drm/i915/gvt: switch from ->track_flush_slot() to ->track_remove_region()

Switch from the poorly named and flawed ->track_flush_slot() to the newly
introduced ->track_remove_region().  From KVMGT's perspective, the two
hooks are functionally equivalent, the only difference being that
->track_remove_region() is called only when KVM is 100% certain the
memory region will be removed, i.e. is invoked slightly later in KVM's
memslot modification flow.

Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
[sean: handle name change, massage changelog, rebase]
Tested-by: Yan Zhao <yan.y.zhao@intel.com>
Tested-by: Yongwei Ma <yongwei.ma@intel.com>
Reviewed-by: Zhi Wang <zhi.a.wang@intel.com>
Link: https://lore.kernel.org/r/20230729013535.1070024-20-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Author: yanzhao56

drivers/gpu/drm/i915/gvt/kvmgt.c

@@ -108,9 +108,8 @@ struct gvt_dma {
 
 static void kvmgt_page_track_write(gpa_t gpa, const u8 *val, int len,
 				   struct kvm_page_track_notifier_node *node);
-static void kvmgt_page_track_flush_slot(struct kvm *kvm,
-		struct kvm_memory_slot *slot,
-		struct kvm_page_track_notifier_node *node);
+static void kvmgt_page_track_remove_region(gfn_t gfn, unsigned long nr_pages,
+					   struct kvm_page_track_notifier_node *node);
 
 static ssize_t intel_vgpu_show_description(struct mdev_type *mtype, char *buf)
 {
@@ -666,7 +665,7 @@ static int intel_vgpu_open_device(struct vfio_device *vfio_dev)
 		return -EEXIST;
 
 	vgpu->track_node.track_write = kvmgt_page_track_write;
-	vgpu->track_node.track_flush_slot = kvmgt_page_track_flush_slot;
+	vgpu->track_node.track_remove_region = kvmgt_page_track_remove_region;
 	kvm_get_kvm(vgpu->vfio_device.kvm);
 	kvm_page_track_register_notifier(vgpu->vfio_device.kvm,
 					 &vgpu->track_node);
@@ -1617,22 +1616,20 @@ static void kvmgt_page_track_write(gpa_t gpa, const u8 *val, int len,
 	mutex_unlock(&info->vgpu_lock);
 }
 
-static void kvmgt_page_track_flush_slot(struct kvm *kvm,
-		struct kvm_memory_slot *slot,
-		struct kvm_page_track_notifier_node *node)
+static void kvmgt_page_track_remove_region(gfn_t gfn, unsigned long nr_pages,
+					   struct kvm_page_track_notifier_node *node)
 {
 	unsigned long i;
-	gfn_t gfn;
 	struct intel_vgpu *info =
 		container_of(node, struct intel_vgpu, track_node);
 
 	mutex_lock(&info->vgpu_lock);
 
-	for (i = 0; i < slot->npages; i++) {
-		gfn = slot->base_gfn + i;
-		if (kvmgt_gfn_is_write_protected(info, gfn))
-			kvmgt_protect_table_del(info, gfn);
+	for (i = 0; i < nr_pages; i++) {
+		if (kvmgt_gfn_is_write_protected(info, gfn + i))
+			kvmgt_protect_table_del(info, gfn + i);
 	}
+
 	mutex_unlock(&info->vgpu_lock);
 }