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.x...@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 majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html