[PATCH v2 02/20] KVM: arm64: Reorder handling of invariant sysregs from userspace

[Marc Zyngier]

In order to allow some further refactor of the sysreg helpers,
move the handling of invariant sysreg to occur before we handle
all the other ones.

Reviewed-by: Reiji Watanabe <reijiw at google.com>
Signed-off-by: Marc Zyngier <maz at kernel.org>
---
 arch/arm64/kvm/sys_regs.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 1f410283c592..9291cb94c2e4 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -2849,6 +2849,7 @@ int kvm_arm_sys_reg_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg
 {
 	const struct sys_reg_desc *r;
 	void __user *uaddr = (void __user *)(unsigned long)reg->addr;
+	int err;
 
 	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX)
 		return demux_c15_get(reg->id, uaddr);
@@ -2856,12 +2857,14 @@ int kvm_arm_sys_reg_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg
 	if (KVM_REG_SIZE(reg->id) != sizeof(__u64))
 		return -ENOENT;
 
+	err = get_invariant_sys_reg(reg->id, uaddr);
+	if (err != -ENOENT)
+		return err;
+
 	r = index_to_sys_reg_desc(vcpu, reg->id);
-	if (!r)
-		return get_invariant_sys_reg(reg->id, uaddr);
 
 	/* Check for regs disabled by runtime config */
-	if (sysreg_hidden(vcpu, r))
+	if (!r || sysreg_hidden(vcpu, r))
 		return -ENOENT;
 
 	if (r->get_user)
@@ -2874,6 +2877,7 @@ int kvm_arm_sys_reg_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg
 {
 	const struct sys_reg_desc *r;
 	void __user *uaddr = (void __user *)(unsigned long)reg->addr;
+	int err;
 
 	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX)
 		return demux_c15_set(reg->id, uaddr);
@@ -2881,12 +2885,14 @@ int kvm_arm_sys_reg_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg
 	if (KVM_REG_SIZE(reg->id) != sizeof(__u64))
 		return -ENOENT;
 
+	err = set_invariant_sys_reg(reg->id, uaddr);
+	if (err != -ENOENT)
+		return err;
+
 	r = index_to_sys_reg_desc(vcpu, reg->id);
-	if (!r)
-		return set_invariant_sys_reg(reg->id, uaddr);
 
 	/* Check for regs disabled by runtime config */
-	if (sysreg_hidden(vcpu, r))
+	if (!r || sysreg_hidden(vcpu, r))
 		return -ENOENT;
 
 	if (r->set_user)
-- 
2.34.1