On Fri, Mar 10, 2023 at 04:22:51PM -0800, Sean Christopherson wrote: > Disable the page-track notifier code at compile time if there are no > external users, i.e. if CONFIG_KVM_EXTERNAL_WRITE_TRACKING=n. KVM itself > now hooks emulated writes directly instead of relying on the page-track > mechanism. > > Signed-off-by: Sean Christopherson <sea...@google.com> > --- > arch/x86/include/asm/kvm_host.h | 2 ++ > arch/x86/include/asm/kvm_page_track.h | 2 ++ > arch/x86/kvm/mmu/page_track.c | 9 ++++----- > arch/x86/kvm/mmu/page_track.h | 29 +++++++++++++++++++++++---- > 4 files changed, 33 insertions(+), 9 deletions(-) > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index 1a4225237564..a3423711e403 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -1265,7 +1265,9 @@ struct kvm_arch { > * create an NX huge page (without hanging the guest). > */ > struct list_head possible_nx_huge_pages; > +#ifdef CONFIG_KVM_EXTERNAL_WRITE_TRACKING > struct kvm_page_track_notifier_head track_notifier_head; > +#endif > /* > * Protects marking pages unsync during page faults, as TDP MMU page > * faults only take mmu_lock for read. For simplicity, the unsync > diff --git a/arch/x86/include/asm/kvm_page_track.h > b/arch/x86/include/asm/kvm_page_track.h > index deece45936a5..53c2adb25a07 100644 > --- a/arch/x86/include/asm/kvm_page_track.h > +++ b/arch/x86/include/asm/kvm_page_track.h The "#ifdef CONFIG_KVM_EXTERNAL_WRITE_TRACKING" can be moved to the front of this file? All the structures are only exposed for external users now.
> @@ -55,6 +55,7 @@ void kvm_slot_page_track_remove_page(struct kvm *kvm, > struct kvm_memory_slot *slot, gfn_t gfn, > enum kvm_page_track_mode mode); > > +#ifdef CONFIG_KVM_EXTERNAL_WRITE_TRACKING > enum pg_level kvm_page_track_max_mapping_level(struct kvm *kvm, gfn_t gfn, > enum pg_level max_level); > > @@ -64,5 +65,6 @@ kvm_page_track_register_notifier(struct kvm *kvm, > void > kvm_page_track_unregister_notifier(struct kvm *kvm, > struct kvm_page_track_notifier_node *n); > +#endif /* CONFIG_KVM_EXTERNAL_WRITE_TRACKING */ > > #endif