[PATCH v2 2/2] drm/i915/kvmgt: Add kvmgt debugfs entry nr_cache_entries under vgpu

[changbin.du at intel.com]

From: Changbin Du <changbin.du at intel.com>

This patch add kvmgt folder under vgpu debugfs path and a new entry
nr_cache_entries which shows the number of entry in dma cache.

$ cat /sys/kernel/debug/gvt/vgpu1/kvmgt/nr_cache_entries
10101

Signed-off-by: Changbin Du <changbin.du at intel.com>
---
 drivers/gpu/drm/i915/gvt/gvt.h   |  1 +
 drivers/gpu/drm/i915/gvt/kvmgt.c | 22 ++++++++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/drivers/gpu/drm/i915/gvt/gvt.h b/drivers/gpu/drm/i915/gvt/gvt.h
index 45209da..910f2a3 100644
--- a/drivers/gpu/drm/i915/gvt/gvt.h
+++ b/drivers/gpu/drm/i915/gvt/gvt.h
@@ -210,6 +210,7 @@ struct intel_vgpu {
 		 */
 		struct rb_root gfn_cache;
 		struct rb_root dma_addr_cache;
+		unsigned long nr_cache_entries;
 		struct mutex cache_lock;
 
 		struct notifier_block iommu_notifier;
diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index e3629de..27752e3 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -84,6 +84,7 @@ struct kvmgt_guest_info {
 #define NR_BKT (1 << 18)
 	struct hlist_head ptable[NR_BKT];
 #undef NR_BKT
+	struct dentry *debugfs;
 };
 
 struct gvt_dma {
@@ -225,6 +226,8 @@ static void __gvt_cache_add(struct intel_vgpu *vgpu, gfn_t gfn,
 	}
 	rb_link_node(&new->dma_addr_node, parent, link);
 	rb_insert_color(&new->dma_addr_node, &vgpu->vdev.dma_addr_cache);
+
+	vgpu->vdev.nr_cache_entries++;
 }
 
 static void __gvt_cache_remove_entry(struct intel_vgpu *vgpu,
@@ -233,6 +236,7 @@ static void __gvt_cache_remove_entry(struct intel_vgpu *vgpu,
 	rb_erase(&entry->gfn_node, &vgpu->vdev.gfn_cache);
 	rb_erase(&entry->dma_addr_node, &vgpu->vdev.dma_addr_cache);
 	kfree(entry);
+	vgpu->vdev.nr_cache_entries--;
 }
 
 static void gvt_cache_destroy(struct intel_vgpu *vgpu)
@@ -258,6 +262,7 @@ static void gvt_cache_init(struct intel_vgpu *vgpu)
 {
 	vgpu->vdev.gfn_cache = RB_ROOT;
 	vgpu->vdev.dma_addr_cache = RB_ROOT;
+	vgpu->vdev.nr_cache_entries = 0;
 	mutex_init(&vgpu->vdev.cache_lock);
 }
 
@@ -1452,6 +1457,20 @@ static bool __kvmgt_vgpu_exist(struct intel_vgpu *vgpu, struct kvm *kvm)
 	return ret;
 }
 
+static void kvmgt_guest_debugfs_init(struct kvmgt_guest_info *info)
+{
+	struct intel_vgpu *vgpu = info->vgpu;
+
+	info->debugfs = debugfs_create_dir("kvmgt", vgpu->debugfs);
+	if (!info->debugfs) {
+		gvt_vgpu_err("Cannot create kvmgt debugfs dir\n");
+		return;
+	}
+
+	debugfs_create_ulong("nr_cache_entries", 0444, info->debugfs,
+			     &vgpu->vdev.nr_cache_entries);
+}
+
 static int kvmgt_guest_init(struct mdev_device *mdev)
 {
 	struct kvmgt_guest_info *info;
@@ -1490,11 +1509,14 @@ static int kvmgt_guest_init(struct mdev_device *mdev)
 	info->track_node.track_flush_slot = kvmgt_page_track_flush_slot;
 	kvm_page_track_register_notifier(kvm, &info->track_node);
 
+	kvmgt_guest_debugfs_init(info);
+
 	return 0;
 }
 
 static bool kvmgt_guest_exit(struct kvmgt_guest_info *info)
 {
+	debugfs_remove_recursive(info->debugfs);
 	kvm_page_track_unregister_notifier(info->kvm, &info->track_node);
 	kvm_put_kvm(info->kvm);
 	kvmgt_protect_table_destroy(info);
-- 
2.7.4