KVM: kvmtrace: replace get_cycles with ktime_get v3

The current kvmtrace code uses get_cycles() while the interpretation would be
easier using using nanoseconds. ktime_get() should give at least the same
accuracy as get_cycles on all architectures (even better on 32bit archs) but
at a better unit (e.g. comparable between hosts with different frequencies.

[avi: avoid ktime_t in public header]

Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 8a16b08..5d08f11 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -322,12 +322,12 @@
 	__u32 vcpu_id;
 	union {
 		struct {
-			__u64 cycle_u64;
+			__u64 timestamp;
 			__u32 extra_u32[KVM_TRC_EXTRA_MAX];
-		} __attribute__((packed)) cycle;
+		} __attribute__((packed)) timestamp;
 		struct {
 			__u32 extra_u32[KVM_TRC_EXTRA_MAX];
-		} nocycle;
+		} notimestamp;
 	} u;
 };