KVM: Add method to check for backwards-compatible API extensions

Signed-off-by: Avi Kivity <avi@qumranet.com>
git-mirror · May 3, 2007 · 5d308f4 · 5d308f4
1 parent 739872c
commit 5d308f4
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Showing 2 changed files with 11 additions and 0 deletions.
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
@@ -2416,6 +2416,12 @@ static long kvm_dev_ioctl(struct file *filp,
 		r = 0;
 		break;
 	}
+	case KVM_CHECK_EXTENSION:
+		/*
+		 * No extensions defined at present.
+		 */
+		r = 0;
+		break;
 	default:
 		;
 	}

diff --git a/include/linux/kvm.h b/include/linux/kvm.h
@@ -232,6 +232,11 @@ struct kvm_cpuid {
 #define KVM_GET_API_VERSION       _IO(KVMIO,   0x00)
 #define KVM_CREATE_VM             _IO(KVMIO,   0x01) /* returns a VM fd */
 #define KVM_GET_MSR_INDEX_LIST    _IOWR(KVMIO, 0x02, struct kvm_msr_list)
+/*
+ * Check if a kvm extension is available.  Argument is extension number,
+ * return is 1 (yes) or 0 (no, sorry).
+ */
+#define KVM_CHECK_EXTENSION       _IO(KVMIO,   0x03)
 
 /*
  * ioctls for VM fds
-Original file line number
+Diff line change
@@ Expand Up / @@ -2416,6 +2416,12 @@ static long kvm_dev_ioctl(struct file *filp, @@
     		r = 0;
     		break;
     	}
+    	case KVM_CHECK_EXTENSION:
+    		/*
+    		 * No extensions defined at present.
+    		 */
+    		r = 0;
+    		break;
     	default:
     		;
     	}
@@ Expand Down @@