KVM: x86/mmu: Revert "Revert "KVM: MMU: show mmu_valid_gen in shadow page related tracepoints""

Now that the fast invalidate mechanism has been reintroduced, restore
tracing of the generation number in shadow page tracepoints.

This reverts commit b59c4830.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/mmutrace.h

@@ -9,12 +9,14 @@
 #define TRACE_SYSTEM kvmmmu
 
 #define KVM_MMU_PAGE_FIELDS			\
+	__field(unsigned long, mmu_valid_gen)	\
 	__field(__u64, gfn)			\
 	__field(__u32, role)			\
 	__field(__u32, root_count)		\
 	__field(bool, unsync)
 
 #define KVM_MMU_PAGE_ASSIGN(sp)				\
+	__entry->mmu_valid_gen = sp->mmu_valid_gen;	\
 	__entry->gfn = sp->gfn;				\
 	__entry->role = sp->role.word;			\
 	__entry->root_count = sp->root_count;		\
@@ -29,8 +31,9 @@
 								        \
 	role.word = __entry->role;					\
 									\
-	trace_seq_printf(p, "sp gfn %llx l%u %u-byte q%u%s %s%s"	\
+	trace_seq_printf(p, "sp gen %lx gfn %llx l%u %u-byte q%u%s %s%s"\
 			 " %snxe %sad root %u %s%c",			\
+			 __entry->mmu_valid_gen,			\
 			 __entry->gfn, role.level,			\
 			 role.gpte_is_8_bytes ? 8 : 4,			\
 			 role.quadrant,					\