vmc_hold
vmp = vmc_hold(vmc, off, prot);
vm_page_t *vmc_hold(vm_client_t *, uintptr_t, int);
vmp = vmc_hold(vmc, gpa, PROT_WRITE);
vmp = vmc_hold(vmc, copyinfo[idx].gpa & PAGEMASK, prot);
*vmp = vmc_hold(vmc, hold_gpa, PROT_READ | PROT_WRITE);
return ((vmm_page_t *)vmc_hold(lease->vml_vmclient, gpa, prot));