diff options
author | Marc Zyngier <maz@kernel.org> | 2023-04-21 11:30:46 +0300 |
---|---|---|
committer | Marc Zyngier <maz@kernel.org> | 2023-04-21 11:30:46 +0300 |
commit | ef5f97e9de9fc0d5bb6136de3d01d78c072a452f (patch) | |
tree | 4e5c64a8c0724b7584928a45c34241dcab0d2c0f | |
parent | 197b6b60ae7bc51dd0814953c562833143b292aa (diff) | |
parent | a189884bdc9238aeba941c50f02e25eb584fafed (diff) | |
download | linux-ef5f97e9de9fc0d5bb6136de3d01d78c072a452f.tar.xz |
Merge branch kvm-arm64/lock-inversion into kvmarm-master/next
* kvm-arm64/lock-inversion:
: .
: vm/vcpu lock inversion fixes, courtesy of Oliver Upton, plus a few
: extra fixes from both Oliver and Reiji Watanabe.
:
: From the initial cover letter:
:
: As it so happens, lock ordering in KVM/arm64 is completely backwards.
: There's a significant amount of VM-wide state that needs to be accessed
: from the context of a vCPU. Until now, this was accomplished by
: acquiring the kvm->lock, but that cannot be nested within vcpu->mutex.
:
: This series fixes the issue with some fine-grained locking for MP state
: and a new, dedicated mutex that can nest with both kvm->lock and
: vcpu->mutex.
: .
KVM: arm64: Have kvm_psci_vcpu_on() use WRITE_ONCE() to update mp_state
KVM: arm64: Acquire mp_state_lock in kvm_arch_vcpu_ioctl_vcpu_init()
KVM: arm64: vgic: Don't acquire its_lock before config_lock
KVM: arm64: Use config_lock to protect vgic state
KVM: arm64: Use config_lock to protect data ordered against KVM_RUN
KVM: arm64: Avoid lock inversion when setting the VM register width
KVM: arm64: Avoid vcpu->mutex v. kvm->lock inversion in CPU_ON
Signed-off-by: Marc Zyngier <maz@kernel.org>
-rw-r--r-- | arch/arm64/include/asm/kvm_host.h | 4 | ||||
-rw-r--r-- | arch/arm64/kvm/arm.c | 59 | ||||
-rw-r--r-- | arch/arm64/kvm/guest.c | 2 | ||||
-rw-r--r-- | arch/arm64/kvm/hypercalls.c | 4 | ||||
-rw-r--r-- | arch/arm64/kvm/pmu-emul.c | 23 | ||||
-rw-r--r-- | arch/arm64/kvm/psci.c | 30 | ||||
-rw-r--r-- | arch/arm64/kvm/reset.c | 15 | ||||
-rw-r--r-- | arch/arm64/kvm/vgic/vgic-debug.c | 8 | ||||
-rw-r--r-- | arch/arm64/kvm/vgic/vgic-init.c | 36 | ||||
-rw-r--r-- | arch/arm64/kvm/vgic/vgic-its.c | 33 | ||||
-rw-r--r-- | arch/arm64/kvm/vgic/vgic-kvm-device.c | 47 | ||||
-rw-r--r-- | arch/arm64/kvm/vgic/vgic-mmio-v3.c | 4 | ||||
-rw-r--r-- | arch/arm64/kvm/vgic/vgic-mmio.c | 12 | ||||
-rw-r--r-- | arch/arm64/kvm/vgic/vgic-v4.c | 11 | ||||
-rw-r--r-- | arch/arm64/kvm/vgic/vgic.c | 12 |
15 files changed, 186 insertions, 114 deletions
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index bcd774d74f34..cd1ef8716719 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -199,6 +199,9 @@ struct kvm_arch { /* Mandated version of PSCI */ u32 psci_version; + /* Protects VM-scoped configuration data */ + struct mutex config_lock; + /* * If we encounter a data abort without valid instruction syndrome * information, report this to user space. User space can (and @@ -522,6 +525,7 @@ struct kvm_vcpu_arch { /* vcpu power state */ struct kvm_mp_state mp_state; + spinlock_t mp_state_lock; /* Cache some mmu pages needed inside spinlock regions */ struct kvm_mmu_memory_cache mmu_page_cache; diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 3bd732eaf087..ad3655a7d122 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -128,6 +128,16 @@ 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; @@ -326,6 +336,16 @@ 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 +463,41 @@ 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 +507,14 @@ 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 +523,8 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu, ret = -EINVAL; } + spin_unlock(&vcpu->arch.mp_state_lock); + return ret; } @@ -593,9 +624,9 @@ 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 +1241,14 @@ 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; } diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c index 07444fa22888..481c79cf22cd 100644 --- a/arch/arm64/kvm/guest.c +++ b/arch/arm64/kvm/guest.c @@ -957,7 +957,9 @@ int kvm_arm_vcpu_arch_set_attr(struct kvm_vcpu *vcpu, switch (attr->group) { case KVM_ARM_VCPU_PMU_V3_CTRL: + mutex_lock(&vcpu->kvm->arch.config_lock); ret = kvm_arm_pmu_v3_set_attr(vcpu, attr); + mutex_unlock(&vcpu->kvm->arch.config_lock); break; case KVM_ARM_VCPU_TIMER_CTRL: ret = kvm_arm_timer_set_attr(vcpu, attr); diff --git a/arch/arm64/kvm/hypercalls.c b/arch/arm64/kvm/hypercalls.c index 5da884e11337..fbdbf4257f76 100644 --- a/arch/arm64/kvm/hypercalls.c +++ b/arch/arm64/kvm/hypercalls.c @@ -377,7 +377,7 @@ static int kvm_arm_set_fw_reg_bmap(struct kvm_vcpu *vcpu, u64 reg_id, u64 val) if (val & ~fw_reg_features) return -EINVAL; - mutex_lock(&kvm->lock); + mutex_lock(&kvm->arch.config_lock); if (test_bit(KVM_ARCH_FLAG_HAS_RAN_ONCE, &kvm->arch.flags) && val != *fw_reg_bmap) { @@ -387,7 +387,7 @@ static int kvm_arm_set_fw_reg_bmap(struct kvm_vcpu *vcpu, u64 reg_id, u64 val) WRITE_ONCE(*fw_reg_bmap, val); out: - mutex_unlock(&kvm->lock); + mutex_unlock(&kvm->arch.config_lock); return ret; } diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c index 24908400e190..240168416838 100644 --- a/arch/arm64/kvm/pmu-emul.c +++ b/arch/arm64/kvm/pmu-emul.c @@ -874,7 +874,7 @@ static int kvm_arm_pmu_v3_set_pmu(struct kvm_vcpu *vcpu, int pmu_id) struct arm_pmu *arm_pmu; int ret = -ENXIO; - mutex_lock(&kvm->lock); + lockdep_assert_held(&kvm->arch.config_lock); mutex_lock(&arm_pmus_lock); list_for_each_entry(entry, &arm_pmus, entry) { @@ -894,7 +894,6 @@ static int kvm_arm_pmu_v3_set_pmu(struct kvm_vcpu *vcpu, int pmu_id) } mutex_unlock(&arm_pmus_lock); - mutex_unlock(&kvm->lock); return ret; } @@ -902,22 +901,20 @@ int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) { struct kvm *kvm = vcpu->kvm; + lockdep_assert_held(&kvm->arch.config_lock); + if (!kvm_vcpu_has_pmu(vcpu)) return -ENODEV; if (vcpu->arch.pmu.created) return -EBUSY; - mutex_lock(&kvm->lock); if (!kvm->arch.arm_pmu) { /* No PMU set, get the default one */ kvm->arch.arm_pmu = kvm_pmu_probe_armpmu(); - if (!kvm->arch.arm_pmu) { - mutex_unlock(&kvm->lock); + if (!kvm->arch.arm_pmu) return -ENODEV; - } } - mutex_unlock(&kvm->lock); switch (attr->attr) { case KVM_ARM_VCPU_PMU_V3_IRQ: { @@ -961,19 +958,13 @@ int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) filter.action != KVM_PMU_EVENT_DENY)) return -EINVAL; - mutex_lock(&kvm->lock); - - if (test_bit(KVM_ARCH_FLAG_HAS_RAN_ONCE, &kvm->arch.flags)) { - mutex_unlock(&kvm->lock); + if (test_bit(KVM_ARCH_FLAG_HAS_RAN_ONCE, &kvm->arch.flags)) return -EBUSY; - } if (!kvm->arch.pmu_filter) { kvm->arch.pmu_filter = bitmap_alloc(nr_events, GFP_KERNEL_ACCOUNT); - if (!kvm->arch.pmu_filter) { - mutex_unlock(&kvm->lock); + if (!kvm->arch.pmu_filter) return -ENOMEM; - } /* * The default depends on the first applied filter. @@ -992,8 +983,6 @@ int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) else bitmap_clear(kvm->arch.pmu_filter, filter.base_event, filter.nevents); - mutex_unlock(&kvm->lock); - return 0; } case KVM_ARM_VCPU_PMU_V3_SET_PMU: { diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c index 7fbc4c1b9df0..d046e82e3723 100644 --- a/arch/arm64/kvm/psci.c +++ b/arch/arm64/kvm/psci.c @@ -62,6 +62,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) struct vcpu_reset_state *reset_state; struct kvm *kvm = source_vcpu->kvm; struct kvm_vcpu *vcpu = NULL; + int ret = PSCI_RET_SUCCESS; unsigned long cpu_id; cpu_id = smccc_get_arg1(source_vcpu); @@ -76,11 +77,15 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) */ if (!vcpu) return PSCI_RET_INVALID_PARAMS; + + spin_lock(&vcpu->arch.mp_state_lock); if (!kvm_arm_vcpu_stopped(vcpu)) { if (kvm_psci_version(source_vcpu) != KVM_ARM_PSCI_0_1) - return PSCI_RET_ALREADY_ON; + ret = PSCI_RET_ALREADY_ON; else - return PSCI_RET_INVALID_PARAMS; + ret = PSCI_RET_INVALID_PARAMS; + + goto out_unlock; } reset_state = &vcpu->arch.reset_state; @@ -96,7 +101,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) */ reset_state->r0 = smccc_get_arg3(source_vcpu); - WRITE_ONCE(reset_state->reset, true); + reset_state->reset = true; kvm_make_request(KVM_REQ_VCPU_RESET, vcpu); /* @@ -105,10 +110,12 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) */ smp_wmb(); - vcpu->arch.mp_state.mp_state = KVM_MP_STATE_RUNNABLE; + WRITE_ONCE(vcpu->arch.mp_state.mp_state, KVM_MP_STATE_RUNNABLE); kvm_vcpu_wake_up(vcpu); - return PSCI_RET_SUCCESS; +out_unlock: + spin_unlock(&vcpu->arch.mp_state_lock); + return ret; } static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu) @@ -168,8 +175,11 @@ static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type, u64 flags) * after this call is handled and before the VCPUs have been * re-initialized. */ - kvm_for_each_vcpu(i, tmp, vcpu->kvm) - tmp->arch.mp_state.mp_state = KVM_MP_STATE_STOPPED; + kvm_for_each_vcpu(i, tmp, vcpu->kvm) { + spin_lock(&tmp->arch.mp_state_lock); + WRITE_ONCE(tmp->arch.mp_state.mp_state, KVM_MP_STATE_STOPPED); + spin_unlock(&tmp->arch.mp_state_lock); + } kvm_make_all_cpus_request(vcpu->kvm, KVM_REQ_SLEEP); memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event)); @@ -229,7 +239,6 @@ static unsigned long kvm_psci_check_allowed_function(struct kvm_vcpu *vcpu, u32 static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) { - struct kvm *kvm = vcpu->kvm; u32 psci_fn = smccc_get_function(vcpu); unsigned long val; int ret = 1; @@ -254,9 +263,7 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) kvm_psci_narrow_to_32bit(vcpu); fallthrough; case PSCI_0_2_FN64_CPU_ON: - mutex_lock(&kvm->lock); val = kvm_psci_vcpu_on(vcpu); - mutex_unlock(&kvm->lock); break; case PSCI_0_2_FN_AFFINITY_INFO: kvm_psci_narrow_to_32bit(vcpu); @@ -395,7 +402,6 @@ static int kvm_psci_1_x_call(struct kvm_vcpu *vcpu, u32 minor) static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu) { - struct kvm *kvm = vcpu->kvm; u32 psci_fn = smccc_get_function(vcpu); unsigned long val; @@ -405,9 +411,7 @@ static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu) val = PSCI_RET_SUCCESS; break; case KVM_PSCI_FN_CPU_ON: - mutex_lock(&kvm->lock); val = kvm_psci_vcpu_on(vcpu); - mutex_unlock(&kvm->lock); break; default: val = PSCI_RET_NOT_SUPPORTED; diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c index 49a3257dec46..b5dee8e57e77 100644 --- a/arch/arm64/kvm/reset.c +++ b/arch/arm64/kvm/reset.c @@ -205,7 +205,7 @@ static int kvm_set_vm_width(struct kvm_vcpu *vcpu) is32bit = vcpu_has_feature(vcpu, KVM_ARM_VCPU_EL1_32BIT); - lockdep_assert_held(&kvm->lock); + lockdep_assert_held(&kvm->arch.config_lock); if (test_bit(KVM_ARCH_FLAG_REG_WIDTH_CONFIGURED, &kvm->arch.flags)) { /* @@ -262,17 +262,18 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu) bool loaded; u32 pstate; - mutex_lock(&vcpu->kvm->lock); + mutex_lock(&vcpu->kvm->arch.config_lock); ret = kvm_set_vm_width(vcpu); - if (!ret) { - reset_state = vcpu->arch.reset_state; - WRITE_ONCE(vcpu->arch.reset_state.reset, false); - } - mutex_unlock(&vcpu->kvm->lock); + mutex_unlock(&vcpu->kvm->arch.config_lock); if (ret) return ret; + spin_lock(&vcpu->arch.mp_state_lock); + reset_state = vcpu->arch.reset_state; + vcpu->arch.reset_state.reset = false; + spin_unlock(&vcpu->arch.mp_state_lock); + /* Reset PMU outside of the non-preemptible section */ kvm_pmu_vcpu_reset(vcpu); diff --git a/arch/arm64/kvm/vgic/vgic-debug.c b/arch/arm64/kvm/vgic/vgic-debug.c index 78cde687383c..07aa0437125a 100644 --- a/arch/arm64/kvm/vgic/vgic-debug.c +++ b/arch/arm64/kvm/vgic/vgic-debug.c @@ -85,7 +85,7 @@ static void *vgic_debug_start(struct seq_file *s, loff_t *pos) struct kvm *kvm = s->private; struct vgic_state_iter *iter; - mutex_lock(&kvm->lock); + mutex_lock(&kvm->arch.config_lock); iter = kvm->arch.vgic.iter; if (iter) { iter = ERR_PTR(-EBUSY); @@ -104,7 +104,7 @@ static void *vgic_debug_start(struct seq_file *s, loff_t *pos) if (end_of_vgic(iter)) iter = NULL; out: - mutex_unlock(&kvm->lock); + mutex_unlock(&kvm->arch.config_lock); return iter; } @@ -132,12 +132,12 @@ static void vgic_debug_stop(struct seq_file *s, void *v) if (IS_ERR(v)) return; - mutex_lock(&kvm->lock); + mutex_lock(&kvm->arch.config_lock); iter = kvm->arch.vgic.iter; kfree(iter->lpi_array); kfree(iter); kvm->arch.vgic.iter = NULL; - mutex_unlock(&kvm->lock); + mutex_unlock(&kvm->arch.config_lock); } static void print_dist_state(struct seq_file *s, struct vgic_dist *dist) diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c index cd134db41a57..9d42c7cb2b58 100644 --- a/arch/arm64/kvm/vgic/vgic-init.c +++ b/arch/arm64/kvm/vgic/vgic-init.c @@ -74,9 +74,6 @@ int kvm_vgic_create(struct kvm *kvm, u32 type) unsigned long i; int ret; - if (irqchip_in_kernel(kvm)) - return -EEXIST; - /* * This function is also called by the KVM_CREATE_IRQCHIP handler, * which had no chance yet to check the availability of the GICv2 @@ -87,10 +84,20 @@ int kvm_vgic_create(struct kvm *kvm, u32 type) !kvm_vgic_global_state.can_emulate_gicv2) return -ENODEV; + /* Must be held to avoid race with vCPU creation */ + lockdep_assert_held(&kvm->lock); + ret = -EBUSY; if (!lock_all_vcpus(kvm)) return ret; + mutex_lock(&kvm->arch.config_lock); + + if (irqchip_in_kernel(kvm)) { + ret = -EEXIST; + goto out_unlock; + } + kvm_for_each_vcpu(i, vcpu, kvm) { if (vcpu_has_run_once(vcpu)) goto out_unlock; @@ -118,6 +125,7 @@ int kvm_vgic_create(struct kvm *kvm, u32 type) INIT_LIST_HEAD(&kvm->arch.vgic.rd_regions); out_unlock: + mutex_unlock(&kvm->arch.config_lock); unlock_all_vcpus(kvm); return ret; } @@ -227,9 +235,9 @@ int kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu) * KVM io device for the redistributor that belongs to this VCPU. */ if (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3) { - mutex_lock(&vcpu->kvm->lock); + mutex_lock(&vcpu->kvm->arch.config_lock); ret = vgic_register_redist_iodev(vcpu); - mutex_unlock(&vcpu->kvm->lock); + mutex_unlock(&vcpu->kvm->arch.config_lock); } return ret; } @@ -250,7 +258,6 @@ static void kvm_vgic_vcpu_enable(struct kvm_vcpu *vcpu) * The function is generally called when nr_spis has been explicitly set * by the guest through the KVM DEVICE API. If not nr_spis is set to 256. * vgic_initialized() returns true when this function has succeeded. - * Must be called with kvm->lock held! */ int vgic_init(struct kvm *kvm) { @@ -259,6 +266,8 @@ int vgic_init(struct kvm *kvm) int ret = 0, i; unsigned long idx; + lockdep_assert_held(&kvm->arch.config_lock); + if (vgic_initialized(kvm)) return 0; @@ -373,12 +382,13 @@ void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu) vgic_cpu->rd_iodev.base_addr = VGIC_ADDR_UNDEF; } -/* To be called with kvm->lock held */ static void __kvm_vgic_destroy(struct kvm *kvm) { struct kvm_vcpu *vcpu; unsigned long i; + lockdep_assert_held(&kvm->arch.config_lock); + vgic_debug_destroy(kvm); kvm_for_each_vcpu(i, vcpu, kvm) @@ -389,9 +399,9 @@ static void __kvm_vgic_destroy(struct kvm *kvm) void kvm_vgic_destroy(struct kvm *kvm) { - mutex_lock(&kvm->lock); + mutex_lock(&kvm->arch.config_lock); __kvm_vgic_destroy(kvm); - mutex_unlock(&kvm->lock); + mutex_unlock(&kvm->arch.config_lock); } /** @@ -414,9 +424,9 @@ int vgic_lazy_init(struct kvm *kvm) if (kvm->arch.vgic.vgic_model != KVM_DEV_TYPE_ARM_VGIC_V2) return -EBUSY; - mutex_lock(&kvm->lock); + mutex_lock(&kvm->arch.config_lock); ret = vgic_init(kvm); - mutex_unlock(&kvm->lock); + mutex_unlock(&kvm->arch.config_lock); } return ret; @@ -441,7 +451,7 @@ int kvm_vgic_map_resources(struct kvm *kvm) if (likely(vgic_ready(kvm))) return 0; - mutex_lock(&kvm->lock); + mutex_lock(&kvm->arch.config_lock); if (vgic_ready(kvm)) goto out; @@ -459,7 +469,7 @@ int kvm_vgic_map_resources(struct kvm *kvm) dist->ready = true; out: - mutex_unlock(&kvm->lock); + mutex_unlock(&kvm->arch.config_lock); return ret; } diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c index 2642e9ce2819..750e51e3779a 100644 --- a/arch/arm64/kvm/vgic/vgic-its.c +++ b/arch/arm64/kvm/vgic/vgic-its.c @@ -1958,6 +1958,16 @@ static int vgic_its_create(struct kvm_device *dev, u32 type) mutex_init(&its->its_lock); mutex_init(&its->cmd_lock); + /* Yep, even more trickery for lock ordering... */ +#ifdef CONFIG_LOCKDEP + mutex_lock(&dev->kvm->arch.config_lock); + mutex_lock(&its->cmd_lock); + mutex_lock(&its->its_lock); + mutex_unlock(&its->its_lock); + mutex_unlock(&its->cmd_lock); + mutex_unlock(&dev->kvm->arch.config_lock); +#endif + its->vgic_its_base = VGIC_ADDR_UNDEF; INIT_LIST_HEAD(&its->device_list); @@ -2045,6 +2055,13 @@ static int vgic_its_attr_regs_access(struct kvm_device *dev, mutex_lock(&dev->kvm->lock); + if (!lock_all_vcpus(dev->kvm)) { + mutex_unlock(&dev->kvm->lock); + return -EBUSY; + } + + mutex_lock(&dev->kvm->arch.config_lock); + if (IS_VGIC_ADDR_UNDEF(its->vgic_its_base)) { ret = -ENXIO; goto out; @@ -2058,11 +2075,6 @@ static int vgic_its_attr_regs_access(struct kvm_device *dev, goto out; } - if (!lock_all_vcpus(dev->kvm)) { - ret = -EBUSY; - goto out; - } - addr = its->vgic_its_base + offset; len = region->access_flags & VGIC_ACCESS_64bit ? 8 : 4; @@ -2076,8 +2088,9 @@ static int vgic_its_attr_regs_access(struct kvm_device *dev, } else { *reg = region->its_read(dev->kvm, its, addr, len); } - unlock_all_vcpus(dev->kvm); out: + mutex_unlock(&dev->kvm->arch.config_lock); + unlock_all_vcpus(dev->kvm); mutex_unlock(&dev->kvm->lock); return ret; } @@ -2749,14 +2762,15 @@ static int vgic_its_ctrl(struct kvm *kvm, struct vgic_its *its, u64 attr) return 0; mutex_lock(&kvm->lock); - mutex_lock(&its->its_lock); if (!lock_all_vcpus(kvm)) { - mutex_unlock(&its->its_lock); mutex_unlock(&kvm->lock); return -EBUSY; } + mutex_lock(&kvm->arch.config_lock); + mutex_lock(&its->its_lock); + switch (attr) { case KVM_DEV_ARM_ITS_CTRL_RESET: vgic_its_reset(kvm, its); @@ -2769,8 +2783,9 @@ static int vgic_its_ctrl(struct kvm *kvm, struct vgic_its *its, u64 attr) break; } - unlock_all_vcpus(kvm); mutex_unlock(&its->its_lock); + mutex_unlock(&kvm->arch.config_lock); + unlock_all_vcpus(kvm); mutex_unlock(&kvm->lock); return ret; } diff --git a/arch/arm64/kvm/vgic/vgic-kvm-device.c b/arch/arm64/kvm/vgic/vgic-kvm-device.c index edeac2380591..07e727023deb 100644 --- a/arch/arm64/kvm/vgic/vgic-kvm-device.c +++ b/arch/arm64/kvm/vgic/vgic-kvm-device.c @@ -46,7 +46,7 @@ int kvm_set_legacy_vgic_v2_addr(struct kvm *kvm, struct kvm_arm_device_addr *dev struct vgic_dist *vgic = &kvm->arch.vgic; int r; - mutex_lock(&kvm->lock); + mutex_lock(&kvm->arch.config_lock); switch (FIELD_GET(KVM_ARM_DEVICE_TYPE_MASK, dev_addr->id)) { case KVM_VGIC_V2_ADDR_TYPE_DIST: r = vgic_check_type(kvm, KVM_DEV_TYPE_ARM_VGIC_V2); @@ -68,7 +68,7 @@ int kvm_set_legacy_vgic_v2_addr(struct kvm *kvm, struct kvm_arm_device_addr *dev r = -ENODEV; } - mutex_unlock(&kvm->lock); + mutex_unlock(&kvm->arch.config_lock); return r; } @@ -102,7 +102,7 @@ static int kvm_vgic_addr(struct kvm *kvm, struct kvm_device_attr *attr, bool wri if (get_user(addr, uaddr)) return -EFAULT; - mutex_lock(&kvm->lock); + mutex_lock(&kvm->arch.config_lock); switch (attr->attr) { case KVM_VGIC_V2_ADDR_TYPE_DIST: r = vgic_check_type(kvm, KVM_DEV_TYPE_ARM_VGIC_V2); @@ -191,7 +191,7 @@ static int kvm_vgic_addr(struct kvm *kvm, struct kvm_device_attr *attr, bool wri } out: - mutex_unlock(&kvm->lock); + mutex_unlock(&kvm->arch.config_lock); if (!r && !write) r = put_user(addr, uaddr); @@ -227,7 +227,7 @@ static int vgic_set_common_attr(struct kvm_device *dev, (val & 31)) return -EINVAL; - mutex_lock(&dev->kvm->lock); + mutex_lock(&dev->kvm->arch.config_lock); if (vgic_ready(dev->kvm) || dev->kvm->arch.vgic.nr_spis) ret = -EBUSY; @@ -235,16 +235,16 @@ static int vgic_set_common_attr(struct kvm_device *dev, dev->kvm->arch.vgic.nr_spis = val - VGIC_NR_PRIVATE_IRQS; - mutex_unlock(&dev->kvm->lock); + mutex_unlock(&dev->kvm->arch.config_lock); return ret; } case KVM_DEV_ARM_VGIC_GRP_CTRL: { switch (attr->attr) { case KVM_DEV_ARM_VGIC_CTRL_INIT: - mutex_lock(&dev->kvm->lock); + mutex_lock(&dev->kvm->arch.config_lock); r = vgic_init(dev->kvm); - mutex_unlock(&dev->kvm->lock); + mutex_unlock(&dev->kvm->arch.config_lock); return r; case KVM_DEV_ARM_VGIC_SAVE_PENDING_TABLES: /* @@ -260,7 +260,10 @@ static int vgic_set_common_attr(struct kvm_device *dev, mutex_unlock(&dev->kvm->lock); return -EBUSY; } + + mutex_lock(&dev->kvm->arch.config_lock); r = vgic_v3_save_pending_tables(dev->kvm); + mutex_unlock(&dev->kvm->arch.config_lock); unlock_all_vcpus(dev->kvm); mutex_unlock(&dev->kvm->lock); return r; @@ -411,15 +414,17 @@ static int vgic_v2_attr_regs_access(struct kvm_device *dev, mutex_lock(&dev->kvm->lock); + if (!lock_all_vcpus(dev->kvm)) { + mutex_unlock(&dev->kvm->lock); + return -EBUSY; + } + + mutex_lock(&dev->kvm->arch.config_lock); + ret = vgic_init(dev->kvm); if (ret) goto out; - if (!lock_all_vcpus(dev->kvm)) { - ret = -EBUSY; - goto out; - } - switch (attr->group) { case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: ret = vgic_v2_cpuif_uaccess(vcpu, is_write, addr, &val); @@ -432,8 +437,9 @@ static int vgic_v2_attr_regs_access(struct kvm_device *dev, break; } - unlock_all_vcpus(dev->kvm); out: + mutex_unlock(&dev->kvm->arch.config_lock); + unlock_all_vcpus(dev->kvm); mutex_unlock(&dev->kvm->lock); if (!ret && !is_write) @@ -569,12 +575,14 @@ static int vgic_v3_attr_regs_access(struct kvm_device *dev, mutex_lock(&dev->kvm->lock); - if (unlikely(!vgic_initialized(dev->kvm))) { - ret = -EBUSY; - goto out; + if (!lock_all_vcpus(dev->kvm)) { + mutex_unlock(&dev->kvm->lock); + return -EBUSY; } - if (!lock_all_vcpus(dev->kvm)) { + mutex_lock(&dev->kvm->arch.config_lock); + + if (unlikely(!vgic_initialized(dev->kvm))) { ret = -EBUSY; goto out; } @@ -609,8 +617,9 @@ static int vgic_v3_attr_regs_access(struct kvm_device *dev, break; } - unlock_all_vcpus(dev->kvm); out: + mutex_unlock(&dev->kvm->arch.config_lock); + unlock_all_vcpus(dev->kvm); mutex_unlock(&dev->kvm->lock); if (!ret && uaccess && !is_write) { diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v3.c b/arch/arm64/kvm/vgic/vgic-mmio-v3.c index 91201f743033..472b18ac92a2 100644 --- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c +++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c @@ -111,7 +111,7 @@ static void vgic_mmio_write_v3_misc(struct kvm_vcpu *vcpu, case GICD_CTLR: { bool was_enabled, is_hwsgi; - mutex_lock(&vcpu->kvm->lock); + mutex_lock(&vcpu->kvm->arch.config_lock); was_enabled = dist->enabled; is_hwsgi = dist->nassgireq; @@ -139,7 +139,7 @@ static void vgic_mmio_write_v3_misc(struct kvm_vcpu *vcpu, else if (!was_enabled && dist->enabled) vgic_kick_vcpus(vcpu->kvm); - mutex_unlock(&vcpu->kvm->lock); + mutex_unlock(&vcpu->kvm->arch.config_lock); break; } case GICD_TYPER: diff --git a/arch/arm64/kvm/vgic/vgic-mmio.c b/arch/arm64/kvm/vgic/vgic-mmio.c index e67b3b2c8044..1939c94e0b24 100644 --- a/arch/arm64/kvm/vgic/vgic-mmio.c +++ b/arch/arm64/kvm/vgic/vgic-mmio.c @@ -530,13 +530,13 @@ unsigned long vgic_mmio_read_active(struct kvm_vcpu *vcpu, u32 intid = VGIC_ADDR_TO_INTID(addr, 1); u32 val; - mutex_lock(&vcpu->kvm->lock); + mutex_lock(&vcpu->kvm->arch.config_lock); vgic_access_active_prepare(vcpu, intid); val = __vgic_mmio_read_active(vcpu, addr, len); vgic_access_active_finish(vcpu, intid); - mutex_unlock(&vcpu->kvm->lock); + mutex_unlock(&vcpu->kvm->arch.config_lock); return val; } @@ -625,13 +625,13 @@ void vgic_mmio_write_cactive(struct kvm_vcpu *vcpu, { u32 intid = VGIC_ADDR_TO_INTID(addr, 1); - mutex_lock(&vcpu->kvm->lock); + mutex_lock(&vcpu->kvm->arch.config_lock); vgic_access_active_prepare(vcpu, intid); __vgic_mmio_write_cactive(vcpu, addr, len, val); vgic_access_active_finish(vcpu, intid); - mutex_unlock(&vcpu->kvm->lock); + mutex_unlock(&vcpu->kvm->arch.config_lock); } int vgic_mmio_uaccess_write_cactive(struct kvm_vcpu *vcpu, @@ -662,13 +662,13 @@ void vgic_mmio_write_sactive(struct kvm_vcpu *vcpu, { u32 intid = VGIC_ADDR_TO_INTID(addr, 1); - mutex_lock(&vcpu->kvm->lock); + mutex_lock(&vcpu->kvm->arch.config_lock); vgic_access_active_prepare(vcpu, intid); __vgic_mmio_write_sactive(vcpu, addr, len, val); vgic_access_active_finish(vcpu, intid); - mutex_unlock(&vcpu->kvm->lock); + mutex_unlock(&vcpu->kvm->arch.config_lock); } int vgic_mmio_uaccess_write_sactive(struct kvm_vcpu *vcpu, diff --git a/arch/arm64/kvm/vgic/vgic-v4.c b/arch/arm64/kvm/vgic/vgic-v4.c index a413718be92b..3bb003478060 100644 --- a/arch/arm64/kvm/vgic/vgic-v4.c +++ b/arch/arm64/kvm/vgic/vgic-v4.c @@ -232,9 +232,8 @@ int vgic_v4_request_vpe_irq(struct kvm_vcpu *vcpu, int irq) * @kvm: Pointer to the VM being initialized * * We may be called each time a vITS is created, or when the - * vgic is initialized. This relies on kvm->lock to be - * held. In both cases, the number of vcpus should now be - * fixed. + * vgic is initialized. In both cases, the number of vcpus + * should now be fixed. */ int vgic_v4_init(struct kvm *kvm) { @@ -243,6 +242,8 @@ int vgic_v4_init(struct kvm *kvm) int nr_vcpus, ret; unsigned long i; + lockdep_assert_held(&kvm->arch.config_lock); + if (!kvm_vgic_global_state.has_gicv4) return 0; /* Nothing to see here... move along. */ @@ -309,14 +310,14 @@ int vgic_v4_init(struct kvm *kvm) /** * vgic_v4_teardown - Free the GICv4 data structures * @kvm: Pointer to the VM being destroyed - * - * Relies on kvm->lock to be held. */ void vgic_v4_teardown(struct kvm *kvm) { struct its_vm *its_vm = &kvm->arch.vgic.its_vm; int i; + lockdep_assert_held(&kvm->arch.config_lock); + if (!its_vm->vpes) return; diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c index d97e6080b421..0a005da83ae6 100644 --- a/arch/arm64/kvm/vgic/vgic.c +++ b/arch/arm64/kvm/vgic/vgic.c @@ -24,11 +24,13 @@ struct vgic_global kvm_vgic_global_state __ro_after_init = { /* * Locking order is always: * kvm->lock (mutex) - * its->cmd_lock (mutex) - * its->its_lock (mutex) - * vgic_cpu->ap_list_lock must be taken with IRQs disabled - * kvm->lpi_list_lock must be taken with IRQs disabled - * vgic_irq->irq_lock must be taken with IRQs disabled + * vcpu->mutex (mutex) + * kvm->arch.config_lock (mutex) + * its->cmd_lock (mutex) + * its->its_lock (mutex) + * vgic_cpu->ap_list_lock must be taken with IRQs disabled + * kvm->lpi_list_lock must be taken with IRQs disabled + * vgic_irq->irq_lock must be taken with IRQs disabled * * As the ap_list_lock might be taken from the timer interrupt handler, * we have to disable IRQs before taking this lock and everything lower |