[Qemu-devel] [PATCH 04/15] kvm: add API to set ioeventfd

["Michael S. Tsirkin" <mst@redhat.com>]

This adds API to set ioeventfd to kvm,
as well as stubs for non-eventfd case,
making it possible for users to use this API
without ifdefs.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 kvm-all.c |   20 ++++++++++++++++++++
 kvm.h     |   16 ++++++++++++++++
 2 files changed, 36 insertions(+), 0 deletions(-)

diff --git a/kvm-all.c b/kvm-all.c
index a312654..beaba6d 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -1113,3 +1113,23 @@ void kvm_remove_all_breakpoints(CPUState *current_env)
 {
 }
 #endif /* !KVM_CAP_SET_GUEST_DEBUG */
+
+#ifdef KVM_IOEVENTFD
+int kvm_set_ioeventfd(uint16_t addr, uint16_t data, int fd, bool assigned)
+{
+    struct kvm_ioeventfd kick = {
+        .datamatch = data,
+        .addr = addr,
+        .len = 2,
+        .flags = KVM_IOEVENTFD_FLAG_DATAMATCH | KVM_IOEVENTFD_FLAG_PIO,
+        .fd = fd,
+    };
+    int r;
+    if (!assigned)
+        kick.flags |= KVM_IOEVENTFD_FLAG_DEASSIGN;
+    r = kvm_vm_ioctl(kvm_state, KVM_IOEVENTFD, &kick);
+    if (r < 0)
+        return r;
+    return 0;
+}
+#endif
diff --git a/kvm.h b/kvm.h
index 672d511..a8a86e7 100644
--- a/kvm.h
+++ b/kvm.h
@@ -14,10 +14,16 @@
 #ifndef QEMU_KVM_H
 #define QEMU_KVM_H
 
+#include <stdbool.h>
+#include <errno.h>
 #include "config.h"
 #include "qemu-queue.h"
 
 #ifdef CONFIG_KVM
+#include <linux/kvm.h>
+#endif
+
+#ifdef CONFIG_KVM
 extern int kvm_allowed;
 
 #define kvm_enabled() (kvm_allowed)
@@ -131,4 +137,14 @@ static inline void cpu_synchronize_state(CPUState *env)
     }
 }
 
+#if defined(KVM_IOEVENTFD) && defined(CONFIG_KVM)
+int kvm_set_ioeventfd(uint16_t addr, uint16_t data, int fd, bool assigned);
+#else
+static inline
+int kvm_set_ioeventfd(uint16_t data, uint16_t addr, int fd, bool assigned)
+{
+    return -ENOSYS;
+}
+#endif
+
 #endif
-- 
1.6.6.144.g5c3af