diff options
| -rw-r--r-- | Documentation/arm64/silicon-errata.rst | 3 | ||||
| -rw-r--r-- | arch/arm64/Kconfig | 19 | ||||
| -rw-r--r-- | arch/arm64/kernel/cpu_errata.c | 7 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/include/hyp/switch.h | 99 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/pgtable.c | 14 | ||||
| -rw-r--r-- | arch/arm64/tools/cpucaps | 1 |
6 files changed, 122 insertions, 21 deletions
diff --git a/Documentation/arm64/silicon-errata.rst b/Documentation/arm64/silicon-errata.rst index 9e311bc43e05..cd46e2b20a81 100644 --- a/Documentation/arm64/silicon-errata.rst +++ b/Documentation/arm64/silicon-errata.rst @@ -52,6 +52,9 @@ stable kernels. | Allwinner | A64/R18 | UNKNOWN1 | SUN50I_ERRATUM_UNKNOWN1 | +----------------+-----------------+-----------------+-----------------------------+ +----------------+-----------------+-----------------+-----------------------------+ +| Ampere | AmpereOne | AC03_CPU_38 | AMPERE_ERRATUM_AC03_CPU_38 | ++----------------+-----------------+-----------------+-----------------------------+ ++----------------+-----------------+-----------------+-----------------------------+ | ARM | Cortex-A510 | #2457168 | ARM64_ERRATUM_2457168 | +----------------+-----------------+-----------------+-----------------------------+ | ARM | Cortex-A510 | #2064142 | ARM64_ERRATUM_2064142 | diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index a6002084f09c..50f6ddc7e3a0 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -407,6 +407,25 @@ menu "Kernel Features" menu "ARM errata workarounds via the alternatives framework" +config AMPERE_ERRATUM_AC03_CPU_38 + bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics" + default y + help + This option adds an alternative code sequence to work around Ampere + erratum AC03_CPU_38 on AmpereOne. + + The affected design reports FEAT_HAFDBS as not implemented in + ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0 + as required by the architecture. The unadvertised HAFDBS + implementation suffers from an additional erratum where hardware + A/D updates can occur after a PTE has been marked invalid. + + The workaround forces KVM to explicitly set VTCR_EL2.HA to 0, + which avoids enabling unadvertised hardware Access Flag management + at stage-2. + + If unsure, say Y. + config ARM64_WORKAROUND_CLEAN_CACHE bool diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index 307faa2b4395..be66e94a21bd 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -730,6 +730,13 @@ const struct arm64_cpu_capabilities arm64_errata[] = { .cpu_enable = cpu_clear_bf16_from_user_emulation, }, #endif +#ifdef CONFIG_AMPERE_ERRATUM_AC03_CPU_38 + { + .desc = "AmpereOne erratum AC03_CPU_38", + .capability = ARM64_WORKAROUND_AMPERE_AC03_CPU_38, + ERRATA_MIDR_ALL_VERSIONS(MIDR_AMPERE1), + }, +#endif { } }; diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h index b5f53d3fc14c..dc584b0f4f12 100644 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -70,6 +70,56 @@ static inline void __activate_traps_fpsimd32(struct kvm_vcpu *vcpu) } } +static inline bool __hfgxtr_traps_required(void) +{ + if (cpus_have_final_cap(ARM64_SME)) + return true; + + if (cpus_have_final_cap(ARM64_WORKAROUND_AMPERE_AC03_CPU_38)) + return true; + + return false; +} + +static inline void __activate_traps_hfgxtr(void) +{ + u64 r_clr = 0, w_clr = 0, r_set = 0, w_set = 0, tmp; + + if (cpus_have_final_cap(ARM64_SME)) { + tmp = HFGxTR_EL2_nSMPRI_EL1_MASK | HFGxTR_EL2_nTPIDR2_EL0_MASK; + + r_clr |= tmp; + w_clr |= tmp; + } + + /* + * Trap guest writes to TCR_EL1 to prevent it from enabling HA or HD. + */ + if (cpus_have_final_cap(ARM64_WORKAROUND_AMPERE_AC03_CPU_38)) + w_set |= HFGxTR_EL2_TCR_EL1_MASK; + + sysreg_clear_set_s(SYS_HFGRTR_EL2, r_clr, r_set); + sysreg_clear_set_s(SYS_HFGWTR_EL2, w_clr, w_set); +} + +static inline void __deactivate_traps_hfgxtr(void) +{ + u64 r_clr = 0, w_clr = 0, r_set = 0, w_set = 0, tmp; + + if (cpus_have_final_cap(ARM64_SME)) { + tmp = HFGxTR_EL2_nSMPRI_EL1_MASK | HFGxTR_EL2_nTPIDR2_EL0_MASK; + + r_set |= tmp; + w_set |= tmp; + } + + if (cpus_have_final_cap(ARM64_WORKAROUND_AMPERE_AC03_CPU_38)) + w_clr |= HFGxTR_EL2_TCR_EL1_MASK; + + sysreg_clear_set_s(SYS_HFGRTR_EL2, r_clr, r_set); + sysreg_clear_set_s(SYS_HFGWTR_EL2, w_clr, w_set); +} + static inline void __activate_traps_common(struct kvm_vcpu *vcpu) { /* Trap on AArch32 cp15 c15 (impdef sysregs) accesses (EL1 or EL0) */ @@ -89,16 +139,8 @@ static inline void __activate_traps_common(struct kvm_vcpu *vcpu) vcpu->arch.mdcr_el2_host = read_sysreg(mdcr_el2); write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2); - if (cpus_have_final_cap(ARM64_SME)) { - sysreg_clear_set_s(SYS_HFGRTR_EL2, - HFGxTR_EL2_nSMPRI_EL1_MASK | - HFGxTR_EL2_nTPIDR2_EL0_MASK, - 0); - sysreg_clear_set_s(SYS_HFGWTR_EL2, - HFGxTR_EL2_nSMPRI_EL1_MASK | - HFGxTR_EL2_nTPIDR2_EL0_MASK, - 0); - } + if (__hfgxtr_traps_required()) + __activate_traps_hfgxtr(); } static inline void __deactivate_traps_common(struct kvm_vcpu *vcpu) @@ -109,14 +151,8 @@ static inline void __deactivate_traps_common(struct kvm_vcpu *vcpu) if (kvm_arm_support_pmu_v3()) write_sysreg(0, pmuserenr_el0); - if (cpus_have_final_cap(ARM64_SME)) { - sysreg_clear_set_s(SYS_HFGRTR_EL2, 0, - HFGxTR_EL2_nSMPRI_EL1_MASK | - HFGxTR_EL2_nTPIDR2_EL0_MASK); - sysreg_clear_set_s(SYS_HFGWTR_EL2, 0, - HFGxTR_EL2_nSMPRI_EL1_MASK | - HFGxTR_EL2_nTPIDR2_EL0_MASK); - } + if (__hfgxtr_traps_required()) + __deactivate_traps_hfgxtr(); } static inline void ___activate_traps(struct kvm_vcpu *vcpu) @@ -384,12 +420,39 @@ static bool kvm_hyp_handle_cntpct(struct kvm_vcpu *vcpu) return true; } +static bool handle_ampere1_tcr(struct kvm_vcpu *vcpu) +{ + u32 sysreg = esr_sys64_to_sysreg(kvm_vcpu_get_esr(vcpu)); + int rt = kvm_vcpu_sys_get_rt(vcpu); + u64 val = vcpu_get_reg(vcpu, rt); + + if (sysreg != SYS_TCR_EL1) + return false; + + /* + * Affected parts do not advertise support for hardware Access Flag / + * Dirty state management in ID_AA64MMFR1_EL1.HAFDBS, but the underlying + * control bits are still functional. The architecture requires these be + * RES0 on systems that do not implement FEAT_HAFDBS. + * + * Uphold the requirements of the architecture by masking guest writes + * to TCR_EL1.{HA,HD} here. + */ + val &= ~(TCR_HD | TCR_HA); + write_sysreg_el1(val, SYS_TCR); + return true; +} + static bool kvm_hyp_handle_sysreg(struct kvm_vcpu *vcpu, u64 *exit_code) { if (cpus_have_final_cap(ARM64_WORKAROUND_CAVIUM_TX2_219_TVM) && handle_tx2_tvm(vcpu)) return true; + if (cpus_have_final_cap(ARM64_WORKAROUND_AMPERE_AC03_CPU_38) && + handle_ampere1_tcr(vcpu)) + return true; + if (static_branch_unlikely(&vgic_v3_cpuif_trap) && __vgic_v3_perform_cpuif_access(vcpu) == 1) return true; diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index a3939a9a4f7a..f5714ba74e9e 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c @@ -628,10 +628,18 @@ u64 kvm_get_vtcr(u64 mmfr0, u64 mmfr1, u32 phys_shift) #ifdef CONFIG_ARM64_HW_AFDBM /* * Enable the Hardware Access Flag management, unconditionally - * on all CPUs. The features is RES0 on CPUs without the support - * and must be ignored by the CPUs. + * on all CPUs. In systems that have asymmetric support for the feature + * this allows KVM to leverage hardware support on the subset of cores + * that implement the feature. + * + * The architecture requires VTCR_EL2.HA to be RES0 (thus ignored by + * hardware) on implementations that do not advertise support for the + * feature. As such, setting HA unconditionally is safe, unless you + * happen to be running on a design that has unadvertised support for + * HAFDBS. Here be dragons. */ - vtcr |= VTCR_EL2_HA; + if (!cpus_have_final_cap(ARM64_WORKAROUND_AMPERE_AC03_CPU_38)) + vtcr |= VTCR_EL2_HA; #endif /* CONFIG_ARM64_HW_AFDBM */ /* Set the vmid bits */ diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps index 99eb7e50b2f4..b21c84672bbf 100644 --- a/arch/arm64/tools/cpucaps +++ b/arch/arm64/tools/cpucaps @@ -79,6 +79,7 @@ WORKAROUND_2077057 WORKAROUND_2457168 WORKAROUND_2645198 WORKAROUND_2658417 +WORKAROUND_AMPERE_AC03_CPU_38 WORKAROUND_TRBE_OVERWRITE_FILL_MODE WORKAROUND_TSB_FLUSH_FAILURE WORKAROUND_TRBE_WRITE_OUT_OF_RANGE |