drm/i915/gvt: Factor intel_vgpu_page_track

As the data structure of "intel_vgpu_guest_page" will become much heavier
in future, it's better to factor out the guest memory page track mechnisim
as early as possible.
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>

drivers/gpu/drm/i915/gvt/gtt.h

@@ -193,18 +193,16 @@ struct intel_vgpu_scratch_pt {
 	unsigned long page_mfn;
 };
 
-
 struct intel_vgpu_gtt {
 	struct intel_vgpu_mm *ggtt_mm;
 	unsigned long active_ppgtt_mm_bitmap;
 	struct list_head mm_list_head;
 	DECLARE_HASHTABLE(shadow_page_hash_table, INTEL_GVT_GTT_HASH_BITS);
-	DECLARE_HASHTABLE(guest_page_hash_table, INTEL_GVT_GTT_HASH_BITS);
-	atomic_t n_write_protected_guest_page;
+	DECLARE_HASHTABLE(tracked_guest_page_hash_table, INTEL_GVT_GTT_HASH_BITS);
+	atomic_t n_tracked_guest_page;
 	struct list_head oos_page_list_head;
 	struct list_head post_shadow_list_head;
 	struct intel_vgpu_scratch_pt scratch_pt[GTT_TYPE_MAX];
-
 };
 
 extern int intel_vgpu_init_gtt(struct intel_vgpu *vgpu);
@@ -228,12 +226,16 @@ struct intel_vgpu_shadow_page {
 	unsigned long mfn;
 };
 
-struct intel_vgpu_guest_page {
+struct intel_vgpu_page_track {
 	struct hlist_node node;
-	bool writeprotection;
+	bool tracked;
 	unsigned long gfn;
 	int (*handler)(void *, u64, void *, int);
 	void *data;
+};
+
+struct intel_vgpu_guest_page {
+	struct intel_vgpu_page_track track;
 	unsigned long write_cnt;
 	struct intel_vgpu_oos_page *oos_page;
 };
@@ -258,22 +260,16 @@ struct intel_vgpu_ppgtt_spt {
 	struct list_head post_shadow_list;
 };
 
-int intel_vgpu_init_guest_page(struct intel_vgpu *vgpu,
-		struct intel_vgpu_guest_page *guest_page,
+int intel_vgpu_init_page_track(struct intel_vgpu *vgpu,
+		struct intel_vgpu_page_track *t,
 		unsigned long gfn,
 		int (*handler)(void *gp, u64, void *, int),
 		void *data);
 
-void intel_vgpu_clean_guest_page(struct intel_vgpu *vgpu,
-		struct intel_vgpu_guest_page *guest_page);
-
-int intel_vgpu_set_guest_page_writeprotection(struct intel_vgpu *vgpu,
-		struct intel_vgpu_guest_page *guest_page);
-
-void intel_vgpu_clear_guest_page_writeprotection(struct intel_vgpu *vgpu,
-		struct intel_vgpu_guest_page *guest_page);
+void intel_vgpu_clean_page_track(struct intel_vgpu *vgpu,
+		struct intel_vgpu_page_track *t);
 
-struct intel_vgpu_guest_page *intel_vgpu_find_guest_page(
+struct intel_vgpu_page_track *intel_vgpu_find_tracked_page(
 		struct intel_vgpu *vgpu, unsigned long gfn);
 
 int intel_vgpu_sync_oos_pages(struct intel_vgpu *vgpu);

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

@@ -117,18 +117,18 @@ static void failsafe_emulate_mmio_rw(struct intel_vgpu *vgpu, uint64_t pa,
 		else
 			memcpy(pt, p_data, bytes);
 
-	} else if (atomic_read(&vgpu->gtt.n_write_protected_guest_page)) {
-		struct intel_vgpu_guest_page *gp;
+	} else if (atomic_read(&vgpu->gtt.n_tracked_guest_page)) {
+		struct intel_vgpu_page_track *t;
 
 		/* Since we enter the failsafe mode early during guest boot,
 		 * guest may not have chance to set up its ppgtt table, so
 		 * there should not be any wp pages for guest. Keep the wp
 		 * related code here in case we need to handle it in furture.
 		 */
-		gp = intel_vgpu_find_guest_page(vgpu, pa >> PAGE_SHIFT);
-		if (gp) {
+		t = intel_vgpu_find_tracked_page(vgpu, pa >> PAGE_SHIFT);
+		if (t) {
 			/* remove write protection to prevent furture traps */
-			intel_vgpu_clean_guest_page(vgpu, gp);
+			intel_vgpu_clean_page_track(vgpu, t);
 			if (read)
 				intel_gvt_hypervisor_read_gpa(vgpu, pa,
 						p_data, bytes);
@@ -170,17 +170,17 @@ int intel_vgpu_emulate_mmio_read(struct intel_vgpu *vgpu, uint64_t pa,
 		return ret;
 	}
 
-	if (atomic_read(&vgpu->gtt.n_write_protected_guest_page)) {
-		struct intel_vgpu_guest_page *gp;
+	if (atomic_read(&vgpu->gtt.n_tracked_guest_page)) {
+		struct intel_vgpu_page_track *t;
 
-		gp = intel_vgpu_find_guest_page(vgpu, pa >> PAGE_SHIFT);
-		if (gp) {
+		t = intel_vgpu_find_tracked_page(vgpu, pa >> PAGE_SHIFT);
+		if (t) {
 			ret = intel_gvt_hypervisor_read_gpa(vgpu, pa,
 					p_data, bytes);
 			if (ret) {
 				gvt_vgpu_err("guest page read error %d, "
 					"gfn 0x%lx, pa 0x%llx, var 0x%x, len %d\n",
-					ret, gp->gfn, pa, *(u32 *)p_data,
+					ret, t->gfn, pa, *(u32 *)p_data,
 					bytes);
 			}
 			mutex_unlock(&gvt->lock);
@@ -267,17 +267,17 @@ int intel_vgpu_emulate_mmio_write(struct intel_vgpu *vgpu, uint64_t pa,
 		return ret;
 	}
 
-	if (atomic_read(&vgpu->gtt.n_write_protected_guest_page)) {
-		struct intel_vgpu_guest_page *gp;
+	if (atomic_read(&vgpu->gtt.n_tracked_guest_page)) {
+		struct intel_vgpu_page_track *t;
 
-		gp = intel_vgpu_find_guest_page(vgpu, pa >> PAGE_SHIFT);
-		if (gp) {
-			ret = gp->handler(gp, pa, p_data, bytes);
+		t = intel_vgpu_find_tracked_page(vgpu, pa >> PAGE_SHIFT);
+		if (t) {
+			ret = t->handler(t, pa, p_data, bytes);
 			if (ret) {
 				gvt_err("guest page write error %d, "
 					"gfn 0x%lx, pa 0x%llx, "
 					"var 0x%x, len %d\n",
-					ret, gp->gfn, pa,
+					ret, t->gfn, pa,
 					*(u32 *)p_data, bytes);
 			}
 			mutex_unlock(&gvt->lock);

drivers/gpu/drm/i915/gvt/mpt.h

@@ -154,51 +154,53 @@ static inline unsigned long intel_gvt_hypervisor_virt_to_mfn(void *p)
 }
 
 /**
- * intel_gvt_hypervisor_set_wp_page - set a guest page to write-protected
+ * intel_gvt_hypervisor_enable - set a guest page to write-protected
  * @vgpu: a vGPU
- * @p: intel_vgpu_guest_page
+ * @t: page track data structure
  *
  * Returns:
  * Zero on success, negative error code if failed.
  */
-static inline int intel_gvt_hypervisor_set_wp_page(struct intel_vgpu *vgpu,
-		struct intel_vgpu_guest_page *p)
+static inline int intel_gvt_hypervisor_enable_page_track(
+		struct intel_vgpu *vgpu,
+		struct intel_vgpu_page_track *t)
 {
 	int ret;
 
-	if (p->writeprotection)
+	if (t->tracked)
 		return 0;
 
-	ret = intel_gvt_host.mpt->set_wp_page(vgpu->handle, p->gfn);
+	ret = intel_gvt_host.mpt->set_wp_page(vgpu->handle, t->gfn);
 	if (ret)
 		return ret;
-	p->writeprotection = true;
-	atomic_inc(&vgpu->gtt.n_write_protected_guest_page);
+	t->tracked = true;
+	atomic_inc(&vgpu->gtt.n_tracked_guest_page);
 	return 0;
 }
 
 /**
- * intel_gvt_hypervisor_unset_wp_page - remove the write-protection of a
+ * intel_gvt_hypervisor_disable_page_track - remove the write-protection of a
  * guest page
  * @vgpu: a vGPU
- * @p: intel_vgpu_guest_page
+ * @t: page track data structure
  *
  * Returns:
  * Zero on success, negative error code if failed.
  */
-static inline int intel_gvt_hypervisor_unset_wp_page(struct intel_vgpu *vgpu,
-		struct intel_vgpu_guest_page *p)
+static inline int intel_gvt_hypervisor_disable_page_track(
+		struct intel_vgpu *vgpu,
+		struct intel_vgpu_page_track *t)
 {
 	int ret;
 
-	if (!p->writeprotection)
+	if (!t->tracked)
 		return 0;
 
-	ret = intel_gvt_host.mpt->unset_wp_page(vgpu->handle, p->gfn);
+	ret = intel_gvt_host.mpt->unset_wp_page(vgpu->handle, t->gfn);
 	if (ret)
 		return ret;
-	p->writeprotection = false;
-	atomic_dec(&vgpu->gtt.n_write_protected_guest_page);
+	t->tracked = false;
+	atomic_dec(&vgpu->gtt.n_tracked_guest_page);
 	return 0;
 }