KVM: Userspace controlled irq routing
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>
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 73f3480..7a5d73a 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -399,6 +399,38 @@
#if defined(CONFIG_X86)
#define KVM_CAP_REINJECT_CONTROL 24
#endif
+#if defined(CONFIG_X86)||defined(CONFIG_IA64)
+#define KVM_CAP_IRQ_ROUTING 25
+#endif
+
+#ifdef KVM_CAP_IRQ_ROUTING
+
+struct kvm_irq_routing_irqchip {
+ __u32 irqchip;
+ __u32 pin;
+};
+
+/* gsi routing entry types */
+#define KVM_IRQ_ROUTING_IRQCHIP 1
+
+struct kvm_irq_routing_entry {
+ __u32 gsi;
+ __u32 type;
+ __u32 flags;
+ __u32 pad;
+ union {
+ struct kvm_irq_routing_irqchip irqchip;
+ __u32 pad[8];
+ } u;
+};
+
+struct kvm_irq_routing {
+ __u32 nr;
+ __u32 flags;
+ struct kvm_irq_routing_entry entries[0];
+};
+
+#endif
/*
* ioctls for VM fds
@@ -430,6 +462,7 @@
_IOW(KVMIO, 0x68, struct kvm_coalesced_mmio_zone)
#define KVM_ASSIGN_PCI_DEVICE _IOR(KVMIO, 0x69, \
struct kvm_assigned_pci_dev)
+#define KVM_SET_GSI_ROUTING _IOW(KVMIO, 0x6a, struct kvm_irq_routing)
#define KVM_ASSIGN_IRQ _IOR(KVMIO, 0x70, \
struct kvm_assigned_irq)
#define KVM_REINJECT_CONTROL _IO(KVMIO, 0x71)
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 99963f3..ce285e0 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -107,6 +107,19 @@
int user_alloc;
};
+struct kvm_kernel_irq_routing_entry {
+ u32 gsi;
+ void (*set)(struct kvm_kernel_irq_routing_entry *e,
+ struct kvm *kvm, int level);
+ union {
+ struct {
+ unsigned irqchip;
+ unsigned pin;
+ } irqchip;
+ };
+ struct list_head link;
+};
+
struct kvm {
struct mutex lock; /* protects the vcpus array and APIC accesses */
spinlock_t mmu_lock;
@@ -128,6 +141,7 @@
#endif
#ifdef CONFIG_HAVE_KVM_IRQCHIP
+ struct list_head irq_routing; /* of kvm_kernel_irq_routing_entry */
struct hlist_head mask_notifier_list;
#endif
@@ -480,4 +494,21 @@
}
#endif
+#ifdef CONFIG_HAVE_KVM_IRQCHIP
+
+#define KVM_MAX_IRQ_ROUTES 1024
+
+int kvm_setup_default_irq_routing(struct kvm *kvm);
+int kvm_set_irq_routing(struct kvm *kvm,
+ const struct kvm_irq_routing_entry *entries,
+ unsigned nr,
+ unsigned flags);
+void kvm_free_irq_routing(struct kvm *kvm);
+
+#else
+
+static inline void kvm_free_irq_routing(struct kvm *kvm) {}
+
+#endif
+
#endif