[PATCH v2 2/2] KVM: arm64: Factor out KVM_GET_REG_LIST core register enumeration

[Dave Martin <Dave.Martin@xxxxxxx>]

Currently, enumeration of the core register IDs for
KVM_GET_REG_LIST is open-coded in kvm_arm_copy_reg_indices().

This will become cumbersome as the enumeration logic becomes more
complex.  In preparation for future patches, this patch factors the
code out into a separate function copy_core_reg_indices(),
consistently with the way other classes of registers are handled.

No functional change.

Signed-off-by: Dave Martin <Dave.Martin@xxxxxxx>
---
 arch/arm64/kvm/guest.c | 65 ++++++++++++++++++++++++++------------------------
 1 file changed, 34 insertions(+), 31 deletions(-)

diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index cbe423b..46eb867 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -205,23 +205,53 @@ int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
 	return -EINVAL;
 }
 
-static unsigned long num_core_regs(void)
+static int copy_core_reg_indices(u64 __user **uind)
 {
 	unsigned int i;
 	int n = 0;
 
 	for (i = 0; i < sizeof(struct kvm_regs) / sizeof(__u32); i++) {
+		u64 reg = KVM_REG_ARM64 | KVM_REG_ARM_CORE | i;
 		int size = core_reg_size_from_offset(i);
 
 		if (size < 0)
 			continue;
 
+		switch (size) {
+		case sizeof(__u32):
+			reg |= KVM_REG_SIZE_U32;
+			break;
+
+		case sizeof(__u64):
+			reg |= KVM_REG_SIZE_U64;
+			break;
+
+		case sizeof(__uint128_t):
+			reg |= KVM_REG_SIZE_U128;
+			break;
+
+		default:
+			WARN_ON(1);
+			continue;
+		}
+
+		if (uind) {
+			if (put_user(reg, *uind))
+				return -EFAULT;
+			++*uind;
+		}
+
 		n++;
 	}
 
 	return n;
 }
 
+static unsigned long num_core_regs(void)
+{
+	return copy_core_reg_indices(NULL);
+}
+
 /**
  * ARM64 versions of the TIMER registers, always available on arm64
  */
@@ -293,38 +323,11 @@ unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu)
  */
 int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
 {
-	unsigned int i;
 	int ret;
 
-	for (i = 0; i < sizeof(struct kvm_regs) / sizeof(__u32); i++) {
-		u64 reg = KVM_REG_ARM64 | KVM_REG_ARM_CORE | i;
-		int size = core_reg_size_from_offset(i);
-
-		if (size < 0)
-			continue;
-
-		switch (size) {
-		case sizeof(__u32):
-			reg |= KVM_REG_SIZE_U32;
-			break;
-
-		case sizeof(__u64):
-			reg |= KVM_REG_SIZE_U64;
-			break;
-
-		case sizeof(__uint128_t):
-			reg |= KVM_REG_SIZE_U128;
-			break;
-
-		default:
-			WARN_ON(1);
-			continue;
-		}
-
-		if (put_user(reg, uindices))
-			return -EFAULT;
-		uindices++;
-	}
+	ret = copy_core_reg_indices(&uindices);
+	if (ret < 0)
+		return ret;
 
 	ret = kvm_arm_copy_fw_reg_indices(vcpu, uindices);
 	if (ret)
-- 
2.1.4

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