[PATCH 2/8] KVM: arm64: Enforce absence of FEAT_FGT2 on FGT2 registers

Marc Zyngier maz at kernel.org
Wed Sep 17 09:58:34 PDT 2025


Signed-off-by: Marc Zyngier <maz at kernel.org>
---
 arch/arm64/kvm/config.c | 86 ++++++++++++++++++++++++-----------------
 1 file changed, 51 insertions(+), 35 deletions(-)

diff --git a/arch/arm64/kvm/config.c b/arch/arm64/kvm/config.c
index 42b834c82a20d..05be2b917c8c0 100644
--- a/arch/arm64/kvm/config.c
+++ b/arch/arm64/kvm/config.c
@@ -185,6 +185,7 @@ struct reg_to_feat_map {
 #define FEAT_SSBS		ID_AA64PFR1_EL1, SSBS, IMP
 #define FEAT_TIDCP1		ID_AA64MMFR1_EL1, TIDCP1, IMP
 #define FEAT_FGT		ID_AA64MMFR0_EL1, FGT, IMP
+#define FEAT_FGT2		ID_AA64MMFR0_EL1, FGT, FGT2
 #define FEAT_MTPMU		ID_AA64DFR0_EL1, MTPMU, IMP
 
 static bool not_feat_aa64el3(struct kvm *kvm)
@@ -767,12 +768,17 @@ struct reg_to_feat_map hafgrtr_feat_map = FEAT_MAP_FGT(hafgrtr_masks,
 						       hafgrtr_bit_feat_map,
 						       FEAT_FGT);
 
-static const struct reg_bits_to_feat_map hfgitr2_feat_map[] = {
+static const struct reg_bits_to_feat_map hfgitr2_bit_feat_map[] = {
 	NEEDS_FEAT(HFGITR2_EL2_nDCCIVAPS, FEAT_PoPS),
 	NEEDS_FEAT(HFGITR2_EL2_TSBCSYNC, FEAT_TRBEv1p1)
 };
 
-static const struct reg_bits_to_feat_map hfgrtr2_feat_map[] = {
+static const
+struct reg_to_feat_map hfgitr2_feat_map = FEAT_MAP_FGT(hfgitr2_masks,
+						       hfgitr2_bit_feat_map,
+						       FEAT_FGT2);
+
+static const struct reg_bits_to_feat_map hfgrtr2_bit_feat_map[] = {
 	NEEDS_FEAT(HFGRTR2_EL2_nPFAR_EL1, FEAT_PFAR),
 	NEEDS_FEAT(HFGRTR2_EL2_nERXGSR_EL1, FEAT_RASv2),
 	NEEDS_FEAT(HFGRTR2_EL2_nACTLRALIAS_EL1	|
@@ -791,7 +797,12 @@ static const struct reg_bits_to_feat_map hfgrtr2_feat_map[] = {
 	NEEDS_FEAT(HFGRTR2_EL2_nRCWSMASK_EL1, FEAT_THE),
 };
 
-static const struct reg_bits_to_feat_map hfgwtr2_feat_map[] = {
+static const
+struct reg_to_feat_map hfgrtr2_feat_map = FEAT_MAP_FGT(hfgrtr2_masks,
+						       hfgrtr2_bit_feat_map,
+						       FEAT_FGT2);
+
+static const struct reg_bits_to_feat_map hfgwtr2_bit_feat_map[] = {
 	NEEDS_FEAT(HFGWTR2_EL2_nPFAR_EL1, FEAT_PFAR),
 	NEEDS_FEAT(HFGWTR2_EL2_nACTLRALIAS_EL1	|
 		   HFGWTR2_EL2_nACTLRMASK_EL1	|
@@ -809,7 +820,12 @@ static const struct reg_bits_to_feat_map hfgwtr2_feat_map[] = {
 	NEEDS_FEAT(HFGWTR2_EL2_nRCWSMASK_EL1, FEAT_THE),
 };
 
-static const struct reg_bits_to_feat_map hdfgrtr2_feat_map[] = {
+static const
+struct reg_to_feat_map hfgwtr2_feat_map = FEAT_MAP_FGT(hfgwtr2_masks,
+						       hfgwtr2_bit_feat_map,
+						       FEAT_FGT2);
+
+static const struct reg_bits_to_feat_map hdfgrtr2_bit_feat_map[] = {
 	NEEDS_FEAT(HDFGRTR2_EL2_nMDSELR_EL1, FEAT_Debugv8p9),
 	NEEDS_FEAT(HDFGRTR2_EL2_nPMECR_EL1, feat_ebep_pmuv3_ss),
 	NEEDS_FEAT(HDFGRTR2_EL2_nTRCITECR_EL1, FEAT_ITE),
@@ -839,7 +855,12 @@ static const struct reg_bits_to_feat_map hdfgrtr2_feat_map[] = {
 	NEEDS_FEAT(HDFGRTR2_EL2_nTRBMPAM_EL1, feat_trbe_mpam),
 };
 
-static const struct reg_bits_to_feat_map hdfgwtr2_feat_map[] = {
+static const
+struct reg_to_feat_map hdfgrtr2_feat_map = FEAT_MAP_FGT(hdfgrtr2_masks,
+							hdfgrtr2_bit_feat_map,
+							FEAT_FGT2);
+
+static const struct reg_bits_to_feat_map hdfgwtr2_bit_feat_map[] = {
 	NEEDS_FEAT(HDFGWTR2_EL2_nMDSELR_EL1, FEAT_Debugv8p9),
 	NEEDS_FEAT(HDFGWTR2_EL2_nPMECR_EL1, feat_ebep_pmuv3_ss),
 	NEEDS_FEAT(HDFGWTR2_EL2_nTRCITECR_EL1, FEAT_ITE),
@@ -867,6 +888,11 @@ static const struct reg_bits_to_feat_map hdfgwtr2_feat_map[] = {
 	NEEDS_FEAT(HDFGWTR2_EL2_nTRBMPAM_EL1, feat_trbe_mpam),
 };
 
+static const
+struct reg_to_feat_map hdfgwtr2_feat_map = FEAT_MAP_FGT(hdfgwtr2_masks,
+							hdfgwtr2_bit_feat_map,
+							FEAT_FGT2);
+
 static const struct reg_bits_to_feat_map hcrx_feat_map[] = {
 	NEEDS_FEAT(HCRX_EL2_PACMEn, feat_pauth_lr),
 	NEEDS_FEAT(HCRX_EL2_EnFPM, FEAT_FPMR),
@@ -1143,6 +1169,11 @@ void __init check_feature_map(void)
 	check_reg_feat_map(&hdfgrtr_feat_map);
 	check_reg_feat_map(&hdfgwtr_feat_map);
 	check_reg_feat_map(&hafgrtr_feat_map);
+	check_reg_feat_map(&hfgrtr2_feat_map);
+	check_reg_feat_map(&hfgwtr2_feat_map);
+	check_reg_feat_map(&hfgitr2_feat_map);
+	check_reg_feat_map(&hdfgrtr2_feat_map);
+	check_reg_feat_map(&hdfgwtr2_feat_map);
 	check_feat_map(hcrx_feat_map, ARRAY_SIZE(hcrx_feat_map),
 		       __HCRX_EL2_RES0, "HCRX_EL2");
 	check_feat_map(hcr_feat_map, ARRAY_SIZE(hcr_feat_map),
@@ -1273,25 +1304,20 @@ void compute_fgu(struct kvm *kvm, enum fgt_group_id fgt)
 					     0, NEVER_FGU);
 		break;
 	case HFGRTR2_GROUP:
-		val |= compute_res0_bits(kvm, hfgrtr2_feat_map,
-					 ARRAY_SIZE(hfgrtr2_feat_map),
-					 0, NEVER_FGU);
-		val |= compute_res0_bits(kvm, hfgwtr2_feat_map,
-					 ARRAY_SIZE(hfgwtr2_feat_map),
-					 0, NEVER_FGU);
+		val |= compute_reg_res0_bits(kvm, &hfgrtr2_feat_map,
+					     0, NEVER_FGU);
+		val |= compute_reg_res0_bits(kvm, &hfgwtr2_feat_map,
+					     0, NEVER_FGU);
 		break;
 	case HFGITR2_GROUP:
-		val |= compute_res0_bits(kvm, hfgitr2_feat_map,
-					 ARRAY_SIZE(hfgitr2_feat_map),
-					 0, NEVER_FGU);
+		val |= compute_reg_res0_bits(kvm, &hfgitr2_feat_map,
+					     0, NEVER_FGU);
 		break;
 	case HDFGRTR2_GROUP:
-		val |= compute_res0_bits(kvm, hdfgrtr2_feat_map,
-					 ARRAY_SIZE(hdfgrtr2_feat_map),
-					 0, NEVER_FGU);
-		val |= compute_res0_bits(kvm, hdfgwtr2_feat_map,
-					 ARRAY_SIZE(hdfgwtr2_feat_map),
-					 0, NEVER_FGU);
+		val |= compute_reg_res0_bits(kvm, &hdfgrtr2_feat_map,
+					     0, NEVER_FGU);
+		val |= compute_reg_res0_bits(kvm, &hdfgwtr2_feat_map,
+					     0, NEVER_FGU);
 		break;
 	default:
 		BUG();
@@ -1330,33 +1356,23 @@ void get_reg_fixed_bits(struct kvm *kvm, enum vcpu_sysreg reg, u64 *res0, u64 *r
 		*res1 = HAFGRTR_EL2_RES1;
 		break;
 	case HFGRTR2_EL2:
-		*res0 = compute_res0_bits(kvm, hfgrtr2_feat_map,
-					  ARRAY_SIZE(hfgrtr2_feat_map), 0, 0);
-		*res0 |= hfgrtr2_masks.res0;
+		*res0 = compute_reg_res0_bits(kvm, &hfgrtr2_feat_map, 0, 0);
 		*res1 = HFGRTR2_EL2_RES1;
 		break;
 	case HFGWTR2_EL2:
-		*res0 = compute_res0_bits(kvm, hfgwtr2_feat_map,
-					  ARRAY_SIZE(hfgwtr2_feat_map), 0, 0);
-		*res0 |= hfgwtr2_masks.res0;
+		*res0 = compute_reg_res0_bits(kvm, &hfgwtr2_feat_map, 0, 0);
 		*res1 = HFGWTR2_EL2_RES1;
 		break;
 	case HFGITR2_EL2:
-		*res0 = compute_res0_bits(kvm, hfgitr2_feat_map,
-					  ARRAY_SIZE(hfgitr2_feat_map), 0, 0);
-		*res0 |= hfgitr2_masks.res0;
+		*res0 = compute_reg_res0_bits(kvm, &hfgitr2_feat_map, 0, 0);
 		*res1 = HFGITR2_EL2_RES1;
 		break;
 	case HDFGRTR2_EL2:
-		*res0 = compute_res0_bits(kvm, hdfgrtr2_feat_map,
-					  ARRAY_SIZE(hdfgrtr2_feat_map), 0, 0);
-		*res0 |= hdfgrtr2_masks.res0;
+		*res0 = compute_reg_res0_bits(kvm, &hdfgrtr2_feat_map, 0, 0);
 		*res1 = HDFGRTR2_EL2_RES1;
 		break;
 	case HDFGWTR2_EL2:
-		*res0 = compute_res0_bits(kvm, hdfgwtr2_feat_map,
-					  ARRAY_SIZE(hdfgwtr2_feat_map), 0, 0);
-		*res0 |= hdfgwtr2_masks.res0;
+		*res0 = compute_reg_res0_bits(kvm, &hdfgwtr2_feat_map, 0, 0);
 		*res1 = HDFGWTR2_EL2_RES1;
 		break;
 	case HCRX_EL2:
-- 
2.39.2




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