diff options
Diffstat (limited to 'arch/arm64/kvm/arm.c')
| -rw-r--r-- | arch/arm64/kvm/arm.c | 222 |
1 files changed, 162 insertions, 60 deletions
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 3bd732eaf087..14391826241c 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -16,7 +16,6 @@ #include <linux/fs.h> #include <linux/mman.h> #include <linux/sched.h> -#include <linux/kmemleak.h> #include <linux/kvm.h> #include <linux/kvm_irqfd.h> #include <linux/irqbypass.h> @@ -46,7 +45,6 @@ #include <kvm/arm_psci.h> 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); @@ -128,6 +126,16 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) { int ret; + mutex_init(&kvm->arch.config_lock); + +#ifdef CONFIG_LOCKDEP + /* Clue in lockdep that the config_lock must be taken inside kvm->lock */ + mutex_lock(&kvm->lock); + mutex_lock(&kvm->arch.config_lock); + mutex_unlock(&kvm->arch.config_lock); + mutex_unlock(&kvm->lock); +#endif + ret = kvm_share_hyp(kvm, kvm + 1); if (ret) return ret; @@ -148,6 +156,8 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) kvm_vgic_early_init(kvm); + kvm_timer_init_vm(kvm); + /* The maximum number of VCPUs is limited by the host's GIC model */ kvm->max_vcpus = kvm_arm_default_max_vcpus(); @@ -192,6 +202,8 @@ void kvm_arch_destroy_vm(struct kvm *kvm) kvm_destroy_vcpus(kvm); kvm_unshare_hyp(kvm, kvm + 1); + + kvm_arm_teardown_hypercalls(kvm); } int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) @@ -220,6 +232,8 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_VCPU_ATTRIBUTES: case KVM_CAP_PTP_KVM: case KVM_CAP_ARM_SYSTEM_SUSPEND: + case KVM_CAP_IRQFD_RESAMPLE: + case KVM_CAP_COUNTER_OFFSET: r = 1; break; case KVM_CAP_SET_GUEST_DEBUG2: @@ -326,6 +340,16 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu) { int err; + spin_lock_init(&vcpu->arch.mp_state_lock); + +#ifdef CONFIG_LOCKDEP + /* Inform lockdep that the config_lock is acquired after vcpu->mutex */ + mutex_lock(&vcpu->mutex); + mutex_lock(&vcpu->kvm->arch.config_lock); + mutex_unlock(&vcpu->kvm->arch.config_lock); + mutex_unlock(&vcpu->mutex); +#endif + /* Force users to call KVM_ARM_VCPU_INIT */ vcpu->arch.target = -1; bitmap_zero(vcpu->arch.features, KVM_VCPU_MAX_FEATURES); @@ -443,34 +467,41 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) vcpu->cpu = -1; } -void kvm_arm_vcpu_power_off(struct kvm_vcpu *vcpu) +static void __kvm_arm_vcpu_power_off(struct kvm_vcpu *vcpu) { - vcpu->arch.mp_state.mp_state = KVM_MP_STATE_STOPPED; + WRITE_ONCE(vcpu->arch.mp_state.mp_state, KVM_MP_STATE_STOPPED); kvm_make_request(KVM_REQ_SLEEP, vcpu); kvm_vcpu_kick(vcpu); } +void kvm_arm_vcpu_power_off(struct kvm_vcpu *vcpu) +{ + spin_lock(&vcpu->arch.mp_state_lock); + __kvm_arm_vcpu_power_off(vcpu); + spin_unlock(&vcpu->arch.mp_state_lock); +} + bool kvm_arm_vcpu_stopped(struct kvm_vcpu *vcpu) { - return vcpu->arch.mp_state.mp_state == KVM_MP_STATE_STOPPED; + return READ_ONCE(vcpu->arch.mp_state.mp_state) == KVM_MP_STATE_STOPPED; } static void kvm_arm_vcpu_suspend(struct kvm_vcpu *vcpu) { - vcpu->arch.mp_state.mp_state = KVM_MP_STATE_SUSPENDED; + WRITE_ONCE(vcpu->arch.mp_state.mp_state, KVM_MP_STATE_SUSPENDED); kvm_make_request(KVM_REQ_SUSPEND, vcpu); kvm_vcpu_kick(vcpu); } static bool kvm_arm_vcpu_suspended(struct kvm_vcpu *vcpu) { - return vcpu->arch.mp_state.mp_state == KVM_MP_STATE_SUSPENDED; + return READ_ONCE(vcpu->arch.mp_state.mp_state) == KVM_MP_STATE_SUSPENDED; } int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu, struct kvm_mp_state *mp_state) { - *mp_state = vcpu->arch.mp_state; + *mp_state = READ_ONCE(vcpu->arch.mp_state); return 0; } @@ -480,12 +511,14 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu, { int ret = 0; + spin_lock(&vcpu->arch.mp_state_lock); + switch (mp_state->mp_state) { case KVM_MP_STATE_RUNNABLE: - vcpu->arch.mp_state = *mp_state; + WRITE_ONCE(vcpu->arch.mp_state, *mp_state); break; case KVM_MP_STATE_STOPPED: - kvm_arm_vcpu_power_off(vcpu); + __kvm_arm_vcpu_power_off(vcpu); break; case KVM_MP_STATE_SUSPENDED: kvm_arm_vcpu_suspend(vcpu); @@ -494,6 +527,8 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu, ret = -EINVAL; } + spin_unlock(&vcpu->arch.mp_state_lock); + return ret; } @@ -593,9 +628,9 @@ int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu) if (kvm_vm_is_protected(kvm)) kvm_call_hyp_nvhe(__pkvm_vcpu_init_traps, vcpu); - mutex_lock(&kvm->lock); + mutex_lock(&kvm->arch.config_lock); set_bit(KVM_ARCH_FLAG_HAS_RAN_ONCE, &kvm->arch.flags); - mutex_unlock(&kvm->lock); + mutex_unlock(&kvm->arch.config_lock); return ret; } @@ -1210,10 +1245,14 @@ static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu, /* * Handle the "start in power-off" case. */ + spin_lock(&vcpu->arch.mp_state_lock); + if (test_bit(KVM_ARM_VCPU_POWER_OFF, vcpu->arch.features)) - kvm_arm_vcpu_power_off(vcpu); + __kvm_arm_vcpu_power_off(vcpu); else - vcpu->arch.mp_state.mp_state = KVM_MP_STATE_RUNNABLE; + WRITE_ONCE(vcpu->arch.mp_state.mp_state, KVM_MP_STATE_RUNNABLE); + + spin_unlock(&vcpu->arch.mp_state_lock); return 0; } @@ -1439,11 +1478,31 @@ static int kvm_vm_ioctl_set_device_addr(struct kvm *kvm, } } -long kvm_arch_vm_ioctl(struct file *filp, - unsigned int ioctl, unsigned long arg) +static int kvm_vm_has_attr(struct kvm *kvm, struct kvm_device_attr *attr) +{ + switch (attr->group) { + case KVM_ARM_VM_SMCCC_CTRL: + return kvm_vm_smccc_has_attr(kvm, attr); + default: + return -ENXIO; + } +} + +static int kvm_vm_set_attr(struct kvm *kvm, struct kvm_device_attr *attr) +{ + switch (attr->group) { + case KVM_ARM_VM_SMCCC_CTRL: + return kvm_vm_smccc_set_attr(kvm, attr); + default: + return -ENXIO; + } +} + +int 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; + struct kvm_device_attr attr; switch (ioctl) { case KVM_CREATE_IRQCHIP: { @@ -1479,11 +1538,73 @@ long kvm_arch_vm_ioctl(struct file *filp, return -EFAULT; return kvm_vm_ioctl_mte_copy_tags(kvm, ©_tags); } + case KVM_ARM_SET_COUNTER_OFFSET: { + struct kvm_arm_counter_offset offset; + + if (copy_from_user(&offset, argp, sizeof(offset))) + return -EFAULT; + return kvm_vm_ioctl_set_counter_offset(kvm, &offset); + } + case KVM_HAS_DEVICE_ATTR: { + if (copy_from_user(&attr, argp, sizeof(attr))) + return -EFAULT; + + return kvm_vm_has_attr(kvm, &attr); + } + case KVM_SET_DEVICE_ATTR: { + if (copy_from_user(&attr, argp, sizeof(attr))) + return -EFAULT; + + return kvm_vm_set_attr(kvm, &attr); + } default: return -EINVAL; } } +/* unlocks vcpus from @vcpu_lock_idx and smaller */ +static void unlock_vcpus(struct kvm *kvm, int vcpu_lock_idx) +{ + struct kvm_vcpu *tmp_vcpu; + + for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) { + tmp_vcpu = kvm_get_vcpu(kvm, vcpu_lock_idx); + mutex_unlock(&tmp_vcpu->mutex); + } +} + +void unlock_all_vcpus(struct kvm *kvm) +{ + lockdep_assert_held(&kvm->lock); + + unlock_vcpus(kvm, atomic_read(&kvm->online_vcpus) - 1); +} + +/* Returns true if all vcpus were locked, false otherwise */ +bool lock_all_vcpus(struct kvm *kvm) +{ + struct kvm_vcpu *tmp_vcpu; + unsigned long c; + + lockdep_assert_held(&kvm->lock); + + /* + * Any time a vcpu is in an ioctl (including running), the + * core KVM code tries to grab the vcpu->mutex. + * + * By grabbing the vcpu->mutex of all VCPUs we ensure that no + * other VCPUs can fiddle with the state while we access it. + */ + kvm_for_each_vcpu(c, tmp_vcpu, kvm) { + if (!mutex_trylock(&tmp_vcpu->mutex)) { + unlock_vcpus(kvm, c - 1); + return false; + } + } + + return true; +} + static unsigned long nvhe_percpu_size(void) { return (unsigned long)CHOOSE_NVHE_SYM(__per_cpu_end) - @@ -1889,9 +2010,33 @@ static int __init do_pkvm_init(u32 hyp_va_bits) return ret; } +static u64 get_hyp_id_aa64pfr0_el1(void) +{ + /* + * Track whether the system isn't affected by spectre/meltdown in the + * hypervisor's view of id_aa64pfr0_el1, used for protected VMs. + * Although this is per-CPU, we make it global for simplicity, e.g., not + * to have to worry about vcpu migration. + * + * Unlike for non-protected VMs, userspace cannot override this for + * protected VMs. + */ + u64 val = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1); + + val &= ~(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV2) | + ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV3)); + + val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV2), + arm64_get_spectre_v2_state() == SPECTRE_UNAFFECTED); + val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV3), + arm64_get_meltdown_state() == SPECTRE_UNAFFECTED); + + return val; +} + static void kvm_hyp_init_symbols(void) { - kvm_nvhe_sym(id_aa64pfr0_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1); + kvm_nvhe_sym(id_aa64pfr0_el1_sys_val) = get_hyp_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); @@ -2105,41 +2250,6 @@ out_err: return err; } -static void __init _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 __init 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); - on_each_cpu(_kvm_host_prot_finalize, &ret, 1); - return ret; -} - -static int __init 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_phys(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; @@ -2257,14 +2367,6 @@ static __init int kvm_arm_init(void) 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_subs; - } - } - if (is_protected_kvm_enabled()) { kvm_info("Protected nVHE mode initialized successfully\n"); } else if (in_hyp_mode) { |