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KVM: Userspace controlled irq routing

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Currently KVM has a static routing from GSI numbers to interrupts (namely,
0-15 are mapped 1:1 to both PIC and IOAPIC, and 16:23 are mapped 1:1 to
the IOAPIC).  This is insufficient for several reasons:

- HPET requires non 1:1 mapping for the timer interrupt
- MSIs need a new method to assign interrupt numbers and dispatch them
- ACPI APIC mode needs to be able to reassign the PCI LINK interrupts to the
  ioapics

This patch implements an interrupt routing table (as a linked list, but this
can be easily changed) and a userspace interface to replace the table.  The
routing table is initialized according to the current hardwired mapping.

Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Avi Kivity
2008-11-19 13:58:46 +02:00
parent 1935547504
commit 399ec807dd
6 changed files with 275 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

168
virt/kvm/irq_comm.c
View File

@@ -24,9 +24,24 @@
#include "ioapic.h"
static void kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
struct kvm *kvm, int level)
{
#ifdef CONFIG_X86
kvm_pic_set_irq(pic_irqchip(kvm), e->irqchip.pin, level);
#endif
}
static void kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
struct kvm *kvm, int level)
{
kvm_ioapic_set_irq(kvm->arch.vioapic, e->irqchip.pin, level);
}
/* This should be called with the kvm->lock mutex held */
void kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level)
{
struct kvm_kernel_irq_routing_entry *e;
unsigned long *irq_state = (unsigned long *)&kvm->arch.irq_states[irq];
/* Logical OR for level trig interrupt */
@@ -39,10 +54,9 @@ void kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level)
* IOAPIC. So set the bit in both. The guest will ignore
* writes to the unused one.
*/
kvm_ioapic_set_irq(kvm->arch.vioapic, irq, !!(*irq_state));
#ifdef CONFIG_X86
kvm_pic_set_irq(pic_irqchip(kvm), irq, !!(*irq_state));
#endif
list_for_each_entry(e, &kvm->irq_routing, link)
if (e->gsi == irq)
e->set(e, kvm, !!(*irq_state));
}
void kvm_notify_acked_irq(struct kvm *kvm, unsigned gsi)
@@ -123,3 +137,149 @@ void kvm_fire_mask_notifiers(struct kvm *kvm, int irq, bool mask)
kimn->func(kimn, mask);
}
static void __kvm_free_irq_routing(struct list_head *irq_routing)
{
struct kvm_kernel_irq_routing_entry *e, *n;
list_for_each_entry_safe(e, n, irq_routing, link)
kfree(e);
}
void kvm_free_irq_routing(struct kvm *kvm)
{
__kvm_free_irq_routing(&kvm->irq_routing);
}
int setup_routing_entry(struct kvm_kernel_irq_routing_entry *e,
const struct kvm_irq_routing_entry *ue)
{
int r = -EINVAL;
int delta;
e->gsi = ue->gsi;
switch (ue->type) {
case KVM_IRQ_ROUTING_IRQCHIP:
delta = 0;
switch (ue->u.irqchip.irqchip) {
case KVM_IRQCHIP_PIC_MASTER:
e->set = kvm_set_pic_irq;
break;
case KVM_IRQCHIP_PIC_SLAVE:
e->set = kvm_set_pic_irq;
delta = 8;
break;
case KVM_IRQCHIP_IOAPIC:
e->set = kvm_set_ioapic_irq;
break;
default:
goto out;
}
e->irqchip.irqchip = ue->u.irqchip.irqchip;
e->irqchip.pin = ue->u.irqchip.pin + delta;
break;
default:
goto out;
}
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 list_head irq_list = LIST_HEAD_INIT(irq_list);
struct list_head tmp = LIST_HEAD_INIT(tmp);
struct kvm_kernel_irq_routing_entry *e = NULL;
unsigned i;
int r;
for (i = 0; i < nr; ++i) {
r = -EINVAL;
if (ue->gsi >= KVM_MAX_IRQ_ROUTES)
goto out;
if (ue->flags)
goto out;
r = -ENOMEM;
e = kzalloc(sizeof(*e), GFP_KERNEL);
if (!e)
goto out;
r = setup_routing_entry(e, ue);
if (r)
goto out;
++ue;
list_add(&e->link, &irq_list);
e = NULL;
}
mutex_lock(&kvm->lock);
list_splice(&kvm->irq_routing, &tmp);
INIT_LIST_HEAD(&kvm->irq_routing);
list_splice(&irq_list, &kvm->irq_routing);
INIT_LIST_HEAD(&irq_list);
list_splice(&tmp, &irq_list);
mutex_unlock(&kvm->lock);
r = 0;
out:
kfree(e);
__kvm_free_irq_routing(&irq_list);
return r;
}
#define IOAPIC_ROUTING_ENTRY(irq) \
{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP, \
.u.irqchip.irqchip = KVM_IRQCHIP_IOAPIC, .u.irqchip.pin = (irq) }
#define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
#ifdef CONFIG_X86
#define SELECT_PIC(irq) \
((irq) < 8 ? KVM_IRQCHIP_PIC_MASTER : KVM_IRQCHIP_PIC_SLAVE)
# define PIC_ROUTING_ENTRY(irq) \
{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP, \
.u.irqchip.irqchip = SELECT_PIC(irq), .u.irqchip.pin = (irq) % 8 }
# define ROUTING_ENTRY2(irq) \
IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
#else
# define ROUTING_ENTRY2(irq) \
IOAPIC_ROUTING_ENTRY(irq)
#endif
static const struct kvm_irq_routing_entry default_routing[] = {
ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
#ifdef CONFIG_IA64
ROUTING_ENTRY1(24), ROUTING_ENTRY1(25),
ROUTING_ENTRY1(26), ROUTING_ENTRY1(27),
ROUTING_ENTRY1(28), ROUTING_ENTRY1(29),
ROUTING_ENTRY1(30), ROUTING_ENTRY1(31),
ROUTING_ENTRY1(32), ROUTING_ENTRY1(33),
ROUTING_ENTRY1(34), ROUTING_ENTRY1(35),
ROUTING_ENTRY1(36), ROUTING_ENTRY1(37),
ROUTING_ENTRY1(38), ROUTING_ENTRY1(39),
ROUTING_ENTRY1(40), ROUTING_ENTRY1(41),
ROUTING_ENTRY1(42), ROUTING_ENTRY1(43),
ROUTING_ENTRY1(44), ROUTING_ENTRY1(45),
ROUTING_ENTRY1(46), ROUTING_ENTRY1(47),
#endif
};
int kvm_setup_default_irq_routing(struct kvm *kvm)
{
return kvm_set_irq_routing(kvm, default_routing,
ARRAY_SIZE(default_routing), 0);
}