drm/i915/gvt: correct the emulation in TLB control handler

Need a explicit write_vreg in TLB MMIO write handler, beside that
TLB vreg should update correspondingly following HW status to do
correct emulation.

Signed-off-by: Ping Gao <ping.a.gao@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

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

@@ -1370,6 +1370,8 @@ static int gvt_reg_tlb_control_handler(struct intel_vgpu *vgpu,
 	int rc = 0;
 	unsigned int id = 0;
 
+	write_vreg(vgpu, offset, p_data, bytes);
+
 	switch (offset) {
 	case 0x4260:
 		id = RCS;

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

@@ -152,6 +152,8 @@ static void handle_tlb_pending_event(struct intel_vgpu *vgpu, int ring_id)
 
 	if (wait_for_atomic((I915_READ_FW(reg) == 0), 50))
 		gvt_err("timeout in invalidate ring (%d) tlb\n", ring_id);
+	else
+		vgpu_vreg(vgpu, regs[ring_id]) = 0;
 
 	intel_uncore_forcewake_put(dev_priv, fw);