Messages in this thread | | | Subject | Re: [PATCH 07/11] KVM: page track: add notifier support | From | Xiao Guangrong <> | Date | Wed, 16 Dec 2015 14:26:52 +0800 |
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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.
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