[PATCH v3 08/12] KVM: x86: Print error code in exception injection tracepoint iff valid

["Maciej S. Szmigiero" <mail@maciej.szmigiero.name>]

From: Sean Christopherson <seanjc@google.com>

Print the error code in the exception injection tracepoint if and only if
the exception has an error code.  Define the entire error code sequence
as a set of formatted strings, print empty strings if there's no error
code, and abuse __print_symbolic() by passing it an empty array to coerce
it into printing the error code as a hex string.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
---
 arch/x86/kvm/trace.h | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h
index d07428e660e3..385436d12024 100644
--- a/arch/x86/kvm/trace.h
+++ b/arch/x86/kvm/trace.h
@@ -376,10 +376,11 @@ TRACE_EVENT(kvm_inj_exception,
 		__entry->reinjected	= reinjected;
 	),
 
-	TP_printk("%s (0x%x)%s",
+	TP_printk("%s%s%s%s%s",
 		  __print_symbolic(__entry->exception, kvm_trace_sym_exc),
-		  /* FIXME: don't print error_code if not present */
-		  __entry->has_error ? __entry->error_code : 0,
+		  !__entry->has_error ? "" : " (",
+		  !__entry->has_error ? "" : __print_symbolic(__entry->error_code, { }),
+		  !__entry->has_error ? "" : ")",
 		  __entry->reinjected ? " [reinjected]" : "")
 );