diff options
Diffstat (limited to 'virt/kvm/arm/vgic/vgic.c')
-rw-r--r-- | virt/kvm/arm/vgic/vgic.c | 731 |
1 files changed, 0 insertions, 731 deletions
diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c deleted file mode 100644 index 6440b56..0000000 --- a/virt/kvm/arm/vgic/vgic.c +++ /dev/null @@ -1,731 +0,0 @@ -/* - * Copyright (C) 2015, 2016 ARM Ltd. - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program. If not, see <http://www.gnu.org/licenses/>. - */ - -#include <linux/kvm.h> -#include <linux/kvm_host.h> -#include <linux/list_sort.h> - -#include "vgic.h" - -#define CREATE_TRACE_POINTS -#include "../trace.h" - -#ifdef CONFIG_DEBUG_SPINLOCK -#define DEBUG_SPINLOCK_BUG_ON(p) BUG_ON(p) -#else -#define DEBUG_SPINLOCK_BUG_ON(p) -#endif - -struct vgic_global __section(.hyp.text) kvm_vgic_global_state = {.gicv3_cpuif = STATIC_KEY_FALSE_INIT,}; - -/* - * Locking order is always: - * its->cmd_lock (mutex) - * its->its_lock (mutex) - * vgic_cpu->ap_list_lock - * kvm->lpi_list_lock - * vgic_irq->irq_lock - * - * 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: - * spin_lock(vcpuX->arch.vgic_cpu.ap_list_lock); - * spin_lock(vcpuY->arch.vgic_cpu.ap_list_lock); - */ - -/* - * 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; - - spin_lock(&dist->lpi_list_lock); - - 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: - spin_unlock(&dist->lpi_list_lock); - - 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) - return &vcpu->arch.vgic_cpu.private_irqs[intid]; - - /* SPIs */ - if (intid <= VGIC_MAX_SPI) - 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) -{ -} - -void vgic_put_irq(struct kvm *kvm, struct vgic_irq *irq) -{ - struct vgic_dist *dist = &kvm->arch.vgic; - - if (irq->intid < VGIC_MIN_LPI) - return; - - spin_lock(&dist->lpi_list_lock); - if (!kref_put(&irq->refcount, vgic_irq_release)) { - spin_unlock(&dist->lpi_list_lock); - return; - }; - - list_del(&irq->lpi_list); - dist->lpi_list_count--; - spin_unlock(&dist->lpi_list_lock); - - kfree(irq); -} - -/** - * 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) -{ - DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&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->pending) { - 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; - - spin_lock(&irqa->irq_lock); - 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 && irqa->pending; - pendb = irqb->enabled && irqb->pending; - - if (!penda || !pendb) { - ret = (int)pendb - (int)penda; - goto out; - } - - /* Both pending and enabled, sort by priority */ - ret = irqa->priority - irqb->priority; -out: - spin_unlock(&irqb->irq_lock); - 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; - - DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&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. - */ -static bool vgic_validate_injection(struct vgic_irq *irq, bool level) -{ - 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) -{ - struct kvm_vcpu *vcpu; - - DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&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. - */ - spin_unlock(&irq->irq_lock); - - /* - * 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_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. - */ - spin_unlock(&irq->irq_lock); - - /* someone can do stuff here, which we re-check below */ - - spin_lock(&vcpu->arch.vgic_cpu.ap_list_lock); - 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))) { - spin_unlock(&irq->irq_lock); - spin_unlock(&vcpu->arch.vgic_cpu.ap_list_lock); - - spin_lock(&irq->irq_lock); - 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; - - spin_unlock(&irq->irq_lock); - spin_unlock(&vcpu->arch.vgic_cpu.ap_list_lock); - - kvm_vcpu_kick(vcpu); - - return true; -} - -static int vgic_update_irq_pending(struct kvm *kvm, int cpuid, - unsigned int intid, bool level, - bool mapped_irq) -{ - struct kvm_vcpu *vcpu; - struct vgic_irq *irq; - 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; - - if (irq->hw != mapped_irq) { - vgic_put_irq(kvm, irq); - return -EINVAL; - } - - spin_lock(&irq->irq_lock); - - if (!vgic_validate_injection(irq, level)) { - /* Nothing to see here, move along... */ - spin_unlock(&irq->irq_lock); - vgic_put_irq(kvm, irq); - return 0; - } - - if (irq->config == VGIC_CONFIG_LEVEL) { - irq->line_level = level; - irq->pending = level || irq->soft_pending; - } else { - irq->pending = true; - } - - vgic_queue_irq_unlock(kvm, irq); - vgic_put_irq(kvm, irq); - - return 0; -} - -/** - * 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 - * - * 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) -{ - return vgic_update_irq_pending(kvm, cpuid, intid, level, false); -} - -int kvm_vgic_inject_mapped_irq(struct kvm *kvm, int cpuid, unsigned int intid, - bool level) -{ - return vgic_update_irq_pending(kvm, cpuid, intid, level, true); -} - -int kvm_vgic_map_phys_irq(struct kvm_vcpu *vcpu, u32 virt_irq, u32 phys_irq) -{ - struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, virt_irq); - - BUG_ON(!irq); - - spin_lock(&irq->irq_lock); - - irq->hw = true; - irq->hwintid = phys_irq; - - spin_unlock(&irq->irq_lock); - vgic_put_irq(vcpu->kvm, irq); - - return 0; -} - -int kvm_vgic_unmap_phys_irq(struct kvm_vcpu *vcpu, unsigned int virt_irq) -{ - struct vgic_irq *irq; - - if (!vgic_initialized(vcpu->kvm)) - return -EAGAIN; - - irq = vgic_get_irq(vcpu->kvm, vcpu, virt_irq); - BUG_ON(!irq); - - spin_lock(&irq->irq_lock); - - irq->hw = false; - irq->hwintid = 0; - - spin_unlock(&irq->irq_lock); - vgic_put_irq(vcpu->kvm, irq); - - return 0; -} - -/** - * 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; - -retry: - 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; - - 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; - 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 */ - spin_unlock(&irq->irq_lock); - continue; - } - - /* This interrupt looks like it has to be migrated. */ - - spin_unlock(&irq->irq_lock); - 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; - } - - spin_lock(&vcpuA->arch.vgic_cpu.ap_list_lock); - spin_lock_nested(&vcpuB->arch.vgic_cpu.ap_list_lock, - SINGLE_DEPTH_NESTING); - 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); - } - - spin_unlock(&irq->irq_lock); - spin_unlock(&vcpuB->arch.vgic_cpu.ap_list_lock); - spin_unlock(&vcpuA->arch.vgic_cpu.ap_list_lock); - goto retry; - } - - spin_unlock(&vgic_cpu->ap_list_lock); -} - -static inline void vgic_process_maintenance_interrupt(struct kvm_vcpu *vcpu) -{ - if (kvm_vgic_global_state.type == VGIC_V2) - vgic_v2_process_maintenance(vcpu); - else - vgic_v3_process_maintenance(vcpu); -} - -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) -{ - DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&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) -{ - struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu; - struct vgic_irq *irq; - int count = 0; - - DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&vgic_cpu->ap_list_lock)); - - list_for_each_entry(irq, &vgic_cpu->ap_list_head, ap_list) { - spin_lock(&irq->irq_lock); - /* GICv2 SGIs can count for more than one... */ - if (vgic_irq_is_sgi(irq->intid) && irq->source) - count += hweight8(irq->source); - else - count++; - spin_unlock(&irq->irq_lock); - } - 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 = 0; - - DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&vgic_cpu->ap_list_lock)); - - if (compute_ap_list_depth(vcpu) > kvm_vgic_global_state.nr_lr) { - vgic_set_underflow(vcpu); - vgic_sort_ap_list(vcpu); - } - - list_for_each_entry(irq, &vgic_cpu->ap_list_head, ap_list) { - spin_lock(&irq->irq_lock); - - if (unlikely(vgic_target_oracle(irq) != vcpu)) - goto next; - - /* - * If we get an SGI with multiple sources, try to get - * them in all at once. - */ - do { - vgic_populate_lr(vcpu, irq, count++); - } while (irq->source && count < kvm_vgic_global_state.nr_lr); - -next: - spin_unlock(&irq->irq_lock); - - if (count == kvm_vgic_global_state.nr_lr) - break; - } - - vcpu->arch.vgic_cpu.used_lrs = count; - - /* Nuke remaining LRs */ - for ( ; count < kvm_vgic_global_state.nr_lr; count++) - vgic_clear_lr(vcpu, count); -} - -/* Sync back the hardware VGIC state into our emulation after a guest's run. */ -void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu) -{ - if (unlikely(!vgic_initialized(vcpu->kvm))) - return; - - vgic_process_maintenance_interrupt(vcpu); - vgic_fold_lr_state(vcpu); - vgic_prune_ap_list(vcpu); -} - -/* Flush our emulation state into the GIC hardware before entering the guest. */ -void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu) -{ - if (unlikely(!vgic_initialized(vcpu->kvm))) - return; - - spin_lock(&vcpu->arch.vgic_cpu.ap_list_lock); - vgic_flush_lr_state(vcpu); - spin_unlock(&vcpu->arch.vgic_cpu.ap_list_lock); -} - -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; - - if (!vcpu->kvm->arch.vgic.enabled) - return false; - - spin_lock(&vgic_cpu->ap_list_lock); - - list_for_each_entry(irq, &vgic_cpu->ap_list_head, ap_list) { - spin_lock(&irq->irq_lock); - pending = irq->pending && irq->enabled; - spin_unlock(&irq->irq_lock); - - if (pending) - break; - } - - spin_unlock(&vgic_cpu->ap_list_lock); - - 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_vcpu_kick(vcpu); - } -} - -bool kvm_vgic_map_is_active(struct kvm_vcpu *vcpu, unsigned int virt_irq) -{ - struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, virt_irq); - bool map_is_active; - - spin_lock(&irq->irq_lock); - map_is_active = irq->hw && irq->active; - spin_unlock(&irq->irq_lock); - vgic_put_irq(vcpu->kvm, irq); - - return map_is_active; -} - |