Reviewed-by: Yan Zhao <[email protected]>
On Fri, May 12, 2023 at 05:35:53PM -0700, 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. > > Provide a stub for "struct kvm_page_track_notifier_node" so that including > headers directly from the command line, e.g. for testing include guards, > doesn't fail due to a struct having an incomplete type. > > Signed-off-by: Sean Christopherson <[email protected]> > --- > arch/x86/include/asm/kvm_host.h | 2 ++ > arch/x86/include/asm/kvm_page_track.h | 22 +++++++++++++------- > arch/x86/kvm/mmu/page_track.c | 10 ++++----- > arch/x86/kvm/mmu/page_track.h | 29 +++++++++++++++++++++++---- > 4 files changed, 47 insertions(+), 16 deletions(-) > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index 113598d3e886..5ce06a75d3de 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -1247,7 +1247,9 @@ 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 76c0070dfe2a..61adb07b5927 100644 > --- a/arch/x86/include/asm/kvm_page_track.h > +++ b/arch/x86/include/asm/kvm_page_track.h > @@ -9,6 +9,14 @@ enum kvm_page_track_mode { > KVM_PAGE_TRACK_MAX, > }; > > +void kvm_slot_page_track_add_page(struct kvm *kvm, > + struct kvm_memory_slot *slot, gfn_t gfn, > + enum kvm_page_track_mode mode); > +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 > /* > * The notifier represented by @kvm_page_track_notifier_node is linked into > * the head which will be notified when guest is triggering the track event. > @@ -48,18 +56,18 @@ struct kvm_page_track_notifier_node { > struct kvm_page_track_notifier_node *node); > }; > > -void kvm_slot_page_track_add_page(struct kvm *kvm, > - struct kvm_memory_slot *slot, gfn_t gfn, > - enum kvm_page_track_mode mode); > -void kvm_slot_page_track_remove_page(struct kvm *kvm, > - struct kvm_memory_slot *slot, gfn_t gfn, > - enum kvm_page_track_mode mode); > - > void > kvm_page_track_register_notifier(struct kvm *kvm, > struct kvm_page_track_notifier_node *n); > void > kvm_page_track_unregister_notifier(struct kvm *kvm, > struct kvm_page_track_notifier_node *n); > +#else > +/* > + * Allow defining a node in a structure even if page tracking is disabled, > e.g. > + * to play nice with testing headers via direct inclusion from the command > line. > + */ > +struct kvm_page_track_notifier_node {}; > +#endif /* CONFIG_KVM_EXTERNAL_WRITE_TRACKING */ > > #endif > diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c > index e15329d48f95..b20aad7ac3fe 100644 > --- a/arch/x86/kvm/mmu/page_track.c > +++ b/arch/x86/kvm/mmu/page_track.c > @@ -194,6 +194,7 @@ bool kvm_slot_page_track_is_active(struct kvm *kvm, > return !!READ_ONCE(slot->arch.gfn_track[mode][index]); > } > > +#ifdef CONFIG_KVM_EXTERNAL_WRITE_TRACKING > void kvm_page_track_cleanup(struct kvm *kvm) > { > struct kvm_page_track_notifier_head *head; > @@ -255,14 +256,13 @@ EXPORT_SYMBOL_GPL(kvm_page_track_unregister_notifier); > * The node should figure out if the written page is the one that node is > * interested in by itself. > */ > -void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new, > - int bytes) > +void __kvm_page_track_write(struct kvm *kvm, gpa_t gpa, const u8 *new, int > bytes) > { > struct kvm_page_track_notifier_head *head; > struct kvm_page_track_notifier_node *n; > int idx; > > - head = &vcpu->kvm->arch.track_notifier_head; > + head = &kvm->arch.track_notifier_head; > > if (hlist_empty(&head->track_notifier_list)) > return; > @@ -273,8 +273,6 @@ void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t > gpa, const u8 *new, > if (n->track_write) > n->track_write(gpa, new, bytes, n); > srcu_read_unlock(&head->track_srcu, idx); > - > - kvm_mmu_track_write(vcpu, gpa, new, bytes); > } > > /* > @@ -299,3 +297,5 @@ void kvm_page_track_delete_slot(struct kvm *kvm, struct > kvm_memory_slot *slot) > n->track_remove_region(slot->base_gfn, slot->npages, n); > srcu_read_unlock(&head->track_srcu, idx); > } > + > +#endif > diff --git a/arch/x86/kvm/mmu/page_track.h b/arch/x86/kvm/mmu/page_track.h > index 89712f123ad3..931b26b8fc8f 100644 > --- a/arch/x86/kvm/mmu/page_track.h > +++ b/arch/x86/kvm/mmu/page_track.h > @@ -6,8 +6,6 @@ > > #include <asm/kvm_page_track.h> > > -int kvm_page_track_init(struct kvm *kvm); > -void kvm_page_track_cleanup(struct kvm *kvm); > > bool kvm_page_track_write_tracking_enabled(struct kvm *kvm); > int kvm_page_track_write_tracking_alloc(struct kvm_memory_slot *slot); > @@ -21,13 +19,36 @@ bool kvm_slot_page_track_is_active(struct kvm *kvm, > const struct kvm_memory_slot *slot, > gfn_t gfn, enum kvm_page_track_mode mode); > > -void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new, > - int bytes); > +#ifdef CONFIG_KVM_EXTERNAL_WRITE_TRACKING > +int kvm_page_track_init(struct kvm *kvm); > +void kvm_page_track_cleanup(struct kvm *kvm); > + > +void __kvm_page_track_write(struct kvm *kvm, gpa_t gpa, const u8 *new, int > bytes); > void kvm_page_track_delete_slot(struct kvm *kvm, struct kvm_memory_slot > *slot); > > static inline bool kvm_page_track_has_external_user(struct kvm *kvm) > { > return hlist_empty(&kvm->arch.track_notifier_head.track_notifier_list); > } > +#else > +static inline int kvm_page_track_init(struct kvm *kvm) { return 0; } > +static inline void kvm_page_track_cleanup(struct kvm *kvm) { } > + > +static inline void __kvm_page_track_write(struct kvm *kvm, gpa_t gpa, > + const u8 *new, int bytes) { } > +static inline void kvm_page_track_delete_slot(struct kvm *kvm, > + struct kvm_memory_slot *slot) { } > + > +static inline bool kvm_page_track_has_external_user(struct kvm *kvm) { > return false; } > + > +#endif /* CONFIG_KVM_EXTERNAL_WRITE_TRACKING */ > + > +static inline void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, > + const u8 *new, int bytes) > +{ > + __kvm_page_track_write(vcpu->kvm, gpa, new, bytes); > + > + kvm_mmu_track_write(vcpu, gpa, new, bytes); > +} > > #endif /* __KVM_X86_PAGE_TRACK_H */ > -- > 2.40.1.606.ga4b1b128d6-goog >
