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@xxxxxxxxxxxxxxx> --- 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@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
