1 files changed, 239 insertions, 0 deletions
diff --git a/virt/kvm/irqchip.c b/virt/kvm/irqchip.c
new file mode 100644
index 0000000000..1e567d1f6d
--- /dev/null
+++ b/virt/kvm/irqchip.c
@@ -0,0 +1,239 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * irqchip.c: Common API for in kernel interrupt controllers
+ * Copyright (c) 2007, Intel Corporation.
+ * Copyright 2010 Red Hat, Inc. and/or its affiliates.
+ * Copyright (c) 2013, Alexander Graf <agraf@suse.de>
+ *
+ * This file is derived from virt/kvm/irq_comm.c.
+ *
+ * Authors:
+ *   Yaozu (Eddie) Dong <Eddie.dong@intel.com>
+ *   Alexander Graf <agraf@suse.de>
+ */
+
+#include <linux/kvm_host.h>
+#include <linux/slab.h>
+#include <linux/srcu.h>
+#include <linux/export.h>
+#include <trace/events/kvm.h>
+
+int kvm_irq_map_gsi(struct kvm *kvm,
+		    struct kvm_kernel_irq_routing_entry *entries, int gsi)
+{
+	struct kvm_irq_routing_table *irq_rt;
+	struct kvm_kernel_irq_routing_entry *e;
+	int n = 0;
+
+	irq_rt = srcu_dereference_check(kvm->irq_routing, &kvm->irq_srcu,
+					lockdep_is_held(&kvm->irq_lock));
+	if (irq_rt && gsi < irq_rt->nr_rt_entries) {
+		hlist_for_each_entry(e, &irq_rt->map[gsi], link) {
+			entries[n] = *e;
+			++n;
+		}
+	}
+
+	return n;
+}
+
+int kvm_irq_map_chip_pin(struct kvm *kvm, unsigned irqchip, unsigned pin)
+{
+	struct kvm_irq_routing_table *irq_rt;
+
+	irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
+	return irq_rt->chip[irqchip][pin];
+}
+
+int kvm_send_userspace_msi(struct kvm *kvm, struct kvm_msi *msi)
+{
+	struct kvm_kernel_irq_routing_entry route;
+
+	if (!kvm_arch_irqchip_in_kernel(kvm) || (msi->flags & ~KVM_MSI_VALID_DEVID))
+		return -EINVAL;
+
+	route.msi.address_lo = msi->address_lo;
+	route.msi.address_hi = msi->address_hi;
+	route.msi.data = msi->data;
+	route.msi.flags = msi->flags;
+	route.msi.devid = msi->devid;
+
+	return kvm_set_msi(&route, kvm, KVM_USERSPACE_IRQ_SOURCE_ID, 1, false);
+}
+
+/*
+ * Return value:
+ *  < 0   Interrupt was ignored (masked or not delivered for other reasons)
+ *  = 0   Interrupt was coalesced (previous irq is still pending)
+ *  > 0   Number of CPUs interrupt was delivered to
+ */
+int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level,
+		bool line_status)
+{
+	struct kvm_kernel_irq_routing_entry irq_set[KVM_NR_IRQCHIPS];
+	int ret = -1, i, idx;
+
+	trace_kvm_set_irq(irq, level, irq_source_id);
+
+	/* Not possible to detect if the guest uses the PIC or the
+	 * IOAPIC.  So set the bit in both. The guest will ignore
+	 * writes to the unused one.
+	 */
+	idx = srcu_read_lock(&kvm->irq_srcu);
+	i = kvm_irq_map_gsi(kvm, irq_set, irq);
+	srcu_read_unlock(&kvm->irq_srcu, idx);
+
+	while (i--) {
+		int r;
+		r = irq_set[i].set(&irq_set[i], kvm, irq_source_id, level,
+				   line_status);
+		if (r < 0)
+			continue;
+
+		ret = r + ((ret < 0) ? 0 : ret);
+	}
+
+	return ret;
+}
+
+static void free_irq_routing_table(struct kvm_irq_routing_table *rt)
+{
+	int i;
+
+	if (!rt)
+		return;
+
+	for (i = 0; i < rt->nr_rt_entries; ++i) {
+		struct kvm_kernel_irq_routing_entry *e;
+		struct hlist_node *n;
+
+		hlist_for_each_entry_safe(e, n, &rt->map[i], link) {
+			hlist_del(&e->link);
+			kfree(e);
+		}
+	}
+
+	kfree(rt);
+}
+
+void kvm_free_irq_routing(struct kvm *kvm)
+{
+	/* Called only during vm destruction. Nobody can use the pointer
+	   at this stage */
+	struct kvm_irq_routing_table *rt = rcu_access_pointer(kvm->irq_routing);
+	free_irq_routing_table(rt);
+}
+
+static int setup_routing_entry(struct kvm *kvm,
+			       struct kvm_irq_routing_table *rt,
+			       struct kvm_kernel_irq_routing_entry *e,
+			       const struct kvm_irq_routing_entry *ue)
+{
+	struct kvm_kernel_irq_routing_entry *ei;
+	int r;
+	u32 gsi = array_index_nospec(ue->gsi, KVM_MAX_IRQ_ROUTES);
+
+	/*
+	 * Do not allow GSI to be mapped to the same irqchip more than once.
+	 * Allow only one to one mapping between GSI and non-irqchip routing.
+	 */
+	hlist_for_each_entry(ei, &rt->map[gsi], link)
+		if (ei->type != KVM_IRQ_ROUTING_IRQCHIP ||
+		    ue->type != KVM_IRQ_ROUTING_IRQCHIP ||
+		    ue->u.irqchip.irqchip == ei->irqchip.irqchip)
+			return -EINVAL;
+
+	e->gsi = gsi;
+	e->type = ue->type;
+	r = kvm_set_routing_entry(kvm, e, ue);
+	if (r)
+		return r;
+	if (e->type == KVM_IRQ_ROUTING_IRQCHIP)
+		rt->chip[e->irqchip.irqchip][e->irqchip.pin] = e->gsi;
+
+	hlist_add_head(&e->link, &rt->map[e->gsi]);
+
+	return 0;
+}
+
+void __attribute__((weak)) kvm_arch_irq_routing_update(struct kvm *kvm)
+{
+}
+
+bool __weak kvm_arch_can_set_irq_routing(struct kvm *kvm)
+{
+	return true;
+}
+
+int kvm_set_irq_routing(struct kvm *kvm,
+			const struct kvm_irq_routing_entry *ue,
+			unsigned nr,
+			unsigned flags)
+{
+	struct kvm_irq_routing_table *new, *old;
+	struct kvm_kernel_irq_routing_entry *e;
+	u32 i, j, nr_rt_entries = 0;
+	int r;
+
+	for (i = 0; i < nr; ++i) {
+		if (ue[i].gsi >= KVM_MAX_IRQ_ROUTES)
+			return -EINVAL;
+		nr_rt_entries = max(nr_rt_entries, ue[i].gsi);
+	}
+
+	nr_rt_entries += 1;
+
+	new = kzalloc(struct_size(new, map, nr_rt_entries), GFP_KERNEL_ACCOUNT);
+	if (!new)
+		return -ENOMEM;
+
+	new->nr_rt_entries = nr_rt_entries;
+	for (i = 0; i < KVM_NR_IRQCHIPS; i++)
+		for (j = 0; j < KVM_IRQCHIP_NUM_PINS; j++)
+			new->chip[i][j] = -1;
+
+	for (i = 0; i < nr; ++i) {
+		r = -ENOMEM;
+		e = kzalloc(sizeof(*e), GFP_KERNEL_ACCOUNT);
+		if (!e)
+			goto out;
+
+		r = -EINVAL;
+		switch (ue->type) {
+		case KVM_IRQ_ROUTING_MSI:
+			if (ue->flags & ~KVM_MSI_VALID_DEVID)
+				goto free_entry;
+			break;
+		default:
+			if (ue->flags)
+				goto free_entry;
+			break;
+		}
+		r = setup_routing_entry(kvm, new, e, ue);
+		if (r)
+			goto free_entry;
+		++ue;
+	}
+
+	mutex_lock(&kvm->irq_lock);
+	old = rcu_dereference_protected(kvm->irq_routing, 1);
+	rcu_assign_pointer(kvm->irq_routing, new);
+	kvm_irq_routing_update(kvm);
+	kvm_arch_irq_routing_update(kvm);
+	mutex_unlock(&kvm->irq_lock);
+
+	kvm_arch_post_irq_routing_update(kvm);
+
+	synchronize_srcu_expedited(&kvm->irq_srcu);
+
+	new = old;
+	r = 0;
+	goto out;
+
+free_entry:
+	kfree(e);
+out:
+	free_irq_routing_table(new);
+
+	return r;
+}