0_2		2 /* CPU uses PSCI v0.2 */
-#define KVM_ARM_VCPU_PMU_V3		3 /* Support guest PMUv3 */
-#define KVM_ARM_VCPU_SVE		4 /* enable SVE for this CPU */
-#define KVM_ARM_VCPU_PTRAUTH_ADDRESS	5 /* VCPU uses address authentication */
-#define KVM_ARM_VCPU_PTRAUTH_GENERIC	6 /* VCPU uses generic authentication */
-#define KVM_ARM_VCPU_HAS_EL2		7 /* Support nested virtualization */
-
-#define KVM_VCPU_MAX_FEATURES 8
-#define KVM_VCPU_VALID_FEATURES	(BIT(KVM_VCPU_MAX_FEATURES) - 1)
+enum kvm_arm_vcpu_features {
+	KVM_ARM_VCPU_POWER_OFF = 0,	/* CPU is started in OFF state */
+	KVM_ARM_VCPU_EL1_32BIT,		/* CPU running a 32bit VM */
+	KVM_ARM_VCPU_PSCI_0_2,		/* CPU uses PSCI v0.2 */
+	KVM_ARM_VCPU_PMU_V3,		/* Support guest PMUv3 */
+	KVM_ARM_VCPU_SVE,		/* enable SVE for this CPU */
+	KVM_ARM_VCPU_PTRAUTH_ADDRESS,	/* VCPU uses address authentication */
+	KVM_ARM_VCPU_PTRAUTH_GENERIC,	/* VCPU uses generic authentication */
+	KVM_ARM_VCPU_HAS_EL2,		/* Support nested virtualization */
+
+	KVM_ARM_VCPU_MAX_FEATURES,	/* Must be last */
+};
+
+#define KVM_ARM_VCPU_VALID_FEATURES	(BIT(KVM_ARM_VCPU_MAX_FEATURES) - 1)
 
 struct kvm_vcpu_init {
 	__u32 target;
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index a0d01c46e408..df17d50887d6 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -211,7 +211,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 
 	kvm_arm_init_hypercalls(kvm);
 
-	bitmap_zero(kvm->arch.vcpu_features, KVM_VCPU_MAX_FEATURES);
+	bitmap_zero(kvm->arch.vcpu_features, KVM_ARM_VCPU_MAX_FEATURES);
 
 	return 0;
 
@@ -1407,7 +1407,7 @@ int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level,
 
 static unsigned long system_supported_vcpu_features(void)
 {
-	unsigned long features = KVM_VCPU_VALID_FEATURES;
+	unsigned long features = KVM_ARM_VCPU_VALID_FEATURES;
 
 	if (!cpus_have_final_cap(ARM64_HAS_32BIT_EL1))
 		clear_bit(KVM_ARM_VCPU_EL1_32BIT, &features);
@@ -1435,7 +1435,7 @@ static int kvm_vcpu_init_check_features(struct kvm_vcpu *vcpu,
 	unsigned long features = init->features[0];
 	int i;
 
-	if (features & ~KVM_VCPU_VALID_FEATURES)
+	if (features & ~KVM_ARM_VCPU_VALID_FEATURES)
 		return -ENOENT;
 
 	for (i = 1; i < ARRAY_SIZE(init->features); i++) {
@@ -1474,7 +1474,7 @@ static bool kvm_vcpu_init_changed(struct kvm_vcpu *vcpu,
 	unsigned long features = init->features[0];
 
 	return !bitmap_equal(vcpu->kvm->arch.vcpu_features, &features,
-			     KVM_VCPU_MAX_FEATURES);
+			     KVM_ARM_VCPU_MAX_FEATURES);
 }
 
 static int kvm_setup_vcpu(struct kvm_vcpu *vcpu)
@@ -1509,7 +1509,7 @@ static int __kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
 	    kvm_vcpu_init_changed(vcpu, init))
 		goto out_unlock;
 
-	bitmap_copy(kvm->arch.vcpu_features, &features, KVM_VCPU_MAX_FEATURES);
+	bitmap_copy(kvm->arch.vcpu_features, &features, KVM_ARM_VCPU_MAX_FEATURES);
 
 	ret = kvm_setup_vcpu(vcpu);
 	if (ret)
-- 
2.47.0.rc1.288.g06298d1525-goog