[PATCH v2 4/4] KVM: arm64: Convert TCR_EL2 to config-driven sanitisation
From: Wei-Lin Chang <hidden>
Date: 2026-09-17 21:42:55
Also in:
kvmarm, lkml
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
Feature dependencies of the fields in TCR_EL2 are extracted from Registers.json of the BSD licenced AARCHMRS (AARCHMRS_OPENSOURCE_A_profile_FAT-2026-06). Places where we slightly deviate from the above: - Stick to the ARM ARM M.c requirement for TCR_EL2.TCMA*, which only depends on FEAT_MTE2. This avoids updating ID_AA64PFR2_EL1 with new VMTE* definitions that we don't know the meaning of, as they aren't present in the ARM ARM yet. - Ignore TCR_EL2.DS's requirement of needing the effective value of TCR2_EL2.D128 be 0. This requires runtime detection of TCR2_EL2.D128 and we don't have D128 support yet. - TCR_EL2.AS is dependent on FEAT_ASID16, this information is missing from the json. Signed-off-by: Wei-Lin Chang <redacted> --- arch/arm64/include/asm/kvm_host.h | 2 +- arch/arm64/kvm/config.c | 113 ++++++++++++++++++++++++++++++ arch/arm64/kvm/nested.c | 4 ++ 3 files changed, 118 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 27fe0cd5b2d7..6a5e22ca3430 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h@@ -516,7 +516,6 @@ enum vcpu_sysreg { HACR_EL2, /* Hypervisor Auxiliary Control Register */ TTBR0_EL2, /* Translation Table Base Register 0 (EL2) */ TTBR1_EL2, /* Translation Table Base Register 1 (EL2) */ - TCR_EL2, /* Translation Control Register (EL2) */ PIRE0_EL2, /* Permission Indirection Register 0 (EL2) */ PIR_EL2, /* Permission Indirection Register 1 (EL2) */ POR_EL2, /* Permission Overlay Register 2 (EL2) */
@@ -541,6 +540,7 @@ enum vcpu_sysreg { /* Anything from this can be RES0/RES1 sanitised */ MARKER(__SANITISED_REG_START__), SCTLR_EL2, /* System Control Register (EL2) */ + TCR_EL2, /* Translation Control Register (EL2) */ TCR2_EL2, /* Extended Translation Control Register (EL2) */ SCTLR2_EL2, /* System Control Register 2 (EL2) */ MDCR_EL2, /* Monitor Debug Configuration Register (EL2) */
diff --git a/arch/arm64/kvm/config.c b/arch/arm64/kvm/config.c
index 1053676551af..080b3510b783 100644
--- a/arch/arm64/kvm/config.c
+++ b/arch/arm64/kvm/config.c@@ -203,8 +203,11 @@ struct reg_feat_map_desc { #define FEAT_CPA2 ID_AA64ISAR3_EL1, CPA, CPA2 #define FEAT_ASID2 ID_AA64MMFR4_EL1, ASID2, IMP #define FEAT_MEC ID_AA64MMFR3_EL1, MEC, IMP +#define FEAT_HAF ID_AA64MMFR1_EL1, HAFDBS, AF #define FEAT_HAFT ID_AA64MMFR1_EL1, HAFDBS, HAFT +#define FEAT_HAFDBS ID_AA64MMFR1_EL1, HAFDBS, DBM #define FEAT_HDBSS ID_AA64MMFR1_EL1, HAFDBS, HDBSS +#define FEAT_HPDS ID_AA64MMFR1_EL1, HPDS, IMP #define FEAT_HPDS2 ID_AA64MMFR1_EL1, HPDS, HPDS2 #define FEAT_BTI ID_AA64PFR1_EL1, BT, IMP #define FEAT_ExS ID_AA64MMFR0_EL1, EXS, IMP
@@ -215,6 +218,10 @@ struct reg_feat_map_desc { #define FEAT_MixedEndEL0 ID_AA64MMFR0_EL1, BIGENDEL0, IMP #define FEAT_MTE_ASYNC ID_AA64PFR1_EL1, MTE_frac, ASYNC #define FEAT_MTE_STORE_ONLY ID_AA64PFR2_EL1, MTESTOREONLY, IMP +#define FEAT_MTE_CANONICAL_TAGS ID_AA64PFR1_EL1, MTEX, MTE4 +#define FEAT_MTE_NO_ADDRESS_TAGS ID_AA64PFR1_EL1, MTEX, MTE4 +#define FEAT_E0PD ID_AA64MMFR2_EL1, E0PD, IMP +#define FEAT_SVE ID_AA64PFR0_EL1, SVE, IMP #define FEAT_PAN ID_AA64MMFR1_EL1, PAN, IMP #define FEAT_PAN3 ID_AA64MMFR1_EL1, PAN, PAN3 #define FEAT_SSBS ID_AA64PFR1_EL1, SSBS, IMP
@@ -227,6 +234,19 @@ struct reg_feat_map_desc { #define FEAT_GCIE ID_AA64PFR2_EL1, GCIE, IMP #define FEAT_NV3 ID_AA64MMFR4_EL1, NV_frac, NV3 +static bool feat_asid16(struct kvm *kvm) +{ + return kvm_has_feat_enum(kvm, ID_AA64MMFR0_EL1, ASIDBITS, 16); +} + +static bool feat_mte_no_addr_tags_or_canonical_tags(struct kvm *kvm) +{ + bool no_addr_tags = kvm_has_feat(kvm, FEAT_MTE_NO_ADDRESS_TAGS); + bool canonical_tags = kvm_has_feat(kvm, FEAT_MTE_CANONICAL_TAGS); + + return no_addr_tags || canonical_tags; +} + static bool not_feat_aa64el3(struct kvm *kvm) { return !kvm_has_feat(kvm, FEAT_AA64EL3);
@@ -1044,6 +1064,91 @@ static const struct reg_bits_to_feat_map sctlr2_feat_map[] = { static const DECLARE_FEAT_MAP(sctlr2_desc, SCTLR2_EL1, sctlr2_feat_map, FEAT_SCTLR2); +static const struct reg_bits_to_feat_map vhe_tcr_el2_feat_map[] = { + NEEDS_FEAT(VHE_TCR_EL2_MTX1 | + VHE_TCR_EL2_MTX0, + feat_mte_no_addr_tags_or_canonical_tags), + NEEDS_FEAT(VHE_TCR_EL2_DS, feat_lpa2), + NEEDS_FEAT(VHE_TCR_EL2_TCMA1 | + VHE_TCR_EL2_TCMA0, + FEAT_MTE2), + NEEDS_FEAT(VHE_TCR_EL2_E0PD1 | + VHE_TCR_EL2_E0PD0, + FEAT_E0PD), + NEEDS_FEAT(VHE_TCR_EL2_NFD1 | + VHE_TCR_EL2_NFD0, + FEAT_SVE), + NEEDS_FEAT(VHE_TCR_EL2_TBID1 | + VHE_TCR_EL2_TBID0, + feat_pauth), + NEEDS_FEAT(VHE_TCR_EL2_HWU162 | + VHE_TCR_EL2_HWU161 | + VHE_TCR_EL2_HWU160 | + VHE_TCR_EL2_HWU159 | + VHE_TCR_EL2_HWU062 | + VHE_TCR_EL2_HWU061 | + VHE_TCR_EL2_HWU060 | + VHE_TCR_EL2_HWU059, + FEAT_HPDS2), + NEEDS_FEAT(VHE_TCR_EL2_HPD1 | + VHE_TCR_EL2_HPD0, + FEAT_HPDS), + NEEDS_FEAT(VHE_TCR_EL2_HD, FEAT_HAFDBS), + NEEDS_FEAT(VHE_TCR_EL2_HA, FEAT_HAF), + NEEDS_FEAT(VHE_TCR_EL2_AS, feat_asid16), + NEEDS_FEAT(VHE_TCR_EL2_TBI1 | + VHE_TCR_EL2_TBI0 | + VHE_TCR_EL2_IPS | + VHE_TCR_EL2_TG1 | + VHE_TCR_EL2_SH1 | + VHE_TCR_EL2_ORGN1 | + VHE_TCR_EL2_IRGN1 | + VHE_TCR_EL2_EPD1 | + VHE_TCR_EL2_A1 | + VHE_TCR_EL2_T1SZ | + VHE_TCR_EL2_TG0 | + VHE_TCR_EL2_SH0 | + VHE_TCR_EL2_ORGN0 | + VHE_TCR_EL2_IRGN0 | + VHE_TCR_EL2_EPD0 | + VHE_TCR_EL2_T0SZ, + FEAT_AA64EL2), + FORCE_RES0(VHE_TCR_EL2_RES0), + FORCE_RES1(VHE_TCR_EL2_RES1), +}; + +static const DECLARE_FEAT_MAP(vhe_tcr_el2_desc, VHE_TCR_EL2, + vhe_tcr_el2_feat_map, FEAT_AA64EL2); + +static const struct reg_bits_to_feat_map tcr_el2_feat_map[] = { + NEEDS_FEAT(TCR_EL2_MTX, + feat_mte_no_addr_tags_or_canonical_tags), + NEEDS_FEAT(TCR_EL2_DS, feat_lpa2), + NEEDS_FEAT(TCR_EL2_TCMA, FEAT_MTE2), + NEEDS_FEAT(TCR_EL2_TBID, feat_pauth), + NEEDS_FEAT(TCR_EL2_HWU62 | + TCR_EL2_HWU61 | + TCR_EL2_HWU60 | + TCR_EL2_HWU59, + FEAT_HPDS2), + NEEDS_FEAT(TCR_EL2_HPD, FEAT_HPDS), + NEEDS_FEAT(TCR_EL2_HD, FEAT_HAFDBS), + NEEDS_FEAT(TCR_EL2_HA, FEAT_HAF), + NEEDS_FEAT(TCR_EL2_TBI | + TCR_EL2_PS | + TCR_EL2_TG0 | + TCR_EL2_SH0 | + TCR_EL2_ORGN0 | + TCR_EL2_IRGN0 | + TCR_EL2_T0SZ, + FEAT_AA64EL2), + FORCE_RES0(TCR_EL2_RES0), + FORCE_RES1(TCR_EL2_RES1), +}; + +static const DECLARE_FEAT_MAP(tcr_el2_desc, TCR_EL2, + tcr_el2_feat_map, FEAT_AA64EL2); + static const struct reg_bits_to_feat_map tcr2_el2_feat_map[] = { NEEDS_FEAT_FLAG(TCR2_EL2_FNG1 | TCR2_EL2_FNG0 |
@@ -1398,6 +1503,8 @@ void __init check_feature_map(void) check_reg_desc(&hcr_desc); check_reg_desc(&nvhcr_desc); check_reg_desc(&sctlr2_desc); + check_reg_desc(&vhe_tcr_el2_desc); + check_reg_desc(&tcr_el2_desc); check_reg_desc(&tcr2_el2_desc); check_reg_desc(&sctlr_el1_desc); check_reg_desc(&sctlr_el2_desc);
@@ -1611,6 +1718,12 @@ struct resx get_reg_fixed_bits(struct kvm *kvm, enum vcpu_sysreg reg) case SCTLR2_EL2: resx = compute_reg_resx_bits(kvm, &sctlr2_desc, 0, 0); break; + case TCR_EL2: + if (kvm_has_feat(kvm, FEAT_E2H0)) + resx = compute_reg_resx_bits(kvm, &tcr_el2_desc, 0, 0); + else + resx = compute_reg_resx_bits(kvm, &vhe_tcr_el2_desc, 0, 0); + break; case TCR2_EL2: resx = compute_reg_resx_bits(kvm, &tcr2_el2_desc, 0, 0); break;
diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
index 4a860904c1ce..2536ea4297b0 100644
--- a/arch/arm64/kvm/nested.c
+++ b/arch/arm64/kvm/nested.c@@ -1957,6 +1957,10 @@ int kvm_init_nv_sysregs(struct kvm_vcpu *vcpu) resx = get_reg_fixed_bits(kvm, HFGITR2_EL2); set_sysreg_masks(kvm, HFGITR2_EL2, resx); + /* TCR_EL2 */ + resx = get_reg_fixed_bits(kvm, TCR_EL2); + set_sysreg_masks(kvm, TCR_EL2, resx); + /* TCR2_EL2 */ resx = get_reg_fixed_bits(kvm, TCR2_EL2); set_sysreg_masks(kvm, TCR2_EL2, resx);
--
2.43.0