KVM: SVM: Add tracepoint for nested #vmexit

This patch adds a tracepoint for every #vmexit we get from a
nested guest.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

arch/x86/kvm/svm.c

@@ -2366,6 +2366,12 @@ static int handle_exit(struct kvm_vcpu *vcpu)
 	if (is_nested(svm)) {
 		int vmexit;
 
+		trace_kvm_nested_vmexit(svm->vmcb->save.rip, exit_code,
+					svm->vmcb->control.exit_info_1,
+					svm->vmcb->control.exit_info_2,
+					svm->vmcb->control.exit_int_info,
+					svm->vmcb->control.exit_int_info_err);
+
 		nsvm_printk("nested handle_exit: 0x%x | 0x%lx | 0x%lx | 0x%lx\n",
 			    exit_code, svm->vmcb->control.exit_info_1,
 			    svm->vmcb->control.exit_info_2, svm->vmcb->save.rip);

arch/x86/kvm/trace.h

@@ -382,6 +382,42 @@ TRACE_EVENT(kvm_nested_vmrun,
 		__entry->npt ? "on" : "off")
 );
 
+/*
+ * Tracepoint for #VMEXIT while nested
+ */
+TRACE_EVENT(kvm_nested_vmexit,
+	    TP_PROTO(__u64 rip, __u32 exit_code,
+		     __u64 exit_info1, __u64 exit_info2,
+		     __u32 exit_int_info, __u32 exit_int_info_err),
+	    TP_ARGS(rip, exit_code, exit_info1, exit_info2,
+		    exit_int_info, exit_int_info_err),
+
+	TP_STRUCT__entry(
+		__field(	__u64,		rip			)
+		__field(	__u32,		exit_code		)
+		__field(	__u64,		exit_info1		)
+		__field(	__u64,		exit_info2		)
+		__field(	__u32,		exit_int_info		)
+		__field(	__u32,		exit_int_info_err	)
+	),
+
+	TP_fast_assign(
+		__entry->rip			= rip;
+		__entry->exit_code		= exit_code;
+		__entry->exit_info1		= exit_info1;
+		__entry->exit_info2		= exit_info2;
+		__entry->exit_int_info		= exit_int_info;
+		__entry->exit_int_info_err	= exit_int_info_err;
+	),
+	TP_printk("rip: 0x%016llx reason: %s ext_inf1: 0x%016llx "
+		  "ext_inf2: 0x%016llx ext_int: 0x%08x ext_int_err: 0x%08x\n",
+		  __entry->rip,
+		  ftrace_print_symbols_seq(p, __entry->exit_code,
+					   kvm_x86_ops->exit_reasons_str),
+		  __entry->exit_info1, __entry->exit_info2,
+		  __entry->exit_int_info, __entry->exit_int_info_err)
+);
+
 #endif /* _TRACE_KVM_H */
 
 /* This part must be outside protection */

arch/x86/kvm/x86.c

@@ -4985,3 +4985,4 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_page_fault);
 EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_msr);
 EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_cr);
 EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_vmrun);
+EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_vmexit);