diff --git a/drivers/gpu/drm/i915/gvt/cfg_space.c b/drivers/gpu/drm/i915/gvt/cfg_space.c
index c62346fdc05d5f241bda610fa7b4ceb901b75553..19cf1bbe059d49018d13e274c8243c4203667320 100644
--- a/drivers/gpu/drm/i915/gvt/cfg_space.c
+++ b/drivers/gpu/drm/i915/gvt/cfg_space.c
@@ -56,6 +56,10 @@ static const u8 pci_cfg_space_rw_bmp[PCI_INTERRUPT_LINE + 4] = {
 
 /**
  * vgpu_pci_cfg_mem_write - write virtual cfg space memory
+ * @vgpu: target vgpu
+ * @off: offset
+ * @src: src ptr to write
+ * @bytes: number of bytes
  *
  * Use this function to write virtual cfg space memory.
  * For standard cfg space, only RW bits can be changed,
@@ -91,6 +95,10 @@ static void vgpu_pci_cfg_mem_write(struct intel_vgpu *vgpu, unsigned int off,
 
 /**
  * intel_vgpu_emulate_cfg_read - emulate vGPU configuration space read
+ * @vgpu: target vgpu
+ * @offset: offset
+ * @p_data: return data ptr
+ * @bytes: number of bytes to read
  *
  * Returns:
  * Zero on success, negative error code if failed.
@@ -278,6 +286,10 @@ static int emulate_pci_bar_write(struct intel_vgpu *vgpu, unsigned int offset,
 
 /**
  * intel_vgpu_emulate_cfg_read - emulate vGPU configuration space write
+ * @vgpu: target vgpu
+ * @offset: offset
+ * @p_data: write data ptr
+ * @bytes: number of bytes to write
  *
  * Returns:
  * Zero on success, negative error code if failed.
diff --git a/drivers/gpu/drm/i915/gvt/cmd_parser.c b/drivers/gpu/drm/i915/gvt/cmd_parser.c
index 0651e63b25fb7bc8a3c748810f2837a690504c1b..865d80919827390833d0222c7991e571b1ad7133 100644
--- a/drivers/gpu/drm/i915/gvt/cmd_parser.c
+++ b/drivers/gpu/drm/i915/gvt/cmd_parser.c
@@ -1817,6 +1817,8 @@ static int cmd_handler_mi_batch_buffer_start(struct parser_exec_state *s)
 	return ret;
 }
 
+static int mi_noop_index;
+
 static struct cmd_info cmd_info[] = {
 	{"MI_NOOP", OP_MI_NOOP, F_LEN_CONST, R_ALL, D_ALL, 0, 1, NULL},
 
@@ -2502,7 +2504,12 @@ static int cmd_parser_exec(struct parser_exec_state *s)
 
 	cmd = cmd_val(s, 0);
 
-	info = get_cmd_info(s->vgpu->gvt, cmd, s->ring_id);
+	/* fastpath for MI_NOOP */
+	if (cmd == MI_NOOP)
+		info = &cmd_info[mi_noop_index];
+	else
+		info = get_cmd_info(s->vgpu->gvt, cmd, s->ring_id);
+
 	if (info == NULL) {
 		gvt_vgpu_err("unknown cmd 0x%x, opcode=0x%x, addr_type=%s, ring %d, workload=%p\n",
 				cmd, get_opcode(cmd, s->ring_id),
@@ -2905,6 +2912,8 @@ static int init_cmd_table(struct intel_gvt *gvt)
 			kfree(e);
 			return -EEXIST;
 		}
+		if (cmd_info[i].opcode == OP_MI_NOOP)
+			mi_noop_index = i;
 
 		INIT_HLIST_NODE(&e->hlist);
 		add_cmd_entry(gvt, e);
diff --git a/drivers/gpu/drm/i915/gvt/display.c b/drivers/gpu/drm/i915/gvt/display.c
index 6ee50cb328f8efb4f8d5c94ffc731ca7195884dc..379fc81da8634be452ecf696fee63981bd7c8078 100644
--- a/drivers/gpu/drm/i915/gvt/display.c
+++ b/drivers/gpu/drm/i915/gvt/display.c
@@ -462,6 +462,7 @@ void intel_vgpu_clean_display(struct intel_vgpu *vgpu)
 /**
  * intel_vgpu_init_display- initialize vGPU virtual display emulation
  * @vgpu: a vGPU
+ * @resolution: resolution index for intel_vgpu_edid
  *
  * This function is used to initialize vGPU virtual display emulation stuffs
  *
diff --git a/drivers/gpu/drm/i915/gvt/edid.c b/drivers/gpu/drm/i915/gvt/edid.c
index 4b98539025c5b51014f9d515285f6c1f90d8cb59..5d4bb35bb889e932c6b2905ac06e4495d57b0cb4 100644
--- a/drivers/gpu/drm/i915/gvt/edid.c
+++ b/drivers/gpu/drm/i915/gvt/edid.c
@@ -340,6 +340,9 @@ static int gmbus2_mmio_write(struct intel_vgpu *vgpu, unsigned int offset,
 /**
  * intel_gvt_i2c_handle_gmbus_read - emulate gmbus register mmio read
  * @vgpu: a vGPU
+ * @offset: reg offset
+ * @p_data: data return buffer
+ * @bytes: access data length
  *
  * This function is used to emulate gmbus register mmio read
  *
@@ -365,6 +368,9 @@ int intel_gvt_i2c_handle_gmbus_read(struct intel_vgpu *vgpu,
 /**
  * intel_gvt_i2c_handle_gmbus_write - emulate gmbus register mmio write
  * @vgpu: a vGPU
+ * @offset: reg offset
+ * @p_data: data return buffer
+ * @bytes: access data length
  *
  * This function is used to emulate gmbus register mmio write
  *
@@ -437,6 +443,9 @@ static inline int get_aux_ch_reg(unsigned int offset)
 /**
  * intel_gvt_i2c_handle_aux_ch_write - emulate AUX channel register write
  * @vgpu: a vGPU
+ * @port_idx: port index
+ * @offset: reg offset
+ * @p_data: write ptr
  *
  * This function is used to emulate AUX channel register write
  *
diff --git a/drivers/gpu/drm/i915/gvt/gtt.c b/drivers/gpu/drm/i915/gvt/gtt.c
index 39980dfbbebde6ff96942eb2ee3bd6875bc880ef..bbfb168a966565698c7fd9827ce4ad051edb2f7d 100644
--- a/drivers/gpu/drm/i915/gvt/gtt.c
+++ b/drivers/gpu/drm/i915/gvt/gtt.c
@@ -1113,6 +1113,10 @@ static inline void ppgtt_generate_shadow_entry(struct intel_gvt_gtt_entry *se,
 }
 
 /**
+ * Check if can do 2M page
+ * @vgpu: target vgpu
+ * @entry: target pfn's gtt entry
+ *
  * Return 1 if 2MB huge gtt shadowing is possilbe, 0 if miscondition,
  * negtive if found err.
  */
@@ -1943,7 +1947,7 @@ void intel_vgpu_unpin_mm(struct intel_vgpu_mm *mm)
 
 /**
  * intel_vgpu_pin_mm - increase the pin count of a vGPU mm object
- * @vgpu: a vGPU
+ * @mm: target vgpu mm
  *
  * This function is called when user wants to use a vGPU mm object. If this
  * mm object hasn't been shadowed yet, the shadow will be populated at this
@@ -2463,8 +2467,7 @@ static int setup_spt_oos(struct intel_gvt *gvt)
 /**
  * intel_vgpu_find_ppgtt_mm - find a PPGTT mm object
  * @vgpu: a vGPU
- * @page_table_level: PPGTT page table level
- * @root_entry: PPGTT page table root pointers
+ * @pdps: pdp root array
  *
  * This function is used to find a PPGTT mm object from mm object pool
  *
diff --git a/drivers/gpu/drm/i915/gvt/gvt.c b/drivers/gpu/drm/i915/gvt/gvt.c
index 712f9d14e7200678228065bd16d5d0bdec7a009b..e14416d97e7398b8b7c6f6980b3ae65c7f632012 100644
--- a/drivers/gpu/drm/i915/gvt/gvt.c
+++ b/drivers/gpu/drm/i915/gvt/gvt.c
@@ -188,7 +188,6 @@ static const struct intel_gvt_ops intel_gvt_ops = {
 
 /**
  * intel_gvt_init_host - Load MPT modules and detect if we're running in host
- * @gvt: intel gvt device
  *
  * This function is called at the driver loading stage. If failed to find a
  * loadable MPT module or detect currently we're running in a VM, then GVT-g
@@ -302,7 +301,7 @@ static int init_service_thread(struct intel_gvt *gvt)
 
 /**
  * intel_gvt_clean_device - clean a GVT device
- * @gvt: intel gvt device
+ * @dev_priv: i915 private
  *
  * This function is called at the driver unloading stage, to free the
  * resources owned by a GVT device.
diff --git a/drivers/gpu/drm/i915/gvt/handlers.c b/drivers/gpu/drm/i915/gvt/handlers.c
index c455d7e71a5b6c20ac4eb48d40abf6a1dc93f72e..ff4435432dc96ff897134fbab3d631388f35cd94 100644
--- a/drivers/gpu/drm/i915/gvt/handlers.c
+++ b/drivers/gpu/drm/i915/gvt/handlers.c
@@ -3399,6 +3399,7 @@ bool intel_gvt_in_force_nonpriv_whitelist(struct intel_gvt *gvt,
  * @offset: register offset
  * @pdata: data buffer
  * @bytes: data length
+ * @is_read: read or write
  *
  * Returns:
  * Zero on success, negative error code if failed.
diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index 4d2f53ae9f0f26907433aabc3cae4c9d1e7d3361..a22d539b9d4e721884e605d0d4106277db4c6bf8 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -1702,7 +1702,7 @@ static unsigned long kvmgt_gfn_to_pfn(unsigned long handle, unsigned long gfn)
 	return pfn;
 }
 
-int kvmgt_dma_map_guest_page(unsigned long handle, unsigned long gfn,
+static int kvmgt_dma_map_guest_page(unsigned long handle, unsigned long gfn,
 		unsigned long size, dma_addr_t *dma_addr)
 {
 	struct kvmgt_guest_info *info;
@@ -1751,7 +1751,7 @@ static void __gvt_dma_release(struct kref *ref)
 	__gvt_cache_remove_entry(entry->vgpu, entry);
 }
 
-void kvmgt_dma_unmap_guest_page(unsigned long handle, dma_addr_t dma_addr)
+static void kvmgt_dma_unmap_guest_page(unsigned long handle, dma_addr_t dma_addr)
 {
 	struct kvmgt_guest_info *info;
 	struct gvt_dma *entry;
diff --git a/drivers/gpu/drm/i915/gvt/mmio.c b/drivers/gpu/drm/i915/gvt/mmio.c
index 994366035364b7576db8ed2ec1036d417cc39d9c..4db817c21ed89e0dcbc6cde8acc511d80ddcf805 100644
--- a/drivers/gpu/drm/i915/gvt/mmio.c
+++ b/drivers/gpu/drm/i915/gvt/mmio.c
@@ -39,6 +39,7 @@
 /**
  * intel_vgpu_gpa_to_mmio_offset - translate a GPA to MMIO offset
  * @vgpu: a vGPU
+ * @gpa: guest physical address
  *
  * Returns:
  * Zero on success, negative error code if failed
@@ -228,7 +229,7 @@ int intel_vgpu_emulate_mmio_write(struct intel_vgpu *vgpu, uint64_t pa,
 /**
  * intel_vgpu_reset_mmio - reset virtual MMIO space
  * @vgpu: a vGPU
- *
+ * @dmlr: whether this is device model level reset
  */
 void intel_vgpu_reset_mmio(struct intel_vgpu *vgpu, bool dmlr)
 {
diff --git a/drivers/gpu/drm/i915/gvt/mmio_context.c b/drivers/gpu/drm/i915/gvt/mmio_context.c
index 20be9a92600f0f99cd5a688929251c071307afe1..d20f2c9bda82ead38bc66c51f22eb3f0d9ed0e2f 100644
--- a/drivers/gpu/drm/i915/gvt/mmio_context.c
+++ b/drivers/gpu/drm/i915/gvt/mmio_context.c
@@ -37,19 +37,6 @@
 #include "gvt.h"
 #include "trace.h"
 
-/**
- * Defined in Intel Open Source PRM.
- * Ref: https://01.org/linuxgraphics/documentation/hardware-specification-prms
- */
-#define TRVATTL3PTRDW(i)	_MMIO(0x4de0 + (i)*4)
-#define TRNULLDETCT		_MMIO(0x4de8)
-#define TRINVTILEDETCT		_MMIO(0x4dec)
-#define TRVADR			_MMIO(0x4df0)
-#define TRTTE			_MMIO(0x4df4)
-#define RING_EXCC(base)		_MMIO((base) + 0x28)
-#define RING_GFX_MODE(base)	_MMIO((base) + 0x29c)
-#define VF_GUARDBAND		_MMIO(0x83a4)
-
 #define GEN9_MOCS_SIZE		64
 
 /* Raw offset is appened to each line for convenience. */
diff --git a/drivers/gpu/drm/i915/gvt/mmio_context.h b/drivers/gpu/drm/i915/gvt/mmio_context.h
index 5c3b9ff9f96aa979edebd277a8b000715a3a7d72..f7eaa442403f7177824ac8f10c47cf0de5c07d85 100644
--- a/drivers/gpu/drm/i915/gvt/mmio_context.h
+++ b/drivers/gpu/drm/i915/gvt/mmio_context.h
@@ -53,5 +53,8 @@ bool is_inhibit_context(struct intel_context *ce);
 
 int intel_vgpu_restore_inhibit_context(struct intel_vgpu *vgpu,
 				       struct i915_request *req);
+#define IS_RESTORE_INHIBIT(a)	\
+	(_MASKED_BIT_ENABLE(CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT) == \
+	((a) & _MASKED_BIT_ENABLE(CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT)))
 
 #endif
diff --git a/drivers/gpu/drm/i915/gvt/opregion.c b/drivers/gpu/drm/i915/gvt/opregion.c
index fa75a2eead9070fbfd1894b659b37f84eed9e11a..82586c8e434fa86062458ff58c3b25ebfdd263ca 100644
--- a/drivers/gpu/drm/i915/gvt/opregion.c
+++ b/drivers/gpu/drm/i915/gvt/opregion.c
@@ -216,7 +216,6 @@ static void virt_vbt_generation(struct vbt *v)
 /**
  * intel_vgpu_init_opregion - initialize the stuff used to emulate opregion
  * @vgpu: a vGPU
- * @gpa: guest physical address of opregion
  *
  * Returns:
  * Zero on success, negative error code if failed.
diff --git a/drivers/gpu/drm/i915/gvt/page_track.c b/drivers/gpu/drm/i915/gvt/page_track.c
index 256d0db8bbb1553f3539925dc8ebab698a6070ef..84856022528ee6fb79747e002a335e8201a8fa39 100644
--- a/drivers/gpu/drm/i915/gvt/page_track.c
+++ b/drivers/gpu/drm/i915/gvt/page_track.c
@@ -41,6 +41,8 @@ struct intel_vgpu_page_track *intel_vgpu_find_page_track(
  * intel_vgpu_register_page_track - register a guest page to be tacked
  * @vgpu: a vGPU
  * @gfn: the gfn of guest page
+ * @handler: page track handler
+ * @priv: tracker private
  *
  * Returns:
  * zero on success, negative error code if failed.
diff --git a/drivers/gpu/drm/i915/gvt/reg.h b/drivers/gpu/drm/i915/gvt/reg.h
index c9d6cf6cc62345c785a6929b7bc4b4ddfac4a82d..428d252344f1e4027bc5ffecb12bf7842a1dbe09 100644
--- a/drivers/gpu/drm/i915/gvt/reg.h
+++ b/drivers/gpu/drm/i915/gvt/reg.h
@@ -86,4 +86,13 @@
 #define PCH_GMBUS4	_MMIO(0xc5110)
 #define PCH_GMBUS5	_MMIO(0xc5120)
 
+#define TRVATTL3PTRDW(i)	_MMIO(0x4de0 + (i) * 4)
+#define TRNULLDETCT		_MMIO(0x4de8)
+#define TRINVTILEDETCT		_MMIO(0x4dec)
+#define TRVADR			_MMIO(0x4df0)
+#define TRTTE			_MMIO(0x4df4)
+#define RING_EXCC(base)		_MMIO((base) + 0x28)
+#define RING_GFX_MODE(base)	_MMIO((base) + 0x29c)
+#define VF_GUARDBAND		_MMIO(0x83a4)
+
 #endif
diff --git a/drivers/gpu/drm/i915/gvt/scheduler.c b/drivers/gpu/drm/i915/gvt/scheduler.c
index b0e566956b8d5ce1609c0f19f31ffa45e610adee..1a88c1972416ddc99fafba74b5d86513a154b703 100644
--- a/drivers/gpu/drm/i915/gvt/scheduler.c
+++ b/drivers/gpu/drm/i915/gvt/scheduler.c
@@ -132,35 +132,6 @@ static int populate_shadow_context(struct intel_vgpu_workload *workload)
 	unsigned long context_gpa, context_page_num;
 	int i;
 
-	gvt_dbg_sched("ring id %d workload lrca %x", ring_id,
-			workload->ctx_desc.lrca);
-
-	context_page_num = gvt->dev_priv->engine[ring_id]->context_size;
-
-	context_page_num = context_page_num >> PAGE_SHIFT;
-
-	if (IS_BROADWELL(gvt->dev_priv) && ring_id == RCS)
-		context_page_num = 19;
-
-	i = 2;
-
-	while (i < context_page_num) {
-		context_gpa = intel_vgpu_gma_to_gpa(vgpu->gtt.ggtt_mm,
-				(u32)((workload->ctx_desc.lrca + i) <<
-				I915_GTT_PAGE_SHIFT));
-		if (context_gpa == INTEL_GVT_INVALID_ADDR) {
-			gvt_vgpu_err("Invalid guest context descriptor\n");
-			return -EFAULT;
-		}
-
-		page = i915_gem_object_get_page(ctx_obj, LRC_HEADER_PAGES + i);
-		dst = kmap(page);
-		intel_gvt_hypervisor_read_gpa(vgpu, context_gpa, dst,
-				I915_GTT_PAGE_SIZE);
-		kunmap(page);
-		i++;
-	}
-
 	page = i915_gem_object_get_page(ctx_obj, LRC_STATE_PN);
 	shadow_ring_context = kmap(page);
 
@@ -195,6 +166,37 @@ static int populate_shadow_context(struct intel_vgpu_workload *workload)
 
 	sr_oa_regs(workload, (u32 *)shadow_ring_context, false);
 	kunmap(page);
+
+	if (IS_RESTORE_INHIBIT(shadow_ring_context->ctx_ctrl.val))
+		return 0;
+
+	gvt_dbg_sched("ring id %d workload lrca %x", ring_id,
+			workload->ctx_desc.lrca);
+
+	context_page_num = gvt->dev_priv->engine[ring_id]->context_size;
+
+	context_page_num = context_page_num >> PAGE_SHIFT;
+
+	if (IS_BROADWELL(gvt->dev_priv) && ring_id == RCS)
+		context_page_num = 19;
+
+	i = 2;
+	while (i < context_page_num) {
+		context_gpa = intel_vgpu_gma_to_gpa(vgpu->gtt.ggtt_mm,
+				(u32)((workload->ctx_desc.lrca + i) <<
+				I915_GTT_PAGE_SHIFT));
+		if (context_gpa == INTEL_GVT_INVALID_ADDR) {
+			gvt_vgpu_err("Invalid guest context descriptor\n");
+			return -EFAULT;
+		}
+
+		page = i915_gem_object_get_page(ctx_obj, LRC_HEADER_PAGES + i);
+		dst = kmap(page);
+		intel_gvt_hypervisor_read_gpa(vgpu, context_gpa, dst,
+				I915_GTT_PAGE_SIZE);
+		kunmap(page);
+		i++;
+	}
 	return 0;
 }
 
@@ -1137,6 +1139,7 @@ int intel_vgpu_setup_submission(struct intel_vgpu *vgpu)
 /**
  * intel_vgpu_select_submission_ops - select virtual submission interface
  * @vgpu: a vGPU
+ * @engine_mask: either ALL_ENGINES or target engine mask
  * @interface: expected vGPU virtual submission interface
  *
  * This function is called when guest configures submission interface.
@@ -1189,7 +1192,7 @@ int intel_vgpu_select_submission_ops(struct intel_vgpu *vgpu,
 
 /**
  * intel_vgpu_destroy_workload - destroy a vGPU workload
- * @vgpu: a vGPU
+ * @workload: workload to destroy
  *
  * This function is called when destroy a vGPU workload.
  *
@@ -1281,6 +1284,7 @@ static int prepare_mm(struct intel_vgpu_workload *workload)
 /**
  * intel_vgpu_create_workload - create a vGPU workload
  * @vgpu: a vGPU
+ * @ring_id: ring index
  * @desc: a guest context descriptor
  *
  * This function is called when creating a vGPU workload.