diff mbox series

[RFC,14/15] KVM: x86/mmu: Add tracepoint for splitting large pages

Message ID 20211119235759.1304274-15-dmatlack@google.com (mailing list archive)
State New, archived
Headers show
Series KVM: x86/mmu: Eager Page Splitting for the TDP MMU | expand

Commit Message

David Matlack Nov. 19, 2021, 11:57 p.m. UTC 
Add a tracepoint that records whenever we split a large page.

Signed-off-by: David Matlack <dmatlack@google.com>
---
 arch/x86/kvm/mmu/mmutrace.h | 20 ++++++++++++++++++++
 arch/x86/kvm/mmu/tdp_mmu.c  |  2 ++
 2 files changed, 22 insertions(+)
diff mbox series

Patch

diff --git a/arch/x86/kvm/mmu/mmutrace.h b/arch/x86/kvm/mmu/mmutrace.h
index b8151bbca36a..4adb794470ae 100644
--- a/arch/x86/kvm/mmu/mmutrace.h
+++ b/arch/x86/kvm/mmu/mmutrace.h
@@ -416,6 +416,26 @@  TRACE_EVENT(
 	)
 );
 
+TRACE_EVENT(
+	kvm_mmu_split_large_page,
+	TP_PROTO(u64 gfn, u64 spte, int level),
+	TP_ARGS(gfn, spte, level),
+
+	TP_STRUCT__entry(
+		__field(u64, gfn)
+		__field(u64, spte)
+		__field(int, level)
+	),
+
+	TP_fast_assign(
+		__entry->gfn = gfn;
+		__entry->spte = spte;
+		__entry->level = level;
+	),
+
+	TP_printk("gfn %llx spte %llx level %d", __entry->gfn, __entry->spte, __entry->level)
+);
+
 #endif /* _TRACE_KVMMMU_H */
 
 #undef TRACE_INCLUDE_PATH
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index 366857b9fb3b..8f60d942c789 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -1284,6 +1284,8 @@  static bool tdp_mmu_split_large_page_atomic(struct kvm *kvm, struct tdp_iter *it
 
 	BUG_ON(mmu_split_caches_need_topup(kvm));
 
+	trace_kvm_mmu_split_large_page(iter->gfn, large_spte, level);
+
 	child_sp = alloc_child_tdp_mmu_page(&kvm->arch.split_caches, iter);
 
 	for (i = 0; i < PT64_ENT_PER_PAGE; i++) {