drm/i915/gvt: let NOPID be the default value of force_to_nonpriv registers

Each ring has a NOPID register and currently they are regarded as default
value of force_to_nonpriv registers in guest drivers

Signed-off-by: Zhao Yan <yan.y.zhao@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

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

@@ -817,8 +817,15 @@ static int force_nonpriv_reg_handler(struct parser_exec_state *s,
 {
 	struct intel_gvt *gvt = s->vgpu->gvt;
 	unsigned int data = cmd_val(s, index + 1);
+	u32 ring_base;
+	u32 nopid;
+	struct drm_i915_private *dev_priv = s->vgpu->gvt->dev_priv;
+
+	ring_base = dev_priv->engine[s->ring_id]->mmio_base;
+	nopid = i915_mmio_reg_offset(RING_NOPID(ring_base));
 
-	if (!intel_gvt_in_force_nonpriv_whitelist(gvt, data)) {
+	if (!intel_gvt_in_force_nonpriv_whitelist(gvt, data) &&
+			data != nopid) {
 		gvt_err("Unexpected forcenonpriv 0x%x LRI write, value=0x%x\n",
 			offset, data);
 		return -EPERM;

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

@@ -474,21 +474,27 @@ static int force_nonpriv_write(struct intel_vgpu *vgpu,
 	unsigned int offset, void *p_data, unsigned int bytes)
 {
 	u32 reg_nonpriv = *(u32 *)p_data;
+	int ring_id = intel_gvt_render_mmio_to_ring_id(vgpu->gvt, offset);
+	u32 ring_base;
+	struct drm_i915_private *dev_priv = vgpu->gvt->dev_priv;
 	int ret = -EINVAL;
 
-	if ((bytes != 4) || ((offset & (bytes - 1)) != 0)) {
-		gvt_err("vgpu(%d) Invalid FORCE_NONPRIV offset %x(%dB)\n",
-			vgpu->id, offset, bytes);
+	if ((bytes != 4) || ((offset & (bytes - 1)) != 0) || ring_id < 0) {
+		gvt_err("vgpu(%d) ring %d Invalid FORCE_NONPRIV offset %x(%dB)\n",
+			vgpu->id, ring_id, offset, bytes);
 		return ret;
 	}
 
-	if (in_whitelist(reg_nonpriv)) {
+	ring_base = dev_priv->engine[ring_id]->mmio_base;
+
+	if (in_whitelist(reg_nonpriv) ||
+		reg_nonpriv == i915_mmio_reg_offset(RING_NOPID(ring_base))) {
 		ret = intel_vgpu_default_mmio_write(vgpu, offset, p_data,
 			bytes);
-	} else {
-		gvt_err("vgpu(%d) Invalid FORCE_NONPRIV write %x\n",
-			vgpu->id, reg_nonpriv);
-	}
+	} else
+		gvt_err("vgpu(%d) Invalid FORCE_NONPRIV write %x at offset %x\n",
+			vgpu->id, reg_nonpriv, offset);
+
 	return ret;
 }