diff mbox

[v9,02/20] Add kvm_eventfds_enabled function

Message ID 1393957383-16685-3-git-send-email-a.motakis@virtualopensystems.com
State New
Headers show

Commit Message

Antonios Motakis March 4, 2014, 6:22 p.m. UTC
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>
---
 include/sysemu/kvm.h | 11 +++++++++++
 kvm-all.c            |  4 ++++
 kvm-stub.c           |  1 +
 3 files changed, 16 insertions(+)
diff mbox

Patch

diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
index a02d67c..3db063e 100644
--- a/include/sysemu/kvm.h
+++ b/include/sysemu/kvm.h
@@ -43,6 +43,7 @@  extern bool kvm_allowed;
 extern bool kvm_kernel_irqchip;
 extern bool kvm_async_interrupts_allowed;
 extern bool kvm_halt_in_kernel_allowed;
+extern bool kvm_eventfds_allowed;
 extern bool kvm_irqfds_allowed;
 extern bool kvm_msi_via_irqfd_allowed;
 extern bool kvm_gsi_routing_allowed;
@@ -83,6 +84,15 @@  extern bool kvm_readonly_mem_allowed;
 #define kvm_halt_in_kernel() (kvm_halt_in_kernel_allowed)
 
 /**
+ * kvm_eventfds_enabled:
+ *
+ * Returns: true if we can use eventfds to receive notifications
+ * from a KVM CPU (ie the kernel supports eventds and we are running
+ * with a configuration where it is meaningful to use them).
+ */
+#define kvm_eventfds_enabled() (kvm_eventfds_allowed)
+
+/**
  * kvm_irqfds_enabled:
  *
  * Returns: true if we can use irqfds to inject interrupts into
@@ -128,6 +138,7 @@  extern bool kvm_readonly_mem_allowed;
 #define kvm_irqchip_in_kernel() (false)
 #define kvm_async_interrupts_enabled() (false)
 #define kvm_halt_in_kernel() (false)
+#define kvm_eventfds_enabled() (false)
 #define kvm_irqfds_enabled() (false)
 #define kvm_msi_via_irqfd_enabled() (false)
 #define kvm_gsi_routing_allowed() (false)
diff --git a/kvm-all.c b/kvm-all.c
index fd8157a..85f31b4 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -110,6 +110,7 @@  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;
@@ -1505,6 +1506,9 @@  int kvm_init(void)
         (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;
diff --git a/kvm-stub.c b/kvm-stub.c
index e979f76..a25cda2 100644
--- a/kvm-stub.c
+++ b/kvm-stub.c
@@ -22,6 +22,7 @@ 
 KVMState *kvm_state;
 bool kvm_kernel_irqchip;
 bool kvm_async_interrupts_allowed;
+bool kvm_eventfds_allowed;
 bool kvm_irqfds_allowed;
 bool kvm_msi_via_irqfd_allowed;
 bool kvm_gsi_routing_allowed;