drm/i915/gvt: handle force-nonpriv registers, cmd parser part

this patch adds force non-priv registers check in LRI cmds handler

v4:
transform is_force_nonpriv_mmio() from macro to inline fuction to eliminate
checkpatch warning

v3:
per zhenyu's comment, fix some style warnings

v2:
per zhenyu's comment, refine the code to remove cascaded ifs

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

@@ -817,6 +817,25 @@ static bool is_shadowed_mmio(unsigned int offset)
 	return ret;
 }
 
+static inline bool is_force_nonpriv_mmio(unsigned int offset)
+{
+	return (offset >= 0x24d0 && offset < 0x2500);
+}
+
+static int force_nonpriv_reg_handler(struct parser_exec_state *s,
+				     unsigned int offset, unsigned int index)
+{
+	struct intel_gvt *gvt = s->vgpu->gvt;
+	unsigned int data = cmd_val(s, index + 1);
+
+	if (!intel_gvt_in_force_nonpriv_whitelist(gvt, data)) {
+		gvt_err("Unexpected forcenonpriv 0x%x LRI write, value=0x%x\n",
+			offset, data);
+		return -EINVAL;
+	}
+	return 0;
+}
+
 static int cmd_reg_handler(struct parser_exec_state *s,
 	unsigned int offset, unsigned int index, char *cmd)
 {
@@ -841,6 +860,10 @@ static int cmd_reg_handler(struct parser_exec_state *s,
 		return 0;
 	}
 
+	if (is_force_nonpriv_mmio(offset) &&
+	    force_nonpriv_reg_handler(s, offset, index))
+		return -EINVAL;
+
 	if (offset == i915_mmio_reg_offset(DERRMR) ||
 		offset == i915_mmio_reg_offset(FORCEWAKE_MT)) {
 		/* Writing to HW VGT_PVINFO_PAGE offset will be discarded */

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

@@ -2988,3 +2988,20 @@ int intel_vgpu_default_mmio_write(struct intel_vgpu *vgpu, unsigned int offset,
 	write_vreg(vgpu, offset, p_data, bytes);
 	return 0;
 }
+
+/**
+ * intel_gvt_in_force_nonpriv_whitelist - if a mmio is in whitelist to be
+ * force-nopriv register
+ *
+ * @gvt: a GVT device
+ * @offset: register offset
+ *
+ * Returns:
+ * True if the register is in force-nonpriv whitelist;
+ * False if outside;
+ */
+bool intel_gvt_in_force_nonpriv_whitelist(struct intel_gvt *gvt,
+					  unsigned int offset)
+{
+	return in_whitelist(offset);
+}

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

@@ -107,4 +107,7 @@ int intel_vgpu_default_mmio_read(struct intel_vgpu *vgpu, unsigned int offset,
 				 void *p_data, unsigned int bytes);
 int intel_vgpu_default_mmio_write(struct intel_vgpu *vgpu, unsigned int offset,
 				  void *p_data, unsigned int bytes);
+
+bool intel_gvt_in_force_nonpriv_whitelist(struct intel_gvt *gvt,
+					  unsigned int offset);
 #endif