ucall_arch_do_ucall
void ucall_arch_do_ucall(vm_vaddr_t uc);
#define GUEST_UCALL_NONE() ucall_arch_do_ucall((vm_vaddr_t)NULL)
ucall_arch_do_ucall((vm_vaddr_t)uc->hva);
ucall_arch_do_ucall((vm_vaddr_t)uc->hva);
ucall_arch_do_ucall(GUEST_UCALL_FAILED);
ucall_arch_do_ucall((vm_vaddr_t)uc->hva);