KVM: x86: Introduce trace_kvm_hv_hypercall_done()

Hypercall failures are unusual with potentially far going consequences
so it would be useful to see their results when tracing.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Siddharth Chandrasekaran <sidcha@amazon.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210730122625.112848-3-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index cb7e045..2945b93 100644 (file)
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -2016,6 +2016,7 @@ static void kvm_hv_hypercall_set_result(struct kvm_vcpu *vcpu, u64 result)
 
 static int kvm_hv_hypercall_complete(struct kvm_vcpu *vcpu, u64 result)
 {
+       trace_kvm_hv_hypercall_done(result);
        kvm_hv_hypercall_set_result(vcpu, result);
        ++vcpu->stat.hypercalls;
        return kvm_skip_emulated_instruction(vcpu);

diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h
index b484141..03ebe36 100644 (file)
--- a/arch/x86/kvm/trace.h
+++ b/arch/x86/kvm/trace.h
@@ -92,6 +92,21 @@ TRACE_EVENT(kvm_hv_hypercall,
                  __entry->outgpa)
 );
 
+TRACE_EVENT(kvm_hv_hypercall_done,
+       TP_PROTO(u64 result),
+       TP_ARGS(result),
+
+       TP_STRUCT__entry(
+               __field(__u64, result)
+       ),
+
+       TP_fast_assign(
+               __entry->result = result;
+       ),
+
+       TP_printk("result 0x%llx", __entry->result)
+);
+
 /*
  * Tracepoint for Xen hypercall.
  */