X86/Hyper-V: Add hyperv_nested_flush_guest_mapping ftrace support

This patch is to add hyperv_nested_flush_guest_mapping support to trace
hvFlushGuestPhysicalAddressSpace hypercall.

Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/hyperv/nested.c

@@ -14,6 +14,8 @@
 #include <asm/mshyperv.h>
 #include <asm/tlbflush.h>
 
+#include <asm/trace/hyperv.h>
+
 int hyperv_flush_guest_mapping(u64 as)
 {
 	struct hv_guest_mapping_flush **flush_pcpu;
@@ -48,6 +50,7 @@ int hyperv_flush_guest_mapping(u64 as)
 		ret = 0;
 
 fault:
+	trace_hyperv_nested_flush_guest_mapping(as, ret);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(hyperv_flush_guest_mapping);

arch/x86/include/asm/trace/hyperv.h

@@ -28,6 +28,20 @@ TRACE_EVENT(hyperv_mmu_flush_tlb_others,
 		      __entry->addr, __entry->end)
 	);
 
+TRACE_EVENT(hyperv_nested_flush_guest_mapping,
+	    TP_PROTO(u64 as, int ret),
+	    TP_ARGS(as, ret),
+
+	    TP_STRUCT__entry(
+		    __field(u64, as)
+		    __field(int, ret)
+		    ),
+	    TP_fast_assign(__entry->as = as;
+			   __entry->ret = ret;
+		    ),
+	    TP_printk("address space %llx ret %d", __entry->as, __entry->ret)
+	);
+
 #endif /* CONFIG_HYPERV */
 
 #undef TRACE_INCLUDE_PATH