KVM: MMU: add tracepoint for check_mmio_spte

It is useful for debug mmio spte invalidation

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 3e893cd9038911e888b03eeab666801256e3e086..417f36b7c0e4f2e89d42512f4489dcd5511c37cb 100644 (file)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -283,8 +283,13 @@ static bool set_mmio_spte(struct kvm *kvm, u64 *sptep, gfn_t gfn,
 
 static bool check_mmio_spte(struct kvm *kvm, u64 spte)
 {
-       return likely(get_mmio_spte_generation(spte) ==
-                       kvm_current_mmio_generation(kvm));
+       unsigned int kvm_gen, spte_gen;
+
+       kvm_gen = kvm_current_mmio_generation(kvm);
+       spte_gen = get_mmio_spte_generation(spte);
+
+       trace_check_mmio_spte(spte, kvm_gen, spte_gen);
+       return likely(kvm_gen == spte_gen);
 }
 
 static inline u64 rsvd_bits(int s, int e)

diff --git a/arch/x86/kvm/mmutrace.h b/arch/x86/kvm/mmutrace.h
index ad24757041adedc6a438d36b27c410dced3e8abb..9d2e0ffcb190989b52b89b8d42be561d8165e911 100644 (file)
--- a/arch/x86/kvm/mmutrace.h
+++ b/arch/x86/kvm/mmutrace.h
@@ -298,6 +298,30 @@ TRACE_EVENT(
                  __entry->mmu_valid_gen, __entry->mmu_used_pages
        )
 );
+
+
+TRACE_EVENT(
+       check_mmio_spte,
+       TP_PROTO(u64 spte, unsigned int kvm_gen, unsigned int spte_gen),
+       TP_ARGS(spte, kvm_gen, spte_gen),
+
+       TP_STRUCT__entry(
+               __field(unsigned int, kvm_gen)
+               __field(unsigned int, spte_gen)
+               __field(u64, spte)
+       ),
+
+       TP_fast_assign(
+               __entry->kvm_gen = kvm_gen;
+               __entry->spte_gen = spte_gen;
+               __entry->spte = spte;
+       ),
+
+       TP_printk("spte %llx kvm_gen %x spte-gen %x valid %d", __entry->spte,
+                 __entry->kvm_gen, __entry->spte_gen,
+                 __entry->kvm_gen == __entry->spte_gen
+       )
+);
 #endif /* _TRACE_KVMMMU_H */
 
 #undef TRACE_INCLUDE_PATH