Merge branch kvm-arm64/raz-sysregs into kvmarm-master/next

* kvm-arm64/raz-sysregs:
  : .
  : Simplify the handling of RAZ register, removing pointless indirections.
  : .
  KVM: arm64: Replace get_raz_id_reg() with get_raz_reg()
  KVM: arm64: Use get_raz_reg() for userspace reads of PMSWINC_EL0
  KVM: arm64: Return early from read_id_reg() if register is RAZ

Signed-off-by: Marc Zyngier <maz@kernel.org>

arch/arm64/kvm/sys_regs.c

@@ -1064,7 +1064,12 @@ static u64 read_id_reg(const struct kvm_vcpu *vcpu,
 		struct sys_reg_desc const *r, bool raz)
 {
 	u32 id = reg_to_encoding(r);
-	u64 val = raz ? 0 : read_sanitised_ftr_reg(id);
+	u64 val;
+
+	if (raz)
+		return 0;
+
+	val = read_sanitised_ftr_reg(id);
 
 	switch (id) {
 	case SYS_ID_AA64PFR0_EL1:
@@ -1268,18 +1273,21 @@ static int set_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
 	return __set_id_reg(vcpu, rd, uaddr, raz);
 }
 
-static int get_raz_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
-			  const struct kvm_one_reg *reg, void __user *uaddr)
-{
-	return __get_id_reg(vcpu, rd, uaddr, true);
-}
-
 static int set_raz_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
 			  const struct kvm_one_reg *reg, void __user *uaddr)
 {
 	return __set_id_reg(vcpu, rd, uaddr, true);
 }
 
+static int get_raz_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
+		       const struct kvm_one_reg *reg, void __user *uaddr)
+{
+	const u64 id = sys_reg_to_index(rd);
+	const u64 val = 0;
+
+	return reg_to_user(uaddr, &val, id);
+}
+
 static int set_wi_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
 		      const struct kvm_one_reg *reg, void __user *uaddr)
 {
@@ -1388,7 +1396,7 @@ static unsigned int mte_visibility(const struct kvm_vcpu *vcpu,
 #define ID_UNALLOCATED(crm, op2) {			\
 	Op0(3), Op1(0), CRn(0), CRm(crm), Op2(op2),	\
 	.access = access_raz_id_reg,			\
-	.get_user = get_raz_id_reg,			\
+	.get_user = get_raz_reg,			\
 	.set_user = set_raz_id_reg,			\
 }
 
@@ -1400,7 +1408,7 @@ static unsigned int mte_visibility(const struct kvm_vcpu *vcpu,
 #define ID_HIDDEN(name) {			\
 	SYS_DESC(SYS_##name),			\
 	.access = access_raz_id_reg,		\
-	.get_user = get_raz_id_reg,		\
+	.get_user = get_raz_reg,		\
 	.set_user = set_raz_id_reg,		\
 }
 
@@ -1642,7 +1650,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 	 * previously (and pointlessly) advertised in the past...
 	 */
 	{ PMU_SYS_REG(SYS_PMSWINC_EL0),
-	  .get_user = get_raz_id_reg, .set_user = set_wi_reg,
+	  .get_user = get_raz_reg, .set_user = set_wi_reg,
 	  .access = access_pmswinc, .reset = NULL },
 	{ PMU_SYS_REG(SYS_PMSELR_EL0),
 	  .access = access_pmselr, .reset = reset_pmselr, .reg = PMSELR_EL0 },