Detecting FEAT_RASv1p1 is rather complicated, as there are two ways for the architecture to advertise the same thing (always a delight...). Add a capability that will advertise this in a synthetic way to the rest of the kernel. Acked-by: Catalin Marinas Signed-off-by: Marc Zyngier --- arch/arm64/kernel/cpufeature.c | 24 ++++++++++++++++++++++++ arch/arm64/tools/cpucaps | 1 + 2 files changed, 25 insertions(+) diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 4dece9ca68bc6..22a94e548362d 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -2235,6 +2235,24 @@ static void cpu_clear_disr(const struct arm64_cpu_capabilities *__unused) /* Firmware may have left a deferred SError in this register. */ write_sysreg_s(0, SYS_DISR_EL1); } +static bool has_rasv1p1(const struct arm64_cpu_capabilities *__unused, int scope) +{ + const struct arm64_cpu_capabilities rasv1p1_caps[] = { + { + ARM64_CPUID_FIELDS(ID_AA64PFR0_EL1, RAS, V1P1) + }, + { + ARM64_CPUID_FIELDS(ID_AA64PFR0_EL1, RAS, IMP) + }, + { + ARM64_CPUID_FIELDS(ID_AA64PFR1_EL1, RAS_frac, RASv1p1) + }, + }; + + return (has_cpuid_feature(&rasv1p1_caps[0], scope) || + (has_cpuid_feature(&rasv1p1_caps[1], scope) && + has_cpuid_feature(&rasv1p1_caps[2], scope))); +} #endif /* CONFIG_ARM64_RAS_EXTN */ #ifdef CONFIG_ARM64_PTR_AUTH @@ -2653,6 +2671,12 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .cpu_enable = cpu_clear_disr, ARM64_CPUID_FIELDS(ID_AA64PFR0_EL1, RAS, IMP) }, + { + .desc = "RASv1p1 Extension Support", + .capability = ARM64_HAS_RASV1P1_EXTN, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .matches = has_rasv1p1, + }, #endif /* CONFIG_ARM64_RAS_EXTN */ #ifdef CONFIG_ARM64_AMU_EXTN { diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps index 115161dd9a24d..eb7f1f5622a8f 100644 --- a/arch/arm64/tools/cpucaps +++ b/arch/arm64/tools/cpucaps @@ -52,6 +52,7 @@ HAS_S1PIE HAS_S1POE HAS_SCTLR2 HAS_RAS_EXTN +HAS_RASV1P1_EXTN HAS_RNG HAS_SB HAS_STAGE2_FWB -- 2.39.2 FEAT_RASv1p1 system registeres are not handled at all so far. KVM will give an embarassed warning on the console and inject an UNDEF, despite RASv1p1 being exposed to the guest on suitable HW. Handle these registers similarly to FEAT_RAS, with the added fun that there are *two* way to indicate the presence of FEAT_RASv1p1. Signed-off-by: Marc Zyngier --- arch/arm64/kvm/sys_regs.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index ad25484772574..1b4114790024e 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -2695,6 +2695,18 @@ static bool access_ras(struct kvm_vcpu *vcpu, struct kvm *kvm = vcpu->kvm; switch(reg_to_encoding(r)) { + case SYS_ERXPFGCDN_EL1: + case SYS_ERXPFGCTL_EL1: + case SYS_ERXPFGF_EL1: + case SYS_ERXMISC2_EL1: + case SYS_ERXMISC3_EL1: + if (!(kvm_has_feat(kvm, ID_AA64PFR0_EL1, RAS, V1P1) || + (kvm_has_feat_enum(kvm, ID_AA64PFR0_EL1, RAS, IMP) && + kvm_has_feat(kvm, ID_AA64PFR1_EL1, RAS_frac, RASv1p1)))) { + kvm_inject_undefined(vcpu); + return false; + } + break; default: if (!kvm_has_feat(kvm, ID_AA64PFR0_EL1, RAS, IMP)) { kvm_inject_undefined(vcpu); @@ -3058,8 +3070,13 @@ static const struct sys_reg_desc sys_reg_descs[] = { { SYS_DESC(SYS_ERXCTLR_EL1), access_ras }, { SYS_DESC(SYS_ERXSTATUS_EL1), access_ras }, { SYS_DESC(SYS_ERXADDR_EL1), access_ras }, + { SYS_DESC(SYS_ERXPFGF_EL1), access_ras }, + { SYS_DESC(SYS_ERXPFGCTL_EL1), access_ras }, + { SYS_DESC(SYS_ERXPFGCDN_EL1), access_ras }, { SYS_DESC(SYS_ERXMISC0_EL1), access_ras }, { SYS_DESC(SYS_ERXMISC1_EL1), access_ras }, + { SYS_DESC(SYS_ERXMISC2_EL1), access_ras }, + { SYS_DESC(SYS_ERXMISC3_EL1), access_ras }, MTE_REG(TFSR_EL1), MTE_REG(TFSRE0_EL1), -- 2.39.2 An EL2 guest can set HCR_EL2.FIEN, which gives access to the RASv1p1 fault injection mechanism. This would allow an EL1 guest to inject error records into the system, which does sound like a terrible idea. Prevent this situation by added FIEN to the list of bits we silently exclude from being inserted into the host configuration. Signed-off-by: Marc Zyngier --- arch/arm64/kvm/hyp/vhe/switch.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c index e482181c66322..0998ad4a25524 100644 --- a/arch/arm64/kvm/hyp/vhe/switch.c +++ b/arch/arm64/kvm/hyp/vhe/switch.c @@ -43,8 +43,11 @@ DEFINE_PER_CPU(unsigned long, kvm_hyp_vector); * * - API/APK: they are already accounted for by vcpu_load(), and can * only take effect across a load/put cycle (such as ERET) + * + * - FIEN: no way we let a guest have access to the RAS "Common Fault + * Injection" thing, whatever that does */ -#define NV_HCR_GUEST_EXCLUDE (HCR_TGE | HCR_API | HCR_APK) +#define NV_HCR_GUEST_EXCLUDE (HCR_TGE | HCR_API | HCR_APK | HCR_FIEN) static u64 __compute_hcr(struct kvm_vcpu *vcpu) { -- 2.39.2 If we have RASv1p1 on the host, advertise it to the guest in the "canonical way", by setting ID_AA64PFR0_EL1 to V1P1, rather than the convoluted RAS+RAS_frac method. Note that this also advertises FEAT_DoubleFault, which doesn't affect the guest at all, as only EL3 is concerned by this. Signed-off-by: Marc Zyngier --- arch/arm64/kvm/sys_regs.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 1b4114790024e..66e5a733e9628 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1800,6 +1800,18 @@ static u64 sanitise_id_aa64pfr0_el1(const struct kvm_vcpu *vcpu, u64 val) if (!vcpu_has_sve(vcpu)) val &= ~ID_AA64PFR0_EL1_SVE_MASK; + /* + * Describe RASv1p1 in a canonical way -- ID_AA64PFR1_EL1.RAS_frac + * is cleared separately. Note that by advertising RASv1p1 here, we + * implicitly advertise FEAT_DoubleFault. However, since that last + * feature is a pure EL3 feature, this is not relevant for the + * guest, and we save on the complexity. + */ + if (cpus_have_final_cap(ARM64_HAS_RASV1P1_EXTN)) { + val &= ~ID_AA64PFR0_EL1_RAS; + val |= SYS_FIELD_PREP_ENUM(ID_AA64PFR0_EL1, RAS, V1P1); + } + /* * The default is to expose CSV2 == 1 if the HW isn't affected. * Although this is a per-CPU feature, we make it global because -- 2.39.2 Make ID_AA64PFR0_EL1.RAS writable so that we can restore a VM from a system without RAS to a RAS-equipped machine (or disable RAS in the guest). Signed-off-by: Marc Zyngier --- arch/arm64/kvm/sys_regs.c | 1 - 1 file changed, 1 deletion(-) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 66e5a733e9628..3a50ade091491 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -2951,7 +2951,6 @@ static const struct sys_reg_desc sys_reg_descs[] = { ~(ID_AA64PFR0_EL1_AMU | ID_AA64PFR0_EL1_MPAM | ID_AA64PFR0_EL1_SVE | - ID_AA64PFR0_EL1_RAS | ID_AA64PFR0_EL1_AdvSIMD | ID_AA64PFR0_EL1_FP)), ID_FILTERED(ID_AA64PFR1_EL1, id_aa64pfr1_el1, -- 2.39.2