Add kvm_eventfds_enabled function

Add a function to check if the eventfd capability is present in KVM in
the host kernel.

Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/kvm-all.c b/kvm-all.c
index 4e19eff0ef..92f56d8a31 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -113,6 +113,7 @@ KVMState *kvm_state;
 bool kvm_kernel_irqchip;
 bool kvm_async_interrupts_allowed;
 bool kvm_halt_in_kernel_allowed;
+bool kvm_eventfds_allowed;
 bool kvm_irqfds_allowed;
 bool kvm_msi_via_irqfd_allowed;
 bool kvm_gsi_routing_allowed;
@@ -1541,6 +1542,9 @@ int kvm_init(MachineClass *mc)
         (kvm_check_extension(s, KVM_CAP_READONLY_MEM) > 0);
 #endif
 
+    kvm_eventfds_allowed =
+        (kvm_check_extension(s, KVM_CAP_IOEVENTFD) > 0);
+
     ret = kvm_arch_init(s);
     if (ret < 0) {
         goto err;