diff options
Diffstat (limited to 'arch/arm64/kvm/vgic/vgic.c')
| -rw-r--r-- | arch/arm64/kvm/vgic/vgic.c | 1020 |
1 files changed, 1020 insertions, 0 deletions
diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c new file mode 100644 index 000000000000..c3643b7f101b --- /dev/null +++ b/arch/arm64/kvm/vgic/vgic.c @@ -0,0 +1,1020 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2015, 2016 ARM Ltd. + */ + +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/kvm.h> +#include <linux/kvm_host.h> +#include <linux/list_sort.h> +#include <linux/nospec.h> + +#include <asm/kvm_hyp.h> + +#include "vgic.h" + +#define CREATE_TRACE_POINTS +#include "trace.h" + +struct vgic_global kvm_vgic_global_state __ro_after_init = { + .gicv3_cpuif = STATIC_KEY_FALSE_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 + * + * 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 + * than it. + * + * If you need to take multiple locks, always take the upper lock first, + * then the lower ones, e.g. first take the its_lock, then the irq_lock. + * If you are already holding a lock and need to take a higher one, you + * have to drop the lower ranking lock first and re-aquire it after having + * taken the upper one. + * + * When taking more than one ap_list_lock at the same time, always take the + * lowest numbered VCPU's ap_list_lock first, so: + * vcpuX->vcpu_id < vcpuY->vcpu_id: + * raw_spin_lock(vcpuX->arch.vgic_cpu.ap_list_lock); + * raw_spin_lock(vcpuY->arch.vgic_cpu.ap_list_lock); + * + * Since the VGIC must support injecting virtual interrupts from ISRs, we have + * to use the raw_spin_lock_irqsave/raw_spin_unlock_irqrestore versions of outer + * spinlocks for any lock that may be taken while injecting an interrupt. + */ + +/* + * Iterate over the VM's list of mapped LPIs to find the one with a + * matching interrupt ID and return a reference to the IRQ structure. + */ +static struct vgic_irq *vgic_get_lpi(struct kvm *kvm, u32 intid) +{ + struct vgic_dist *dist = &kvm->arch.vgic; + struct vgic_irq *irq = NULL; + unsigned long flags; + + raw_spin_lock_irqsave(&dist->lpi_list_lock, flags); + + list_for_each_entry(irq, &dist->lpi_list_head, lpi_list) { + if (irq->intid != intid) + continue; + + /* + * This increases the refcount, the caller is expected to + * call vgic_put_irq() later once it's finished with the IRQ. + */ + vgic_get_irq_kref(irq); + goto out_unlock; + } + irq = NULL; + +out_unlock: + raw_spin_unlock_irqrestore(&dist->lpi_list_lock, flags); + + return irq; +} + +/* + * This looks up the virtual interrupt ID to get the corresponding + * struct vgic_irq. It also increases the refcount, so any caller is expected + * to call vgic_put_irq() once it's finished with this IRQ. + */ +struct vgic_irq *vgic_get_irq(struct kvm *kvm, struct kvm_vcpu *vcpu, + u32 intid) +{ + /* SGIs and PPIs */ + if (intid <= VGIC_MAX_PRIVATE) { + intid = array_index_nospec(intid, VGIC_MAX_PRIVATE + 1); + return &vcpu->arch.vgic_cpu.private_irqs[intid]; + } + + /* SPIs */ + if (intid < (kvm->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS)) { + intid = array_index_nospec(intid, kvm->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS); + return &kvm->arch.vgic.spis[intid - VGIC_NR_PRIVATE_IRQS]; + } + + /* LPIs */ + if (intid >= VGIC_MIN_LPI) + return vgic_get_lpi(kvm, intid); + + WARN(1, "Looking up struct vgic_irq for reserved INTID"); + return NULL; +} + +/* + * We can't do anything in here, because we lack the kvm pointer to + * lock and remove the item from the lpi_list. So we keep this function + * empty and use the return value of kref_put() to trigger the freeing. + */ +static void vgic_irq_release(struct kref *ref) +{ +} + +/* + * Drop the refcount on the LPI. Must be called with lpi_list_lock held. + */ +void __vgic_put_lpi_locked(struct kvm *kvm, struct vgic_irq *irq) +{ + struct vgic_dist *dist = &kvm->arch.vgic; + + if (!kref_put(&irq->refcount, vgic_irq_release)) + return; + + list_del(&irq->lpi_list); + dist->lpi_list_count--; + + kfree(irq); +} + +void vgic_put_irq(struct kvm *kvm, struct vgic_irq *irq) +{ + struct vgic_dist *dist = &kvm->arch.vgic; + unsigned long flags; + + if (irq->intid < VGIC_MIN_LPI) + return; + + raw_spin_lock_irqsave(&dist->lpi_list_lock, flags); + __vgic_put_lpi_locked(kvm, irq); + raw_spin_unlock_irqrestore(&dist->lpi_list_lock, flags); +} + +void vgic_flush_pending_lpis(struct kvm_vcpu *vcpu) +{ + struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu; + struct vgic_irq *irq, *tmp; + unsigned long flags; + + raw_spin_lock_irqsave(&vgic_cpu->ap_list_lock, flags); + + list_for_each_entry_safe(irq, tmp, &vgic_cpu->ap_list_head, ap_list) { + if (irq->intid >= VGIC_MIN_LPI) { + raw_spin_lock(&irq->irq_lock); + list_del(&irq->ap_list); + irq->vcpu = NULL; + raw_spin_unlock(&irq->irq_lock); + vgic_put_irq(vcpu->kvm, irq); + } + } + + raw_spin_unlock_irqrestore(&vgic_cpu->ap_list_lock, flags); +} + +void vgic_irq_set_phys_pending(struct vgic_irq *irq, bool pending) +{ + WARN_ON(irq_set_irqchip_state(irq->host_irq, + IRQCHIP_STATE_PENDING, + pending)); +} + +bool vgic_get_phys_line_level(struct vgic_irq *irq) +{ + bool line_level; + + BUG_ON(!irq->hw); + + if (irq->get_input_level) + return irq->get_input_level(irq->intid); + + WARN_ON(irq_get_irqchip_state(irq->host_irq, + IRQCHIP_STATE_PENDING, + &line_level)); + return line_level; +} + +/* Set/Clear the physical active state */ +void vgic_irq_set_phys_active(struct vgic_irq *irq, bool active) +{ + + BUG_ON(!irq->hw); + WARN_ON(irq_set_irqchip_state(irq->host_irq, + IRQCHIP_STATE_ACTIVE, + active)); +} + +/** + * kvm_vgic_target_oracle - compute the target vcpu for an irq + * + * @irq: The irq to route. Must be already locked. + * + * Based on the current state of the interrupt (enabled, pending, + * active, vcpu and target_vcpu), compute the next vcpu this should be + * given to. Return NULL if this shouldn't be injected at all. + * + * Requires the IRQ lock to be held. + */ +static struct kvm_vcpu *vgic_target_oracle(struct vgic_irq *irq) +{ + lockdep_assert_held(&irq->irq_lock); + + /* If the interrupt is active, it must stay on the current vcpu */ + if (irq->active) + return irq->vcpu ? : irq->target_vcpu; + + /* + * If the IRQ is not active but enabled and pending, we should direct + * it to its configured target VCPU. + * If the distributor is disabled, pending interrupts shouldn't be + * forwarded. + */ + if (irq->enabled && irq_is_pending(irq)) { + if (unlikely(irq->target_vcpu && + !irq->target_vcpu->kvm->arch.vgic.enabled)) + return NULL; + + return irq->target_vcpu; + } + + /* If neither active nor pending and enabled, then this IRQ should not + * be queued to any VCPU. + */ + return NULL; +} + +/* + * The order of items in the ap_lists defines how we'll pack things in LRs as + * well, the first items in the list being the first things populated in the + * LRs. + * + * A hard rule is that active interrupts can never be pushed out of the LRs + * (and therefore take priority) since we cannot reliably trap on deactivation + * of IRQs and therefore they have to be present in the LRs. + * + * Otherwise things should be sorted by the priority field and the GIC + * hardware support will take care of preemption of priority groups etc. + * + * Return negative if "a" sorts before "b", 0 to preserve order, and positive + * to sort "b" before "a". + */ +static int vgic_irq_cmp(void *priv, struct list_head *a, struct list_head *b) +{ + struct vgic_irq *irqa = container_of(a, struct vgic_irq, ap_list); + struct vgic_irq *irqb = container_of(b, struct vgic_irq, ap_list); + bool penda, pendb; + int ret; + + /* + * list_sort may call this function with the same element when + * the list is fairly long. + */ + if (unlikely(irqa == irqb)) + return 0; + + raw_spin_lock(&irqa->irq_lock); + raw_spin_lock_nested(&irqb->irq_lock, SINGLE_DEPTH_NESTING); + + if (irqa->active || irqb->active) { + ret = (int)irqb->active - (int)irqa->active; + goto out; + } + + penda = irqa->enabled && irq_is_pending(irqa); + pendb = irqb->enabled && irq_is_pending(irqb); + + if (!penda || !pendb) { + ret = (int)pendb - (int)penda; + goto out; + } + + /* Both pending and enabled, sort by priority */ + ret = irqa->priority - irqb->priority; +out: + raw_spin_unlock(&irqb->irq_lock); + raw_spin_unlock(&irqa->irq_lock); + return ret; +} + +/* Must be called with the ap_list_lock held */ +static void vgic_sort_ap_list(struct kvm_vcpu *vcpu) +{ + struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu; + + lockdep_assert_held(&vgic_cpu->ap_list_lock); + + list_sort(NULL, &vgic_cpu->ap_list_head, vgic_irq_cmp); +} + +/* + * Only valid injection if changing level for level-triggered IRQs or for a + * rising edge, and in-kernel connected IRQ lines can only be controlled by + * their owner. + */ +static bool vgic_validate_injection(struct vgic_irq *irq, bool level, void *owner) +{ + if (irq->owner != owner) + return false; + + switch (irq->config) { + case VGIC_CONFIG_LEVEL: + return irq->line_level != level; + case VGIC_CONFIG_EDGE: + return level; + } + + return false; +} + +/* + * Check whether an IRQ needs to (and can) be queued to a VCPU's ap list. + * Do the queuing if necessary, taking the right locks in the right order. + * Returns true when the IRQ was queued, false otherwise. + * + * Needs to be entered with the IRQ lock already held, but will return + * with all locks dropped. + */ +bool vgic_queue_irq_unlock(struct kvm *kvm, struct vgic_irq *irq, + unsigned long flags) +{ + struct kvm_vcpu *vcpu; + + lockdep_assert_held(&irq->irq_lock); + +retry: + vcpu = vgic_target_oracle(irq); + if (irq->vcpu || !vcpu) { + /* + * If this IRQ is already on a VCPU's ap_list, then it + * cannot be moved or modified and there is no more work for + * us to do. + * + * Otherwise, if the irq is not pending and enabled, it does + * not need to be inserted into an ap_list and there is also + * no more work for us to do. + */ + raw_spin_unlock_irqrestore(&irq->irq_lock, flags); + + /* + * We have to kick the VCPU here, because we could be + * queueing an edge-triggered interrupt for which we + * get no EOI maintenance interrupt. In that case, + * while the IRQ is already on the VCPU's AP list, the + * VCPU could have EOI'ed the original interrupt and + * won't see this one until it exits for some other + * reason. + */ + if (vcpu) { + kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu); + kvm_vcpu_kick(vcpu); + } + return false; + } + + /* + * We must unlock the irq lock to take the ap_list_lock where + * we are going to insert this new pending interrupt. + */ + raw_spin_unlock_irqrestore(&irq->irq_lock, flags); + + /* someone can do stuff here, which we re-check below */ + + raw_spin_lock_irqsave(&vcpu->arch.vgic_cpu.ap_list_lock, flags); + raw_spin_lock(&irq->irq_lock); + + /* + * Did something change behind our backs? + * + * There are two cases: + * 1) The irq lost its pending state or was disabled behind our + * backs and/or it was queued to another VCPU's ap_list. + * 2) Someone changed the affinity on this irq behind our + * backs and we are now holding the wrong ap_list_lock. + * + * In both cases, drop the locks and retry. + */ + + if (unlikely(irq->vcpu || vcpu != vgic_target_oracle(irq))) { + raw_spin_unlock(&irq->irq_lock); + raw_spin_unlock_irqrestore(&vcpu->arch.vgic_cpu.ap_list_lock, + flags); + + raw_spin_lock_irqsave(&irq->irq_lock, flags); + goto retry; + } + + /* + * Grab a reference to the irq to reflect the fact that it is + * now in the ap_list. + */ + vgic_get_irq_kref(irq); + list_add_tail(&irq->ap_list, &vcpu->arch.vgic_cpu.ap_list_head); + irq->vcpu = vcpu; + + raw_spin_unlock(&irq->irq_lock); + raw_spin_unlock_irqrestore(&vcpu->arch.vgic_cpu.ap_list_lock, flags); + + kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu); + kvm_vcpu_kick(vcpu); + + return true; +} + +/** + * kvm_vgic_inject_irq - Inject an IRQ from a device to the vgic + * @kvm: The VM structure pointer + * @cpuid: The CPU for PPIs + * @intid: The INTID to inject a new state to. + * @level: Edge-triggered: true: to trigger the interrupt + * false: to ignore the call + * Level-sensitive true: raise the input signal + * false: lower the input signal + * @owner: The opaque pointer to the owner of the IRQ being raised to verify + * that the caller is allowed to inject this IRQ. Userspace + * injections will have owner == NULL. + * + * The VGIC is not concerned with devices being active-LOW or active-HIGH for + * level-sensitive interrupts. You can think of the level parameter as 1 + * being HIGH and 0 being LOW and all devices being active-HIGH. + */ +int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int intid, + bool level, void *owner) +{ + struct kvm_vcpu *vcpu; + struct vgic_irq *irq; + unsigned long flags; + int ret; + + trace_vgic_update_irq_pending(cpuid, intid, level); + + ret = vgic_lazy_init(kvm); + if (ret) + return ret; + + vcpu = kvm_get_vcpu(kvm, cpuid); + if (!vcpu && intid < VGIC_NR_PRIVATE_IRQS) + return -EINVAL; + + irq = vgic_get_irq(kvm, vcpu, intid); + if (!irq) + return -EINVAL; + + raw_spin_lock_irqsave(&irq->irq_lock, flags); + + if (!vgic_validate_injection(irq, level, owner)) { + /* Nothing to see here, move along... */ + raw_spin_unlock_irqrestore(&irq->irq_lock, flags); + vgic_put_irq(kvm, irq); + return 0; + } + + if (irq->config == VGIC_CONFIG_LEVEL) + irq->line_level = level; + else + irq->pending_latch = true; + + vgic_queue_irq_unlock(kvm, irq, flags); + vgic_put_irq(kvm, irq); + + return 0; +} + +/* @irq->irq_lock must be held */ +static int kvm_vgic_map_irq(struct kvm_vcpu *vcpu, struct vgic_irq *irq, + unsigned int host_irq, + bool (*get_input_level)(int vindid)) +{ + struct irq_desc *desc; + struct irq_data *data; + + /* + * Find the physical IRQ number corresponding to @host_irq + */ + desc = irq_to_desc(host_irq); + if (!desc) { + kvm_err("%s: no interrupt descriptor\n", __func__); + return -EINVAL; + } + data = irq_desc_get_irq_data(desc); + while (data->parent_data) + data = data->parent_data; + + irq->hw = true; + irq->host_irq = host_irq; + irq->hwintid = data->hwirq; + irq->get_input_level = get_input_level; + return 0; +} + +/* @irq->irq_lock must be held */ +static inline void kvm_vgic_unmap_irq(struct vgic_irq *irq) +{ + irq->hw = false; + irq->hwintid = 0; + irq->get_input_level = NULL; +} + +int kvm_vgic_map_phys_irq(struct kvm_vcpu *vcpu, unsigned int host_irq, + u32 vintid, bool (*get_input_level)(int vindid)) +{ + struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, vintid); + unsigned long flags; + int ret; + + BUG_ON(!irq); + + raw_spin_lock_irqsave(&irq->irq_lock, flags); + ret = kvm_vgic_map_irq(vcpu, irq, host_irq, get_input_level); + raw_spin_unlock_irqrestore(&irq->irq_lock, flags); + vgic_put_irq(vcpu->kvm, irq); + + return ret; +} + +/** + * kvm_vgic_reset_mapped_irq - Reset a mapped IRQ + * @vcpu: The VCPU pointer + * @vintid: The INTID of the interrupt + * + * Reset the active and pending states of a mapped interrupt. Kernel + * subsystems injecting mapped interrupts should reset their interrupt lines + * when we are doing a reset of the VM. + */ +void kvm_vgic_reset_mapped_irq(struct kvm_vcpu *vcpu, u32 vintid) +{ + struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, vintid); + unsigned long flags; + + if (!irq->hw) + goto out; + + raw_spin_lock_irqsave(&irq->irq_lock, flags); + irq->active = false; + irq->pending_latch = false; + irq->line_level = false; + raw_spin_unlock_irqrestore(&irq->irq_lock, flags); +out: + vgic_put_irq(vcpu->kvm, irq); +} + +int kvm_vgic_unmap_phys_irq(struct kvm_vcpu *vcpu, unsigned int vintid) +{ + struct vgic_irq *irq; + unsigned long flags; + + if (!vgic_initialized(vcpu->kvm)) + return -EAGAIN; + + irq = vgic_get_irq(vcpu->kvm, vcpu, vintid); + BUG_ON(!irq); + + raw_spin_lock_irqsave(&irq->irq_lock, flags); + kvm_vgic_unmap_irq(irq); + raw_spin_unlock_irqrestore(&irq->irq_lock, flags); + vgic_put_irq(vcpu->kvm, irq); + + return 0; +} + +/** + * kvm_vgic_set_owner - Set the owner of an interrupt for a VM + * + * @vcpu: Pointer to the VCPU (used for PPIs) + * @intid: The virtual INTID identifying the interrupt (PPI or SPI) + * @owner: Opaque pointer to the owner + * + * Returns 0 if intid is not already used by another in-kernel device and the + * owner is set, otherwise returns an error code. + */ +int kvm_vgic_set_owner(struct kvm_vcpu *vcpu, unsigned int intid, void *owner) +{ + struct vgic_irq *irq; + unsigned long flags; + int ret = 0; + + if (!vgic_initialized(vcpu->kvm)) + return -EAGAIN; + + /* SGIs and LPIs cannot be wired up to any device */ + if (!irq_is_ppi(intid) && !vgic_valid_spi(vcpu->kvm, intid)) + return -EINVAL; + + irq = vgic_get_irq(vcpu->kvm, vcpu, intid); + raw_spin_lock_irqsave(&irq->irq_lock, flags); + if (irq->owner && irq->owner != owner) + ret = -EEXIST; + else + irq->owner = owner; + raw_spin_unlock_irqrestore(&irq->irq_lock, flags); + + return ret; +} + +/** + * vgic_prune_ap_list - Remove non-relevant interrupts from the list + * + * @vcpu: The VCPU pointer + * + * Go over the list of "interesting" interrupts, and prune those that we + * won't have to consider in the near future. + */ +static void vgic_prune_ap_list(struct kvm_vcpu *vcpu) +{ + struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu; + struct vgic_irq *irq, *tmp; + + DEBUG_SPINLOCK_BUG_ON(!irqs_disabled()); + +retry: + raw_spin_lock(&vgic_cpu->ap_list_lock); + + list_for_each_entry_safe(irq, tmp, &vgic_cpu->ap_list_head, ap_list) { + struct kvm_vcpu *target_vcpu, *vcpuA, *vcpuB; + bool target_vcpu_needs_kick = false; + + raw_spin_lock(&irq->irq_lock); + + BUG_ON(vcpu != irq->vcpu); + + target_vcpu = vgic_target_oracle(irq); + + if (!target_vcpu) { + /* + * We don't need to process this interrupt any + * further, move it off the list. + */ + list_del(&irq->ap_list); + irq->vcpu = NULL; + raw_spin_unlock(&irq->irq_lock); + + /* + * This vgic_put_irq call matches the + * vgic_get_irq_kref in vgic_queue_irq_unlock, + * where we added the LPI to the ap_list. As + * we remove the irq from the list, we drop + * also drop the refcount. + */ + vgic_put_irq(vcpu->kvm, irq); + continue; + } + + if (target_vcpu == vcpu) { + /* We're on the right CPU */ + raw_spin_unlock(&irq->irq_lock); + continue; + } + + /* This interrupt looks like it has to be migrated. */ + + raw_spin_unlock(&irq->irq_lock); + raw_spin_unlock(&vgic_cpu->ap_list_lock); + + /* + * Ensure locking order by always locking the smallest + * ID first. + */ + if (vcpu->vcpu_id < target_vcpu->vcpu_id) { + vcpuA = vcpu; + vcpuB = target_vcpu; + } else { + vcpuA = target_vcpu; + vcpuB = vcpu; + } + + raw_spin_lock(&vcpuA->arch.vgic_cpu.ap_list_lock); + raw_spin_lock_nested(&vcpuB->arch.vgic_cpu.ap_list_lock, + SINGLE_DEPTH_NESTING); + raw_spin_lock(&irq->irq_lock); + + /* + * If the affinity has been preserved, move the + * interrupt around. Otherwise, it means things have + * changed while the interrupt was unlocked, and we + * need to replay this. + * + * In all cases, we cannot trust the list not to have + * changed, so we restart from the beginning. + */ + if (target_vcpu == vgic_target_oracle(irq)) { + struct vgic_cpu *new_cpu = &target_vcpu->arch.vgic_cpu; + + list_del(&irq->ap_list); + irq->vcpu = target_vcpu; + list_add_tail(&irq->ap_list, &new_cpu->ap_list_head); + target_vcpu_needs_kick = true; + } + + raw_spin_unlock(&irq->irq_lock); + raw_spin_unlock(&vcpuB->arch.vgic_cpu.ap_list_lock); + raw_spin_unlock(&vcpuA->arch.vgic_cpu.ap_list_lock); + + if (target_vcpu_needs_kick) { + kvm_make_request(KVM_REQ_IRQ_PENDING, target_vcpu); + kvm_vcpu_kick(target_vcpu); + } + + goto retry; + } + + raw_spin_unlock(&vgic_cpu->ap_list_lock); +} + +static inline void vgic_fold_lr_state(struct kvm_vcpu *vcpu) +{ + if (kvm_vgic_global_state.type == VGIC_V2) + vgic_v2_fold_lr_state(vcpu); + else + vgic_v3_fold_lr_state(vcpu); +} + +/* Requires the irq_lock to be held. */ +static inline void vgic_populate_lr(struct kvm_vcpu *vcpu, + struct vgic_irq *irq, int lr) +{ + lockdep_assert_held(&irq->irq_lock); + + if (kvm_vgic_global_state.type == VGIC_V2) + vgic_v2_populate_lr(vcpu, irq, lr); + else + vgic_v3_populate_lr(vcpu, irq, lr); +} + +static inline void vgic_clear_lr(struct kvm_vcpu *vcpu, int lr) +{ + if (kvm_vgic_global_state.type == VGIC_V2) + vgic_v2_clear_lr(vcpu, lr); + else + vgic_v3_clear_lr(vcpu, lr); +} + +static inline void vgic_set_underflow(struct kvm_vcpu *vcpu) +{ + if (kvm_vgic_global_state.type == VGIC_V2) + vgic_v2_set_underflow(vcpu); + else + vgic_v3_set_underflow(vcpu); +} + +/* Requires the ap_list_lock to be held. */ +static int compute_ap_list_depth(struct kvm_vcpu *vcpu, + bool *multi_sgi) +{ + struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu; + struct vgic_irq *irq; + int count = 0; + + *multi_sgi = false; + + lockdep_assert_held(&vgic_cpu->ap_list_lock); + + list_for_each_entry(irq, &vgic_cpu->ap_list_head, ap_list) { + int w; + + raw_spin_lock(&irq->irq_lock); + /* GICv2 SGIs can count for more than one... */ + w = vgic_irq_get_lr_count(irq); + raw_spin_unlock(&irq->irq_lock); + + count += w; + *multi_sgi |= (w > 1); + } + return count; +} + +/* Requires the VCPU's ap_list_lock to be held. */ +static void vgic_flush_lr_state(struct kvm_vcpu *vcpu) +{ + struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu; + struct vgic_irq *irq; + int count; + bool multi_sgi; + u8 prio = 0xff; + int i = 0; + + lockdep_assert_held(&vgic_cpu->ap_list_lock); + + count = compute_ap_list_depth(vcpu, &multi_sgi); + if (count > kvm_vgic_global_state.nr_lr || multi_sgi) + vgic_sort_ap_list(vcpu); + + count = 0; + + list_for_each_entry(irq, &vgic_cpu->ap_list_head, ap_list) { + raw_spin_lock(&irq->irq_lock); + + /* + * If we have multi-SGIs in the pipeline, we need to + * guarantee that they are all seen before any IRQ of + * lower priority. In that case, we need to filter out + * these interrupts by exiting early. This is easy as + * the AP list has been sorted already. + */ + if (multi_sgi && irq->priority > prio) { + _raw_spin_unlock(&irq->irq_lock); + break; + } + + if (likely(vgic_target_oracle(irq) == vcpu)) { + vgic_populate_lr(vcpu, irq, count++); + + if (irq->source) + prio = irq->priority; + } + + raw_spin_unlock(&irq->irq_lock); + + if (count == kvm_vgic_global_state.nr_lr) { + if (!list_is_last(&irq->ap_list, + &vgic_cpu->ap_list_head)) + vgic_set_underflow(vcpu); + break; + } + } + + /* Nuke remaining LRs */ + for (i = count ; i < kvm_vgic_global_state.nr_lr; i++) + vgic_clear_lr(vcpu, i); + + if (!static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) + vcpu->arch.vgic_cpu.vgic_v2.used_lrs = count; + else + vcpu->arch.vgic_cpu.vgic_v3.used_lrs = count; +} + +static inline bool can_access_vgic_from_kernel(void) +{ + /* + * GICv2 can always be accessed from the kernel because it is + * memory-mapped, and VHE systems can access GICv3 EL2 system + * registers. + */ + return !static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif) || has_vhe(); +} + +static inline void vgic_save_state(struct kvm_vcpu *vcpu) +{ + if (!static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) + vgic_v2_save_state(vcpu); + else + __vgic_v3_save_state(&vcpu->arch.vgic_cpu.vgic_v3); +} + +/* Sync back the hardware VGIC state into our emulation after a guest's run. */ +void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu) +{ + int used_lrs; + + /* An empty ap_list_head implies used_lrs == 0 */ + if (list_empty(&vcpu->arch.vgic_cpu.ap_list_head)) + return; + + if (can_access_vgic_from_kernel()) + vgic_save_state(vcpu); + + if (!static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) + used_lrs = vcpu->arch.vgic_cpu.vgic_v2.used_lrs; + else + used_lrs = vcpu->arch.vgic_cpu.vgic_v3.used_lrs; + + if (used_lrs) + vgic_fold_lr_state(vcpu); + vgic_prune_ap_list(vcpu); +} + +static inline void vgic_restore_state(struct kvm_vcpu *vcpu) +{ + if (!static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) + vgic_v2_restore_state(vcpu); + else + __vgic_v3_restore_state(&vcpu->arch.vgic_cpu.vgic_v3); +} + +/* Flush our emulation state into the GIC hardware before entering the guest. */ +void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu) +{ + /* + * If there are no virtual interrupts active or pending for this + * VCPU, then there is no work to do and we can bail out without + * taking any lock. There is a potential race with someone injecting + * interrupts to the VCPU, but it is a benign race as the VCPU will + * either observe the new interrupt before or after doing this check, + * and introducing additional synchronization mechanism doesn't change + * this. + * + * Note that we still need to go through the whole thing if anything + * can be directly injected (GICv4). + */ + if (list_empty(&vcpu->arch.vgic_cpu.ap_list_head) && + !vgic_supports_direct_msis(vcpu->kvm)) + return; + + DEBUG_SPINLOCK_BUG_ON(!irqs_disabled()); + + if (!list_empty(&vcpu->arch.vgic_cpu.ap_list_head)) { + raw_spin_lock(&vcpu->arch.vgic_cpu.ap_list_lock); + vgic_flush_lr_state(vcpu); + raw_spin_unlock(&vcpu->arch.vgic_cpu.ap_list_lock); + } + + if (can_access_vgic_from_kernel()) + vgic_restore_state(vcpu); +} + +void kvm_vgic_load(struct kvm_vcpu *vcpu) +{ + if (unlikely(!vgic_initialized(vcpu->kvm))) + return; + + if (kvm_vgic_global_state.type == VGIC_V2) + vgic_v2_load(vcpu); + else + vgic_v3_load(vcpu); +} + +void kvm_vgic_put(struct kvm_vcpu *vcpu) +{ + if (unlikely(!vgic_initialized(vcpu->kvm))) + return; + + if (kvm_vgic_global_state.type == VGIC_V2) + vgic_v2_put(vcpu); + else + vgic_v3_put(vcpu); +} + +void kvm_vgic_vmcr_sync(struct kvm_vcpu *vcpu) +{ + if (unlikely(!irqchip_in_kernel(vcpu->kvm))) + return; + + if (kvm_vgic_global_state.type == VGIC_V2) + vgic_v2_vmcr_sync(vcpu); + else + vgic_v3_vmcr_sync(vcpu); +} + +int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu) +{ + struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu; + struct vgic_irq *irq; + bool pending = false; + unsigned long flags; + struct vgic_vmcr vmcr; + + if (!vcpu->kvm->arch.vgic.enabled) + return false; + + if (vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last) + return true; + + vgic_get_vmcr(vcpu, &vmcr); + + raw_spin_lock_irqsave(&vgic_cpu->ap_list_lock, flags); + + list_for_each_entry(irq, &vgic_cpu->ap_list_head, ap_list) { + raw_spin_lock(&irq->irq_lock); + pending = irq_is_pending(irq) && irq->enabled && + !irq->active && + irq->priority < vmcr.pmr; + raw_spin_unlock(&irq->irq_lock); + + if (pending) + break; + } + + raw_spin_unlock_irqrestore(&vgic_cpu->ap_list_lock, flags); + + return pending; +} + +void vgic_kick_vcpus(struct kvm *kvm) +{ + struct kvm_vcpu *vcpu; + int c; + + /* + * We've injected an interrupt, time to find out who deserves + * a good kick... + */ + kvm_for_each_vcpu(c, vcpu, kvm) { + if (kvm_vgic_vcpu_pending_irq(vcpu)) { + kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu); + kvm_vcpu_kick(vcpu); + } + } +} + +bool kvm_vgic_map_is_active(struct kvm_vcpu *vcpu, unsigned int vintid) +{ + struct vgic_irq *irq; + bool map_is_active; + unsigned long flags; + + if (!vgic_initialized(vcpu->kvm)) + return false; + + irq = vgic_get_irq(vcpu->kvm, vcpu, vintid); + raw_spin_lock_irqsave(&irq->irq_lock, flags); + map_is_active = irq->hw && irq->active; + raw_spin_unlock_irqrestore(&irq->irq_lock, flags); + vgic_put_irq(vcpu->kvm, irq); + + return map_is_active; +} |