Re: [PATCH 07/11] KVM: page track: add notifier support
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 --- 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 majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 07/11] KVM: page track: add notifier support
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 --- 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; +
[PATCH 07/11] KVM: page track: add notifier support
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 --- 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); +}; + +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