From: David Matlack Date: Tue, 13 Jul 2021 22:09:53 +0000 Subject: KVM: x86/mmu: Fix use of enums in trace_fast_page_fault Git-commit: 61bcd360aa9851cec969b7b40f23fd1faa7f85a4 Patch-mainline: v5.15-rc1 References: bsc#1194638 Enum values have to be exported to userspace since the formatting is not done in the kernel. Without doing this perf maps RET_PF_FIXED and RET_PF_SPURIOUS to 0, which results in incorrect output: $ perf record -a -e kvmmmu:fast_page_fault --filter "ret==3" -- ./access_tracking_perf_test $ perf script | head -1 [...] new 610006048d25877 spurious 0 fixed 0 <------ should be 1 Fix this by exporting the enum values to userspace with TRACE_DEFINE_ENUM. Fixes: c4371c2a682e ("KVM: x86/mmu: Return unique RET_PF_* values if the fault was fixed") Signed-off-by: David Matlack Message-Id: <20210713220957.3493520-3-dmatlack@google.com> Signed-off-by: Paolo Bonzini Acked-by: Dario Faggioli --- arch/x86/kvm/mmu/mmu_internal.h | 3 +++ arch/x86/kvm/mmu/mmutrace.h | 6 ++++++ 2 files changed, 9 insertions(+) diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h index 35567293c1fd..626cb848dab4 100644 --- a/arch/x86/kvm/mmu/mmu_internal.h +++ b/arch/x86/kvm/mmu/mmu_internal.h @@ -140,6 +140,9 @@ void kvm_flush_remote_tlbs_with_address(struct kvm *kvm, * RET_PF_INVALID: the spte is invalid, let the real page fault path update it. * RET_PF_FIXED: The faulting entry has been fixed. * RET_PF_SPURIOUS: The faulting entry was already fixed, e.g. by another vCPU. + * + * Any names added to this enum should be exported to userspace for use in + * tracepoints via TRACE_DEFINE_ENUM() in mmutrace.h */ enum { RET_PF_RETRY = 0, diff --git a/arch/x86/kvm/mmu/mmutrace.h b/arch/x86/kvm/mmu/mmutrace.h index efbad33a0645..2924a4081a19 100644 --- a/arch/x86/kvm/mmu/mmutrace.h +++ b/arch/x86/kvm/mmu/mmutrace.h @@ -54,6 +54,12 @@ { PFERR_RSVD_MASK, "RSVD" }, \ { PFERR_FETCH_MASK, "F" } +TRACE_DEFINE_ENUM(RET_PF_RETRY); +TRACE_DEFINE_ENUM(RET_PF_EMULATE); +TRACE_DEFINE_ENUM(RET_PF_INVALID); +TRACE_DEFINE_ENUM(RET_PF_FIXED); +TRACE_DEFINE_ENUM(RET_PF_SPURIOUS); + /* * A pagetable walk has started */