From 34fa9dece52757727ed2ffd5cf4713c6cd0b707f Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Wed, 14 May 2025 11:34:46 +0100 Subject: [PATCH] KVM: arm64: nv: Extract translation helper from the AT code The address translation infrastructure is currently pretty tied to the AT emulation. However, we also need to features that require the use of VAs, such as VNCR_EL2 (and maybe one of these days SPE), meaning that we need a slightly more generic infrastructure. Start this by introducing a new helper (__kvm_translate_va()) that performs a S1 walk for a given translation regime, EL and PAN settings. Reviewed-by: Oliver Upton Link: https://lore.kernel.org/r/20250514103501.2225951-4-maz@kernel.org Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/kvm_nested.h | 54 ++++++++++++++++ arch/arm64/kvm/at.c | 96 +++++++++++------------------ 2 files changed, 91 insertions(+), 59 deletions(-) diff --git a/arch/arm64/include/asm/kvm_nested.h b/arch/arm64/include/asm/kvm_nested.h index 692f403c1896..c8a779b393c2 100644 --- a/arch/arm64/include/asm/kvm_nested.h +++ b/arch/arm64/include/asm/kvm_nested.h @@ -245,4 +245,58 @@ static inline unsigned int ps_to_output_size(unsigned int ps) } } +enum trans_regime { + TR_EL10, + TR_EL20, + TR_EL2, +}; + +struct s1_walk_info { + u64 baddr; + enum trans_regime regime; + unsigned int max_oa_bits; + unsigned int pgshift; + unsigned int txsz; + int sl; + bool as_el0; + bool hpd; + bool e0poe; + bool poe; + bool pan; + bool be; + bool s2; +}; + +struct s1_walk_result { + union { + struct { + u64 desc; + u64 pa; + s8 level; + u8 APTable; + bool UXNTable; + bool PXNTable; + bool uwxn; + bool uov; + bool ur; + bool uw; + bool ux; + bool pwxn; + bool pov; + bool pr; + bool pw; + bool px; + }; + struct { + u8 fst; + bool ptw; + bool s2; + }; + }; + bool failed; +}; + +int __kvm_translate_va(struct kvm_vcpu *vcpu, struct s1_walk_info *wi, + struct s1_walk_result *wr, u64 va); + #endif /* __ARM64_KVM_NESTED_H */ diff --git a/arch/arm64/kvm/at.c b/arch/arm64/kvm/at.c index 7a5267f43b51..71406908d4f4 100644 --- a/arch/arm64/kvm/at.c +++ b/arch/arm64/kvm/at.c @@ -10,56 +10,6 @@ #include #include -enum trans_regime { - TR_EL10, - TR_EL20, - TR_EL2, -}; - -struct s1_walk_info { - u64 baddr; - enum trans_regime regime; - unsigned int max_oa_bits; - unsigned int pgshift; - unsigned int txsz; - int sl; - bool hpd; - bool e0poe; - bool poe; - bool pan; - bool be; - bool s2; -}; - -struct s1_walk_result { - union { - struct { - u64 desc; - u64 pa; - s8 level; - u8 APTable; - bool UXNTable; - bool PXNTable; - bool uwxn; - bool uov; - bool ur; - bool uw; - bool ux; - bool pwxn; - bool pov; - bool pr; - bool pw; - bool px; - }; - struct { - u8 fst; - bool ptw; - bool s2; - }; - }; - bool failed; -}; - static void fail_s1_walk(struct s1_walk_result *wr, u8 fst, bool s1ptw) { wr->fst = fst; @@ -145,20 +95,15 @@ static void compute_s1poe(struct kvm_vcpu *vcpu, struct s1_walk_info *wi) } } -static int setup_s1_walk(struct kvm_vcpu *vcpu, u32 op, struct s1_walk_info *wi, +static int setup_s1_walk(struct kvm_vcpu *vcpu, struct s1_walk_info *wi, struct s1_walk_result *wr, u64 va) { u64 hcr, sctlr, tcr, tg, ps, ia_bits, ttbr; unsigned int stride, x; - bool va55, tbi, lva, as_el0; + bool va55, tbi, lva; hcr = __vcpu_sys_reg(vcpu, HCR_EL2); - wi->regime = compute_translation_regime(vcpu, op); - as_el0 = (op == OP_AT_S1E0R || op == OP_AT_S1E0W); - wi->pan = (op == OP_AT_S1E1RP || op == OP_AT_S1E1WP) && - (*vcpu_cpsr(vcpu) & PSR_PAN_BIT); - va55 = va & BIT(55); if (wi->regime == TR_EL2 && va55) @@ -319,7 +264,7 @@ static int setup_s1_walk(struct kvm_vcpu *vcpu, u32 op, struct s1_walk_info *wi, /* R_BNDVG and following statements */ if (kvm_has_feat(vcpu->kvm, ID_AA64MMFR2_EL1, E0PD, IMP) && - as_el0 && (tcr & (va55 ? TCR_E0PD1 : TCR_E0PD0))) + wi->as_el0 && (tcr & (va55 ? TCR_E0PD1 : TCR_E0PD0))) goto transfault_l0; /* AArch64.S1StartLevel() */ @@ -1155,7 +1100,12 @@ static u64 handle_at_slow(struct kvm_vcpu *vcpu, u32 op, u64 vaddr) bool perm_fail = false; int ret, idx; - ret = setup_s1_walk(vcpu, op, &wi, &wr, vaddr); + wi.regime = compute_translation_regime(vcpu, op); + wi.as_el0 = (op == OP_AT_S1E0R || op == OP_AT_S1E0W); + wi.pan = (op == OP_AT_S1E1RP || op == OP_AT_S1E1WP) && + (*vcpu_cpsr(vcpu) & PSR_PAN_BIT); + + ret = setup_s1_walk(vcpu, &wi, &wr, vaddr); if (ret) goto compute_par; @@ -1457,3 +1407,31 @@ void __kvm_at_s12(struct kvm_vcpu *vcpu, u32 op, u64 vaddr) par = compute_par_s12(vcpu, par, &out); vcpu_write_sys_reg(vcpu, par, PAR_EL1); } + +/* + * Translate a VA for a given EL in a given translation regime, with + * or without PAN. This requires wi->{regime, as_el0, pan} to be + * set. The rest of the wi and wr should be 0-initialised. + */ +int __kvm_translate_va(struct kvm_vcpu *vcpu, struct s1_walk_info *wi, + struct s1_walk_result *wr, u64 va) +{ + int ret; + + ret = setup_s1_walk(vcpu, wi, wr, va); + if (ret) + return ret; + + if (wr->level == S1_MMU_DISABLED) { + wr->ur = wr->uw = wr->ux = true; + wr->pr = wr->pw = wr->px = true; + } else { + ret = walk_s1(vcpu, wi, wr, va); + if (ret) + return ret; + + compute_s1_permissions(vcpu, wi, wr); + } + + return 0; +} -- 2.50.1