vm_gpa_hold
hva = vm_gpa_hold(vcpu, copyinfo[idx].gpa,
ptr = vm_gpa_hold(vcpu, ptpphys, len, VM_PROT_RW, cookie);
ptr = vm_gpa_hold(vcpu, ptpphys, len, VM_PROT_RW, cookie);
void *vm_gpa_hold(struct vcpu *vcpu, vm_paddr_t gpa, size_t len,