I finally got the answer that the vtpm_manager (run in the Dom0)  can not response the pcr_read request in time. There is no problem in IMA and vtpm, i just insert a mdelay() function in ima_init.c to gernerate a 10 seconds pause before IMA init. And everything is ok.

Test mode without tpm support also works fine. 
I think there is no need to make new patch, IMA works perfectly in domU and dom0.