KVM: arm64: Consolidate REG_HIDDEN_GUEST/USER

REG_HIDDEN_GUEST and REG_HIDDEN_USER are always used together.
Consolidate them into a single REG_HIDDEN flag. We can always
add another flag later if some register needs to expose itself
differently to the guest than it does to userspace.

No functional change intended.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201105091022.15373-3-drjones@redhat.com

Author: Andrew Jones

arch/arm64/kvm/sys_regs.c

@@ -1069,7 +1069,7 @@ static bool trap_ptrauth(struct kvm_vcpu *vcpu,
 static unsigned int ptrauth_visibility(const struct kvm_vcpu *vcpu,
 			const struct sys_reg_desc *rd)
 {
-	return vcpu_has_ptrauth(vcpu) ? 0 : REG_HIDDEN_USER | REG_HIDDEN_GUEST;
+	return vcpu_has_ptrauth(vcpu) ? 0 : REG_HIDDEN;
 }
 
 #define __PTRAUTH_KEY(k)						\
@@ -1190,7 +1190,7 @@ static unsigned int sve_visibility(const struct kvm_vcpu *vcpu,
 	if (vcpu_has_sve(vcpu))
 		return 0;
 
-	return REG_HIDDEN_USER | REG_HIDDEN_GUEST;
+	return REG_HIDDEN;
 }
 
 /* Generate the emulated ID_AA64ZFR0_EL1 value exposed to the guest */
@@ -2153,7 +2153,7 @@ static void perform_access(struct kvm_vcpu *vcpu,
 	trace_kvm_sys_access(*vcpu_pc(vcpu), params, r);
 
 	/* Check for regs disabled by runtime config */
-	if (sysreg_hidden_from_guest(vcpu, r)) {
+	if (sysreg_hidden(vcpu, r)) {
 		kvm_inject_undefined(vcpu);
 		return;
 	}
@@ -2652,7 +2652,7 @@ int kvm_arm_sys_reg_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg
 		return get_invariant_sys_reg(reg->id, uaddr);
 
 	/* Check for regs disabled by runtime config */
-	if (sysreg_hidden_from_user(vcpu, r))
+	if (sysreg_hidden(vcpu, r))
 		return -ENOENT;
 
 	if (r->get_user)
@@ -2677,7 +2677,7 @@ int kvm_arm_sys_reg_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg
 		return set_invariant_sys_reg(reg->id, uaddr);
 
 	/* Check for regs disabled by runtime config */
-	if (sysreg_hidden_from_user(vcpu, r))
+	if (sysreg_hidden(vcpu, r))
 		return -ENOENT;
 
 	if (r->set_user)
@@ -2748,7 +2748,7 @@ static int walk_one_sys_reg(const struct kvm_vcpu *vcpu,
 	if (!(rd->reg || rd->get_user))
 		return 0;
 
-	if (sysreg_hidden_from_user(vcpu, rd))
+	if (sysreg_hidden(vcpu, rd))
 		return 0;
 
 	if (!copy_reg_to_user(rd, uind))

arch/arm64/kvm/sys_regs.h

@@ -59,8 +59,7 @@ struct sys_reg_desc {
 				   const struct sys_reg_desc *rd);
 };
 
-#define REG_HIDDEN_USER		(1 << 0) /* hidden from userspace ioctls */
-#define REG_HIDDEN_GUEST	(1 << 1) /* hidden from guest */
+#define REG_HIDDEN		(1 << 0) /* hidden from userspace and guest */
 
 static __printf(2, 3)
 inline void print_sys_reg_msg(const struct sys_reg_params *p,
@@ -111,22 +110,13 @@ static inline void reset_val(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r
 	__vcpu_sys_reg(vcpu, r->reg) = r->val;
 }
 
-static inline bool sysreg_hidden_from_guest(const struct kvm_vcpu *vcpu,
-					    const struct sys_reg_desc *r)
-{
-	if (likely(!r->visibility))
-		return false;
-
-	return r->visibility(vcpu, r) & REG_HIDDEN_GUEST;
-}
-
-static inline bool sysreg_hidden_from_user(const struct kvm_vcpu *vcpu,
-					   const struct sys_reg_desc *r)
+static inline bool sysreg_hidden(const struct kvm_vcpu *vcpu,
+				 const struct sys_reg_desc *r)
 {
 	if (likely(!r->visibility))
 		return false;
 
-	return r->visibility(vcpu, r) & REG_HIDDEN_USER;
+	return r->visibility(vcpu, r) & REG_HIDDEN;
 }
 
 static inline int cmp_sys_reg(const struct sys_reg_desc *i1,