From 14d4802dc22acf670333c8aad4e1931e7d6ee412 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 29 Jul 2025 12:06:14 +0100 Subject: [PATCH] KVM: arm64: Allow use of S1 PTW for non-NV vcpus As we are about to use the S1 PTW in non-NV contexts, we must make sure that we don't evaluate the EL2 state when dealing with the EL1&0 translation regime. Reviewed-by: Oliver Upton Signed-off-by: Marc Zyngier --- arch/arm64/kvm/at.c | 58 ++++++++++++++++++++++----------------------- 1 file changed, 28 insertions(+), 30 deletions(-) diff --git a/arch/arm64/kvm/at.c b/arch/arm64/kvm/at.c index 7b9711021db0..9baa929c102f 100644 --- a/arch/arm64/kvm/at.c +++ b/arch/arm64/kvm/at.c @@ -98,21 +98,26 @@ static enum trans_regime compute_translation_regime(struct kvm_vcpu *vcpu, u32 o } } +static u64 effective_tcr2(struct kvm_vcpu *vcpu, enum trans_regime regime) +{ + if (regime == TR_EL10) { + if (vcpu_has_nv(vcpu) && + !(__vcpu_sys_reg(vcpu, HCRX_EL2) & HCRX_EL2_TCR2En)) + return 0; + + return __vcpu_sys_reg(vcpu, TCR2_EL1); + } + + return vcpu_read_sys_reg(vcpu, TCR2_EL2); +} + static bool s1pie_enabled(struct kvm_vcpu *vcpu, enum trans_regime regime) { if (!kvm_has_s1pie(vcpu->kvm)) return false; - switch (regime) { - case TR_EL2: - case TR_EL20: - return vcpu_read_sys_reg(vcpu, TCR2_EL2) & TCR2_EL2_PIE; - case TR_EL10: - return (__vcpu_sys_reg(vcpu, HCRX_EL2) & HCRX_EL2_TCR2En) && - (__vcpu_sys_reg(vcpu, TCR2_EL1) & TCR2_EL1_PIE); - default: - BUG(); - } + /* Abuse TCR2_EL1_PIE and use it for EL2 as well */ + return effective_tcr2(vcpu, regime) & TCR2_EL1_PIE; } static void compute_s1poe(struct kvm_vcpu *vcpu, struct s1_walk_info *wi) @@ -124,23 +129,11 @@ static void compute_s1poe(struct kvm_vcpu *vcpu, struct s1_walk_info *wi) return; } - switch (wi->regime) { - case TR_EL2: - case TR_EL20: - val = vcpu_read_sys_reg(vcpu, TCR2_EL2); - wi->poe = val & TCR2_EL2_POE; - wi->e0poe = (wi->regime == TR_EL20) && (val & TCR2_EL2_E0POE); - break; - case TR_EL10: - if (__vcpu_sys_reg(vcpu, HCRX_EL2) & HCRX_EL2_TCR2En) { - wi->poe = wi->e0poe = false; - return; - } + val = effective_tcr2(vcpu, wi->regime); - val = __vcpu_sys_reg(vcpu, TCR2_EL1); - wi->poe = val & TCR2_EL1_POE; - wi->e0poe = val & TCR2_EL1_E0POE; - } + /* Abuse TCR2_EL1_* for EL2 */ + wi->poe = val & TCR2_EL1_POE; + wi->e0poe = (wi->regime != TR_EL2) && (val & TCR2_EL1_E0POE); } static int setup_s1_walk(struct kvm_vcpu *vcpu, struct s1_walk_info *wi, @@ -150,11 +143,16 @@ static int setup_s1_walk(struct kvm_vcpu *vcpu, struct s1_walk_info *wi, unsigned int stride, x; bool va55, tbi, lva; - hcr = __vcpu_sys_reg(vcpu, HCR_EL2); - va55 = va & BIT(55); - wi->s2 = wi->regime == TR_EL10 && (hcr & (HCR_VM | HCR_DC)); + if (vcpu_has_nv(vcpu)) { + hcr = __vcpu_sys_reg(vcpu, HCR_EL2); + wi->s2 = wi->regime == TR_EL10 && (hcr & (HCR_VM | HCR_DC)); + } else { + WARN_ON_ONCE(wi->regime != TR_EL10); + wi->s2 = false; + hcr = 0; + } switch (wi->regime) { case TR_EL10: @@ -851,7 +849,7 @@ static u64 compute_par_s1(struct kvm_vcpu *vcpu, struct s1_walk_info *wi, par = SYS_PAR_EL1_NSE; par |= wr->pa & SYS_PAR_EL1_PA; - if (wi->regime == TR_EL10 && + if (wi->regime == TR_EL10 && vcpu_has_nv(vcpu) && (__vcpu_sys_reg(vcpu, HCR_EL2) & HCR_DC)) { par |= FIELD_PREP(SYS_PAR_EL1_ATTR, MEMATTR(WbRaWa, WbRaWa)); -- 2.47.3