linux/virt/kvm/irqchip.c
Paul Mackerras 8ba918d488 KVM: irqchip: Provide and use accessors for irq routing table
This provides accessor functions for the KVM interrupt mappings, in
order to reduce the amount of code that accesses the fields of the
kvm_irq_routing_table struct, and restrict that code to one file,
virt/kvm/irqchip.c.  The new functions are kvm_irq_map_gsi(), which
maps from a global interrupt number to a set of IRQ routing entries,
and kvm_irq_map_chip_pin, which maps from IRQ chip and pin numbers to
a global interrupt number.

This also moves the update of kvm_irq_routing_table::chip[][]
into irqchip.c, out of the various kvm_set_routing_entry
implementations.  That means that none of the kvm_set_routing_entry
implementations need the kvm_irq_routing_table argument anymore,
so this removes it.

This does not change any locking or data lifetime rules.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Tested-by: Eric Auger <eric.auger@linaro.org>
Tested-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-05 14:26:16 +02:00

265 lines
6.7 KiB
C

/*
* 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 program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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, write to the Free Software Foundation, Inc., 59 Temple
* Place - Suite 330, Boston, MA 02111-1307 USA.
*
* 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>
#include "irq.h"
int kvm_irq_map_gsi(struct kvm_kernel_irq_routing_entry *entries,
struct kvm_irq_routing_table *irq_rt, int gsi)
{
struct kvm_kernel_irq_routing_entry *e;
int n = 0;
if (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_irq_routing_table *irq_rt,
unsigned irqchip, unsigned pin)
{
return irq_rt->chip[irqchip][pin];
}
bool kvm_irq_has_notifier(struct kvm *kvm, unsigned irqchip, unsigned pin)
{
struct kvm_irq_routing_table *irq_rt;
struct kvm_irq_ack_notifier *kian;
int gsi, idx;
idx = srcu_read_lock(&kvm->irq_srcu);
irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
gsi = kvm_irq_map_chip_pin(irq_rt, irqchip, pin);
if (gsi != -1)
hlist_for_each_entry_rcu(kian, &kvm->irq_ack_notifier_list,
link)
if (kian->gsi == gsi) {
srcu_read_unlock(&kvm->irq_srcu, idx);
return true;
}
srcu_read_unlock(&kvm->irq_srcu, idx);
return false;
}
EXPORT_SYMBOL_GPL(kvm_irq_has_notifier);
void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin)
{
struct kvm_irq_routing_table *irq_rt;
struct kvm_irq_ack_notifier *kian;
int gsi, idx;
trace_kvm_ack_irq(irqchip, pin);
idx = srcu_read_lock(&kvm->irq_srcu);
irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
gsi = kvm_irq_map_chip_pin(irq_rt, irqchip, pin);
if (gsi != -1)
hlist_for_each_entry_rcu(kian, &kvm->irq_ack_notifier_list,
link)
if (kian->gsi == gsi)
kian->irq_acked(kian);
srcu_read_unlock(&kvm->irq_srcu, idx);
}
void kvm_register_irq_ack_notifier(struct kvm *kvm,
struct kvm_irq_ack_notifier *kian)
{
mutex_lock(&kvm->irq_lock);
hlist_add_head_rcu(&kian->link, &kvm->irq_ack_notifier_list);
mutex_unlock(&kvm->irq_lock);
#ifdef __KVM_HAVE_IOAPIC
kvm_vcpu_request_scan_ioapic(kvm);
#endif
}
void kvm_unregister_irq_ack_notifier(struct kvm *kvm,
struct kvm_irq_ack_notifier *kian)
{
mutex_lock(&kvm->irq_lock);
hlist_del_init_rcu(&kian->link);
mutex_unlock(&kvm->irq_lock);
synchronize_srcu(&kvm->irq_srcu);
#ifdef __KVM_HAVE_IOAPIC
kvm_vcpu_request_scan_ioapic(kvm);
#endif
}
int kvm_send_userspace_msi(struct kvm *kvm, struct kvm_msi *msi)
{
struct kvm_kernel_irq_routing_entry route;
if (!irqchip_in_kernel(kvm) || msi->flags != 0)
return -EINVAL;
route.msi.address_lo = msi->address_lo;
route.msi.address_hi = msi->address_hi;
route.msi.data = msi->data;
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;
struct kvm_irq_routing_table *irq_rt;
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);
irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
i = kvm_irq_map_gsi(irq_set, irq_rt, 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;
}
void kvm_free_irq_routing(struct kvm *kvm)
{
/* Called only during vm destruction. Nobody can use the pointer
at this stage */
kfree(kvm->irq_routing);
}
static int setup_routing_entry(struct kvm_irq_routing_table *rt,
struct kvm_kernel_irq_routing_entry *e,
const struct kvm_irq_routing_entry *ue)
{
int r = -EINVAL;
struct kvm_kernel_irq_routing_entry *ei;
/*
* Do not allow GSI to be mapped to the same irqchip more than once.
* Allow only one to one mapping between GSI and MSI.
*/
hlist_for_each_entry(ei, &rt->map[ue->gsi], link)
if (ei->type == KVM_IRQ_ROUTING_MSI ||
ue->type == KVM_IRQ_ROUTING_MSI ||
ue->u.irqchip.irqchip == ei->irqchip.irqchip)
return r;
e->gsi = ue->gsi;
e->type = ue->type;
r = kvm_set_routing_entry(e, ue);
if (r)
goto out;
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]);
r = 0;
out:
return r;
}
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;
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(sizeof(*new) + (nr_rt_entries * sizeof(struct hlist_head))
+ (nr * sizeof(struct kvm_kernel_irq_routing_entry)),
GFP_KERNEL);
if (!new)
return -ENOMEM;
new->rt_entries = (void *)&new->map[nr_rt_entries];
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 = -EINVAL;
if (ue->flags)
goto out;
r = setup_routing_entry(new, &new->rt_entries[i], ue);
if (r)
goto out;
++ue;
}
mutex_lock(&kvm->irq_lock);
old = kvm->irq_routing;
kvm_irq_routing_update(kvm, new);
mutex_unlock(&kvm->irq_lock);
synchronize_srcu_expedited(&kvm->irq_srcu);
new = old;
r = 0;
out:
kfree(new);
return r;
}