From: Marc Zyngier Date: Thu, 18 Sep 2025 15:13:55 +0000 (+0100) Subject: KVM: arm64: Enforce absence of FEAT_FGT on FGT registers X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=7d3a4d048925d52e5511d82e479cbdcf7354aa7c;p=users%2Fhch%2Fmisc.git KVM: arm64: Enforce absence of FEAT_FGT on FGT registers As we want to enforce FGT registers behaving as RES0 when FEAT_FGT is not exposed to the guest, We move a bumch of things that are so far passed as parameter into a structure that points to the bit description. Reviewed-by: Oliver Upton Signed-off-by: Marc Zyngier --- diff --git a/arch/arm64/kvm/config.c b/arch/arm64/kvm/config.c index c2bfffe660bc..887e7338fffe 100644 --- a/arch/arm64/kvm/config.c +++ b/arch/arm64/kvm/config.c @@ -458,6 +458,10 @@ static const struct reg_bits_to_feat_map hfgrtr_feat_map[] = { NEVER_FGU, FEAT_AA64EL1), }; + +static const DECLARE_FEAT_MAP_FGT(hfgrtr_desc, hfgrtr_masks, + hfgrtr_feat_map, FEAT_FGT); + static const struct reg_bits_to_feat_map hfgwtr_feat_map[] = { NEEDS_FEAT(HFGWTR_EL2_nAMAIR2_EL1 | HFGWTR_EL2_nMAIR2_EL1, @@ -522,6 +526,9 @@ static const struct reg_bits_to_feat_map hfgwtr_feat_map[] = { NEVER_FGU, FEAT_AA64EL1), }; +static const DECLARE_FEAT_MAP_FGT(hfgwtr_desc, hfgwtr_masks, + hfgwtr_feat_map, FEAT_FGT); + static const struct reg_bits_to_feat_map hdfgrtr_feat_map[] = { NEEDS_FEAT(HDFGRTR_EL2_PMBIDR_EL1 | HDFGRTR_EL2_PMSLATFR_EL1 | @@ -589,6 +596,9 @@ static const struct reg_bits_to_feat_map hdfgrtr_feat_map[] = { NEVER_FGU, FEAT_AA64EL1) }; +static const DECLARE_FEAT_MAP_FGT(hdfgrtr_desc, hdfgrtr_masks, + hdfgrtr_feat_map, FEAT_FGT); + static const struct reg_bits_to_feat_map hdfgwtr_feat_map[] = { NEEDS_FEAT(HDFGWTR_EL2_PMSLATFR_EL1 | HDFGWTR_EL2_PMSIRR_EL1 | @@ -649,6 +659,8 @@ static const struct reg_bits_to_feat_map hdfgwtr_feat_map[] = { NEEDS_FEAT(HDFGWTR_EL2_TRFCR_EL1, FEAT_TRF), }; +static const DECLARE_FEAT_MAP_FGT(hdfgwtr_desc, hdfgwtr_masks, + hdfgwtr_feat_map, FEAT_FGT); static const struct reg_bits_to_feat_map hfgitr_feat_map[] = { NEEDS_FEAT(HFGITR_EL2_PSBCSYNC, FEAT_SPEv1p5), @@ -723,6 +735,9 @@ static const struct reg_bits_to_feat_map hfgitr_feat_map[] = { NEVER_FGU, FEAT_AA64EL1), }; +static const DECLARE_FEAT_MAP_FGT(hfgitr_desc, hfgitr_masks, + hfgitr_feat_map, FEAT_FGT); + static const struct reg_bits_to_feat_map hafgrtr_feat_map[] = { NEEDS_FEAT(HAFGRTR_EL2_AMEVTYPER115_EL0 | HAFGRTR_EL2_AMEVTYPER114_EL0 | @@ -765,6 +780,9 @@ static const struct reg_bits_to_feat_map hafgrtr_feat_map[] = { FEAT_AMUv1), }; +static const DECLARE_FEAT_MAP_FGT(hafgrtr_desc, hafgrtr_masks, + hafgrtr_feat_map, FEAT_FGT); + static const struct reg_bits_to_feat_map hfgitr2_feat_map[] = { NEEDS_FEAT(HFGITR2_EL2_nDCCIVAPS, FEAT_PoPS), NEEDS_FEAT(HFGITR2_EL2_TSBCSYNC, FEAT_TRBEv1p1) @@ -1122,20 +1140,25 @@ static void __init check_feat_map(const struct reg_bits_to_feat_map *map, str, mask ^ ~res0); } +static u64 reg_feat_map_bits(const struct reg_bits_to_feat_map *map) +{ + return map->flags & RES0_POINTER ? ~(*map->res0p) : map->bits; +} + +static void __init check_reg_desc(const struct reg_feat_map_desc *r) +{ + check_feat_map(r->bit_feat_map, r->bit_feat_map_sz, + ~reg_feat_map_bits(&r->feat_map), r->name); +} + void __init check_feature_map(void) { - check_feat_map(hfgrtr_feat_map, ARRAY_SIZE(hfgrtr_feat_map), - hfgrtr_masks.res0, hfgrtr_masks.str); - check_feat_map(hfgwtr_feat_map, ARRAY_SIZE(hfgwtr_feat_map), - hfgwtr_masks.res0, hfgwtr_masks.str); - check_feat_map(hfgitr_feat_map, ARRAY_SIZE(hfgitr_feat_map), - hfgitr_masks.res0, hfgitr_masks.str); - check_feat_map(hdfgrtr_feat_map, ARRAY_SIZE(hdfgrtr_feat_map), - hdfgrtr_masks.res0, hdfgrtr_masks.str); - check_feat_map(hdfgwtr_feat_map, ARRAY_SIZE(hdfgwtr_feat_map), - hdfgwtr_masks.res0, hdfgwtr_masks.str); - check_feat_map(hafgrtr_feat_map, ARRAY_SIZE(hafgrtr_feat_map), - hafgrtr_masks.res0, hafgrtr_masks.str); + check_reg_desc(&hfgrtr_desc); + check_reg_desc(&hfgwtr_desc); + check_reg_desc(&hfgitr_desc); + check_reg_desc(&hdfgrtr_desc); + check_reg_desc(&hdfgwtr_desc); + check_reg_desc(&hafgrtr_desc); 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), @@ -1190,7 +1213,7 @@ static u64 __compute_fixed_bits(struct kvm *kvm, match = idreg_feat_match(kvm, &map[i]); if (!match || (map[i].flags & FIXED_VALUE)) - val |= map[i].bits; + val |= reg_feat_map_bits(&map[i]); } return val; @@ -1206,6 +1229,29 @@ static u64 compute_res0_bits(struct kvm *kvm, require, exclude | FIXED_VALUE); } +static u64 compute_reg_res0_bits(struct kvm *kvm, + const struct reg_feat_map_desc *r, + unsigned long require, unsigned long exclude) + +{ + u64 res0; + + res0 = compute_res0_bits(kvm, r->bit_feat_map, r->bit_feat_map_sz, + require, exclude); + + /* + * If computing FGUs, don't take RES0 or register existence + * into account -- we're not computing bits for the register + * itself. + */ + if (!(exclude & NEVER_FGU)) { + res0 |= compute_res0_bits(kvm, &r->feat_map, 1, require, exclude); + res0 |= ~reg_feat_map_bits(&r->feat_map); + } + + return res0; +} + static u64 compute_fixed_bits(struct kvm *kvm, const struct reg_bits_to_feat_map *map, int map_size, @@ -1223,30 +1269,24 @@ void compute_fgu(struct kvm *kvm, enum fgt_group_id fgt) switch (fgt) { case HFGRTR_GROUP: - val |= compute_res0_bits(kvm, hfgrtr_feat_map, - ARRAY_SIZE(hfgrtr_feat_map), - 0, NEVER_FGU); - val |= compute_res0_bits(kvm, hfgwtr_feat_map, - ARRAY_SIZE(hfgwtr_feat_map), - 0, NEVER_FGU); + val |= compute_reg_res0_bits(kvm, &hfgrtr_desc, + 0, NEVER_FGU); + val |= compute_reg_res0_bits(kvm, &hfgwtr_desc, + 0, NEVER_FGU); break; case HFGITR_GROUP: - val |= compute_res0_bits(kvm, hfgitr_feat_map, - ARRAY_SIZE(hfgitr_feat_map), - 0, NEVER_FGU); + val |= compute_reg_res0_bits(kvm, &hfgitr_desc, + 0, NEVER_FGU); break; case HDFGRTR_GROUP: - val |= compute_res0_bits(kvm, hdfgrtr_feat_map, - ARRAY_SIZE(hdfgrtr_feat_map), - 0, NEVER_FGU); - val |= compute_res0_bits(kvm, hdfgwtr_feat_map, - ARRAY_SIZE(hdfgwtr_feat_map), - 0, NEVER_FGU); + val |= compute_reg_res0_bits(kvm, &hdfgrtr_desc, + 0, NEVER_FGU); + val |= compute_reg_res0_bits(kvm, &hdfgwtr_desc, + 0, NEVER_FGU); break; case HAFGRTR_GROUP: - val |= compute_res0_bits(kvm, hafgrtr_feat_map, - ARRAY_SIZE(hafgrtr_feat_map), - 0, NEVER_FGU); + val |= compute_reg_res0_bits(kvm, &hafgrtr_desc, + 0, NEVER_FGU); break; case HFGRTR2_GROUP: val |= compute_res0_bits(kvm, hfgrtr2_feat_map, @@ -1282,39 +1322,27 @@ void get_reg_fixed_bits(struct kvm *kvm, enum vcpu_sysreg reg, u64 *res0, u64 *r switch (reg) { case HFGRTR_EL2: - *res0 = compute_res0_bits(kvm, hfgrtr_feat_map, - ARRAY_SIZE(hfgrtr_feat_map), 0, 0); - *res0 |= hfgrtr_masks.res0; + *res0 = compute_reg_res0_bits(kvm, &hfgrtr_desc, 0, 0); *res1 = HFGRTR_EL2_RES1; break; case HFGWTR_EL2: - *res0 = compute_res0_bits(kvm, hfgwtr_feat_map, - ARRAY_SIZE(hfgwtr_feat_map), 0, 0); - *res0 |= hfgwtr_masks.res0; + *res0 = compute_reg_res0_bits(kvm, &hfgwtr_desc, 0, 0); *res1 = HFGWTR_EL2_RES1; break; case HFGITR_EL2: - *res0 = compute_res0_bits(kvm, hfgitr_feat_map, - ARRAY_SIZE(hfgitr_feat_map), 0, 0); - *res0 |= hfgitr_masks.res0; + *res0 = compute_reg_res0_bits(kvm, &hfgitr_desc, 0, 0); *res1 = HFGITR_EL2_RES1; break; case HDFGRTR_EL2: - *res0 = compute_res0_bits(kvm, hdfgrtr_feat_map, - ARRAY_SIZE(hdfgrtr_feat_map), 0, 0); - *res0 |= hdfgrtr_masks.res0; + *res0 = compute_reg_res0_bits(kvm, &hdfgrtr_desc, 0, 0); *res1 = HDFGRTR_EL2_RES1; break; case HDFGWTR_EL2: - *res0 = compute_res0_bits(kvm, hdfgwtr_feat_map, - ARRAY_SIZE(hdfgwtr_feat_map), 0, 0); - *res0 |= hdfgwtr_masks.res0; + *res0 = compute_reg_res0_bits(kvm, &hdfgwtr_desc, 0, 0); *res1 = HDFGWTR_EL2_RES1; break; case HAFGRTR_EL2: - *res0 = compute_res0_bits(kvm, hafgrtr_feat_map, - ARRAY_SIZE(hafgrtr_feat_map), 0, 0); - *res0 |= hafgrtr_masks.res0; + *res0 = compute_reg_res0_bits(kvm, &hafgrtr_desc, 0, 0); *res1 = HAFGRTR_EL2_RES1; break; case HFGRTR2_EL2: