[PATCH 1/2] kvm: libkvm: support for irq routing

Avi Kivity
2009-01-14T13:53:15Z

Signed-off-by: Avi Kivity <avi@redhat.com>
---
libkvm/kvm-common.h | 4 ++
libkvm/libkvm.c | 107 +++++++++++++++++++++++++++++++++++++++++++++++++++
libkvm/libkvm.h | 62 +++++++++++++++++++++++++++++
3 files changed, 173 insertions(+), 0 deletions(-)

diff --git a/libkvm/kvm-common.h b/libkvm/kvm-common.h
index c5beacc..e09c07c 100644
--- a/libkvm/kvm-common.h
+++ b/libkvm/kvm-common.h
@@ -61,6 +61,10 @@ struct kvm_context {
int pit_in_kernel;
/// in-kernel coalesced mmio
int coalesced_mmio;
+#ifdef KVM_CAP_IRQ_ROUTING
+ struct kvm_irq_routing *irq_routes;
+ int nr_allocated_irq_routes;
+#endif
};

void init_slots(void);
diff --git a/libkvm/libkvm.c b/libkvm/libkvm.c
index 0408fdb..1004fa6 100644
--- a/libkvm/libkvm.c
+++ b/libkvm/libkvm.c
@@ -381,6 +381,14 @@ int kvm_create_vm(kvm_context_t kvm)
{
int fd = kvm->fd;

+#ifdef KVM_CAP_IRQ_ROUTING
+ kvm->irq_routes = malloc(sizeof(*kvm->irq_routes));
+ if (!kvm->irq_routes)
+ return -ENOMEM;
+ memset(kvm->irq_routes, 0, sizeof(*kvm->irq_routes));
+ kvm->nr_allocated_irq_routes = 0;
+#endif
+
kvm->vcpu_fd[0] = -1;

fd = ioctl(fd, KVM_CREATE_VM, 0);
@@ -1164,3 +1172,102 @@ int kvm_reinject_control(kvm_context_t kvm, int pit_reinject)
#endif
return -ENOSYS;
}
+
+int kvm_has_gsi_routing(kvm_context_t kvm)
+{
+ int r = 0;
+
+#ifdef KVM_CAP_IRQ_ROUTING
+ r = kvm_check_extension(kvm, KVM_CAP_IRQ_ROUTING);
+#endif
+ return r;
+}
+
+int kvm_get_gsi_count(kvm_context_t kvm)
+{
+#ifdef KVM_CAP_IRQ_ROUTING
+ return kvm_check_extension(kvm, KVM_CAP_IRQ_ROUTING);
+#else
+ return -EINVAL;
+#endif
+}
+
+int kvm_clear_gsi_routes(kvm_context_t kvm)
+{
+#ifdef KVM_CAP_IRQ_ROUTING
+ kvm->irq_routes->nr = 0;
+ return 0;
+#else
+ return -EINVAL;
+#endif
+}
+
+int kvm_add_irq_route(kvm_context_t kvm, int gsi, int irqchip, int pin)
+{
+#ifdef KVM_CAP_IRQ_ROUTING
+ struct kvm_irq_routing *z;
+ struct kvm_irq_routing_entry *e;
+ int n, size;
+
+ if (kvm->irq_routes->nr == kvm->nr_allocated_irq_routes) {
+ n = kvm->nr_allocated_irq_routes * 2;
+ if (n < 64)
+ n = 64;
+ size = sizeof(struct kvm_irq_routing);
+ size += n * sizeof(*e);
+ z = realloc(kvm->irq_routes, size);
+ if (!z)
+ return -ENOMEM;
+ kvm->nr_allocated_irq_routes = n;
+ kvm->irq_routes = z;
+ }
+ n = kvm->irq_routes->nr++;
+ e = &kvm->irq_routes->entries[n];
+ memset(e, 0, sizeof(*e));
+ e->gsi = gsi;
+ e->type = KVM_IRQ_ROUTING_IRQCHIP;
+ e->flags = 0;
+ e->u.irqchip.irqchip = irqchip;
+ e->u.irqchip.pin = pin;
+ return 0;
+#else
+ return -ENOSYS;
+#endif
+}
+
+int kvm_del_irq_route(kvm_context_t kvm, int gsi, int irqchip, int pin)
+{
+#ifdef KVM_CAP_IRQ_ROUTING
+ struct kvm_irq_routing_entry *e, *p;
+ int i;
+
+ for (i = 0; i < kvm->irq_routes->nr; ++i) {
+ e = &kvm->irq_routes->entries[i];
+ if (e->type == KVM_IRQ_ROUTING_IRQCHIP
+ && e->gsi == gsi
+ && e->u.irqchip.irqchip == irqchip
+ && e->u.irqchip.pin == pin) {
+ p = &kvm->irq_routes->entries[--kvm->irq_routes->nr];
+ *e = *p;
+ return 0;
+ }
+ }
+ return -ESRCH;
+#else
+ return -ENOSYS;
+#endif
+}
+
+int kvm_commit_irq_routes(kvm_context_t kvm)
+{
+#ifdef KVM_CAP_IRQ_ROUTING
+ int r;
+
+ kvm->irq_routes->flags = 0;
+ r = ioctl(kvm->vm_fd, KVM_SET_GSI_ROUTING, kvm->irq_routes);
+ if (r == -1)
+ r = -errno;
+#else
+ return -ENOSYS;
+#endif
+}
diff --git a/libkvm/libkvm.h b/libkvm/libkvm.h
index ee1ba68..85012ff 100644
--- a/libkvm/libkvm.h
+++ b/libkvm/libkvm.h
@@ -720,4 +720,66 @@ int kvm_assign_irq(kvm_context_t kvm,
*/
int kvm_destroy_memory_region_works(kvm_context_t kvm);
#endif
+
+
+/*!
+ * \brief Checks whether the generic irq routing capability is present
+ *
+ * Checks whether kvm can reroute interrupts among the various interrupt
+ * controllers.
+ *
+ * \param kvm Pointer to the current kvm_context
+ */
+int kvm_has_gsi_routing(kvm_context_t kvm);
+
+/*!
+ * \brief Determines the number of gsis that can be routed
+ *
+ * Returns the number of distinct gsis that can be routed by kvm. This is
+ * also the number of distinct routes (if a gsi has two routes, than another
+ * gsi cannot be used...)
+ *
+ * \param kvm Pointer to the current kvm_context
+ */
+int kvm_get_gsi_count(kvm_context_t kvm);
+
+/*!
+ * \brief Clears the temporary irq routing table
+ *
+ * Clears the temporary irq routing table. Nothing is committed to the
+ * running VM.
+ *
+ * \param kvm Pointer to the current kvm_context
+ */
+int kvm_clear_gsi_routes(kvm_context_t kvm);
+
+/*!
+ * \brief Adds an irq route to the temporary irq routing table
+ *
+ * Adds an irq route to the temporary irq routing table. Nothing is
+ * committed to the running VM.
+ *
+ * \param kvm Pointer to the current kvm_context
+ */
+int kvm_add_irq_route(kvm_context_t kvm, int gsi, int irqchip, int pin);
+
+/*!
+ * \brief Removes an irq route from the temporary irq routing table
+ *
+ * Adds an irq route to the temporary irq routing table. Nothing is
+ * committed to the running VM.
+ *
+ * \param kvm Pointer to the current kvm_context
+ */
+int kvm_del_irq_route(kvm_context_t kvm, int gsi, int irqchip, int pin);
+
+/*!
+ * \brief Commit the temporary irq routing table
+ *
+ * Commit the temporary irq routing table to the running VM.
+ *
+ * \param kvm Pointer to the current kvm_context
+ */
+int kvm_commit_irq_routes(kvm_context_t kvm);
+
#endif
--
1.6.0.6