KVM: fix tracing kvm_try_async_get_page

Tracing 'async' and *pfn is useless, since 'async' is always true,
and '*pfn' is always "fault_pfn'

We can trace 'gva' and 'gfn' instead, it can help us to see the
life-cycle of an async_pf

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

arch/x86/kvm/mmu.c

@@ -2628,7 +2628,7 @@ static bool try_async_pf(struct kvm_vcpu *vcpu, bool no_apf, gfn_t gfn,
 	put_page(pfn_to_page(*pfn));
 
 	if (!no_apf && can_do_async_pf(vcpu)) {
-		trace_kvm_try_async_get_page(async, *pfn);
+		trace_kvm_try_async_get_page(gva, gfn);
 		if (kvm_find_async_pf_gfn(vcpu, gfn)) {
 			trace_kvm_async_pf_doublefault(gva, gfn);
 			kvm_make_request(KVM_REQ_APF_HALT, vcpu);

include/trace/events/kvm.h

@@ -218,18 +218,20 @@ TRACE_EVENT(kvm_age_page,
 #ifdef CONFIG_KVM_ASYNC_PF
 TRACE_EVENT(
 	kvm_try_async_get_page,
-	TP_PROTO(bool async, u64 pfn),
-	TP_ARGS(async, pfn),
+	TP_PROTO(u64 gva, u64 gfn),
+	TP_ARGS(gva, gfn),
 
 	TP_STRUCT__entry(
-		__field(__u64, pfn)
+		__field(u64, gva)
+		__field(u64, gfn)
 		),
 
 	TP_fast_assign(
-		__entry->pfn = (!async) ? pfn : (u64)-1;
+		__entry->gva = gva;
+		__entry->gfn = gfn;
 		),
 
-	TP_printk("pfn %#llx", __entry->pfn)
+	TP_printk("gva = %#llx, gfn = %#llx", __entry->gva, __entry->gfn)
 );
 
 TRACE_EVENT(