KVM: arm64: Drop raz parameter from read_id_reg()

There is no longer a need for caller-specified RAZ visibility. Hoist the
call to sysreg_visible_as_raz() into read_id_reg() and drop the
parameter.

No functional change intended.
Suggested-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220913094441.3957645-4-oliver.upton@linux.dev

arch/arm64/kvm/sys_regs.c

@@ -1063,13 +1063,12 @@ static bool access_arch_timer(struct kvm_vcpu *vcpu,
 }
 
 /* Read a sanitised cpufeature ID register by sys_reg_desc */
-static u64 read_id_reg(const struct kvm_vcpu *vcpu,
-		struct sys_reg_desc const *r, bool raz)
+static u64 read_id_reg(const struct kvm_vcpu *vcpu, struct sys_reg_desc const *r)
 {
 	u32 id = reg_to_encoding(r);
 	u64 val;
 
-	if (raz)
+	if (sysreg_visible_as_raz(vcpu, r))
 		return 0;
 
 	val = read_sanitised_ftr_reg(id);
@@ -1157,12 +1156,10 @@ static bool access_id_reg(struct kvm_vcpu *vcpu,
 			  struct sys_reg_params *p,
 			  const struct sys_reg_desc *r)
 {
-	bool raz = sysreg_visible_as_raz(vcpu, r);
-
 	if (p->is_write)
 		return write_to_read_only(vcpu, p, r);
 
-	p->regval = read_id_reg(vcpu, r, raz);
+	p->regval = read_id_reg(vcpu, r);
 	return true;
 }
 
@@ -1199,7 +1196,7 @@ static int set_id_aa64pfr0_el1(struct kvm_vcpu *vcpu,
 		return -EINVAL;
 
 	/* We can only differ with CSV[23], and anything else is an error */
-	val ^= read_id_reg(vcpu, rd, false);
+	val ^= read_id_reg(vcpu, rd);
 	val &= ~((0xFUL << ID_AA64PFR0_CSV2_SHIFT) |
 		 (0xFUL << ID_AA64PFR0_CSV3_SHIFT));
 	if (val)
@@ -1221,19 +1218,15 @@ static int set_id_aa64pfr0_el1(struct kvm_vcpu *vcpu,
 static int get_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
 		      u64 *val)
 {
-	bool raz = sysreg_visible_as_raz(vcpu, rd);
-
-	*val = read_id_reg(vcpu, rd, raz);
+	*val = read_id_reg(vcpu, rd);
 	return 0;
 }
 
 static int set_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
 		      u64 val)
 {
-	bool raz = sysreg_visible_as_raz(vcpu, rd);
-
 	/* This is what we mean by invariant: you can't change it. */
-	if (val != read_id_reg(vcpu, rd, raz))
+	if (val != read_id_reg(vcpu, rd))
 		return -EINVAL;
 
 	return 0;