| Message ID | 1448907973-36066-8-git-send-email-guangrong.xiao@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 12/01/2015 02:26 AM, Xiao Guangrong wrote: > Notifier list is introduced so that any node wants to receive the track > event can register to the list > > Two APIs are introduced here: > - kvm_page_track_register_notifier(): register the notifier to receive > track event > > - kvm_page_track_unregister_notifier(): stop receiving track event by > unregister the notifier > > The callback, node->track_write() is called when a write access on the > write tracked page happens > > Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com> > --- > arch/x86/include/asm/kvm_host.h | 1 + > arch/x86/include/asm/kvm_page_track.h | 39 ++++++++++++++++++++ > arch/x86/kvm/page_track.c | 67 +++++++++++++++++++++++++++++++++++ > arch/x86/kvm/x86.c | 4 +++ > 4 files changed, 111 insertions(+) > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index afff1f1..0f7b940 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -658,6 +658,7 @@ struct kvm_arch { > */ > struct list_head active_mmu_pages; > struct list_head zapped_obsolete_pages; > + struct kvm_page_track_notifier_head track_notifier_head; > > struct list_head assigned_dev_head; > struct iommu_domain *iommu_domain; > diff --git a/arch/x86/include/asm/kvm_page_track.h b/arch/x86/include/asm/kvm_page_track.h > index f223201..6744234 100644 > --- a/arch/x86/include/asm/kvm_page_track.h > +++ b/arch/x86/include/asm/kvm_page_track.h > @@ -6,6 +6,36 @@ enum kvm_page_track_mode { > KVM_PAGE_TRACK_MAX, > }; > > +/* > + * 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. > + * > + * Write access on the head is protected by kvm->mmu_lock, read access > + * is protected by track_srcu. > + */ > +struct kvm_page_track_notifier_head { > + struct srcu_struct track_srcu; > + struct hlist_head track_notifier_list; > +}; > + > +struct kvm_page_track_notifier_node { > + struct hlist_node node; > + > + /* > + * It is called when guest is writing the write-tracked page > + * and write emulation is finished at that time. > + * > + * @vcpu: the vcpu where the write access happened. > + * @gpa: the physical address written by guest. > + * @new: the data was written to the address. > + * @bytes: the written length. > + */ > + void (*track_write)(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new, > + int bytes); Sir, is it possible to make this non-void? as you described below, the callback may find this gpa isn't the page being tracked, so it probably want to return something to indicate: not my business, continue :) > +}; > + > +void kvm_page_track_init(struct kvm *kvm); > + > int kvm_page_track_create_memslot(struct kvm_memory_slot *slot, > unsigned long npages); > void kvm_page_track_free_memslot(struct kvm_memory_slot *free, > @@ -17,4 +47,13 @@ void kvm_page_track_remove_page(struct kvm *kvm, gfn_t gfn, > enum kvm_page_track_mode mode); > bool kvm_page_track_check_mode(struct kvm_vcpu *vcpu, 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); > +void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new, > + int bytes); > #endif > diff --git a/arch/x86/kvm/page_track.c b/arch/x86/kvm/page_track.c > index dc2da12..84420df 100644 > --- a/arch/x86/kvm/page_track.c > +++ b/arch/x86/kvm/page_track.c > @@ -165,3 +165,70 @@ bool kvm_page_track_check_mode(struct kvm_vcpu *vcpu, gfn_t gfn, > > return !!ACCESS_ONCE(slot->arch.gfn_track[mode][index]); > } > + > +void kvm_page_track_init(struct kvm *kvm) > +{ > + struct kvm_page_track_notifier_head *head; > + > + head = &kvm->arch.track_notifier_head; > + init_srcu_struct(&head->track_srcu); > + INIT_HLIST_HEAD(&head->track_notifier_list); > +} > + > +/* > + * register the notifier so that event interception for the tracked guest > + * pages can be received. > + */ > +void > +kvm_page_track_register_notifier(struct kvm *kvm, > + struct kvm_page_track_notifier_node *n) > +{ > + struct kvm_page_track_notifier_head *head; > + > + head = &kvm->arch.track_notifier_head; > + > + spin_lock(&kvm->mmu_lock); > + hlist_add_head_rcu(&n->node, &head->track_notifier_list); > + spin_unlock(&kvm->mmu_lock); > +} > + > +/* > + * stop receiving the event interception. It is the opposed operation of > + * kvm_page_track_register_notifier(). > + */ > +void > +kvm_page_track_unregister_notifier(struct kvm *kvm, > + struct kvm_page_track_notifier_node *n) > +{ > + struct kvm_page_track_notifier_head *head; > + > + head = &kvm->arch.track_notifier_head; > + > + spin_lock(&kvm->mmu_lock); > + hlist_del_rcu(&n->node); > + spin_unlock(&kvm->mmu_lock); > + synchronize_srcu(&head->track_srcu); > +} > + > +/* > + * Notify the node that write access is intercepted and write emulation is > + * finished at this time. > + * > + * 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) > +{ > + struct kvm_page_track_notifier_head *head; > + struct kvm_page_track_notifier_node *n; > + int idx; > + > + head = &vcpu->kvm->arch.track_notifier_head; > + > + idx = srcu_read_lock(&head->track_srcu); > + hlist_for_each_entry_rcu(n, &head->track_notifier_list, node) > + if (n->track_write) > + n->track_write(vcpu, gpa, new, bytes); > + srcu_read_unlock(&head->track_srcu, idx); > +} > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index ad4888a..64dbc69 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -4328,6 +4328,7 @@ int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa, > if (ret < 0) > return 0; > kvm_mmu_pte_write(vcpu, gpa, val, bytes); > + kvm_page_track_write(vcpu, gpa, val, bytes); > return 1; > } > > @@ -4586,6 +4587,7 @@ static int emulator_cmpxchg_emulated(struct x86_emulate_ctxt *ctxt, > > kvm_vcpu_mark_page_dirty(vcpu, gpa >> PAGE_SHIFT); > kvm_mmu_pte_write(vcpu, gpa, new, bytes); > + kvm_page_track_write(vcpu, gpa, new, bytes); > > return X86EMUL_CONTINUE; > > @@ -7691,6 +7693,8 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) > INIT_DELAYED_WORK(&kvm->arch.kvmclock_update_work, kvmclock_update_fn); > INIT_DELAYED_WORK(&kvm->arch.kvmclock_sync_work, kvmclock_sync_fn); > > + kvm_page_track_init(kvm); > + > return 0; > } > > -- Thanks, Jike -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 12/16/2015 01:53 PM, Jike Song wrote: > On 12/01/2015 02:26 AM, Xiao Guangrong wrote: >> Notifier list is introduced so that any node wants to receive the track >> event can register to the list >> >> Two APIs are introduced here: >> - kvm_page_track_register_notifier(): register the notifier to receive >> track event >> >> - kvm_page_track_unregister_notifier(): stop receiving track event by >> unregister the notifier >> >> The callback, node->track_write() is called when a write access on the >> write tracked page happens >> >> Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com> >> --- >> arch/x86/include/asm/kvm_host.h | 1 + >> arch/x86/include/asm/kvm_page_track.h | 39 ++++++++++++++++++++ >> arch/x86/kvm/page_track.c | 67 +++++++++++++++++++++++++++++++++++ >> arch/x86/kvm/x86.c | 4 +++ >> 4 files changed, 111 insertions(+) >> >> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h >> index afff1f1..0f7b940 100644 >> --- a/arch/x86/include/asm/kvm_host.h >> +++ b/arch/x86/include/asm/kvm_host.h >> @@ -658,6 +658,7 @@ struct kvm_arch { >> */ >> struct list_head active_mmu_pages; >> struct list_head zapped_obsolete_pages; >> + struct kvm_page_track_notifier_head track_notifier_head; >> >> struct list_head assigned_dev_head; >> struct iommu_domain *iommu_domain; >> diff --git a/arch/x86/include/asm/kvm_page_track.h b/arch/x86/include/asm/kvm_page_track.h >> index f223201..6744234 100644 >> --- a/arch/x86/include/asm/kvm_page_track.h >> +++ b/arch/x86/include/asm/kvm_page_track.h >> @@ -6,6 +6,36 @@ enum kvm_page_track_mode { >> KVM_PAGE_TRACK_MAX, >> }; >> >> +/* >> + * 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. >> + * >> + * Write access on the head is protected by kvm->mmu_lock, read access >> + * is protected by track_srcu. >> + */ >> +struct kvm_page_track_notifier_head { >> + struct srcu_struct track_srcu; >> + struct hlist_head track_notifier_list; >> +}; >> + >> +struct kvm_page_track_notifier_node { >> + struct hlist_node node; >> + >> + /* >> + * It is called when guest is writing the write-tracked page >> + * and write emulation is finished at that time. >> + * >> + * @vcpu: the vcpu where the write access happened. >> + * @gpa: the physical address written by guest. >> + * @new: the data was written to the address. >> + * @bytes: the written length. >> + */ >> + void (*track_write)(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new, >> + int bytes); > > Sir, is it possible to make this non-void? as you described below, the > callback may find this gpa isn't the page being tracked, so it probably > want to return something to indicate: not my business, continue :) Currently the return value is useless and it is not ABI so we can extend it if it is needed in the future. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index afff1f1..0f7b940 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -658,6 +658,7 @@ struct kvm_arch { */ struct list_head active_mmu_pages; struct list_head zapped_obsolete_pages; + struct kvm_page_track_notifier_head track_notifier_head; struct list_head assigned_dev_head; struct iommu_domain *iommu_domain; diff --git a/arch/x86/include/asm/kvm_page_track.h b/arch/x86/include/asm/kvm_page_track.h index f223201..6744234 100644 --- a/arch/x86/include/asm/kvm_page_track.h +++ b/arch/x86/include/asm/kvm_page_track.h @@ -6,6 +6,36 @@ enum kvm_page_track_mode { KVM_PAGE_TRACK_MAX, }; +/* + * 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. + * + * Write access on the head is protected by kvm->mmu_lock, read access + * is protected by track_srcu. + */ +struct kvm_page_track_notifier_head { + struct srcu_struct track_srcu; + struct hlist_head track_notifier_list; +}; + +struct kvm_page_track_notifier_node { + struct hlist_node node; + + /* + * It is called when guest is writing the write-tracked page + * and write emulation is finished at that time. + * + * @vcpu: the vcpu where the write access happened. + * @gpa: the physical address written by guest. + * @new: the data was written to the address. + * @bytes: the written length. + */ + void (*track_write)(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new, + int bytes); +}; + +void kvm_page_track_init(struct kvm *kvm); + int kvm_page_track_create_memslot(struct kvm_memory_slot *slot, unsigned long npages); void kvm_page_track_free_memslot(struct kvm_memory_slot *free, @@ -17,4 +47,13 @@ void kvm_page_track_remove_page(struct kvm *kvm, gfn_t gfn, enum kvm_page_track_mode mode); bool kvm_page_track_check_mode(struct kvm_vcpu *vcpu, 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); +void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new, + int bytes); #endif diff --git a/arch/x86/kvm/page_track.c b/arch/x86/kvm/page_track.c index dc2da12..84420df 100644 --- a/arch/x86/kvm/page_track.c +++ b/arch/x86/kvm/page_track.c @@ -165,3 +165,70 @@ bool kvm_page_track_check_mode(struct kvm_vcpu *vcpu, gfn_t gfn, return !!ACCESS_ONCE(slot->arch.gfn_track[mode][index]); } + +void kvm_page_track_init(struct kvm *kvm) +{ + struct kvm_page_track_notifier_head *head; + + head = &kvm->arch.track_notifier_head; + init_srcu_struct(&head->track_srcu); + INIT_HLIST_HEAD(&head->track_notifier_list); +} + +/* + * register the notifier so that event interception for the tracked guest + * pages can be received. + */ +void +kvm_page_track_register_notifier(struct kvm *kvm, + struct kvm_page_track_notifier_node *n) +{ + struct kvm_page_track_notifier_head *head; + + head = &kvm->arch.track_notifier_head; + + spin_lock(&kvm->mmu_lock); + hlist_add_head_rcu(&n->node, &head->track_notifier_list); + spin_unlock(&kvm->mmu_lock); +} + +/* + * stop receiving the event interception. It is the opposed operation of + * kvm_page_track_register_notifier(). + */ +void +kvm_page_track_unregister_notifier(struct kvm *kvm, + struct kvm_page_track_notifier_node *n) +{ + struct kvm_page_track_notifier_head *head; + + head = &kvm->arch.track_notifier_head; + + spin_lock(&kvm->mmu_lock); + hlist_del_rcu(&n->node); + spin_unlock(&kvm->mmu_lock); + synchronize_srcu(&head->track_srcu); +} + +/* + * Notify the node that write access is intercepted and write emulation is + * finished at this time. + * + * 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) +{ + struct kvm_page_track_notifier_head *head; + struct kvm_page_track_notifier_node *n; + int idx; + + head = &vcpu->kvm->arch.track_notifier_head; + + idx = srcu_read_lock(&head->track_srcu); + hlist_for_each_entry_rcu(n, &head->track_notifier_list, node) + if (n->track_write) + n->track_write(vcpu, gpa, new, bytes); + srcu_read_unlock(&head->track_srcu, idx); +} diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index ad4888a..64dbc69 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4328,6 +4328,7 @@ int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa, if (ret < 0) return 0; kvm_mmu_pte_write(vcpu, gpa, val, bytes); + kvm_page_track_write(vcpu, gpa, val, bytes); return 1; } @@ -4586,6 +4587,7 @@ static int emulator_cmpxchg_emulated(struct x86_emulate_ctxt *ctxt, kvm_vcpu_mark_page_dirty(vcpu, gpa >> PAGE_SHIFT); kvm_mmu_pte_write(vcpu, gpa, new, bytes); + kvm_page_track_write(vcpu, gpa, new, bytes); return X86EMUL_CONTINUE; @@ -7691,6 +7693,8 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) INIT_DELAYED_WORK(&kvm->arch.kvmclock_update_work, kvmclock_update_fn); INIT_DELAYED_WORK(&kvm->arch.kvmclock_sync_work, kvmclock_sync_fn); + kvm_page_track_init(kvm); + return 0; }
Notifier list is introduced so that any node wants to receive the track event can register to the list Two APIs are introduced here: - kvm_page_track_register_notifier(): register the notifier to receive track event - kvm_page_track_unregister_notifier(): stop receiving track event by unregister the notifier The callback, node->track_write() is called when a write access on the write tracked page happens Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com> --- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/include/asm/kvm_page_track.h | 39 ++++++++++++++++++++ arch/x86/kvm/page_track.c | 67 +++++++++++++++++++++++++++++++++++ arch/x86/kvm/x86.c | 4 +++ 4 files changed, 111 insertions(+)