virt/kvm/irqchip.c - linux - Git at Google

 // 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;
 }

 /*
  * Allocate empty IRQ routing by default so that additional setup isn't needed
  * when userspace-driven IRQ routing is activated, and so that kvm->irq_routing
  * is guaranteed to be non-NULL.
  */
 int kvm_init_irq_routing(struct kvm *kvm)
 {
 	struct kvm_irq_routing_table *new;
 	int chip_size;

 	new = kzalloc(struct_size(new, map, 1), GFP_KERNEL_ACCOUNT);
 	if (!new)
 		return -ENOMEM;

 	new->nr_rt_entries = 1;

 	chip_size = sizeof(int) * KVM_NR_IRQCHIPS * KVM_IRQCHIP_NUM_PINS;
 	memset(new->chip, -1, chip_size);

 	RCU_INIT_POINTER(kvm->irq_routing, new);

 	return 0;
 }
	// 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;
	}

	/*
	* Allocate empty IRQ routing by default so that additional setup isn't needed
	* when userspace-driven IRQ routing is activated, and so that kvm->irq_routing
	* is guaranteed to be non-NULL.
	*/
	int kvm_init_irq_routing(struct kvm *kvm)
	{
	struct kvm_irq_routing_table *new;
	int chip_size;

	new = kzalloc(struct_size(new, map, 1), GFP_KERNEL_ACCOUNT);
	if (!new)
	return -ENOMEM;

	new->nr_rt_entries = 1;

	chip_size = sizeof(int) * KVM_NR_IRQCHIPS * KVM_IRQCHIP_NUM_PINS;
	memset(new->chip, -1, chip_size);

	RCU_INIT_POINTER(kvm->irq_routing, new);

	return 0;
	}