Add a function to check if the eventfd capability is present in KVM in
the host kernel.
Signed-off-by: Antonios Motakis <a.mota...@virtualopensystems.com>
Signed-off-by: Nikolay Nikolaev <n.nikol...@virtualopensystems.com>
---
include/sysemu/kvm.h | 11 +++++++++++
kvm-all.c | 4 ++++
kvm-stub.c | 1 +
3 files changed, 16 insertions(+)
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;
--
1.8.3.2
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