KVM: arm64: Enforce absence of FEAT_TCR2 on TCR2_EL2

Enforce that TCR2_EL2 are RES0 when FEAT_TCR2 isn't present.

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>

Author: Marc Zyngier

arch/arm64/kvm/config.c

@@ -1051,6 +1051,9 @@ static const struct reg_bits_to_feat_map tcr2_el2_feat_map[] = {
 	NEEDS_FEAT(TCR2_EL2_PIE, FEAT_S1PIE),
 };
 
+static const DECLARE_FEAT_MAP(tcr2_el2_desc, TCR2_EL2,
+			      tcr2_el2_feat_map, FEAT_TCR2);
+
 static const struct reg_bits_to_feat_map sctlr_el1_feat_map[] = {
 	NEEDS_FEAT(SCTLR_EL1_CP15BEN	|
 		   SCTLR_EL1_ITD	|
@@ -1196,8 +1199,7 @@ void __init check_feature_map(void)
 	check_reg_desc(&hcrx_desc);
 	check_reg_desc(&hcr_desc);
 	check_reg_desc(&sctlr2_desc);
-	check_feat_map(tcr2_el2_feat_map, ARRAY_SIZE(tcr2_el2_feat_map),
-		       TCR2_EL2_RES0, "TCR2_EL2");
+	check_reg_desc(&tcr2_el2_desc);
 	check_feat_map(sctlr_el1_feat_map, ARRAY_SIZE(sctlr_el1_feat_map),
 		       SCTLR_EL1_RES0, "SCTLR_EL1");
 	check_feat_map(mdcr_el2_feat_map, ARRAY_SIZE(mdcr_el2_feat_map),
@@ -1405,9 +1407,7 @@ void get_reg_fixed_bits(struct kvm *kvm, enum vcpu_sysreg reg, u64 *res0, u64 *r
 		*res1 = SCTLR2_EL1_RES1;
 		break;
 	case TCR2_EL2:
-		*res0 = compute_res0_bits(kvm, tcr2_el2_feat_map,
-					  ARRAY_SIZE(tcr2_el2_feat_map), 0, 0);
-		*res0 |= TCR2_EL2_RES0;
+		*res0 = compute_reg_res0_bits(kvm, &tcr2_el2_desc, 0, 0);
 		*res1 = TCR2_EL2_RES1;
 		break;
 	case SCTLR_EL1: