[PATCH] KVM: API versioning

Add compile-time and run-time API versioning.

Signed-off-by: Avi Kivity <avi@qumranet.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 6 insertions, 0 deletions

diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index bc2e6c19f855..9f24f22e4cb2 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -1603,6 +1603,9 @@ static long kvm_dev_ioctl(struct file *filp,
         int r = -EINVAL;
 
         switch (ioctl) {
+        case KVM_GET_API_VERSION:
+                r = KVM_API_VERSION;
+                break;
         case KVM_CREATE_VCPU: {
                 r = kvm_dev_ioctl_create_vcpu(kvm, arg);
                 if (r)
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 5bb2c3c585c1..28fdce1ac1db 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -11,6 +11,8 @@
 #include <asm/types.h>
 #include <linux/ioctl.h>
 
+#define KVM_API_VERSION 1
+
 /*
  * Architectural interrupt line count, and the size of the bitmap needed
  * to hold them.
@@ -209,6 +211,7 @@ struct kvm_dirty_log {
 
 #define KVMIO 0xAE
 
+#define KVM_GET_API_VERSION       _IO(KVMIO, 1)
 #define KVM_RUN                   _IOWR(KVMIO, 2, struct kvm_run)
 #define KVM_GET_REGS              _IOWR(KVMIO, 3, struct kvm_regs)
 #define KVM_SET_REGS              _IOW(KVMIO, 4, struct kvm_regs)