[PATCH 01/11] KVM: arm64: nv: Convert masks to denylists in limit_nv_id_reg()

[Oliver Upton <oliver.upton@linux.dev>]

Consistently use denylisting of features such that the limitations of
KVM's nested implementation are explicitly documented (rather than
implied).

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
---
 arch/arm64/kvm/nested.c | 47 +++++++++++++++++++++++++++++------------
 1 file changed, 33 insertions(+), 14 deletions(-)

diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
index 77db81bae86f..53c57d105c93 100644
--- a/arch/arm64/kvm/nested.c
+++ b/arch/arm64/kvm/nested.c
@@ -1462,9 +1462,18 @@ u64 limit_nv_id_reg(struct kvm *kvm, u32 reg, u64 val)
 
 	case SYS_ID_AA64PFR1_EL1:
 		/* Only support BTI, SSBS, CSV2_frac */
-		val &= (ID_AA64PFR1_EL1_BT	|
-			ID_AA64PFR1_EL1_SSBS	|
-			ID_AA64PFR1_EL1_CSV2_frac);
+		val &= ~(ID_AA64PFR1_EL1_PFAR		|
+			 ID_AA64PFR1_EL1_DF2		|
+			 ID_AA64PFR1_EL1_MTEX		|
+			 ID_AA64PFR1_EL1_THE		|
+			 ID_AA64PFR1_EL1_GCS		|
+			 ID_AA64PFR1_EL1_MTE_frac	|
+			 ID_AA64PFR1_EL1_NMI		|
+			 ID_AA64PFR1_EL1_SME		|
+			 ID_AA64PFR1_EL1_RES0		|
+			 ID_AA64PFR1_EL1_MPAM_frac	|
+			 ID_AA64PFR1_EL1_RAS_frac	|
+			 ID_AA64PFR1_EL1_MTE);
 		break;
 
 	case SYS_ID_AA64MMFR0_EL1:
@@ -1517,12 +1526,16 @@ u64 limit_nv_id_reg(struct kvm *kvm, u32 reg, u64 val)
 		break;
 
 	case SYS_ID_AA64MMFR1_EL1:
-		val &= (ID_AA64MMFR1_EL1_HCX	|
-			ID_AA64MMFR1_EL1_PAN	|
-			ID_AA64MMFR1_EL1_LO	|
-			ID_AA64MMFR1_EL1_HPDS	|
-			ID_AA64MMFR1_EL1_VH	|
-			ID_AA64MMFR1_EL1_VMIDBits);
+		val &= ~(ID_AA64MMFR1_EL1_ECBHB		|
+			 ID_AA64MMFR1_EL1_CMOW		|
+			 ID_AA64MMFR1_EL1_TIDCP1	|
+			 ID_AA64MMFR1_EL1_nTLBPA	|
+			 ID_AA64MMFR1_EL1_AFP		|
+			 ID_AA64MMFR1_EL1_ETS		|
+			 ID_AA64MMFR1_EL1_TWED		|
+			 ID_AA64MMFR1_EL1_XNX		|
+			 ID_AA64MMFR1_EL1_SpecSEI	|
+			 ID_AA64MMFR1_EL1_HAFDBS);
 		/* FEAT_E2H0 implies no VHE */
 		if (test_bit(KVM_ARM_VCPU_HAS_EL2_E2H0, kvm->arch.vcpu_features))
 			val &= ~ID_AA64MMFR1_EL1_VH;
@@ -1564,11 +1577,17 @@ u64 limit_nv_id_reg(struct kvm *kvm, u32 reg, u64 val)
 
 	case SYS_ID_AA64DFR0_EL1:
 		/* Only limited support for PMU, Debug, BPs, WPs, and HPMN0 */
-		val &= (ID_AA64DFR0_EL1_PMUVer	|
-			ID_AA64DFR0_EL1_WRPs	|
-			ID_AA64DFR0_EL1_BRPs	|
-			ID_AA64DFR0_EL1_DebugVer|
-			ID_AA64DFR0_EL1_HPMN0);
+		val &= ~(ID_AA64DFR0_EL1_ExtTrcBuff	|
+			 ID_AA64DFR0_EL1_BRBE		|
+			 ID_AA64DFR0_EL1_MTPMU		|
+			 ID_AA64DFR0_EL1_TraceBuffer	|
+			 ID_AA64DFR0_EL1_TraceFilt	|
+			 ID_AA64DFR0_EL1_DoubleLock	|
+			 ID_AA64DFR0_EL1_PMSVer		|
+			 ID_AA64DFR0_EL1_CTX_CMPs	|
+			 ID_AA64DFR0_EL1_SEBEP		|
+			 ID_AA64DFR0_EL1_PMSS		|
+			 ID_AA64DFR0_EL1_TraceVer);
 
 		/* Cap Debug to ARMv8.1 */
 		val = ID_REG_LIMIT_FIELD_ENUM(val, ID_AA64DFR0_EL1, DebugVer, VHE);
-- 
2.39.5