>
> I think you need to add more printk to find out.
>
> Wei.
>

Thanks for the suggestion, after adding printk to all the routines
of xc_altp2m_set_vcpu_enable_notify, it turns out that the problem is
because the check of is_hvm_domain()
<http://xenbits.xen.org/gitweb/?p=xen.git;a=blob;f=xen/arch/x86/hvm/hvm.c;h=615fa8908375aaad452e2be69fe183c2a12b82bf;hb=b24ad7ba911a9f0688ab179736476e44c52144f1#l6204>
failed in function do_altp2m_op()
<http://xenbits.xen.org/gitweb/?p=xen.git;a=blob;f=xen/arch/x86/hvm/hvm.c;h=615fa8908375aaad452e2be69fe183c2a12b82bf;hb=b24ad7ba911a9f0688ab179736476e44c52144f1#l6179>.
However, I've already configure the VM to build as a HVM by adding option
"builder=hvm" in the config file, but for unknown reason the .printk of
domain->type is guest_type_pv. I've tried both windows and linux as the
guest VM, both failed for the same reason. Any ideas?