kvm/eventfd: add arch-specific set_irq

Allow for arch-specific interrupt types to be set.  For that, add
kvm_arch_set_irq() which takes interrupt type-specific action if it
recognizes the interrupt type given, and -EWOULDBLOCK otherwise.

The default implementation always returns -EWOULDBLOCK.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Vitaly Kuznetsov <vkuznets@redhat.com>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

2 files changed, 16 insertions, 1 deletions

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index b66861c297c4..eba9caebc9c1 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -828,6 +828,10 @@ int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level,
 int kvm_set_irq_inatomic(struct kvm *kvm, int irq_source_id, u32 irq, int level);
 int kvm_set_msi(struct kvm_kernel_irq_routing_entry *irq_entry, struct kvm *kvm,
                 int irq_source_id, int level, bool line_status);
+
+int kvm_arch_set_irq(struct kvm_kernel_irq_routing_entry *irq, struct kvm *kvm,
+                     int irq_source_id, int level, bool line_status);
+
 bool kvm_irq_has_notifier(struct kvm *kvm, unsigned irqchip, unsigned pin);
 void kvm_notify_acked_gsi(struct kvm *kvm, int gsi);
 void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin);
diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
index f6b986a41823..e29fd2640709 100644
--- a/virt/kvm/eventfd.c
+++ b/virt/kvm/eventfd.c
@@ -171,6 +171,15 @@ irqfd_deactivate(struct kvm_kernel_irqfd *irqfd)
         queue_work(irqfd_cleanup_wq, &irqfd->shutdown);
 }
 
+int __attribute__((weak)) kvm_arch_set_irq(
+                                struct kvm_kernel_irq_routing_entry *irq,
+                                struct kvm *kvm, int irq_source_id,
+                                int level,
+                                bool line_status)
+{
+        return -EWOULDBLOCK;
+}
+
 /*
  * Called with wqh->lock held and interrupts disabled
  */
@@ -195,7 +204,9 @@ irqfd_wakeup(wait_queue_t *wait, unsigned mode, int sync, void *key)
                 if (irq.type == KVM_IRQ_ROUTING_MSI)
                         kvm_set_msi(&irq, kvm, KVM_USERSPACE_IRQ_SOURCE_ID, 1,
                                         false);
-                else
+                else if (kvm_arch_set_irq(&irq, kvm,
+                                          KVM_USERSPACE_IRQ_SOURCE_ID, 1,
+                                          false) == -EWOULDBLOCK)
                         schedule_work(&irqfd->inject);
                 srcu_read_unlock(&kvm->irq_srcu, idx);
         }