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>
        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)
 
 #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.
 
 #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)