diff options
| -rw-r--r-- | arch/arm64/include/asm/kvm_arm.h | 1 | ||||
| -rw-r--r-- | arch/arm64/include/asm/kvm_asm.h | 1 | ||||
| -rw-r--r-- | arch/arm64/include/asm/kvm_host.h | 2 | ||||
| -rw-r--r-- | arch/arm64/include/asm/kvm_hyp.h | 5 | ||||
| -rw-r--r-- | arch/arm64/kvm/arm.c | 13 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/include/hyp/fault.h | 75 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/include/hyp/switch.h | 235 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/include/nvhe/fixed_config.h | 200 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/include/nvhe/trap_handler.h | 2 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/Makefile | 2 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/hyp-main.c | 11 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/mem_protect.c | 8 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/pkvm.c | 185 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/setup.c | 3 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/switch.c | 99 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/sys_regs.c | 487 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/vhe/switch.c | 16 | ||||
| -rw-r--r-- | arch/arm64/kvm/sys_regs.c | 10 |
18 files changed, 1200 insertions, 155 deletions
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index 327120c0089f..a39fcf318c77 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -295,6 +295,7 @@ #define MDCR_EL2_HPMFZO (UL(1) << 29) #define MDCR_EL2_MTPME (UL(1) << 28) #define MDCR_EL2_TDCC (UL(1) << 27) +#define MDCR_EL2_HLP (UL(1) << 26) #define MDCR_EL2_HCCD (UL(1) << 23) #define MDCR_EL2_TTRF (UL(1) << 19) #define MDCR_EL2_HPMD (UL(1) << 17) diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h index 4654d27fd221..0167f3702c61 100644 --- a/arch/arm64/include/asm/kvm_asm.h +++ b/arch/arm64/include/asm/kvm_asm.h @@ -74,6 +74,7 @@ enum __kvm_host_smccc_func { __KVM_HOST_SMCCC_FUNC___vgic_v3_write_vmcr, __KVM_HOST_SMCCC_FUNC___vgic_v3_save_aprs, __KVM_HOST_SMCCC_FUNC___vgic_v3_restore_aprs, + __KVM_HOST_SMCCC_FUNC___pkvm_vcpu_init_traps, }; #define DECLARE_KVM_VHE_SYM(sym) extern char sym[] diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 019490c67976..d0221fb69a60 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -781,6 +781,8 @@ static inline bool kvm_vm_is_protected(struct kvm *kvm) return false; } +void kvm_init_protected_traps(struct kvm_vcpu *vcpu); + int kvm_arm_vcpu_finalize(struct kvm_vcpu *vcpu, int feature); bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu); diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h index 657d0c94cf82..5afd14ab15b9 100644 --- a/arch/arm64/include/asm/kvm_hyp.h +++ b/arch/arm64/include/asm/kvm_hyp.h @@ -115,7 +115,12 @@ int __pkvm_init(phys_addr_t phys, unsigned long size, unsigned long nr_cpus, void __noreturn __host_enter(struct kvm_cpu_context *host_ctxt); #endif +extern u64 kvm_nvhe_sym(id_aa64pfr0_el1_sys_val); +extern u64 kvm_nvhe_sym(id_aa64pfr1_el1_sys_val); +extern u64 kvm_nvhe_sym(id_aa64isar0_el1_sys_val); +extern u64 kvm_nvhe_sym(id_aa64isar1_el1_sys_val); extern u64 kvm_nvhe_sym(id_aa64mmfr0_el1_sys_val); extern u64 kvm_nvhe_sym(id_aa64mmfr1_el1_sys_val); +extern u64 kvm_nvhe_sym(id_aa64mmfr2_el1_sys_val); #endif /* __ARM64_KVM_HYP_H__ */ diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index a469a817ca86..24a1e86d7128 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -622,6 +622,14 @@ static int kvm_vcpu_first_run_init(struct kvm_vcpu *vcpu) ret = kvm_arm_pmu_v3_enable(vcpu); + /* + * Initialize traps for protected VMs. + * NOTE: Move to run in EL2 directly, rather than via a hypercall, once + * the code is in place for first run initialization at EL2. + */ + if (kvm_vm_is_protected(kvm)) + kvm_call_hyp_nvhe(__pkvm_vcpu_init_traps, vcpu); + return ret; } @@ -1819,8 +1827,13 @@ static int kvm_hyp_init_protection(u32 hyp_va_bits) void *addr = phys_to_virt(hyp_mem_base); int ret; + kvm_nvhe_sym(id_aa64pfr0_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1); + kvm_nvhe_sym(id_aa64pfr1_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64PFR1_EL1); + kvm_nvhe_sym(id_aa64isar0_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64ISAR0_EL1); + kvm_nvhe_sym(id_aa64isar1_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64ISAR1_EL1); kvm_nvhe_sym(id_aa64mmfr0_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1); kvm_nvhe_sym(id_aa64mmfr1_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1); + kvm_nvhe_sym(id_aa64mmfr2_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64MMFR2_EL1); ret = create_hyp_mappings(addr, addr + hyp_mem_size, PAGE_HYP); if (ret) diff --git a/arch/arm64/kvm/hyp/include/hyp/fault.h b/arch/arm64/kvm/hyp/include/hyp/fault.h new file mode 100644 index 000000000000..1b8a2dcd712f --- /dev/null +++ b/arch/arm64/kvm/hyp/include/hyp/fault.h @@ -0,0 +1,75 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2015 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@arm.com> + */ + +#ifndef __ARM64_KVM_HYP_FAULT_H__ +#define __ARM64_KVM_HYP_FAULT_H__ + +#include <asm/kvm_asm.h> +#include <asm/kvm_emulate.h> +#include <asm/kvm_hyp.h> +#include <asm/kvm_mmu.h> + +static inline bool __translate_far_to_hpfar(u64 far, u64 *hpfar) +{ + u64 par, tmp; + + /* + * Resolve the IPA the hard way using the guest VA. + * + * Stage-1 translation already validated the memory access + * rights. As such, we can use the EL1 translation regime, and + * don't have to distinguish between EL0 and EL1 access. + * + * We do need to save/restore PAR_EL1 though, as we haven't + * saved the guest context yet, and we may return early... + */ + par = read_sysreg_par(); + if (!__kvm_at("s1e1r", far)) + tmp = read_sysreg_par(); + else + tmp = SYS_PAR_EL1_F; /* back to the guest */ + write_sysreg(par, par_el1); + + if (unlikely(tmp & SYS_PAR_EL1_F)) + return false; /* Translation failed, back to guest */ + + /* Convert PAR to HPFAR format */ + *hpfar = PAR_TO_HPFAR(tmp); + return true; +} + +static inline bool __get_fault_info(u64 esr, struct kvm_vcpu_fault_info *fault) +{ + u64 hpfar, far; + + far = read_sysreg_el2(SYS_FAR); + + /* + * The HPFAR can be invalid if the stage 2 fault did not + * happen during a stage 1 page table walk (the ESR_EL2.S1PTW + * bit is clear) and one of the two following cases are true: + * 1. The fault was due to a permission fault + * 2. The processor carries errata 834220 + * + * Therefore, for all non S1PTW faults where we either have a + * permission fault or the errata workaround is enabled, we + * resolve the IPA using the AT instruction. + */ + if (!(esr & ESR_ELx_S1PTW) && + (cpus_have_final_cap(ARM64_WORKAROUND_834220) || + (esr & ESR_ELx_FSC_TYPE) == FSC_PERM)) { + if (!__translate_far_to_hpfar(far, &hpfar)) + return false; + } else { + hpfar = read_sysreg(hpfar_el2); + } + + fault->far_el2 = far; + fault->hpfar_el2 = hpfar; + return true; +} + +#endif diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h index a0e78a6027be..c6e98c7e918b 100644 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -8,6 +8,7 @@ #define __ARM64_KVM_HYP_SWITCH_H__ #include <hyp/adjust_pc.h> +#include <hyp/fault.h> #include <linux/arm-smccc.h> #include <linux/kvm_host.h> @@ -133,78 +134,9 @@ static inline void ___deactivate_traps(struct kvm_vcpu *vcpu) } } -static inline bool __translate_far_to_hpfar(u64 far, u64 *hpfar) -{ - u64 par, tmp; - - /* - * Resolve the IPA the hard way using the guest VA. - * - * Stage-1 translation already validated the memory access - * rights. As such, we can use the EL1 translation regime, and - * don't have to distinguish between EL0 and EL1 access. - * - * We do need to save/restore PAR_EL1 though, as we haven't - * saved the guest context yet, and we may return early... - */ - par = read_sysreg_par(); - if (!__kvm_at("s1e1r", far)) - tmp = read_sysreg_par(); - else - tmp = SYS_PAR_EL1_F; /* back to the guest */ - write_sysreg(par, par_el1); - - if (unlikely(tmp & SYS_PAR_EL1_F)) - return false; /* Translation failed, back to guest */ - - /* Convert PAR to HPFAR format */ - *hpfar = PAR_TO_HPFAR(tmp); - return true; -} - -static inline bool __get_fault_info(u64 esr, struct kvm_vcpu_fault_info *fault) -{ - u64 hpfar, far; - - far = read_sysreg_el2(SYS_FAR); - - /* - * The HPFAR can be invalid if the stage 2 fault did not - * happen during a stage 1 page table walk (the ESR_EL2.S1PTW - * bit is clear) and one of the two following cases are true: - * 1. The fault was due to a permission fault - * 2. The processor carries errata 834220 - * - * Therefore, for all non S1PTW faults where we either have a - * permission fault or the errata workaround is enabled, we - * resolve the IPA using the AT instruction. - */ - if (!(esr & ESR_ELx_S1PTW) && - (cpus_have_final_cap(ARM64_WORKAROUND_834220) || - (esr & ESR_ELx_FSC_TYPE) == FSC_PERM)) { - if (!__translate_far_to_hpfar(far, &hpfar)) - return false; - } else { - hpfar = read_sysreg(hpfar_el2); - } - - fault->far_el2 = far; - fault->hpfar_el2 = hpfar; - return true; -} - static inline bool __populate_fault_info(struct kvm_vcpu *vcpu) { - u8 ec; - u64 esr; - - esr = vcpu->arch.fault.esr_el2; - ec = ESR_ELx_EC(esr); - - if (ec != ESR_ELx_EC_DABT_LOW && ec != ESR_ELx_EC_IABT_LOW) - return true; - - return __get_fault_info(esr, &vcpu->arch.fault); + return __get_fault_info(vcpu->arch.fault.esr_el2, &vcpu->arch.fault); } static inline void __hyp_sve_save_host(struct kvm_vcpu *vcpu) @@ -225,8 +157,13 @@ static inline void __hyp_sve_restore_guest(struct kvm_vcpu *vcpu) write_sysreg_el1(__vcpu_sys_reg(vcpu, ZCR_EL1), SYS_ZCR); } -/* Check for an FPSIMD/SVE trap and handle as appropriate */ -static inline bool __hyp_handle_fpsimd(struct kvm_vcpu *vcpu) +/* + * We trap the first access to the FP/SIMD to save the host context and + * restore the guest context lazily. + * If FP/SIMD is not implemented, handle the trap and inject an undefined + * instruction exception to the guest. Similarly for trapped SVE accesses. + */ +static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code) { bool sve_guest, sve_host; u8 esr_ec; @@ -244,9 +181,6 @@ static inline bool __hyp_handle_fpsimd(struct kvm_vcpu *vcpu) } esr_ec = kvm_vcpu_trap_get_class(vcpu); - if (esr_ec != ESR_ELx_EC_FP_ASIMD && - esr_ec != ESR_ELx_EC_SVE) - return false; /* Don't handle SVE traps for non-SVE vcpus here: */ if (!sve_guest && esr_ec != ESR_ELx_EC_FP_ASIMD) @@ -348,14 +282,6 @@ static inline bool handle_tx2_tvm(struct kvm_vcpu *vcpu) static inline bool esr_is_ptrauth_trap(u32 esr) { - u32 ec = ESR_ELx_EC(esr); - - if (ec == ESR_ELx_EC_PAC) - return true; - - if (ec != ESR_ELx_EC_SYS64) - return false; - switch (esr_sys64_to_sysreg(esr)) { case SYS_APIAKEYLO_EL1: case SYS_APIAKEYHI_EL1: @@ -384,13 +310,12 @@ static inline bool esr_is_ptrauth_trap(u32 esr) DECLARE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt); -static inline bool __hyp_handle_ptrauth(struct kvm_vcpu *vcpu) +static bool kvm_hyp_handle_ptrauth(struct kvm_vcpu *vcpu, u64 *exit_code) { struct kvm_cpu_context *ctxt; u64 val; - if (!vcpu_has_ptrauth(vcpu) || - !esr_is_ptrauth_trap(kvm_vcpu_get_esr(vcpu))) + if (!vcpu_has_ptrauth(vcpu)) return false; ctxt = this_cpu_ptr(&kvm_hyp_ctxt); @@ -409,6 +334,90 @@ static inline bool __hyp_handle_ptrauth(struct kvm_vcpu *vcpu) 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 (static_branch_unlikely(&vgic_v3_cpuif_trap) && + __vgic_v3_perform_cpuif_access(vcpu) == 1) + return true; + + if (esr_is_ptrauth_trap(kvm_vcpu_get_esr(vcpu))) + return kvm_hyp_handle_ptrauth(vcpu, exit_code); + + return false; +} + +static bool kvm_hyp_handle_cp15_32(struct kvm_vcpu *vcpu, u64 *exit_code) +{ + if (static_branch_unlikely(&vgic_v3_cpuif_trap) && + __vgic_v3_perform_cpuif_access(vcpu) == 1) + return true; + + return false; +} + +static bool kvm_hyp_handle_iabt_low(struct kvm_vcpu *vcpu, u64 *exit_code) +{ + if (!__populate_fault_info(vcpu)) + return true; + + return false; +} + +static bool kvm_hyp_handle_dabt_low(struct kvm_vcpu *vcpu, u64 *exit_code) +{ + if (!__populate_fault_info(vcpu)) + return true; + + if (static_branch_unlikely(&vgic_v2_cpuif_trap)) { + bool valid; + + valid = kvm_vcpu_trap_get_fault_type(vcpu) == FSC_FAULT && + kvm_vcpu_dabt_isvalid(vcpu) && + !kvm_vcpu_abt_issea(vcpu) && + !kvm_vcpu_abt_iss1tw(vcpu); + + if (valid) { + int ret = __vgic_v2_perform_cpuif_access(vcpu); + + if (ret == 1) + return true; + + /* Promote an illegal access to an SError.*/ + if (ret == -1) + *exit_code = ARM_EXCEPTION_EL1_SERROR; + } + } + + return false; +} + +typedef bool (*exit_handler_fn)(struct kvm_vcpu *, u64 *); + +static const exit_handler_fn *kvm_get_exit_handler_array(struct kvm_vcpu *vcpu); + +/* + * Allow the hypervisor to handle the exit with an exit handler if it has one. + * + * Returns true if the hypervisor handled the exit, and control should go back + * to the guest, or false if it hasn't. + */ +static inline bool kvm_hyp_handle_exit(struct kvm_vcpu *vcpu, u64 *exit_code) +{ + const exit_handler_fn *handlers = kvm_get_exit_handler_array(vcpu); + exit_handler_fn fn; + + fn = handlers[kvm_vcpu_trap_get_class(vcpu)]; + + if (fn) + return fn(vcpu, exit_code); + + return false; +} + /* * Return true when we were able to fixup the guest exit and should return to * the guest, false when we should restore the host state and return to the @@ -443,59 +452,9 @@ static inline bool fixup_guest_exit(struct kvm_vcpu *vcpu, u64 *exit_code) if (*exit_code != ARM_EXCEPTION_TRAP) goto exit; - if (cpus_have_final_cap(ARM64_WORKAROUND_CAVIUM_TX2_219_TVM) && - kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_SYS64 && - handle_tx2_tvm(vcpu)) + /* Check if there's an exit handler and allow it to handle the exit. */ + if (kvm_hyp_handle_exit(vcpu, exit_code)) goto guest; - - /* - * We trap the first access to the FP/SIMD to save the host context - * and restore the guest context lazily. - * If FP/SIMD is not implemented, handle the trap and inject an - * undefined instruction exception to the guest. - * Similarly for trapped SVE accesses. - */ - if (__hyp_handle_fpsimd(vcpu)) - goto guest; - - if (__hyp_handle_ptrauth(vcpu)) - goto guest; - - if (!__populate_fault_info(vcpu)) - goto guest; - - if (static_branch_unlikely(&vgic_v2_cpuif_trap)) { - bool valid; - - valid = kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_DABT_LOW && - kvm_vcpu_trap_get_fault_type(vcpu) == FSC_FAULT && - kvm_vcpu_dabt_isvalid(vcpu) && - !kvm_vcpu_abt_issea(vcpu) && - !kvm_vcpu_abt_iss1tw(vcpu); - - if (valid) { - int ret = __vgic_v2_perform_cpuif_access(vcpu); - - if (ret == 1) - goto guest; - - /* Promote an illegal access to an SError.*/ - if (ret == -1) - *exit_code = ARM_EXCEPTION_EL1_SERROR; - - goto exit; - } - } - - if (static_branch_unlikely(&vgic_v3_cpuif_trap) && - (kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_SYS64 || - kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_CP15_32)) { - int ret = __vgic_v3_perform_cpuif_access(vcpu); - - if (ret == 1) - goto guest; - } - exit: /* Return to the host kernel and handle the exit */ return false; diff --git a/arch/arm64/kvm/hyp/include/nvhe/fixed_config.h b/arch/arm64/kvm/hyp/include/nvhe/fixed_config.h new file mode 100644 index 000000000000..eea1f6a53723 --- /dev/null +++ b/arch/arm64/kvm/hyp/include/nvhe/fixed_config.h @@ -0,0 +1,200 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2021 Google LLC + * Author: Fuad Tabba <tabba@google.com> + */ + +#ifndef __ARM64_KVM_FIXED_CONFIG_H__ +#define __ARM64_KVM_FIXED_CONFIG_H__ + +#include <asm/sysreg.h> + +/* + * This file contains definitions for features to be allowed or restricted for + * guest virtual machines, depending on the mode KVM is running in and on the + * type of guest that is running. + * + * The ALLOW masks represent a bitmask of feature fields that are allowed + * without any restrictions as long as they are supported by the system. + * + * The RESTRICT_UNSIGNED masks, if present, represent unsigned fields for + * features that are restricted to support at most the specified feature. + * + * If a feature field is not present in either, than it is not supported. + * + * The approach taken for protected VMs is to allow features that are: + * - Needed by common Linux distributions (e.g., floating point) + * - Trivial to support, e.g., supporting the feature does not introduce or + * require tracking of additional state in KVM + * - Cannot be trapped or prevent the guest from using anyway + */ + +/* + * Allow for protected VMs: + * - Floating-point and Advanced SIMD + * - Data Independent Timing + */ +#define PVM_ID_AA64PFR0_ALLOW (\ + ARM64_FEATURE_MASK(ID_AA64PFR0_FP) | \ + ARM64_FEATURE_MASK(ID_AA64PFR0_ASIMD) | \ + ARM64_FEATURE_MASK(ID_AA64PFR0_DIT) \ + ) + +/* + * Restrict to the following *unsigned* features for protected VMs: + * - AArch64 guests only (no support for AArch32 guests): + * AArch32 adds complexity in trap handling, emulation, condition codes, + * etc... + * - RAS (v1) + * Supported by KVM + */ +#define PVM_ID_AA64PFR0_RESTRICT_UNSIGNED (\ + FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL0), ID_AA64PFR0_ELx_64BIT_ONLY) | \ + FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1), ID_AA64PFR0_ELx_64BIT_ONLY) | \ + FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL2), ID_AA64PFR0_ELx_64BIT_ONLY) | \ + FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL3), ID_AA64PFR0_ELx_64BIT_ONLY) | \ + FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_RAS), ID_AA64PFR0_RAS_V1) \ + ) + +/* + * Allow for protected VMs: + * - Branch Target Identification + * - Speculative Store Bypassing + */ +#define PVM_ID_AA64PFR1_ALLOW (\ + ARM64_FEATURE_MASK(ID_AA64PFR1_BT) | \ + ARM64_FEATURE_MASK(ID_AA64PFR1_SSBS) \ + ) + +/* + * Allow for protected VMs: + * - Mixed-endian + * - Distinction between Secure and Non-secure Memory + * - Mixed-endian at EL0 only + * - Non-context synchronizing exception entry and exit + */ +#define PVM_ID_AA64MMFR0_ALLOW (\ + ARM64_FEATURE_MASK(ID_AA64MMFR0_BIGENDEL) | \ + ARM64_FEATURE_MASK(ID_AA64MMFR0_SNSMEM) | \ + ARM64_FEATURE_MASK(ID_AA64MMFR0_BIGENDEL0) | \ + ARM64_FEATURE_MASK(ID_AA64MMFR0_EXS) \ + ) + +/* + * Restrict to the following *unsigned* features for protected VMs: + * - 40-bit IPA + * - 16-bit ASID + */ +#define PVM_ID_AA64MMFR0_RESTRICT_UNSIGNED (\ + FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64MMFR0_PARANGE), ID_AA64MMFR0_PARANGE_40) | \ + FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64MMFR0_ASID), ID_AA64MMFR0_ASID_16) \ + ) + +/* + * Allow for protected VMs: + * - Hardware translation table updates to Access flag and Dirty state + * - Number of VMID bits from CPU + * - Hierarchical Permission Disables + * - Privileged Access Never + * - SError interrupt exceptions from speculative reads + * - Enhanced Translation Synchronization + */ +#define PVM_ID_AA64MMFR1_ALLOW (\ + ARM64_FEATURE_MASK(ID_AA64MMFR1_HADBS) | \ + ARM64_FEATURE_MASK(ID_AA64MMFR1_VMIDBITS) | \ + ARM64_FEATURE_MASK(ID_AA64MMFR1_HPD) | \ + ARM64_FEATURE_MASK(ID_AA64MMFR1_PAN) | \ + ARM64_FEATURE_MASK(ID_AA64MMFR1_SPECSEI) | \ + ARM64_FEATURE_MASK(ID_AA64MMFR1_ETS) \ + ) + +/* + * Allow for protected VMs: + * - Common not Private translations + * - User Access Override + * - IESB bit in the SCTLR_ELx registers + * - Unaligned single-copy atomicity and atomic functions + * - ESR_ELx.EC value on an exception by read access to feature ID space + * - TTL field in address operations. + * - Break-before-make sequences when changing translation block size + * - E0PDx mechanism + */ +#define PVM_ID_AA64MMFR2_ALLOW (\ + ARM64_FEATURE_MASK(ID_AA64MMFR2_CNP) | \ + ARM64_FEATURE_MASK(ID_AA64MMFR2_UAO) | \ + ARM64_FEATURE_MASK(ID_AA64MMFR2_IESB) | \ + ARM64_FEATURE_MASK(ID_AA64MMFR2_AT) | \ + ARM64_FEATURE_MASK(ID_AA64MMFR2_IDS) | \ + ARM64_FEATURE_MASK(ID_AA64MMFR2_TTL) | \ + ARM64_FEATURE_MASK(ID_AA64MMFR2_BBM) | \ + ARM64_FEATURE_MASK(ID_AA64MMFR2_E0PD) \ + ) + +/* + * No support for Scalable Vectors for protected VMs: + * Requires additional support from KVM, e.g., context-switching and + * trapping at EL2 + */ +#define PVM_ID_AA64ZFR0_ALLOW (0ULL) + +/* + * No support for debug, including breakpoints, and watchpoints for protected + * VMs: + * The Arm architecture mandates support for at least the Armv8 debug + * architecture, which would include at least 2 hardware breakpoints and + * watchpoints. Providing that support to protected guests adds + * considerable state and complexity. Therefore, the reserved value of 0 is + * used for debug-related fields. + */ +#define PVM_ID_AA64DFR0_ALLOW (0ULL) +#define PVM_ID_AA64DFR1_ALLOW (0ULL) + +/* + * No support for implementation defined features. + */ +#define PVM_ID_AA64AFR0_ALLOW (0ULL) +#define PVM_ID_AA64AFR1_ALLOW (0ULL) + +/* + * No restrictions on instructions implemented in AArch64. + */ +#define PVM_ID_AA64ISAR0_ALLOW (\ + ARM64_FEATURE_MASK(ID_AA64ISAR0_AES) | \ + ARM64_FEATURE_MASK(ID_AA64ISAR0_SHA1) | \ + ARM64_FEATURE_MASK(ID_AA64ISAR0_SHA2) | \ + ARM64_FEATURE_MASK(ID_AA64ISAR0_CRC32) | \ + ARM64_FEATURE_MASK(ID_AA64ISAR0_ATOMICS) | \ + ARM64_FEATURE_MASK(ID_AA64ISAR0_RDM) | \ + ARM64_FEATURE_MASK(ID_AA64ISAR0_SHA3) | \ + ARM64_FEATURE_MASK(ID_AA64ISAR0_SM3) | \ + ARM64_FEATURE_MASK(ID_AA64ISAR0_SM4) | \ + ARM64_FEATURE_MASK(ID_AA64ISAR0_DP) | \ + ARM64_FEATURE_MASK(ID_AA64ISAR0_FHM) | \ + ARM64_FEATURE_MASK(ID_AA64ISAR0_TS) | \ + ARM64_FEATURE_MASK(ID_AA64ISAR0_TLB) | \ + ARM64_FEATURE_MASK(ID_AA64ISAR0_RNDR) \ + ) + +#define PVM_ID_AA64ISAR1_ALLOW (\ + ARM64_FEATURE_MASK(ID_AA64ISAR1_DPB) | \ + ARM64_FEATURE_MASK(ID_AA64ISAR1_APA) | \ + ARM64_FEATURE_MASK(ID_AA64ISAR1_API) | \ + ARM64_FEATURE_MASK(ID_AA64ISAR1_JSCVT) | \ + ARM64_FEATURE_MASK(ID_AA64ISAR1_FCMA) | \ + ARM64_FEATURE_MASK(ID_AA64ISAR1_LRCPC) | \ + ARM64_FEATURE_MASK(ID_AA64ISAR1_GPA) | \ + ARM64_FEATURE_MASK(ID_AA64ISAR1_GPI) | \ + ARM64_FEATURE_MASK(ID_AA64ISAR1_FRINTTS) | \ + ARM64_FEATURE_MASK(ID_AA64ISAR1_SB) | \ + ARM64_FEATURE_MASK(ID_AA64ISAR1_SPECRES) | \ + ARM64_FEATURE_MASK(ID_AA64ISAR1_BF16) | \ + ARM64_FEATURE_MASK(ID_AA64ISAR1_DGH) | \ + ARM64_FEATURE_MASK(ID_AA64ISAR1_I8MM) \ + ) + +u64 pvm_read_id_reg(const struct kvm_vcpu *vcpu, u32 id); +bool kvm_handle_pvm_sysreg(struct kvm_vcpu *vcpu, u64 *exit_code); +bool kvm_handle_pvm_restricted(struct kvm_vcpu *vcpu, u64 *exit_code); +int kvm_check_pvm_sysreg_table(void); + +#endif /* __ARM64_KVM_FIXED_CONFIG_H__ */ diff --git a/arch/arm64/kvm/hyp/include/nvhe/trap_handler.h b/arch/arm64/kvm/hyp/include/nvhe/trap_handler.h index 1e6d995968a1..45a84f0ade04 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/trap_handler.h +++ b/arch/arm64/kvm/hyp/include/nvhe/trap_handler.h @@ -15,4 +15,6 @@ #define DECLARE_REG(type, name, ctxt, reg) \ type name = (type)cpu_reg(ctxt, (reg)) +void __pkvm_vcpu_init_traps(struct kvm_vcpu *vcpu); + #endif /* __ARM64_KVM_NVHE_TRAP_HANDLER_H__ */ diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile index 8d741f71377f..c3c11974fa3b 100644 --- a/arch/arm64/kvm/hyp/nvhe/Makefile +++ b/arch/arm64/kvm/hyp/nvhe/Makefile @@ -14,7 +14,7 @@ lib-objs := $(addprefix ../../../lib/, $(lib-objs)) obj-y := timer-sr.o sysreg-sr.o debug-sr.o switch.o tlb.o hyp-init.o host.o \ hyp-main.o hyp-smp.o psci-relay.o early_alloc.o stub.o page_alloc.o \ - cache.o setup.o mm.o mem_protect.o + cache.o setup.o mm.o mem_protect.o sys_regs.o pkvm.o obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \ ../fpsimd.o ../hyp-entry.o ../exception.o ../pgtable.o obj-y += $(lib-objs) diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c index 8566805ef62c..b096bf009144 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -4,7 +4,7 @@ * Author: Andrew Scull <ascull@google.com> */ -#include <hyp/switch.h> +#include <hyp/adjust_pc.h> #include <asm/pgtable-types.h> #include <asm/kvm_asm.h> @@ -160,6 +160,14 @@ static void handle___pkvm_prot_finalize(struct kvm_cpu_context *host_ctxt) { cpu_reg(host_ctxt, 1) = __pkvm_prot_finalize(); } + +static void handle___pkvm_vcpu_init_traps(struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(struct kvm_vcpu *, vcpu, host_ctxt, 1); + + __pkvm_vcpu_init_traps(kern_hyp_va(vcpu)); +} + typedef void (*hcall_t)(struct kvm_cpu_context *); #define HANDLE_FUNC(x) [__KVM_HOST_SMCCC_FUNC_##x] = (hcall_t)handle_##x @@ -187,6 +195,7 @@ static const hcall_t host_hcall[] = { HANDLE_FUNC(__vgic_v3_write_vmcr), HANDLE_FUNC(__vgic_v3_save_aprs), HANDLE_FUNC(__vgic_v3_restore_aprs), + HANDLE_FUNC(__pkvm_vcpu_init_traps), }; static void handle_host_hcall(struct kvm_cpu_context *host_ctxt) diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c index cafe17e5fa8f..1f0fb0780622 100644 --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c @@ -11,7 +11,7 @@ #include <asm/kvm_pgtable.h> #include <asm/stage2_pgtable.h> -#include <hyp/switch.h> +#include <hyp/fault.h> #include <nvhe/gfp.h> #include <nvhe/memory.h> @@ -25,12 +25,6 @@ struct host_kvm host_kvm; static struct hyp_pool host_s2_pool; -/* - * Copies of the host's CPU features registers holding sanitized values. - */ -u64 id_aa64mmfr0_el1_sys_val; -u64 id_aa64mmfr1_el1_sys_val; - const u8 pkvm_hyp_id = 1; static void *host_s2_zalloc_pages_exact(size_t size) diff --git a/arch/arm64/kvm/hyp/nvhe/pkvm.c b/arch/arm64/kvm/hyp/nvhe/pkvm.c new file mode 100644 index 000000000000..99c8d8b73e70 --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/pkvm.c @@ -0,0 +1,185 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2021 Google LLC + * Author: Fuad Tabba <tabba@google.com> + */ + +#include <linux/kvm_host.h> +#include <linux/mm.h> +#include <nvhe/fixed_config.h> +#include <nvhe/trap_handler.h> + +/* + * Set trap register values based on features in ID_AA64PFR0. + */ +static void pvm_init_traps_aa64pfr0(struct kvm_vcpu *vcpu) +{ + const u64 feature_ids = pvm_read_id_reg(vcpu, SYS_ID_AA64PFR0_EL1); + u64 hcr_set = HCR_RW; + u64 hcr_clear = 0; + u64 cptr_set = 0; + + /* Protected KVM does not support AArch32 guests. */ + BUILD_BUG_ON(FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL0), + PVM_ID_AA64PFR0_RESTRICT_UNSIGNED) != ID_AA64PFR0_ELx_64BIT_ONLY); + BUILD_BUG_ON(FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1), + PVM_ID_AA64PFR0_RESTRICT_UNSIGNED) != ID_AA64PFR0_ELx_64BIT_ONLY); + + /* + * Linux guests assume support for floating-point and Advanced SIMD. Do + * not change the trapping behavior for these from the KVM default. + */ + BUILD_BUG_ON(!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_FP), + PVM_ID_AA64PFR0_ALLOW)); + BUILD_BUG_ON(!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_ASIMD), + PVM_ID_AA64PFR0_ALLOW)); + + /* Trap RAS unless all current versions are supported */ + if (FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_RAS), feature_ids) < + ID_AA64PFR0_RAS_V1P1) { + hcr_set |= HCR_TERR | HCR_TEA; + hcr_clear |= HCR_FIEN; + } + + /* Trap AMU */ + if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_AMU), feature_ids)) { + hcr_clear |= HCR_AMVOFFEN; + cptr_set |= CPTR_EL2_TAM; + } + + /* Trap SVE */ + if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_SVE), feature_ids)) + cptr_set |= CPTR_EL2_TZ; + + vcpu->arch.hcr_el2 |= hcr_set; + vcpu->arch.hcr_el2 &= ~hcr_clear; + vcpu->arch.cptr_el2 |= cptr_set; +} + +/* + * Set trap register values based on features in ID_AA64PFR1. + */ +static void pvm_init_traps_aa64pfr1(struct kvm_vcpu *vcpu) +{ + const u64 feature_ids = pvm_read_id_reg(vcpu, SYS_ID_AA64PFR1_EL1); + u64 hcr_set = 0; + u64 hcr_clear = 0; + + /* Memory Tagging: Trap and Treat as Untagged if not supported. */ + if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR1_MTE), feature_ids)) { + hcr_set |= HCR_TID5; + hcr_clear |= HCR_DCT | HCR_ATA; + } + + vcpu->arch.hcr_el2 |= hcr_set; + vcpu->arch.hcr_el2 &= ~hcr_clear; +} + +/* + * Set trap register values based on features in ID_AA64DFR0. + */ +static void pvm_init_traps_aa64dfr0(struct kvm_vcpu *vcpu) +{ + const u64 feature_ids = pvm_read_id_reg(vcpu, SYS_ID_AA64DFR0_EL1); + u64 mdcr_set = 0; + u64 mdcr_clear = 0; + u64 cptr_set = 0; + + /* Trap/constrain PMU */ + if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_PMUVER), feature_ids)) { + mdcr_set |= MDCR_EL2_TPM | MDCR_EL2_TPMCR; + mdcr_clear |= MDCR_EL2_HPME | MDCR_EL2_MTPME | + MDCR_EL2_HPMN_MASK; + } + + /* Trap Debug */ + if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_DEBUGVER), feature_ids)) + mdcr_set |= MDCR_EL2_TDRA | MDCR_EL2_TDA | MDCR_EL2_TDE; + + /* Trap OS Double Lock */ + if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_DOUBLELOCK), feature_ids)) + mdcr_set |= MDCR_EL2_TDOSA; + + /* Trap SPE */ + if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_PMSVER), feature_ids)) { + mdcr_set |= MDCR_EL2_TPMS; + mdcr_clear |= MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT; + } + + /* Trap Trace Filter */ + if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_TRACE_FILT), feature_ids)) + mdcr_set |= MDCR_EL2_TTRF; + + /* Trap Trace */ + if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_TRACEVER), feature_ids)) + cptr_set |= CPTR_EL2_TTA; + + vcpu->arch.mdcr_el2 |= mdcr_set; + vcpu->arch.mdcr_el2 &= ~mdcr_clear; + vcpu->arch.cptr_el2 |= cptr_set; +} + +/* + * Set trap register values based on features in ID_AA64MMFR0. + */ +static void pvm_init_traps_aa64mmfr0(struct kvm_vcpu *vcpu) +{ + const u64 feature_ids = pvm_read_id_reg(vcpu, SYS_ID_AA64MMFR0_EL1); + u64 mdcr_set = 0; + + /* Trap Debug Communications Channel registers */ + if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64MMFR0_FGT), feature_ids)) + mdcr_set |= MDCR_EL2_TDCC; + + vcpu->arch.mdcr_el2 |= mdcr_set; +} + +/* + * Set trap register values based on features in ID_AA64MMFR1. + */ +static void pvm_init_traps_aa64mmfr1(struct kvm_vcpu *vcpu) +{ + const u64 feature_ids = pvm_read_id_reg(vcpu, SYS_ID_AA64MMFR1_EL1); + u64 hcr_set = 0; + + /* Trap LOR */ + if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64MMFR1_LOR), feature_ids)) + hcr_set |= HCR_TLOR; + + vcpu->arch.hcr_el2 |= hcr_set; +} + +/* + * Set baseline trap register values. + */ +static void pvm_init_trap_regs(struct kvm_vcpu *vcpu) +{ + const u64 hcr_trap_feat_regs = HCR_TID3; + const u64 hcr_trap_impdef = HCR_TACR | HCR_TIDCP | HCR_TID1; + + /* + * Always trap: + * - Feature id registers: to control features exposed to guests + * - Implementation-defined features + */ + vcpu->arch.hcr_el2 |= hcr_trap_feat_regs | hcr_trap_impdef; + + /* Clear res0 and set res1 bits to trap potential new features. */ + vcpu->arch.hcr_el2 &= ~(HCR_RES0); + vcpu->arch.mdcr_el2 &= ~(MDCR_EL2_RES0); + vcpu->arch.cptr_el2 |= CPTR_NVHE_EL2_RES1; + vcpu->arch.cptr_el2 &= ~(CPTR_NVHE_EL2_RES0); +} + +/* + * Initialize trap register values for protected VMs. + */ +void __pkvm_vcpu_init_traps(struct kvm_vcpu *vcpu) +{ + pvm_init_trap_regs(vcpu); + pvm_init_traps_aa64pfr0(vcpu); + pvm_init_traps_aa64pfr1(vcpu); + pvm_init_traps_aa64dfr0(vcpu); + pvm_init_traps_aa64mmfr0(vcpu); + pvm_init_traps_aa64mmfr1(vcpu); +} diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c index 57c27846320f..862c7b514e20 100644 --- a/arch/arm64/kvm/hyp/nvhe/setup.c +++ b/arch/arm64/kvm/hyp/nvhe/setup.c @@ -10,6 +10,7 @@ #include <asm/kvm_pgtable.h> #include <nvhe/early_alloc.h> +#include <nvhe/fixed_config.h> #include <nvhe/gfp.h> #include <nvhe/memory.h> #include <nvhe/mem_protect.h> @@ -260,6 +261,8 @@ int __pkvm_init(phys_addr_t phys, unsigned long size, unsigned long nr_cpus, void (*fn)(phys_addr_t params_pa, void *finalize_fn_va); int ret; + BUG_ON(kvm_check_pvm_sysreg_table()); + if (!PAGE_ALIGNED(phys) || !PAGE_ALIGNED(size)) return -EINVAL; diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c index a34b01cc8ab9..c0e3fed26d93 100644 --- a/arch/arm64/kvm/hyp/nvhe/switch.c +++ b/arch/arm64/kvm/hyp/nvhe/switch.c @@ -27,6 +27,7 @@ #include <asm/processor.h> #include <asm/thread_info.h> +#include <nvhe/fixed_config.h> #include <nvhe/mem_protect.h> /* Non-VHE specific context */ @@ -158,6 +159,101 @@ static void __pmu_switch_to_host(struct kvm_cpu_context *host_ctxt) write_sysreg(pmu->events_host, pmcntenset_el0); } +/** + * Handler for protected VM MSR, MRS or System instruction execution in AArch64. + * + * Returns true if the hypervisor has handled the exit, and control should go + * back to the guest, or false if it hasn't. + */ +static bool kvm_handle_pvm_sys64(struct kvm_vcpu *vcpu, u64 *exit_code) +{ + /* + * Make sure we handle the exit for workarounds and ptrauth + * before the pKVM handling, as the latter could decide to + * UNDEF. + */ + return (kvm_hyp_handle_sysreg(vcpu, exit_code) || + kvm_handle_pvm_sysreg(vcpu, exit_code)); +} + +/** + * Handler for protected floating-point and Advanced SIMD accesses. + * + * Returns true if the hypervisor has handled the exit, and control should go + * back to the guest, or false if it hasn't. + */ +static bool kvm_handle_pvm_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code) +{ + /* Linux guests assume support for floating-point and Advanced SIMD. */ + BUILD_BUG_ON(!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_FP), + PVM_ID_AA64PFR0_ALLOW)); + BUILD_BUG_ON(!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_ASIMD), + PVM_ID_AA64PFR0_ALLOW)); + + return kvm_hyp_handle_fpsimd(vcpu, exit_code); +} + +static const exit_handler_fn hyp_exit_handlers[] = { + [0 ... ESR_ELx_EC_MAX] = NULL, + [ESR_ELx_EC_CP15_32] = kvm_hyp_handle_cp15_32, + [ESR_ELx_EC_SYS64] = kvm_hyp_handle_sysreg, + [ESR_ELx_EC_SVE] = kvm_hyp_handle_fpsimd, + [ESR_ELx_EC_FP_ASIMD] = kvm_hyp_handle_fpsimd, + [ESR_ELx_EC_IABT_LOW] = kvm_hyp_handle_iabt_low, + [ESR_ELx_EC_DABT_LOW] = kvm_hyp_handle_dabt_low, + [ESR_ELx_EC_PAC] = kvm_hyp_handle_ptrauth, +}; + +static const exit_handler_fn pvm_exit_handlers[] = { + [0 ... ESR_ELx_EC_MAX] = NULL, + [ESR_ELx_EC_SYS64] = kvm_handle_pvm_sys64, + [ESR_ELx_EC_SVE] = kvm_handle_pvm_restricted, + [ESR_ELx_EC_FP_ASIMD] = kvm_handle_pvm_fpsimd, + [ESR_ELx_EC_IABT_LOW] = kvm_hyp_handle_iabt_low, + [ESR_ELx_EC_DABT_LOW] = kvm_hyp_handle_dabt_low, + [ESR_ELx_EC_PAC] = kvm_hyp_handle_ptrauth, +}; + +static const exit_handler_fn *kvm_get_exit_handler_array(struct kvm_vcpu *vcpu) +{ + if (unlikely(kvm_vm_is_protected(kern_hyp_va(vcpu->kvm)))) + return pvm_exit_handlers; + + return hyp_exit_handlers; +} + +/* + * Some guests (e.g., protected VMs) are not be allowed to run in AArch32. + * The ARMv8 architecture does not give the hypervisor a mechanism to prevent a + * guest from dropping to AArch32 EL0 if implemented by the CPU. If the + * hypervisor spots a guest in such a state ensure it is handled, and don't + * trust the host to spot or fix it. The check below is based on the one in + * kvm_arch_vcpu_ioctl_run(). + * + * Returns false if the guest ran in AArch32 when it shouldn't have, and + * thus should exit to the host, or true if a the guest run loop can continue. + */ +static bool handle_aarch32_guest(struct kvm_vcpu *vcpu, u64 *exit_code) +{ + struct kvm *kvm = kern_hyp_va(vcpu->kvm); + + if (kvm_vm_is_protected(kvm) && vcpu_mode_is_32bit(vcpu)) { + /* + * As we have caught the guest red-handed, decide that it isn't + * fit for purpose anymore by making the vcpu invalid. The VMM + * can try and fix it by re-initializing the vcpu with + * KVM_ARM_VCPU_INIT, however, this is likely not possible for + * protected VMs. + */ + vcpu->arch.target = -1; + *exit_code &= BIT(ARM_EXIT_WITH_SERROR_BIT); + *exit_code |= ARM_EXCEPTION_IL; + return false; + } + + return true; +} + /* Switch to the guest for legacy non-VHE systems */ int __kvm_vcpu_run(struct kvm_vcpu *vcpu) { @@ -220,6 +316,9 @@ int __kvm_vcpu_run(struct kvm_vcpu *vcpu) /* Jump in the fire! */ exit_code = __guest_enter(vcpu); + if (unlikely(!handle_aarch32_guest(vcpu, &exit_code))) + break; + /* And we're baaack! */ } while (fixup_guest_exit(vcpu, &exit_code)); diff --git a/arch/arm64/kvm/hyp/nvhe/sys_regs.c b/arch/arm64/kvm/hyp/nvhe/sys_regs.c new file mode 100644 index 000000000000..3787ee6fb1a2 --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/sys_regs.c @@ -0,0 +1,487 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2021 Google LLC + * Author: Fuad Tabba <tabba@google.com> + */ + +#include <linux/irqchip/arm-gic-v3.h> + +#include <asm/kvm_asm.h> +#include <asm/kvm_mmu.h> + +#include <hyp/adjust_pc.h> + +#include <nvhe/fixed_config.h> + +#include "../../sys_regs.h" + +/* + * Copies of the host's CPU features registers holding sanitized values at hyp. + */ +u64 id_aa64pfr0_el1_sys_val; +u64 id_aa64pfr1_el1_sys_val; +u64 id_aa64isar0_el1_sys_val; +u64 id_aa64isar1_el1_sys_val; +u64 id_aa64mmfr0_el1_sys_val; +u64 id_aa64mmfr1_el1_sys_val; +u64 id_aa64mmfr2_el1_sys_val; + +/* + * Inject an unknown/undefined exception to an AArch64 guest while most of its + * sysregs are live. + */ +static void inject_undef64(struct kvm_vcpu *vcpu) +{ + u32 esr = (ESR_ELx_EC_UNKNOWN << ESR_ELx_EC_SHIFT); + + *vcpu_pc(vcpu) = read_sysreg_el2(SYS_ELR); + *vcpu_cpsr(vcpu) = read_sysreg_el2(SYS_SPSR); + + vcpu->arch.flags |= (KVM_ARM64_EXCEPT_AA64_EL1 | + KVM_ARM64_EXCEPT_AA64_ELx_SYNC | + KVM_ARM64_PENDING_EXCEPTION); + + __kvm_adjust_pc(vcpu); + + write_sysreg_el1(esr, SYS_ESR); + write_sysreg_el1(read_sysreg_el2(SYS_ELR), SYS_ELR); + write_sysreg_el2(*vcpu_pc(vcpu), SYS_ELR); + write_sysreg_el2(*vcpu_cpsr(vcpu), SYS_SPSR); +} + +/* + * Returns the restricted features values of the feature register based on the + * limitations in restrict_fields. + * A feature id field value of 0b0000 does not impose any restrictions. + * Note: Use only for unsigned feature field values. + */ +static u64 get_restricted_features_unsigned(u64 sys_reg_val, + u64 restrict_fields) +{ + u64 value = 0UL; + u64 mask = GENMASK_ULL(ARM64_FEATURE_FIELD_BITS - 1, 0); + + /* + * According to the Arm Architecture Reference Manual, feature fields + * use increasing values to indicate increases in functionality. + * Iterate over the restricted feature fields and calculate the minimum + * unsigned value between the one supported by the system, and what the + * value is being restricted to. + */ + while (sys_reg_val && restrict_fields) { + value |= min(sys_reg_val & mask, restrict_fields & mask); + sys_reg_val &= ~mask; + restrict_fields &= ~mask; + mask <<= ARM64_FEATURE_FIELD_BITS; + } + + return value; +} + +/* + * Functions that return the value of feature id registers for protected VMs + * based on allowed features, system features, and KVM support. + */ + +static u64 get_pvm_id_aa64pfr0(const struct kvm_vcpu *vcpu) +{ + const struct kvm *kvm = (const struct kvm *)kern_hyp_va(vcpu->kvm); + u64 set_mask = 0; + u64 allow_mask = PVM_ID_AA64PFR0_ALLOW; + + if (!vcpu_has_sve(vcpu)) + allow_mask &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_SVE); + + set_mask |= get_restricted_features_unsigned(id_aa64pfr0_el1_sys_val, + PVM_ID_AA64PFR0_RESTRICT_UNSIGNED); + + /* Spectre and Meltdown mitigation in KVM */ + set_mask |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_CSV2), + (u64)kvm->arch.pfr0_csv2); + set_mask |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_CSV3), + (u64)kvm->arch.pfr0_csv3); + + return (id_aa64pfr0_el1_sys_val & allow_mask) | set_mask; +} + +static u64 get_pvm_id_aa64pfr1(const struct kvm_vcpu *vcpu) +{ + const struct kvm *kvm = (const struct kvm *)kern_hyp_va(vcpu->kvm); + u64 allow_mask = PVM_ID_AA64PFR1_ALLOW; + + if (!kvm_has_mte(kvm)) + allow_mask &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_MTE); + + return id_aa64pfr1_el1_sys_val & allow_mask; +} + +static u64 get_pvm_id_aa64zfr0(const struct kvm_vcpu *vcpu) +{ + /* + * No support for Scalable Vectors, therefore, hyp has no sanitized + * copy of the feature id register. + */ + BUILD_BUG_ON(PVM_ID_AA64ZFR0_ALLOW != 0ULL); + return 0; +} + +static u64 get_pvm_id_aa64dfr0(const struct kvm_vcpu *vcpu) +{ + /* + * No support for debug, including breakpoints, and watchpoints, + * therefore, pKVM has no sanitized copy of the feature id register. + */ + BUILD_BUG_ON(PVM_ID_AA64DFR0_ALLOW != 0ULL); + return 0; +} + +static u64 get_pvm_id_aa64dfr1(const struct kvm_vcpu *vcpu) +{ + /* + * No support for debug, therefore, hyp has no sanitized copy of the + * feature id register. + */ + BUILD_BUG_ON(PVM_ID_AA64DFR1_ALLOW != 0ULL); + return 0; +} + +static u64 get_pvm_id_aa64afr0(const struct kvm_vcpu *vcpu) +{ + /* + * No support for implementation defined features, therefore, hyp has no + * sanitized copy of the feature id register. + */ + BUILD_BUG_ON(PVM_ID_AA64AFR0_ALLOW != 0ULL); + return 0; +} + +static u64 get_pvm_id_aa64afr1(const struct kvm_vcpu *vcpu) +{ + /* + * No support for implementation defined features, therefore, hyp has no + * sanitized copy of the feature id register. + */ + BUILD_BUG_ON(PVM_ID_AA64AFR1_ALLOW != 0ULL); + return 0; +} + +static u64 get_pvm_id_aa64isar0(const struct kvm_vcpu *vcpu) +{ + return id_aa64isar0_el1_sys_val & PVM_ID_AA64ISAR0_ALLOW; +} + +static u64 get_pvm_id_aa64isar1(const struct kvm_vcpu *vcpu) +{ + u64 allow_mask = PVM_ID_AA64ISAR1_ALLOW; + + if (!vcpu_has_ptrauth(vcpu)) + allow_mask &= ~(ARM64_FEATURE_MASK(ID_AA64ISAR1_APA) | + ARM64_FEATURE_MASK(ID_AA64ISAR1_API) | + ARM64_FEATURE_MASK(ID_AA64ISAR1_GPA) | + ARM64_FEATURE_MASK(ID_AA64ISAR1_GPI)); + + return id_aa64isar1_el1_sys_val & allow_mask; +} + +static u64 get_pvm_id_aa64mmfr0(const struct kvm_vcpu *vcpu) +{ + u64 set_mask; + + set_mask = get_restricted_features_unsigned(id_aa64mmfr0_el1_sys_val, + PVM_ID_AA64MMFR0_RESTRICT_UNSIGNED); + + return (id_aa64mmfr0_el1_sys_val & PVM_ID_AA64MMFR0_ALLOW) | set_mask; +} + +static u64 get_pvm_id_aa64mmfr1(const struct kvm_vcpu *vcpu) +{ + return id_aa64mmfr1_el1_sys_val & PVM_ID_AA64MMFR1_ALLOW; +} + +static u64 get_pvm_id_aa64mmfr2(const struct kvm_vcpu *vcpu) +{ + return id_aa64mmfr2_el1_sys_val & PVM_ID_AA64MMFR2_ALLOW; +} + +/* Read a sanitized cpufeature ID register by its encoding */ +u64 pvm_read_id_reg(const struct kvm_vcpu *vcpu, u32 id) +{ + switch (id) { + case SYS_ID_AA64PFR0_EL1: + return get_pvm_id_aa64pfr0(vcpu); + case SYS_ID_AA64PFR1_EL1: + return get_pvm_id_aa64pfr1(vcpu); + case SYS_ID_AA64ZFR0_EL1: + return get_pvm_id_aa64zfr0(vcpu); + case SYS_ID_AA64DFR0_EL1: + return get_pvm_id_aa64dfr0(vcpu); + case SYS_ID_AA64DFR1_EL1: + return get_pvm_id_aa64dfr1(vcpu); + case SYS_ID_AA64AFR0_EL1: + return get_pvm_id_aa64afr0(vcpu); + case SYS_ID_AA64AFR1_EL1: + return get_pvm_id_aa64afr1(vcpu); + case SYS_ID_AA64ISAR0_EL1: + return get_pvm_id_aa64isar0(vcpu); + case SYS_ID_AA64ISAR1_EL1: + return get_pvm_id_aa64isar1(vcpu); + case SYS_ID_AA64MMFR0_EL1: + return get_pvm_id_aa64mmfr0(vcpu); + case SYS_ID_AA64MMFR1_EL1: + return get_pvm_id_aa64mmfr1(vcpu); + case SYS_ID_AA64MMFR2_EL1: + return get_pvm_id_aa64mmfr2(vcpu); + default: + /* + * Should never happen because all cases are covered in + * pvm_sys_reg_descs[]. + */ + WARN_ON(1); + break; + } + + return 0; +} + +static u64 read_id_reg(const struct kvm_vcpu *vcpu, + struct sys_reg_desc const *r) +{ + return pvm_read_id_reg(vcpu, reg_to_encoding(r)); +} + +/* Handler to RAZ/WI sysregs */ +static bool pvm_access_raz_wi(struct kvm_vcpu *vcpu, struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + if (!p->is_write) + p->regval = 0; + + return true; +} + +/* + * Accessor for AArch32 feature id registers. + * + * The value of these registers is "unknown" according to the spec if AArch32 + * isn't supported. + */ +static bool pvm_access_id_aarch32(struct kvm_vcpu *vcpu, + struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + if (p->is_write) { + inject_undef64(vcpu); + return false; + } + + /* + * No support for AArch32 guests, therefore, pKVM has no sanitized copy + * of AArch32 feature id registers. + */ + BUILD_BUG_ON(FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1), + PVM_ID_AA64PFR0_RESTRICT_UNSIGNED) > ID_AA64PFR0_ELx_64BIT_ONLY); + + return pvm_access_raz_wi(vcpu, p, r); +} + +/* + * Accessor for AArch64 feature id registers. + * + * If access is allowed, set the regval to the protected VM's view of the + * register and return true. + * Otherwise, inject an undefined exception and return false. + */ +static bool pvm_access_id_aarch64(struct kvm_vcpu *vcpu, + struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + if (p->is_write) { + inject_undef64(vcpu); + return false; + } + + p->regval = read_id_reg(vcpu, r); + return true; +} + +static bool pvm_gic_read_sre(struct kvm_vcpu *vcpu, + struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + /* pVMs only support GICv3. 'nuf said. */ + if (!p->is_write) + p->regval = ICC_SRE_EL1_DIB | ICC_SRE_EL1_DFB | ICC_SRE_EL1_SRE; + + return true; +} + +/* Mark the specified system register as an AArch32 feature id register. */ +#define AARCH32(REG) { SYS_DESC(REG), .access = pvm_access_id_aarch32 } + +/* Mark the specified system register as an AArch64 feature id register. */ +#define AARCH64(REG) { SYS_DESC(REG), .access = pvm_access_id_aarch64 } + +/* Mark the specified system register as Read-As-Zero/Write-Ignored */ +#define RAZ_WI(REG) { SYS_DESC(REG), .access = pvm_access_raz_wi } + +/* Mark the specified system register as not being handled in hyp. */ +#define HOST_HANDLED(REG) { SYS_DESC(REG), .access = NULL } + +/* + * Architected system registers. + * Important: Must be sorted ascending by Op0, Op1, CRn, CRm, Op2 + * + * NOTE: Anything not explicitly listed here is *restricted by default*, i.e., + * it will lead to injecting an exception into the guest. + */ +static const struct sys_reg_desc pvm_sys_reg_descs[] = { + /* Cache maintenance by set/way operations are restricted. */ + + /* Debug and Trace Registers are restricted. */ + + /* AArch64 mappings of the AArch32 ID registers */ + /* CRm=1 */ + AARCH32(SYS_ID_PFR0_EL1), + AARCH32(SYS_ID_PFR1_EL1), + AARCH32(SYS_ID_DFR0_EL1), + AARCH32(SYS_ID_AFR0_EL1), + AARCH32(SYS_ID_MMFR0_EL1), + AARCH32(SYS_ID_MMFR1_EL1), + AARCH32(SYS_ID_MMFR2_EL1), + AARCH32(SYS_ID_MMFR3_EL1), + + /* CRm=2 */ + AARCH32(SYS_ID_ISAR0_EL1), + AARCH32(SYS_ID_ISAR1_EL1), + AARCH32(SYS_ID_ISAR2_EL1), + AARCH32(SYS_ID_ISAR3_EL1), + AARCH32(SYS_ID_ISAR4_EL1), + AARCH32(SYS_ID_ISAR5_EL1), + AARCH32(SYS_ID_MMFR4_EL1), + AARCH32(SYS_ID_ISAR6_EL1), + + /* CRm=3 */ + AARCH32(SYS_MVFR0_EL1), + AARCH32(SYS_MVFR1_EL1), + AARCH32(SYS_MVFR2_EL1), + AARCH32(SYS_ID_PFR2_EL1), + AARCH32(SYS_ID_DFR1_EL1), + AARCH32(SYS_ID_MMFR5_EL1), + + /* AArch64 ID registers */ + /* CRm=4 */ + AARCH64(SYS_ID_AA64PFR0_EL1), + AARCH64(SYS_ID_AA64PFR1_EL1), + AARCH64(SYS_ID_AA64ZFR0_EL1), + AARCH64(SYS_ID_AA64DFR0_EL1), + AARCH64(SYS_ID_AA64DFR1_EL1), + AARCH64(SYS_ID_AA64AFR0_EL1), + AARCH64(SYS_ID_AA64AFR1_EL1), + AARCH64(SYS_ID_AA64ISAR0_EL1), + AARCH64(SYS_ID_AA64ISAR1_EL1), + AARCH64(SYS_ID_AA64MMFR0_EL1), + AARCH64(SYS_ID_AA64MMFR1_EL1), + AARCH64(SYS_ID_AA64MMFR2_EL1), + + /* Scalable Vector Registers are restricted. */ + + RAZ_WI(SYS_ERRIDR_EL1), + RAZ_WI(SYS_ERRSELR_EL1), + RAZ_WI(SYS_ERXFR_EL1), + RAZ_WI(SYS_ERXCTLR_EL1), + RAZ_WI(SYS_ERXSTATUS_EL1), + RAZ_WI(SYS_ERXADDR_EL1), + RAZ_WI(SYS_ERXMISC0_EL1), + RAZ_WI(SYS_ERXMISC1_EL1), + + /* Performance Monitoring Registers are restricted. */ + + /* Limited Ordering Regions Registers are restricted. */ + + HOST_HANDLED(SYS_ICC_SGI1R_EL1), + HOST_HANDLED(SYS_ICC_ASGI1R_EL1), + HOST_HANDLED(SYS_ICC_SGI0R_EL1), + { SYS_DESC(SYS_ICC_SRE_EL1), .access = pvm_gic_read_sre, }, + + HOST_HANDLED(SYS_CCSIDR_EL1), + HOST_HANDLED(SYS_CLIDR_EL1), + HOST_HANDLED(SYS_CSSELR_EL1), + HOST_HANDLED(SYS_CTR_EL0), + + /* Performance Monitoring Registers are restricted. */ + + /* Activity Monitoring Registers are restricted. */ + + HOST_HANDLED(SYS_CNTP_TVAL_EL0), + HOST_HANDLED(SYS_CNTP_CTL_EL0), + HOST_HANDLED(SYS_CNTP_CVAL_EL0), + + /* Performance Monitoring Registers are restricted. */ +}; + +/* + * Checks that the sysreg table is unique and in-order. + * + * Returns 0 if the table is consistent, or 1 otherwise. + */ +int kvm_check_pvm_sysreg_table(void) +{ + unsigned int i; + + for (i = 1; i < ARRAY_SIZE(pvm_sys_reg_descs); i++) { + if (cmp_sys_reg(&pvm_sys_reg_descs[i-1], &pvm_sys_reg_descs[i]) >= 0) + return 1; + } + + return 0; +} + +/* + * Handler for protected VM MSR, MRS or System instruction execution. + * + * Returns true if the hypervisor has handled the exit, and control should go + * back to the guest, or false if it hasn't, to be handled by the host. + */ +bool kvm_handle_pvm_sysreg(struct kvm_vcpu *vcpu, u64 *exit_code) +{ + const struct sys_reg_desc *r; + struct sys_reg_params params; + unsigned long esr = kvm_vcpu_get_esr(vcpu); + int Rt = kvm_vcpu_sys_get_rt(vcpu); + + params = esr_sys64_to_params(esr); + params.regval = vcpu_get_reg(vcpu, Rt); + + r = find_reg(¶ms, pvm_sys_reg_descs, ARRAY_SIZE(pvm_sys_reg_descs)); + + /* Undefined (RESTRICTED). */ + if (r == NULL) { + inject_undef64(vcpu); + return true; + } + + /* Handled by the host (HOST_HANDLED) */ + if (r->access == NULL) + return false; + + /* Handled by hyp: skip instruction if instructed to do so. */ + if (r->access(vcpu, ¶ms, r)) + __kvm_skip_instr(vcpu); + + if (!params.is_write) + vcpu_set_reg(vcpu, Rt, params.regval); + + return true; +} + +/** + * Handler for protected VM restricted exceptions. + * + * Inject an undefined exception into the guest and return true to indicate that + * the hypervisor has handled the exit, and control should go back to the guest. + */ +bool kvm_handle_pvm_restricted(struct kvm_vcpu *vcpu, u64 *exit_code) +{ + inject_undef64(vcpu); + return true; +} diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c index ded2c66675f0..5a2cb5d9bc4b 100644 --- a/arch/arm64/kvm/hyp/vhe/switch.c +++ b/arch/arm64/kvm/hyp/vhe/switch.c @@ -96,6 +96,22 @@ void deactivate_traps_vhe_put(struct kvm_vcpu *vcpu) __deactivate_traps_common(vcpu); } +static const exit_handler_fn hyp_exit_handlers[] = { + [0 ... ESR_ELx_EC_MAX] = NULL, + [ESR_ELx_EC_CP15_32] = kvm_hyp_handle_cp15_32, + [ESR_ELx_EC_SYS64] = kvm_hyp_handle_sysreg, + [ESR_ELx_EC_SVE] = kvm_hyp_handle_fpsimd, + [ESR_ELx_EC_FP_ASIMD] = kvm_hyp_handle_fpsimd, + [ESR_ELx_EC_IABT_LOW] = kvm_hyp_handle_iabt_low, + [ESR_ELx_EC_DABT_LOW] = kvm_hyp_handle_dabt_low, + [ESR_ELx_EC_PAC] = kvm_hyp_handle_ptrauth, +}; + +static const exit_handler_fn *kvm_get_exit_handler_array(struct kvm_vcpu *vcpu) +{ + return hyp_exit_handlers; +} + /* Switch to the guest for VHE systems running in EL2 */ static int __kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu) { diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 1acbc0bbb394..e3ec1a44f94d 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1087,14 +1087,8 @@ static u64 read_id_reg(const struct kvm_vcpu *vcpu, } break; case SYS_ID_AA64PFR1_EL1: - val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_MTE); - if (kvm_has_mte(vcpu->kvm)) { - u64 pfr, mte; - - pfr = read_sanitised_ftr_reg(SYS_ID_AA64PFR1_EL1); - mte = cpuid_feature_extract_unsigned_field(pfr, ID_AA64PFR1_MTE_SHIFT); - val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR1_MTE), mte); - } + if (!kvm_has_mte(vcpu->kvm)) + val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_MTE); break; case SYS_ID_AA64ISAR1_EL1: if (!vcpu_has_ptrauth(vcpu)) |