// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2012 - Virtual Open Systems and Columbia University * Author: Christoffer Dall */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define CREATE_TRACE_POINTS #include "trace_arm.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static enum kvm_mode kvm_mode = KVM_MODE_DEFAULT; DEFINE_STATIC_KEY_FALSE(kvm_protected_mode_initialized); DECLARE_KVM_HYP_PER_CPU(unsigned long, kvm_hyp_vector); static DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page); DECLARE_KVM_NVHE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params); /* The VMID used in the VTTBR */ static atomic64_t kvm_vmid_gen = ATOMIC64_INIT(1); static u32 kvm_next_vmid; static DEFINE_SPINLOCK(kvm_vmid_lock); static bool vgic_present; static DEFINE_PER_CPU(unsigned char, kvm_arm_hardware_enabled); DEFINE_STATIC_KEY_FALSE(userspace_irqchip_in_use); int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu) { return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE; } int kvm_arch_hardware_setup(void *opaque) { return 0; } int kvm_arch_check_processor_compat(void *opaque) { return 0; } int kvm_vm_ioctl_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap) { int r; /* Capabilities with flags */ switch (cap->cap) { case KVM_CAP_ARM_PROTECTED_VM: return kvm_arm_vm_ioctl_pkvm(kvm, cap); default: if (cap->flags) return -EINVAL; } /* Capabilities without flags */ switch (cap->cap) { case KVM_CAP_ARM_NISV_TO_USER: if (kvm_vm_is_protected(kvm)) { r = -EINVAL; } else { r = 0; set_bit(KVM_ARCH_FLAG_RETURN_NISV_IO_ABORT_TO_USER, &kvm->arch.flags); } break; case KVM_CAP_ARM_MTE: mutex_lock(&kvm->lock); if (!system_supports_mte() || kvm->created_vcpus) { r = -EINVAL; } else { r = 0; set_bit(KVM_ARCH_FLAG_MTE_ENABLED, &kvm->arch.flags); } mutex_unlock(&kvm->lock); break; default: r = -EINVAL; break; } return r; } static int kvm_arm_default_max_vcpus(void) { return vgic_present ? kvm_vgic_get_max_vcpus() : KVM_MAX_VCPUS; } static void set_default_spectre(struct kvm *kvm) { /* * 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 * asymmetric systems are just a nuisance. * * Userspace can override this as long as it doesn't promise * the impossible. */ if (arm64_get_spectre_v2_state() == SPECTRE_UNAFFECTED) kvm->arch.pfr0_csv2 = 1; if (arm64_get_meltdown_state() == SPECTRE_UNAFFECTED) kvm->arch.pfr0_csv3 = 1; } /** * kvm_arch_init_vm - initializes a VM data structure * @kvm: pointer to the KVM struct */ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) { int ret; if (type & ~KVM_VM_TYPE_MASK) return -EINVAL; ret = kvm_share_hyp(kvm, kvm + 1); if (ret) return ret; ret = kvm_init_pvm(kvm, type); if (ret) return ret; ret = kvm_init_stage2_mmu(kvm, &kvm->arch.mmu, type); if (ret) return ret; kvm_vgic_early_init(kvm); /* The maximum number of VCPUs is limited by the host's GIC model */ kvm->arch.max_vcpus = kvm_arm_default_max_vcpus(); set_default_spectre(kvm); return ret; } vm_fault_t kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf) { return VM_FAULT_SIGBUS; } /** * kvm_arch_destroy_vm - destroy the VM data structure * @kvm: pointer to the KVM struct */ void kvm_arch_destroy_vm(struct kvm *kvm) { int i; bitmap_free(kvm->arch.pmu_filter); kvm_vgic_destroy(kvm); if (is_protected_kvm_enabled()) kvm_shadow_destroy(kvm); for (i = 0; i < KVM_MAX_VCPUS; ++i) { if (kvm->vcpus[i]) { kvm_vcpu_destroy(kvm->vcpus[i]); kvm->vcpus[i] = NULL; } } atomic_set(&kvm->online_vcpus, 0); kvm_unshare_hyp(kvm, kvm + 1); } static int kvm_check_extension(struct kvm *kvm, long ext) { int r; switch (ext) { case KVM_CAP_IRQCHIP: r = vgic_present; break; case KVM_CAP_IOEVENTFD: case KVM_CAP_DEVICE_CTRL: case KVM_CAP_USER_MEMORY: case KVM_CAP_SYNC_MMU: case KVM_CAP_DESTROY_MEMORY_REGION_WORKS: case KVM_CAP_ONE_REG: case KVM_CAP_ARM_PSCI: case KVM_CAP_ARM_PSCI_0_2: case KVM_CAP_READONLY_MEM: case KVM_CAP_MP_STATE: case KVM_CAP_IMMEDIATE_EXIT: case KVM_CAP_VCPU_EVENTS: case KVM_CAP_ARM_IRQ_LINE_LAYOUT_2: case KVM_CAP_ARM_INJECT_EXT_DABT: case KVM_CAP_SET_GUEST_DEBUG: case KVM_CAP_VCPU_ATTRIBUTES: case KVM_CAP_PTP_KVM: r = 1; break; case KVM_CAP_ARM_NISV_TO_USER: r = !kvm || !kvm_vm_is_protected(kvm); break; case KVM_CAP_SET_GUEST_DEBUG2: return KVM_GUESTDBG_VALID_MASK; case KVM_CAP_ARM_SET_DEVICE_ADDR: r = 1; break; case KVM_CAP_NR_VCPUS: /* * ARM64 treats KVM_CAP_NR_CPUS differently from all other * architectures, as it does not always bound it to * KVM_CAP_MAX_VCPUS. It should not matter much because * this is just an advisory value. */ r = min_t(unsigned int, num_online_cpus(), kvm_arm_default_max_vcpus()); break; case KVM_CAP_MAX_VCPUS: case KVM_CAP_MAX_VCPU_ID: if (kvm) r = kvm->arch.max_vcpus; else r = kvm_arm_default_max_vcpus(); break; case KVM_CAP_MSI_DEVID: if (!kvm) r = -EINVAL; else r = kvm->arch.vgic.msis_require_devid; break; case KVM_CAP_ARM_USER_IRQ: /* * 1: EL1_VTIMER, EL1_PTIMER, and PMU. * (bump this number if adding more devices) */ r = 1; break; case KVM_CAP_ARM_MTE: r = system_supports_mte(); break; case KVM_CAP_STEAL_TIME: r = kvm_arm_pvtime_supported(); break; case KVM_CAP_ARM_EL1_32BIT: r = cpus_have_const_cap(ARM64_HAS_32BIT_EL1); break; case KVM_CAP_GUEST_DEBUG_HW_BPS: r = get_num_brps(); break; case KVM_CAP_GUEST_DEBUG_HW_WPS: r = get_num_wrps(); break; case KVM_CAP_ARM_PMU_V3: r = kvm_arm_support_pmu_v3(); break; case KVM_CAP_ARM_INJECT_SERROR_ESR: r = cpus_have_const_cap(ARM64_HAS_RAS_EXTN); break; case KVM_CAP_ARM_VM_IPA_SIZE: r = get_kvm_ipa_limit(); break; case KVM_CAP_ARM_SVE: r = system_supports_sve() && !is_protected_kvm_enabled(); break; case KVM_CAP_ARM_PTRAUTH_ADDRESS: case KVM_CAP_ARM_PTRAUTH_GENERIC: r = system_has_full_ptr_auth(); break; default: r = 0; } return r; } /* * Checks whether the exctension specified in ext is supported for protected * vms. The capabilities supported by kvm in general are passed in kvm_cap. */ static int pkvm_check_extension(struct kvm *kvm, long ext, int kvm_cap) { int r; switch (ext) { case KVM_CAP_IRQCHIP: case KVM_CAP_ARM_PSCI: case KVM_CAP_ARM_PSCI_0_2: case KVM_CAP_NR_VCPUS: case KVM_CAP_MAX_VCPUS: case KVM_CAP_MAX_VCPU_ID: case KVM_CAP_MSI_DEVID: case KVM_CAP_ARM_VM_IPA_SIZE: r = kvm_cap; break; case KVM_CAP_GUEST_DEBUG_HW_BPS: r = min(kvm_cap, pkvm_get_max_brps()); break; case KVM_CAP_GUEST_DEBUG_HW_WPS: r = min(kvm_cap, pkvm_get_max_wrps()); break; case KVM_CAP_ARM_PMU_V3: r = kvm_cap && FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_PMUVER), PVM_ID_AA64DFR0_ALLOW); break; case KVM_CAP_ARM_SVE: r = kvm_cap && FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_SVE), PVM_ID_AA64PFR0_RESTRICT_UNSIGNED); break; case KVM_CAP_ARM_PTRAUTH_ADDRESS: r = kvm_cap && FIELD_GET(ARM64_FEATURE_MASK(ID_AA64ISAR1_API), PVM_ID_AA64ISAR1_ALLOW) && FIELD_GET(ARM64_FEATURE_MASK(ID_AA64ISAR1_APA), PVM_ID_AA64ISAR1_ALLOW); break; case KVM_CAP_ARM_PTRAUTH_GENERIC: r = kvm_cap && FIELD_GET(ARM64_FEATURE_MASK(ID_AA64ISAR1_GPI), PVM_ID_AA64ISAR1_ALLOW) && FIELD_GET(ARM64_FEATURE_MASK(ID_AA64ISAR1_GPA), PVM_ID_AA64ISAR1_ALLOW); break; case KVM_CAP_ARM_PROTECTED_VM: r = 1; break; default: r = 0; break; } return r; } int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) { int r = kvm_check_extension(kvm, ext); if (unlikely(kvm && kvm_vm_is_protected(kvm))) r = pkvm_check_extension(kvm, ext, r); return r; } long kvm_arch_dev_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { return -EINVAL; } struct kvm *kvm_arch_alloc_vm(void) { size_t sz = sizeof(struct kvm); if (!has_vhe()) return kzalloc(sz, GFP_KERNEL_ACCOUNT); return __vmalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_HIGHMEM | __GFP_ZERO); } void kvm_arch_free_vm(struct kvm *kvm) { if (!has_vhe()) kfree(kvm); else vfree(kvm); } int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id) { if (irqchip_in_kernel(kvm) && vgic_initialized(kvm)) return -EBUSY; if (id >= kvm->arch.max_vcpus) return -EINVAL; return 0; } int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu) { int err; /* Force users to call KVM_ARM_VCPU_INIT */ vcpu->arch.target = -1; bitmap_zero(vcpu->arch.features, KVM_VCPU_MAX_FEATURES); vcpu->arch.mmu_page_cache.gfp_zero = __GFP_ZERO; /* Set up the timer */ kvm_timer_vcpu_init(vcpu); kvm_pmu_vcpu_init(vcpu); kvm_arm_reset_debug_ptr(vcpu); kvm_arm_pvtime_vcpu_init(&vcpu->arch); vcpu->arch.hw_mmu = &vcpu->kvm->arch.mmu; err = kvm_vgic_vcpu_init(vcpu); if (err) return err; return kvm_share_hyp(vcpu, vcpu + 1); } void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu) { } void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu) { if (vcpu_has_run_once(vcpu) && unlikely(!irqchip_in_kernel(vcpu->kvm))) static_branch_dec(&userspace_irqchip_in_use); if (is_protected_kvm_enabled()) free_hyp_memcache(&vcpu->arch.pkvm_memcache); else kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_cache); kvm_timer_vcpu_terminate(vcpu); kvm_pmu_vcpu_destroy(vcpu); kvm_vgic_vcpu_destroy(vcpu); kvm_arm_vcpu_destroy(vcpu); } int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu) { return kvm_timer_is_pending(vcpu); } void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) { /* * If we're about to block (most likely because we've just hit a * WFI), we need to sync back the state of the GIC CPU interface * so that we have the latest PMR and group enables. This ensures * that kvm_arch_vcpu_runnable has up-to-date data to decide * whether we have pending interrupts. * * For the same reason, we want to tell GICv4 that we need * doorbells to be signalled, should an interrupt become pending. */ preempt_disable(); kvm_vgic_put(vcpu, true); preempt_enable(); } void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) { preempt_disable(); kvm_vgic_load(vcpu); preempt_enable(); } void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) { struct kvm_s2_mmu *mmu; int *last_ran; if (is_protected_kvm_enabled()) goto nommu; mmu = vcpu->arch.hw_mmu; last_ran = this_cpu_ptr(mmu->last_vcpu_ran); /* * We guarantee that both TLBs and I-cache are private to each * vcpu. If detecting that a vcpu from the same VM has * previously run on the same physical CPU, call into the * hypervisor code to nuke the relevant contexts. * * We might get preempted before the vCPU actually runs, but * over-invalidation doesn't affect correctness. */ if (*last_ran != vcpu->vcpu_id) { kvm_call_hyp(__kvm_flush_cpu_context, mmu); *last_ran = vcpu->vcpu_id; } nommu: vcpu->cpu = cpu; kvm_vgic_load(vcpu); kvm_timer_vcpu_load(vcpu); if (has_vhe()) kvm_vcpu_load_sysregs_vhe(vcpu); kvm_arch_vcpu_load_fp(vcpu); kvm_vcpu_pmu_restore_guest(vcpu); if (kvm_arm_is_pvtime_enabled(&vcpu->arch)) kvm_make_request(KVM_REQ_RECORD_STEAL, vcpu); if (single_task_running()) vcpu_clear_wfx_traps(vcpu); else vcpu_set_wfx_traps(vcpu); if (vcpu_has_ptrauth(vcpu)) vcpu_ptrauth_disable(vcpu); kvm_arch_vcpu_load_debug_state_flags(vcpu); if (is_protected_kvm_enabled()) { kvm_call_hyp_nvhe(__pkvm_vcpu_load, vcpu->kvm->arch.pkvm.shadow_handle, vcpu->vcpu_idx, vcpu->arch.hcr_el2); kvm_call_hyp(__vgic_v3_restore_vmcr_aprs, &vcpu->arch.vgic_cpu.vgic_v3); } } void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) { if (is_protected_kvm_enabled()) { kvm_call_hyp(__vgic_v3_save_vmcr_aprs, &vcpu->arch.vgic_cpu.vgic_v3); kvm_call_hyp_nvhe(__pkvm_vcpu_put); /* __pkvm_vcpu_put implies a sync of the state */ if (!kvm_vm_is_protected(vcpu->kvm)) vcpu->arch.flags |= KVM_ARM64_PKVM_STATE_DIRTY; } kvm_arch_vcpu_put_debug_state_flags(vcpu); kvm_arch_vcpu_put_fp(vcpu); if (has_vhe()) kvm_vcpu_put_sysregs_vhe(vcpu); kvm_timer_vcpu_put(vcpu); kvm_vgic_put(vcpu, false); kvm_vcpu_pmu_restore_host(vcpu); vcpu->cpu = -1; } static void vcpu_power_off(struct kvm_vcpu *vcpu) { vcpu->arch.power_off = true; kvm_make_request(KVM_REQ_SLEEP, vcpu); kvm_vcpu_kick(vcpu); } int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu, struct kvm_mp_state *mp_state) { if (vcpu->arch.power_off) mp_state->mp_state = KVM_MP_STATE_STOPPED; else mp_state->mp_state = KVM_MP_STATE_RUNNABLE; return 0; } int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu, struct kvm_mp_state *mp_state) { int ret = 0; switch (mp_state->mp_state) { case KVM_MP_STATE_RUNNABLE: vcpu->arch.power_off = false; break; case KVM_MP_STATE_STOPPED: vcpu_power_off(vcpu); break; default: ret = -EINVAL; } return ret; } /** * kvm_arch_vcpu_runnable - determine if the vcpu can be scheduled * @v: The VCPU pointer * * If the guest CPU is not waiting for interrupts or an interrupt line is * asserted, the CPU is by definition runnable. */ int kvm_arch_vcpu_runnable(struct kvm_vcpu *v) { bool irq_lines = *vcpu_hcr(v) & (HCR_VI | HCR_VF); return ((irq_lines || kvm_vgic_vcpu_pending_irq(v)) && !v->arch.power_off && !v->arch.pause); } bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu) { return vcpu_mode_priv(vcpu); } /* Just ensure a guest exit from a particular CPU */ static void exit_vm_noop(void *info) { } void force_vm_exit(const cpumask_t *mask) { preempt_disable(); smp_call_function_many(mask, exit_vm_noop, NULL, true); preempt_enable(); } /** * need_new_vmid_gen - check that the VMID is still valid * @vmid: The VMID to check * * return true if there is a new generation of VMIDs being used * * The hardware supports a limited set of values with the value zero reserved * for the host, so we check if an assigned value belongs to a previous * generation, which requires us to assign a new value. If we're the first to * use a VMID for the new generation, we must flush necessary caches and TLBs * on all CPUs. */ static bool need_new_vmid_gen(struct kvm_vmid *vmid) { u64 current_vmid_gen = atomic64_read(&kvm_vmid_gen); smp_rmb(); /* Orders read of kvm_vmid_gen and kvm->arch.vmid */ return unlikely(READ_ONCE(vmid->vmid_gen) != current_vmid_gen); } /** * update_vmid - Update the vmid with a valid VMID for the current generation * @vmid: The stage-2 VMID information struct */ static void update_vmid(struct kvm_vmid *vmid) { if (!need_new_vmid_gen(vmid)) return; spin_lock(&kvm_vmid_lock); /* * We need to re-check the vmid_gen here to ensure that if another vcpu * already allocated a valid vmid for this vm, then this vcpu should * use the same vmid. */ if (!need_new_vmid_gen(vmid)) { spin_unlock(&kvm_vmid_lock); return; } /* First user of a new VMID generation? */ if (unlikely(kvm_next_vmid == 0)) { atomic64_inc(&kvm_vmid_gen); kvm_next_vmid = 1; /* * On SMP we know no other CPUs can use this CPU's or each * other's VMID after force_vm_exit returns since the * kvm_vmid_lock blocks them from reentry to the guest. */ force_vm_exit(cpu_all_mask); /* * Now broadcast TLB + ICACHE invalidation over the inner * shareable domain to make sure all data structures are * clean. */ kvm_call_hyp(__kvm_flush_vm_context); } WRITE_ONCE(vmid->vmid, kvm_next_vmid); kvm_next_vmid++; kvm_next_vmid &= (1 << kvm_get_vmid_bits()) - 1; smp_wmb(); WRITE_ONCE(vmid->vmid_gen, atomic64_read(&kvm_vmid_gen)); spin_unlock(&kvm_vmid_lock); } static int kvm_vcpu_initialized(struct kvm_vcpu *vcpu) { return vcpu->arch.target >= 0; } /* * Handle both the initialisation that is being done when the vcpu is * run for the first time, as well as the updates that must be * performed each time we get a new thread dealing with this vcpu. */ int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu) { struct kvm *kvm = vcpu->kvm; int ret; if (!kvm_vcpu_initialized(vcpu)) return -ENOEXEC; if (!kvm_arm_vcpu_is_finalized(vcpu)) return -EPERM; ret = kvm_arch_vcpu_run_map_fp(vcpu); if (ret) return ret; if (likely(vcpu_has_run_once(vcpu))) return 0; kvm_arm_vcpu_init_debug(vcpu); if (likely(irqchip_in_kernel(kvm))) { /* * Map the VGIC hardware resources before running a vcpu the * first time on this VM. */ ret = kvm_vgic_map_resources(kvm); if (ret) return ret; } ret = kvm_timer_enable(vcpu); if (ret) return ret; ret = kvm_arm_pmu_v3_enable(vcpu); if (ret) return ret; if (!irqchip_in_kernel(kvm)) { /* * Tell the rest of the code that there are userspace irqchip * VMs in the wild. */ static_branch_inc(&userspace_irqchip_in_use); } if (is_protected_kvm_enabled()) { /* Start with the vcpu in a dirty state */ if (!kvm_vm_is_protected(vcpu->kvm)) vcpu->arch.flags |= KVM_ARM64_PKVM_STATE_DIRTY; ret = create_el2_shadow(kvm); } return ret; } bool kvm_arch_intc_initialized(struct kvm *kvm) { return vgic_initialized(kvm); } void kvm_arm_halt_guest(struct kvm *kvm) { int i; struct kvm_vcpu *vcpu; kvm_for_each_vcpu(i, vcpu, kvm) vcpu->arch.pause = true; kvm_make_all_cpus_request(kvm, KVM_REQ_SLEEP); } void kvm_arm_resume_guest(struct kvm *kvm) { int i; struct kvm_vcpu *vcpu; kvm_for_each_vcpu(i, vcpu, kvm) { vcpu->arch.pause = false; rcuwait_wake_up(kvm_arch_vcpu_get_wait(vcpu)); } } static void vcpu_req_sleep(struct kvm_vcpu *vcpu) { struct rcuwait *wait = kvm_arch_vcpu_get_wait(vcpu); rcuwait_wait_event(wait, (!vcpu->arch.power_off) &&(!vcpu->arch.pause), TASK_INTERRUPTIBLE); if (vcpu->arch.power_off || vcpu->arch.pause) { /* Awaken to handle a signal, request we sleep again later. */ kvm_make_request(KVM_REQ_SLEEP, vcpu); } /* * Make sure we will observe a potential reset request if we've * observed a change to the power state. Pairs with the smp_wmb() in * kvm_psci_vcpu_on(). */ smp_rmb(); } static void check_vcpu_requests(struct kvm_vcpu *vcpu) { if (kvm_request_pending(vcpu)) { if (kvm_check_request(KVM_REQ_SLEEP, vcpu)) vcpu_req_sleep(vcpu); if (kvm_check_request(KVM_REQ_VCPU_RESET, vcpu)) kvm_reset_vcpu(vcpu); /* * Clear IRQ_PENDING requests that were made to guarantee * that a VCPU sees new virtual interrupts. */ kvm_check_request(KVM_REQ_IRQ_PENDING, vcpu); if (kvm_check_request(KVM_REQ_RECORD_STEAL, vcpu)) kvm_update_stolen_time(vcpu); if (kvm_check_request(KVM_REQ_RELOAD_GICv4, vcpu)) { /* The distributor enable bits were changed */ preempt_disable(); vgic_v4_put(vcpu, false); vgic_v4_load(vcpu); preempt_enable(); } if (kvm_check_request(KVM_REQ_RELOAD_PMU, vcpu)) kvm_pmu_handle_pmcr(vcpu, __vcpu_sys_reg(vcpu, PMCR_EL0)); } } static bool vcpu_mode_is_bad_32bit(struct kvm_vcpu *vcpu) { if (likely(!vcpu_mode_is_32bit(vcpu))) return false; return !kvm_supports_32bit_el0(); } /** * kvm_vcpu_exit_request - returns true if the VCPU should *not* enter the guest * @vcpu: The VCPU pointer * @ret: Pointer to write optional return code * * Returns: true if the VCPU needs to return to a preemptible + interruptible * and skip guest entry. * * This function disambiguates between two different types of exits: exits to a * preemptible + interruptible kernel context and exits to userspace. For an * exit to userspace, this function will write the return code to ret and return * true. For an exit to preemptible + interruptible kernel context (i.e. check * for pending work and re-enter), return true without writing to ret. */ static bool kvm_vcpu_exit_request(struct kvm_vcpu *vcpu, int *ret) { struct kvm_run *run = vcpu->run; /* * If we're using a userspace irqchip, then check if we need * to tell a userspace irqchip about timer or PMU level * changes and if so, exit to userspace (the actual level * state gets updated in kvm_timer_update_run and * kvm_pmu_update_run below). */ if (static_branch_unlikely(&userspace_irqchip_in_use)) { if (kvm_timer_should_notify_user(vcpu) || kvm_pmu_should_notify_user(vcpu)) { *ret = -EINTR; run->exit_reason = KVM_EXIT_INTR; return true; } } return kvm_request_pending(vcpu) || need_new_vmid_gen(&vcpu->arch.hw_mmu->vmid) || xfer_to_guest_mode_work_pending(); } /* * Actually run the vCPU, entering an RCU extended quiescent state (EQS) while * the vCPU is running. * * This must be noinstr as instrumentation may make use of RCU, and this is not * safe during the EQS. */ static int noinstr kvm_arm_vcpu_enter_exit(struct kvm_vcpu *vcpu) { int ret; guest_state_enter_irqoff(); ret = kvm_call_hyp_ret(__kvm_vcpu_run, vcpu); guest_state_exit_irqoff(); return ret; } /** * kvm_arch_vcpu_ioctl_run - the main VCPU run function to execute guest code * @vcpu: The VCPU pointer * * This function is called through the VCPU_RUN ioctl called from user space. It * will execute VM code in a loop until the time slice for the process is used * or some emulation is needed from user space in which case the function will * return with return value 0 and with the kvm_run structure filled in with the * required data for the requested emulation. */ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) { struct kvm_run *run = vcpu->run; int ret; if (run->exit_reason == KVM_EXIT_MMIO) { ret = kvm_handle_mmio_return(vcpu); if (ret) return ret; } vcpu_load(vcpu); if (run->immediate_exit) { ret = -EINTR; goto out; } kvm_sigset_activate(vcpu); ret = 1; run->exit_reason = KVM_EXIT_UNKNOWN; while (ret > 0) { /* * Check conditions before entering the guest */ ret = xfer_to_guest_mode_handle_work(vcpu); if (!ret) ret = 1; update_vmid(&vcpu->arch.hw_mmu->vmid); check_vcpu_requests(vcpu); /* * Preparing the interrupts to be injected also * involves poking the GIC, which must be done in a * non-preemptible context. */ preempt_disable(); kvm_pmu_flush_hwstate(vcpu); local_irq_disable(); kvm_vgic_flush_hwstate(vcpu); /* * Ensure we set mode to IN_GUEST_MODE after we disable * interrupts and before the final VCPU requests check. * See the comment in kvm_vcpu_exiting_guest_mode() and * Documentation/virt/kvm/vcpu-requests.rst */ smp_store_mb(vcpu->mode, IN_GUEST_MODE); if (ret <= 0 || kvm_vcpu_exit_request(vcpu, &ret)) { vcpu->mode = OUTSIDE_GUEST_MODE; isb(); /* Ensure work in x_flush_hwstate is committed */ kvm_pmu_sync_hwstate(vcpu); if (static_branch_unlikely(&userspace_irqchip_in_use)) kvm_timer_sync_user(vcpu); kvm_vgic_sync_hwstate(vcpu); local_irq_enable(); preempt_enable(); continue; } kvm_arm_setup_debug(vcpu); kvm_arch_vcpu_ctxflush_fp(vcpu); /************************************************************** * Enter the guest */ trace_kvm_entry(*vcpu_pc(vcpu)); guest_timing_enter_irqoff(); ret = kvm_arm_vcpu_enter_exit(vcpu); vcpu->mode = OUTSIDE_GUEST_MODE; vcpu->stat.exits++; /* * Back from guest *************************************************************/ kvm_arm_clear_debug(vcpu); /* * We must sync the PMU state before the vgic state so * that the vgic can properly sample the updated state of the * interrupt line. */ kvm_pmu_sync_hwstate(vcpu); /* * Sync the vgic state before syncing the timer state because * the timer code needs to know if the virtual timer * interrupts are active. */ kvm_vgic_sync_hwstate(vcpu); /* * Sync the timer hardware state before enabling interrupts as * we don't want vtimer interrupts to race with syncing the * timer virtual interrupt state. */ if (static_branch_unlikely(&userspace_irqchip_in_use)) kvm_timer_sync_user(vcpu); kvm_arch_vcpu_ctxsync_fp(vcpu); /* * We must ensure that any pending interrupts are taken before * we exit guest timing so that timer ticks are accounted as * guest time. Transiently unmask interrupts so that any * pending interrupts are taken. * * Per ARM DDI 0487G.b section D1.13.4, an ISB (or other * context synchronization event) is necessary to ensure that * pending interrupts are taken. */ local_irq_enable(); isb(); local_irq_disable(); guest_timing_exit_irqoff(); local_irq_enable(); trace_kvm_exit(ret, kvm_vcpu_trap_get_class(vcpu), *vcpu_pc(vcpu)); /* Exit types that need handling before we can be preempted */ handle_exit_early(vcpu, ret); preempt_enable(); /* * The ARMv8 architecture doesn't give the hypervisor * a mechanism to prevent a guest from dropping to AArch32 EL0 * if implemented by the CPU. If we spot the guest in such * state and that we decided it wasn't supposed to do so (like * with the asymmetric AArch32 case), return to userspace with * a fatal error. */ if (vcpu_mode_is_bad_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 issuing a * KVM_ARM_VCPU_INIT if it really wants to. */ vcpu->arch.target = -1; ret = ARM_EXCEPTION_IL; } ret = handle_exit(vcpu, ret); } /* Tell userspace about in-kernel device output levels */ if (unlikely(!irqchip_in_kernel(vcpu->kvm))) { kvm_timer_update_run(vcpu); kvm_pmu_update_run(vcpu); } kvm_sigset_deactivate(vcpu); out: /* * In the unlikely event that we are returning to userspace * with pending exceptions or PC adjustment, commit these * adjustments in order to give userspace a consistent view of * the vcpu state. Note that this relies on __kvm_adjust_pc() * being preempt-safe on VHE. */ if (unlikely(vcpu->arch.flags & (KVM_ARM64_PENDING_EXCEPTION | KVM_ARM64_INCREMENT_PC))) kvm_call_hyp(__kvm_adjust_pc, vcpu); vcpu_put(vcpu); return ret; } static int vcpu_interrupt_line(struct kvm_vcpu *vcpu, int number, bool level) { int bit_index; bool set; unsigned long *hcr; if (number == KVM_ARM_IRQ_CPU_IRQ) bit_index = __ffs(HCR_VI); else /* KVM_ARM_IRQ_CPU_FIQ */ bit_index = __ffs(HCR_VF); hcr = vcpu_hcr(vcpu); if (level) set = test_and_set_bit(bit_index, hcr); else set = test_and_clear_bit(bit_index, hcr); /* * If we didn't change anything, no need to wake up or kick other CPUs */ if (set == level) return 0; /* * The vcpu irq_lines field was updated, wake up sleeping VCPUs and * trigger a world-switch round on the running physical CPU to set the * virtual IRQ/FIQ fields in the HCR appropriately. */ kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu); kvm_vcpu_kick(vcpu); return 0; } int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level, bool line_status) { u32 irq = irq_level->irq; unsigned int irq_type, vcpu_idx, irq_num; int nrcpus = atomic_read(&kvm->online_vcpus); struct kvm_vcpu *vcpu = NULL; bool level = irq_level->level; irq_type = (irq >> KVM_ARM_IRQ_TYPE_SHIFT) & KVM_ARM_IRQ_TYPE_MASK; vcpu_idx = (irq >> KVM_ARM_IRQ_VCPU_SHIFT) & KVM_ARM_IRQ_VCPU_MASK; vcpu_idx += ((irq >> KVM_ARM_IRQ_VCPU2_SHIFT) & KVM_ARM_IRQ_VCPU2_MASK) * (KVM_ARM_IRQ_VCPU_MASK + 1); irq_num = (irq >> KVM_ARM_IRQ_NUM_SHIFT) & KVM_ARM_IRQ_NUM_MASK; trace_kvm_irq_line(irq_type, vcpu_idx, irq_num, irq_level->level); switch (irq_type) { case KVM_ARM_IRQ_TYPE_CPU: if (irqchip_in_kernel(kvm)) return -ENXIO; if (vcpu_idx >= nrcpus) return -EINVAL; vcpu = kvm_get_vcpu(kvm, vcpu_idx); if (!vcpu) return -EINVAL; if (irq_num > KVM_ARM_IRQ_CPU_FIQ) return -EINVAL; return vcpu_interrupt_line(vcpu, irq_num, level); case KVM_ARM_IRQ_TYPE_PPI: if (!irqchip_in_kernel(kvm)) return -ENXIO; if (vcpu_idx >= nrcpus) return -EINVAL; vcpu = kvm_get_vcpu(kvm, vcpu_idx); if (!vcpu) return -EINVAL; if (irq_num < VGIC_NR_SGIS || irq_num >= VGIC_NR_PRIVATE_IRQS) return -EINVAL; return kvm_vgic_inject_irq(kvm, vcpu->vcpu_id, irq_num, level, NULL); case KVM_ARM_IRQ_TYPE_SPI: if (!irqchip_in_kernel(kvm)) return -ENXIO; if (irq_num < VGIC_NR_PRIVATE_IRQS) return -EINVAL; return kvm_vgic_inject_irq(kvm, 0, irq_num, level, NULL); } return -EINVAL; } static int kvm_vcpu_set_target(struct kvm_vcpu *vcpu, const struct kvm_vcpu_init *init) { unsigned int i, ret; u32 phys_target = kvm_target_cpu(); if (init->target != phys_target) return -EINVAL; /* * Secondary and subsequent calls to KVM_ARM_VCPU_INIT must * use the same target. */ if (vcpu->arch.target != -1 && vcpu->arch.target != init->target) return -EINVAL; /* -ENOENT for unknown features, -EINVAL for invalid combinations. */ for (i = 0; i < sizeof(init->features) * 8; i++) { bool set = (init->features[i / 32] & (1 << (i % 32))); if (set && i >= KVM_VCPU_MAX_FEATURES) return -ENOENT; /* * Secondary and subsequent calls to KVM_ARM_VCPU_INIT must * use the same feature set. */ if (vcpu->arch.target != -1 && i < KVM_VCPU_MAX_FEATURES && test_bit(i, vcpu->arch.features) != set) return -EINVAL; if (set) set_bit(i, vcpu->arch.features); } vcpu->arch.target = phys_target; /* Now we know what it is, we can reset it. */ ret = kvm_reset_vcpu(vcpu); if (ret) { vcpu->arch.target = -1; bitmap_zero(vcpu->arch.features, KVM_VCPU_MAX_FEATURES); } return ret; } static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu, struct kvm_vcpu_init *init) { int ret; ret = kvm_vcpu_set_target(vcpu, init); if (ret) return ret; /* * Ensure a rebooted VM will fault in RAM pages and detect if the * guest MMU is turned off and flush the caches as needed. * * S2FWB enforces all memory accesses to RAM being cacheable, * ensuring that the data side is always coherent. We still * need to invalidate the I-cache though, as FWB does *not* * imply CTR_EL0.DIC. */ if (vcpu_has_run_once(vcpu)) { if (!cpus_have_final_cap(ARM64_HAS_STAGE2_FWB)) stage2_unmap_vm(vcpu->kvm); else icache_inval_all_pou(); } vcpu_reset_hcr(vcpu); vcpu->arch.cptr_el2 = CPTR_EL2_DEFAULT; /* * Handle the "start in power-off" case. */ if (test_bit(KVM_ARM_VCPU_POWER_OFF, vcpu->arch.features)) vcpu_power_off(vcpu); else vcpu->arch.power_off = false; return 0; } static int kvm_arm_vcpu_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) { int ret = -ENXIO; switch (attr->group) { default: ret = kvm_arm_vcpu_arch_set_attr(vcpu, attr); break; } return ret; } static int kvm_arm_vcpu_get_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) { int ret = -ENXIO; switch (attr->group) { default: ret = kvm_arm_vcpu_arch_get_attr(vcpu, attr); break; } return ret; } static int kvm_arm_vcpu_has_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) { int ret = -ENXIO; switch (attr->group) { default: ret = kvm_arm_vcpu_arch_has_attr(vcpu, attr); break; } return ret; } static int kvm_arm_vcpu_get_events(struct kvm_vcpu *vcpu, struct kvm_vcpu_events *events) { memset(events, 0, sizeof(*events)); return __kvm_arm_vcpu_get_events(vcpu, events); } static int kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu, struct kvm_vcpu_events *events) { int i; /* check whether the reserved field is zero */ for (i = 0; i < ARRAY_SIZE(events->reserved); i++) if (events->reserved[i]) return -EINVAL; /* check whether the pad field is zero */ for (i = 0; i < ARRAY_SIZE(events->exception.pad); i++) if (events->exception.pad[i]) return -EINVAL; return __kvm_arm_vcpu_set_events(vcpu, events); } long kvm_arch_vcpu_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { struct kvm_vcpu *vcpu = filp->private_data; void __user *argp = (void __user *)arg; struct kvm_device_attr attr; long r; switch (ioctl) { case KVM_ARM_VCPU_INIT: { struct kvm_vcpu_init init; r = -EFAULT; if (copy_from_user(&init, argp, sizeof(init))) break; r = kvm_arch_vcpu_ioctl_vcpu_init(vcpu, &init); break; } case KVM_SET_ONE_REG: case KVM_GET_ONE_REG: { struct kvm_one_reg reg; r = -ENOEXEC; if (unlikely(!kvm_vcpu_initialized(vcpu))) break; r = -EFAULT; if (copy_from_user(®, argp, sizeof(reg))) break; /* * We could owe a reset due to PSCI. Handle the pending reset * here to ensure userspace register accesses are ordered after * the reset. */ if (kvm_check_request(KVM_REQ_VCPU_RESET, vcpu)) kvm_reset_vcpu(vcpu); if (ioctl == KVM_SET_ONE_REG) r = kvm_arm_set_reg(vcpu, ®); else r = kvm_arm_get_reg(vcpu, ®); break; } case KVM_GET_REG_LIST: { struct kvm_reg_list __user *user_list = argp; struct kvm_reg_list reg_list; unsigned n; r = -ENOEXEC; if (unlikely(!kvm_vcpu_initialized(vcpu))) break; r = -EPERM; if (!kvm_arm_vcpu_is_finalized(vcpu)) break; r = -EFAULT; if (copy_from_user(®_list, user_list, sizeof(reg_list))) break; n = reg_list.n; reg_list.n = kvm_arm_num_regs(vcpu); if (copy_to_user(user_list, ®_list, sizeof(reg_list))) break; r = -E2BIG; if (n < reg_list.n) break; r = kvm_arm_copy_reg_indices(vcpu, user_list->reg); break; } case KVM_SET_DEVICE_ATTR: { r = -EFAULT; if (copy_from_user(&attr, argp, sizeof(attr))) break; r = kvm_arm_vcpu_set_attr(vcpu, &attr); break; } case KVM_GET_DEVICE_ATTR: { r = -EFAULT; if (copy_from_user(&attr, argp, sizeof(attr))) break; r = kvm_arm_vcpu_get_attr(vcpu, &attr); break; } case KVM_HAS_DEVICE_ATTR: { r = -EFAULT; if (copy_from_user(&attr, argp, sizeof(attr))) break; r = kvm_arm_vcpu_has_attr(vcpu, &attr); break; } case KVM_GET_VCPU_EVENTS: { struct kvm_vcpu_events events; if (kvm_arm_vcpu_get_events(vcpu, &events)) return -EINVAL; if (copy_to_user(argp, &events, sizeof(events))) return -EFAULT; return 0; } case KVM_SET_VCPU_EVENTS: { struct kvm_vcpu_events events; if (copy_from_user(&events, argp, sizeof(events))) return -EFAULT; return kvm_arm_vcpu_set_events(vcpu, &events); } case KVM_ARM_VCPU_FINALIZE: { int what; if (!kvm_vcpu_initialized(vcpu)) return -ENOEXEC; if (get_user(what, (const int __user *)argp)) return -EFAULT; return kvm_arm_vcpu_finalize(vcpu, what); } default: r = -EINVAL; } return r; } void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot) { } void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm, const struct kvm_memory_slot *memslot) { kvm_flush_remote_tlbs(kvm); } static int kvm_vm_ioctl_set_device_addr(struct kvm *kvm, struct kvm_arm_device_addr *dev_addr) { unsigned long dev_id, type; dev_id = (dev_addr->id & KVM_ARM_DEVICE_ID_MASK) >> KVM_ARM_DEVICE_ID_SHIFT; type = (dev_addr->id & KVM_ARM_DEVICE_TYPE_MASK) >> KVM_ARM_DEVICE_TYPE_SHIFT; switch (dev_id) { case KVM_ARM_DEVICE_VGIC_V2: if (!vgic_present) return -ENXIO; return kvm_vgic_addr(kvm, type, &dev_addr->addr, true); default: return -ENODEV; } } long kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { struct kvm *kvm = filp->private_data; void __user *argp = (void __user *)arg; switch (ioctl) { case KVM_CREATE_IRQCHIP: { int ret; if (!vgic_present) return -ENXIO; mutex_lock(&kvm->lock); ret = kvm_vgic_create(kvm, KVM_DEV_TYPE_ARM_VGIC_V2); mutex_unlock(&kvm->lock); return ret; } case KVM_ARM_SET_DEVICE_ADDR: { struct kvm_arm_device_addr dev_addr; if (copy_from_user(&dev_addr, argp, sizeof(dev_addr))) return -EFAULT; return kvm_vm_ioctl_set_device_addr(kvm, &dev_addr); } case KVM_ARM_PREFERRED_TARGET: { struct kvm_vcpu_init init; kvm_vcpu_preferred_target(&init); if (copy_to_user(argp, &init, sizeof(init))) return -EFAULT; return 0; } case KVM_ARM_MTE_COPY_TAGS: { struct kvm_arm_copy_mte_tags copy_tags; if (copy_from_user(©_tags, argp, sizeof(copy_tags))) return -EFAULT; return kvm_vm_ioctl_mte_copy_tags(kvm, ©_tags); } default: return -EINVAL; } } static unsigned long nvhe_percpu_size(void) { return (unsigned long)CHOOSE_NVHE_SYM(__per_cpu_end) - (unsigned long)CHOOSE_NVHE_SYM(__per_cpu_start); } static unsigned long nvhe_percpu_order(void) { unsigned long size = nvhe_percpu_size(); return size ? get_order(size) : 0; } /* A lookup table holding the hypervisor VA for each vector slot */ static void *hyp_spectre_vector_selector[BP_HARDEN_EL2_SLOTS]; static void kvm_init_vector_slot(void *base, enum arm64_hyp_spectre_vector slot) { hyp_spectre_vector_selector[slot] = __kvm_vector_slot2addr(base, slot); } static int kvm_init_vector_slots(void) { int err; void *base; base = kern_hyp_va(kvm_ksym_ref(__kvm_hyp_vector)); kvm_init_vector_slot(base, HYP_VECTOR_DIRECT); base = kern_hyp_va(kvm_ksym_ref(__bp_harden_hyp_vecs)); kvm_init_vector_slot(base, HYP_VECTOR_SPECTRE_DIRECT); if (kvm_system_needs_idmapped_vectors() && !is_protected_kvm_enabled()) { err = create_hyp_exec_mappings(__pa_symbol(__bp_harden_hyp_vecs), __BP_HARDEN_HYP_VECS_SZ, &base); if (err) return err; } kvm_init_vector_slot(base, HYP_VECTOR_INDIRECT); kvm_init_vector_slot(base, HYP_VECTOR_SPECTRE_INDIRECT); return 0; } static void cpu_prepare_hyp_mode(int cpu) { struct kvm_nvhe_init_params *params = per_cpu_ptr_nvhe_sym(kvm_init_params, cpu); unsigned long tcr; /* * Calculate the raw per-cpu offset without a translation from the * kernel's mapping to the linear mapping, and store it in tpidr_el2 * so that we can use adr_l to access per-cpu variables in EL2. * Also drop the KASAN tag which gets in the way... */ params->tpidr_el2 = (unsigned long)kasan_reset_tag(per_cpu_ptr_nvhe_sym(__per_cpu_start, cpu)) - (unsigned long)kvm_ksym_ref(CHOOSE_NVHE_SYM(__per_cpu_start)); params->mair_el2 = read_sysreg(mair_el1); /* * The ID map may be configured to use an extended virtual address * range. This is only the case if system RAM is out of range for the * currently configured page size and VA_BITS, in which case we will * also need the extended virtual range for the HYP ID map, or we won't * be able to enable the EL2 MMU. * * However, at EL2, there is only one TTBR register, and we can't switch * between translation tables *and* update TCR_EL2.T0SZ at the same * time. Bottom line: we need to use the extended range with *both* our * translation tables. * * So use the same T0SZ value we use for the ID map. */ tcr = (read_sysreg(tcr_el1) & TCR_EL2_MASK) | TCR_EL2_RES1; tcr &= ~TCR_T0SZ_MASK; tcr |= (idmap_t0sz & GENMASK(TCR_TxSZ_WIDTH - 1, 0)) << TCR_T0SZ_OFFSET; params->tcr_el2 = tcr; params->stack_hyp_va = kern_hyp_va(per_cpu(kvm_arm_hyp_stack_page, cpu) + PAGE_SIZE); params->pgd_pa = kvm_mmu_get_httbr(); if (is_protected_kvm_enabled()) params->hcr_el2 = HCR_HOST_NVHE_PROTECTED_FLAGS; else params->hcr_el2 = HCR_HOST_NVHE_FLAGS; params->vttbr = params->vtcr = 0; /* * Flush the init params from the data cache because the struct will * be read while the MMU is off. */ kvm_flush_dcache_to_poc(params, sizeof(*params)); } static void hyp_install_host_vector(void) { struct kvm_nvhe_init_params *params; struct arm_smccc_res res; /* Switch from the HYP stub to our own HYP init vector */ __hyp_set_vectors(kvm_get_idmap_vector()); /* * Call initialization code, and switch to the full blown HYP code. * If the cpucaps haven't been finalized yet, something has gone very * wrong, and hyp will crash and burn when it uses any * cpus_have_const_cap() wrapper. */ BUG_ON(!system_capabilities_finalized()); params = this_cpu_ptr_nvhe_sym(kvm_init_params); arm_smccc_1_1_hvc(KVM_HOST_SMCCC_FUNC(__kvm_hyp_init), virt_to_phys(params), &res); WARN_ON(res.a0 != SMCCC_RET_SUCCESS); } static void cpu_init_hyp_mode(void) { hyp_install_host_vector(); /* * Disabling SSBD on a non-VHE system requires us to enable SSBS * at EL2. */ if (this_cpu_has_cap(ARM64_SSBS) && arm64_get_spectre_v4_state() == SPECTRE_VULNERABLE) { kvm_call_hyp_nvhe(__kvm_enable_ssbs); } } static void cpu_hyp_reset(void) { if (!is_kernel_in_hyp_mode()) __hyp_reset_vectors(); } /* * EL2 vectors can be mapped and rerouted in a number of ways, * depending on the kernel configuration and CPU present: * * - If the CPU is affected by Spectre-v2, the hardening sequence is * placed in one of the vector slots, which is executed before jumping * to the real vectors. * * - If the CPU also has the ARM64_SPECTRE_V3A cap, the slot * containing the hardening sequence is mapped next to the idmap page, * and executed before jumping to the real vectors. * * - If the CPU only has the ARM64_SPECTRE_V3A cap, then an * empty slot is selected, mapped next to the idmap page, and * executed before jumping to the real vectors. * * Note that ARM64_SPECTRE_V3A is somewhat incompatible with * VHE, as we don't have hypervisor-specific mappings. If the system * is VHE and yet selects this capability, it will be ignored. */ static void cpu_set_hyp_vector(void) { struct bp_hardening_data *data = this_cpu_ptr(&bp_hardening_data); void *vector = hyp_spectre_vector_selector[data->slot]; if (!is_protected_kvm_enabled()) *this_cpu_ptr_hyp_sym(kvm_hyp_vector) = (unsigned long)vector; else kvm_call_hyp_nvhe(__pkvm_cpu_set_vector, data->slot); } static void cpu_hyp_init_context(void) { kvm_init_host_cpu_context(&this_cpu_ptr_hyp_sym(kvm_host_data)->host_ctxt); if (!is_kernel_in_hyp_mode()) cpu_init_hyp_mode(); } static void cpu_hyp_init_features(void) { cpu_set_hyp_vector(); kvm_arm_init_debug(); if (is_kernel_in_hyp_mode()) kvm_timer_init_vhe(); if (vgic_present) kvm_vgic_init_cpu_hardware(); } static void cpu_hyp_reinit(void) { cpu_hyp_reset(); cpu_hyp_init_context(); cpu_hyp_init_features(); } static void _kvm_arch_hardware_enable(void *discard) { if (!__this_cpu_read(kvm_arm_hardware_enabled)) { cpu_hyp_reinit(); __this_cpu_write(kvm_arm_hardware_enabled, 1); } } int kvm_arch_hardware_enable(void) { _kvm_arch_hardware_enable(NULL); return 0; } static void _kvm_arch_hardware_disable(void *discard) { if (__this_cpu_read(kvm_arm_hardware_enabled)) { cpu_hyp_reset(); __this_cpu_write(kvm_arm_hardware_enabled, 0); } } void kvm_arch_hardware_disable(void) { if (!is_protected_kvm_enabled()) _kvm_arch_hardware_disable(NULL); } #ifdef CONFIG_CPU_PM static int hyp_init_cpu_pm_notifier(struct notifier_block *self, unsigned long cmd, void *v) { /* * kvm_arm_hardware_enabled is left with its old value over * PM_ENTER->PM_EXIT. It is used to indicate PM_EXIT should * re-enable hyp. */ switch (cmd) { case CPU_PM_ENTER: if (__this_cpu_read(kvm_arm_hardware_enabled)) /* * don't update kvm_arm_hardware_enabled here * so that the hardware will be re-enabled * when we resume. See below. */ cpu_hyp_reset(); return NOTIFY_OK; case CPU_PM_ENTER_FAILED: case CPU_PM_EXIT: if (__this_cpu_read(kvm_arm_hardware_enabled)) /* The hardware was enabled before suspend. */ cpu_hyp_reinit(); return NOTIFY_OK; default: return NOTIFY_DONE; } } static struct notifier_block hyp_init_cpu_pm_nb = { .notifier_call = hyp_init_cpu_pm_notifier, }; static void hyp_cpu_pm_init(void) { if (!is_protected_kvm_enabled()) cpu_pm_register_notifier(&hyp_init_cpu_pm_nb); } static void hyp_cpu_pm_exit(void) { if (!is_protected_kvm_enabled()) cpu_pm_unregister_notifier(&hyp_init_cpu_pm_nb); } #else static inline void hyp_cpu_pm_init(void) { } static inline void hyp_cpu_pm_exit(void) { } #endif static void init_cpu_logical_map(void) { unsigned int cpu; /* * Copy the MPIDR <-> logical CPU ID mapping to hyp. * Only copy the set of online CPUs whose features have been chacked * against the finalized system capabilities. The hypervisor will not * allow any other CPUs from the `possible` set to boot. */ for_each_online_cpu(cpu) hyp_cpu_logical_map[cpu] = cpu_logical_map(cpu); } #define init_psci_0_1_impl_state(config, what) \ config.psci_0_1_ ## what ## _implemented = psci_ops.what static bool init_psci_relay(void) { /* * If PSCI has not been initialized, protected KVM cannot install * itself on newly booted CPUs. */ if (!psci_ops.get_version) { kvm_err("Cannot initialize protected mode without PSCI\n"); return false; } kvm_host_psci_config.version = psci_ops.get_version(); kvm_host_psci_config.smccc_version = arm_smccc_get_version(); if (kvm_host_psci_config.version == PSCI_VERSION(0, 1)) { kvm_host_psci_config.function_ids_0_1 = get_psci_0_1_function_ids(); init_psci_0_1_impl_state(kvm_host_psci_config, cpu_suspend); init_psci_0_1_impl_state(kvm_host_psci_config, cpu_on); init_psci_0_1_impl_state(kvm_host_psci_config, cpu_off); init_psci_0_1_impl_state(kvm_host_psci_config, migrate); } return true; } static int init_subsystems(void) { int err = 0; /* * Enable hardware so that subsystem initialisation can access EL2. */ on_each_cpu(_kvm_arch_hardware_enable, NULL, 1); /* * Register CPU lower-power notifier */ hyp_cpu_pm_init(); /* * Init HYP view of VGIC */ err = kvm_vgic_hyp_init(); switch (err) { case 0: vgic_present = true; break; case -ENODEV: case -ENXIO: vgic_present = false; err = 0; break; default: goto out; } /* * Init HYP architected timer support */ err = kvm_timer_hyp_init(vgic_present); if (err) goto out; kvm_perf_init(); kvm_sys_reg_table_init(); out: if (err || !is_protected_kvm_enabled()) on_each_cpu(_kvm_arch_hardware_disable, NULL, 1); return err; } static void teardown_hyp_mode(void) { int cpu; free_hyp_pgds(); for_each_possible_cpu(cpu) { free_page(per_cpu(kvm_arm_hyp_stack_page, cpu)); free_pages(kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[cpu], nvhe_percpu_order()); } } static int do_pkvm_init(u32 hyp_va_bits) { void *per_cpu_base = kvm_ksym_ref(kvm_nvhe_sym(kvm_arm_hyp_percpu_base)); int ret; preempt_disable(); cpu_hyp_init_context(); ret = kvm_call_hyp_nvhe(__pkvm_init, hyp_mem_base, hyp_mem_size, num_possible_cpus(), kern_hyp_va(per_cpu_base), hyp_va_bits); cpu_hyp_init_features(); /* * The stub hypercalls are now disabled, so set our local flag to * prevent a later re-init attempt in kvm_arch_hardware_enable(). */ __this_cpu_write(kvm_arm_hardware_enabled, 1); preempt_enable(); return ret; } 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); kvm_nvhe_sym(__icache_flags) = __icache_flags; kvm_nvhe_sym(smccc_trng_available) = smccc_trng_available; ret = create_hyp_mappings(addr, addr + hyp_mem_size, PAGE_HYP); if (ret) return ret; ret = do_pkvm_init(hyp_va_bits); if (ret) return ret; free_hyp_pgds(); return 0; } /** * Inits Hyp-mode on all online CPUs */ static int init_hyp_mode(void) { u32 hyp_va_bits; int cpu; int err = -ENOMEM; /* * The protected Hyp-mode cannot be initialized if the memory pool * allocation has failed. */ if (is_protected_kvm_enabled() && !hyp_mem_base) goto out_err; /* * Allocate Hyp PGD and setup Hyp identity mapping */ err = kvm_mmu_init(&hyp_va_bits); if (err) goto out_err; /* * Allocate stack pages for Hypervisor-mode */ for_each_possible_cpu(cpu) { unsigned long stack_page; stack_page = __get_free_page(GFP_KERNEL); if (!stack_page) { err = -ENOMEM; goto out_err; } per_cpu(kvm_arm_hyp_stack_page, cpu) = stack_page; } /* * Allocate and initialize pages for Hypervisor-mode percpu regions. */ for_each_possible_cpu(cpu) { struct page *page; void *page_addr; page = alloc_pages(GFP_KERNEL, nvhe_percpu_order()); if (!page) { err = -ENOMEM; goto out_err; } page_addr = page_address(page); memcpy(page_addr, CHOOSE_NVHE_SYM(__per_cpu_start), nvhe_percpu_size()); kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[cpu] = (unsigned long)page_addr; } /* * Map the Hyp-code called directly from the host */ err = create_hyp_mappings(kvm_ksym_ref(__hyp_text_start), kvm_ksym_ref(__hyp_text_end), PAGE_HYP_EXEC); if (err) { kvm_err("Cannot map world-switch code\n"); goto out_err; } err = create_hyp_mappings(kvm_ksym_ref(__hyp_data_start), kvm_ksym_ref(__hyp_data_end), PAGE_HYP); if (err) { kvm_err("Cannot map .hyp.data section\n"); goto out_err; } err = create_hyp_mappings(kvm_ksym_ref(__hyp_rodata_start), kvm_ksym_ref(__hyp_rodata_end), PAGE_HYP_RO); if (err) { kvm_err("Cannot map .hyp.rodata section\n"); goto out_err; } err = create_hyp_mappings(kvm_ksym_ref(__start_rodata), kvm_ksym_ref(__end_rodata), PAGE_HYP_RO); if (err) { kvm_err("Cannot map rodata section\n"); goto out_err; } /* * .hyp.bss is guaranteed to be placed at the beginning of the .bss * section thanks to an assertion in the linker script. Map it RW and * the rest of .bss RO. */ err = create_hyp_mappings(kvm_ksym_ref(__hyp_bss_start), kvm_ksym_ref(__hyp_bss_end), PAGE_HYP); if (err) { kvm_err("Cannot map hyp bss section: %d\n", err); goto out_err; } err = create_hyp_mappings(kvm_ksym_ref(__hyp_bss_end), kvm_ksym_ref(__bss_stop), PAGE_HYP_RO); if (err) { kvm_err("Cannot map bss section\n"); goto out_err; } /* * Map the Hyp stack pages */ for_each_possible_cpu(cpu) { char *stack_page = (char *)per_cpu(kvm_arm_hyp_stack_page, cpu); err = create_hyp_mappings(stack_page, stack_page + PAGE_SIZE, PAGE_HYP); if (err) { kvm_err("Cannot map hyp stack\n"); goto out_err; } } for_each_possible_cpu(cpu) { char *percpu_begin = (char *)kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[cpu]; char *percpu_end = percpu_begin + nvhe_percpu_size(); /* Map Hyp percpu pages */ err = create_hyp_mappings(percpu_begin, percpu_end, PAGE_HYP); if (err) { kvm_err("Cannot map hyp percpu region\n"); goto out_err; } /* Prepare the CPU initialization parameters */ cpu_prepare_hyp_mode(cpu); } if (is_protected_kvm_enabled()) { init_cpu_logical_map(); if (!init_psci_relay()) { err = -ENODEV; goto out_err; } } if (is_protected_kvm_enabled()) { err = kvm_hyp_init_protection(hyp_va_bits); if (err) { kvm_err("Failed to init hyp memory protection\n"); goto out_err; } } return 0; out_err: teardown_hyp_mode(); kvm_err("error initializing Hyp mode: %d\n", err); return err; } static void _kvm_host_prot_finalize(void *arg) { int *err = arg; if (WARN_ON(kvm_call_hyp_nvhe(__pkvm_prot_finalize))) WRITE_ONCE(*err, -EINVAL); } static int pkvm_drop_host_privileges(void) { int ret = 0; /* * Flip the static key upfront as that may no longer be possible * once the host stage 2 is installed. */ static_branch_enable(&kvm_protected_mode_initialized); /* * Fixup the boot mode so that we don't take spurious round * trips via EL2 on cpu_resume. Flush to the PoC for a good * measure, so that it can be observed by a CPU coming out of * suspend with the MMU off. */ __boot_cpu_mode[0] = __boot_cpu_mode[1] = BOOT_CPU_MODE_EL1; dcache_clean_poc((unsigned long)__boot_cpu_mode, (unsigned long)(__boot_cpu_mode + 2)); on_each_cpu(_kvm_host_prot_finalize, &ret, 1); return ret; } static int finalize_hyp_mode(void) { if (!is_protected_kvm_enabled()) return 0; /* * Exclude HYP sections from kmemleak so that they don't get peeked * at, which would end badly once inaccessible. */ kmemleak_free_part(__hyp_bss_start, __hyp_bss_end - __hyp_bss_start); kmemleak_free_part(__hyp_data_start, __hyp_data_end - __hyp_data_start); kmemleak_free_part(__va(hyp_mem_base), hyp_mem_size); return pkvm_drop_host_privileges(); } struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr) { struct kvm_vcpu *vcpu; int i; mpidr &= MPIDR_HWID_BITMASK; kvm_for_each_vcpu(i, vcpu, kvm) { if (mpidr == kvm_vcpu_get_mpidr_aff(vcpu)) return vcpu; } return NULL; } bool kvm_arch_has_irq_bypass(void) { return true; } int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons, struct irq_bypass_producer *prod) { struct kvm_kernel_irqfd *irqfd = container_of(cons, struct kvm_kernel_irqfd, consumer); return kvm_vgic_v4_set_forwarding(irqfd->kvm, prod->irq, &irqfd->irq_entry); } void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons, struct irq_bypass_producer *prod) { struct kvm_kernel_irqfd *irqfd = container_of(cons, struct kvm_kernel_irqfd, consumer); kvm_vgic_v4_unset_forwarding(irqfd->kvm, prod->irq, &irqfd->irq_entry); } void kvm_arch_irq_bypass_stop(struct irq_bypass_consumer *cons) { struct kvm_kernel_irqfd *irqfd = container_of(cons, struct kvm_kernel_irqfd, consumer); kvm_arm_halt_guest(irqfd->kvm); } void kvm_arch_irq_bypass_start(struct irq_bypass_consumer *cons) { struct kvm_kernel_irqfd *irqfd = container_of(cons, struct kvm_kernel_irqfd, consumer); kvm_arm_resume_guest(irqfd->kvm); } /** * Initialize Hyp-mode and memory mappings on all CPUs. */ int kvm_arch_init(void *opaque) { int err; bool in_hyp_mode; if (!is_hyp_mode_available()) { kvm_info("HYP mode not available\n"); return -ENODEV; } if (kvm_get_mode() == KVM_MODE_NONE) { kvm_info("KVM disabled from command line\n"); return -ENODEV; } in_hyp_mode = is_kernel_in_hyp_mode(); if (cpus_have_final_cap(ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE) || cpus_have_final_cap(ARM64_WORKAROUND_1508412)) kvm_info("Guests without required CPU erratum workarounds can deadlock system!\n" \ "Only trusted guests should be used on this system.\n"); err = kvm_set_ipa_limit(); if (err) return err; err = kvm_arm_init_sve(); if (err) return err; if (!in_hyp_mode) { err = init_hyp_mode(); if (err) goto out_err; } err = kvm_init_vector_slots(); if (err) { kvm_err("Cannot initialise vector slots\n"); goto out_err; } err = init_subsystems(); if (err) goto out_hyp; if (!in_hyp_mode) { err = finalize_hyp_mode(); if (err) { kvm_err("Failed to finalize Hyp protection\n"); goto out_hyp; } } if (is_protected_kvm_enabled()) { kvm_info("Protected nVHE mode initialized successfully\n"); } else if (in_hyp_mode) { kvm_info("VHE mode initialized successfully\n"); } else { kvm_info("Hyp mode initialized successfully\n"); } return 0; out_hyp: hyp_cpu_pm_exit(); if (!in_hyp_mode) teardown_hyp_mode(); out_err: return err; } /* NOP: Compiling as a module not supported */ void kvm_arch_exit(void) { kvm_perf_teardown(); } static int __init early_kvm_mode_cfg(char *arg) { if (!arg) return -EINVAL; if (strcmp(arg, "none") == 0) { kvm_mode = KVM_MODE_NONE; return 0; } if (!is_hyp_mode_available()) { pr_warn_once("KVM is not available. Ignoring kvm-arm.mode\n"); return 0; } if (strcmp(arg, "protected") == 0) { if (!is_kernel_in_hyp_mode()) kvm_mode = KVM_MODE_PROTECTED; else pr_warn_once("Protected KVM not available with VHE\n"); return 0; } if (strcmp(arg, "nvhe") == 0 && !WARN_ON(is_kernel_in_hyp_mode())) { kvm_mode = KVM_MODE_DEFAULT; return 0; } return -EINVAL; } early_param("kvm-arm.mode", early_kvm_mode_cfg); enum kvm_mode kvm_get_mode(void) { return kvm_mode; } static int arm_init(void) { int rc = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE); return rc; } module_init(arm_init);