diff options
| author | Ben Gardon <bgardon@google.com> | 2020-10-27 10:59:44 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-11-19 10:57:16 -0500 |
| commit | b9a98c3437e353b269ebf3567acc5c3dc757c7a5 (patch) | |
| tree | 9e831cd0d246bff6c042d9adb8ff48865e195b1c | |
| parent | 33dd3574f5fef57c2c6caccf98925d63aa2a8d09 (diff) | |
kvm: x86/mmu: Add TDP MMU SPTE changed trace point
Add an extremely verbose trace point to the TDP MMU to log all SPTE
changes, regardless of callstack / motivation. This is useful when a
complete picture of the paging structure is needed or a change cannot be
explained with the other, existing trace points.
Tested: ran the demand paging selftest on an Intel Skylake machine with
all the trace points used by the TDP MMU enabled and observed
them firing with expected values.
This patch can be viewed in Gerrit at:
https://linux-review.googlesource.com/c/virt/kvm/kvm/+/3813
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20201027175944.1183301-2-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/mmu/mmutrace.h | 29 | ||||
| -rw-r--r-- | arch/x86/kvm/mmu/tdp_mmu.c | 2 |
2 files changed, 31 insertions, 0 deletions
diff --git a/arch/x86/kvm/mmu/mmutrace.h b/arch/x86/kvm/mmu/mmutrace.h index 213699b27b44..e798489b56b5 100644 --- a/arch/x86/kvm/mmu/mmutrace.h +++ b/arch/x86/kvm/mmu/mmutrace.h @@ -381,6 +381,35 @@ TRACE_EVENT( ) ); +TRACE_EVENT( + kvm_tdp_mmu_spte_changed, + TP_PROTO(int as_id, gfn_t gfn, int level, u64 old_spte, u64 new_spte), + TP_ARGS(as_id, gfn, level, old_spte, new_spte), + + TP_STRUCT__entry( + __field(u64, gfn) + __field(u64, old_spte) + __field(u64, new_spte) + /* Level cannot be larger than 5 on x86, so it fits in a u8. */ + __field(u8, level) + /* as_id can only be 0 or 1 x86, so it fits in a u8. */ + __field(u8, as_id) + ), + + TP_fast_assign( + __entry->gfn = gfn; + __entry->old_spte = old_spte; + __entry->new_spte = new_spte; + __entry->level = level; + __entry->as_id = as_id; + ), + + TP_printk("as id %d gfn %llx level %d old_spte %llx new_spte %llx", + __entry->as_id, __entry->gfn, __entry->level, + __entry->old_spte, __entry->new_spte + ) +); + #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 d6354f379554..75db27fda8f3 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -248,6 +248,8 @@ static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn, if (old_spte == new_spte) return; + trace_kvm_tdp_mmu_spte_changed(as_id, gfn, level, old_spte, new_spte); + /* * The only times a SPTE should be changed from a non-present to * non-present state is when an MMIO entry is installed/modified/ |