1 files changed, 619 insertions, 0 deletions

diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
new file mode 100644
index 0000000..69b61ab
--- /dev/null
+++ b/virt/kvm/arm/vgic/vgic.c
@@ -0,0 +1,619 @@
+/*
+ * 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;
+
+/*
+ * Locking order is always:
+ *   vgic_cpu->ap_list_lock
+ *     vgic_irq->irq_lock
+ *
+ * (that is, always take the ap_list_lock before the struct vgic_irq lock).
+ *
+ * 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);
+ */
+
+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 are not yet covered */
+	if (intid >= VGIC_MIN_LPI)
+		return NULL;
+
+	WARN(1, "Looking up struct vgic_irq for reserved INTID");
+	return NULL;
+}
+
+/**
+ * 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);
+		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;
+	}
+
+	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)
+		return -EINVAL;
+
+	spin_lock(&irq->irq_lock);
+
+	if (!vgic_validate_injection(irq, level)) {
+		/* Nothing to see here, move along... */
+		spin_unlock(&irq->irq_lock);
+		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);
+
+	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);
+
+	return 0;
+}
+
+int kvm_vgic_unmap_phys_irq(struct kvm_vcpu *vcpu, unsigned int virt_irq)
+{
+	struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, virt_irq);
+
+	BUG_ON(!irq);
+
+	if (!vgic_initialized(vcpu->kvm))
+		return -EAGAIN;
+
+	spin_lock(&irq->irq_lock);
+
+	irq->hw = false;
+	irq->hwintid = 0;
+
+	spin_unlock(&irq->irq_lock);
+
+	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);
+			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)
+{
+	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)
+{
+	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);
+
+	return map_is_active;
+}