// SPDX-License-Identifier: GPL-2.0
/*
* Copyright 2020-2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*/
/**
* DOC: Sample flow of using the ioctl interface provided by the Nitro Enclaves (NE)
* kernel driver.
*
* Usage
* -----
*
* Load the nitro_enclaves module, setting also the enclave CPU pool. The
* enclave CPUs need to be full cores from the same NUMA node. CPU 0 and its
* siblings have to remain available for the primary / parent VM, so they
* cannot be included in the enclave CPU pool.
*
* See the cpu list section from the kernel documentation.
* https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html#cpu-lists
*
* insmod drivers/virt/nitro_enclaves/nitro_enclaves.ko
* lsmod
*
* The CPU pool can be set at runtime, after the kernel module is loaded.
*
* echo <cpu-list> > /sys/module/nitro_enclaves/parameters/ne_cpus
*
* NUMA and CPU siblings information can be found using:
*
* lscpu
* /proc/cpuinfo
*
* Check the online / offline CPU list. The CPUs from the pool should be
* offlined.
*
* lscpu
*
* Check dmesg for any warnings / errors through the NE driver lifetime / usage.
* The NE logs contain the "nitro_enclaves" or "pci 0000:00:02.0" pattern.
*
* dmesg
*
* Setup hugetlbfs huge pages. The memory needs to be from the same NUMA node as
* the enclave CPUs.
*
* https://www.kernel.org/doc/html/latest/admin-guide/mm/hugetlbpage.html
*
* By default, the allocation of hugetlb pages are distributed on all possible
* NUMA nodes. Use the following configuration files to set the number of huge
* pages from a NUMA node:
*
* /sys/devices/system/node/node<X>/hugepages/hugepages-2048kB/nr_hugepages
* /sys/devices/system/node/node<X>/hugepages/hugepages-1048576kB/nr_hugepages
*
* or, if not on a system with multiple NUMA nodes, can also set the number
* of 2 MiB / 1 GiB huge pages using
*
* /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages
* /sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages
*
* In this example 256 hugepages of 2 MiB are used.
*
* Build and run the NE sample.
*
* make -C samples/nitro_enclaves clean
* make -C samples/nitro_enclaves
* ./samples/nitro_enclaves/ne_ioctl_sample <path_to_enclave_image>
*
* Unload the nitro_enclaves module.
*
* rmmod nitro_enclaves
* lsmod
*/
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <poll.h>
#include <pthread.h>
#include <string.h>
#include <sys/eventfd.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <linux/mman.h>
#include <linux/nitro_enclaves.h>
#include <linux/vm_sockets.h>
/**
* NE_DEV_NAME - Nitro Enclaves (NE) misc device that provides the ioctl interface.
*/
#define NE_DEV_NAME "/dev/nitro_enclaves"
/**
* NE_POLL_WAIT_TIME - Timeout in seconds for each poll event.
*/
#define NE_POLL_WAIT_TIME (60)
/**
* NE_POLL_WAIT_TIME_MS - Timeout in milliseconds for each poll event.
*/
#define NE_POLL_WAIT_TIME_MS (NE_POLL_WAIT_TIME * 1000)
/**
* NE_SLEEP_TIME - Amount of time in seconds for the process to keep the enclave alive.
*/
#define NE_SLEEP_TIME (300)
/**
* NE_DEFAULT_NR_VCPUS - Default number of vCPUs set for an enclave.
*/
#define NE_DEFAULT_NR_VCPUS (2)
/**
* NE_MIN_MEM_REGION_SIZE - Minimum size of a memory region - 2 MiB.
*/
#define NE_MIN_MEM_REGION_SIZE (2 * 1024 * 1024)
/**
* NE_DEFAULT_NR_MEM_REGIONS - Default number of memory regions of 2 MiB set for
* an enclave.
*/
#define NE_DEFAULT_NR_MEM_REGIONS (256)
/**
* NE_IMAGE_LOAD_HEARTBEAT_CID - Vsock CID for enclave image loading heartbeat logic.
*/
#define NE_IMAGE_LOAD_HEARTBEAT_CID (3)
/**
* NE_IMAGE_LOAD_HEARTBEAT_PORT - Vsock port for enclave image loading heartbeat logic.
*/
#define NE_IMAGE_LOAD_HEARTBEAT_PORT (9000)
/**
* NE_IMAGE_LOAD_HEARTBEAT_VALUE - Heartbeat value for enclave image loading.
*/
#define NE_IMAGE_LOAD_HEARTBEAT_VALUE (0xb7)
/**
* struct ne_user_mem_region - User space memory region set for an enclave.
* @userspace_addr: Address of the user space memory region.
* @memory_size: Size of the user space memory region.
*/
struct ne_user_mem_region {
void *userspace_addr;
size_t memory_size;
};
/**
* ne_create_vm() - Create a slot for the enclave VM.
* @ne_dev_fd: The file descriptor of the NE misc device.
* @slot_uid: The generated slot uid for the enclave.
* @enclave_fd : The generated file descriptor for the enclave.
*
* Context: Process context.
* Return:
* * 0 on success.
* * Negative return value on failure.
*/
static int ne_create_vm(int ne_dev_fd, unsigned long *slot_uid, int *enclave_fd)
{
int rc = -EINVAL;
*enclave_fd = ioctl(ne_dev_fd, NE_CREATE_VM, slot_uid);
if (*enclave_fd < 0) {
rc = *enclave_fd;
switch (errno) {
case NE_ERR_NO_CPUS_AVAIL_IN_POOL: {
printf("Error in create VM, no CPUs available in the NE CPU pool\n");
break;
}
default:
printf("Error in create VM [%m]\n");
}
return rc;
}
return 0;
}
/**
* ne_poll_enclave_fd() - Thread function for polling the enclave fd.
* @data: Argument provided for the polling function.
*
* Context: Process context.
* Return:
* * NULL on success / failure.
*/
void *ne_poll_enclave_fd(void *data)
{
int enclave_fd = *(int *)data;
struct pollfd fds[1] = {};
int i = 0;
int rc = -EINVAL;
printf("Running from poll thread, enclave fd %d\n", enclave_fd);
fds[0].fd = enclave_fd;
fds[0].events = POLLIN | POLLERR | POLLHUP;
/* Keep on polling until the current process is terminated. */
while (1) {
printf("[iter %d] Polling ...\n", i);
rc = poll(fds, 1, NE_POLL_WAIT_TIME_MS);
if (rc < 0) {
printf("Error in poll [%m]\n");
return NULL;
}
i++;
if (!rc) {
printf("Poll: %d seconds elapsed\n",
i * NE_POLL_WAIT_TIME);
continue;
}
printf("Poll received value 0x%x\n", fds[0].revents);
if (fds[0].revents & POLLHUP) {
printf("Received POLLHUP\n");
return NULL;
}
if (fds[0].revents & POLLNVAL) {
printf("Received POLLNVAL\n");
return NULL;
}
}
return NULL;
}
/**
* ne_alloc_user_mem_region() - Allocate a user space memory region for an enclave.
* @ne_user_mem_region: User space memory region allocated using hugetlbfs.
*
* Context: Process context.
* Return:
* * 0 on success.
* * Negative return value on failure.
*/
static int ne_alloc_user_mem_region(struct ne_user_mem_region *ne_user_mem_region)
{
/**
* Check available hugetlb encodings for different huge page sizes in
* include/uapi/linux/mman.h.
*/
ne_user_mem_region->userspace_addr = mmap(NULL, ne_user_mem_region->memory_size,
PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS |
MAP_HUGETLB | MAP_HUGE_2MB, -1, 0);
if (ne_user_mem_region->userspace_addr == MAP_FAILED) {
printf("Error in mmap memory [%m]\n");
return -1;
}
return 0;
}
/**
* ne_load_enclave_image() - Place the enclave image in the enclave memory.
* @enclave_fd : The file descriptor associated with the enclave.
* @ne_user_mem_regions: User space memory regions allocated for the enclave.
* @enclave_image_path : The file path of the enclave image.
*
* Context: Process context.
* Return:
* * 0 on success.
* * Negative return value on failure.
*/
static int ne_load_enclave_image(int enclave_fd, struct ne_user_mem_region ne_user_mem_regions[],
char *enclave_image_path)
{
unsigned char *enclave_image = NULL;
int enclave_image_fd = -1;
size_t enclave_image_size = 0;
size_t enclave_memory_size = 0;
unsigned long i = 0;
size_t image_written_bytes = 0;
struct ne_image_load_info image_load_info = {
.flags = NE_EIF_IMAGE,
};
struct stat image_stat_buf = {};
int rc = -EINVAL;
size_t temp_image_offset = 0;
for (i = 0; i < NE_DEFAULT_NR_MEM_REGIONS; i++)
enclave_memory_size += ne_user_mem_regions[i].memory_size;
rc = stat(enclave_image_path, &image_stat_buf);
if (rc < 0) {
printf("Error in get image stat info [%m]\n");
return rc;
}
enclave_image_size = image_stat_buf.st_size;
if (enclave_memory_size < enclave_image_size) {
printf("The enclave memory is smaller than the enclave image size\n");
return -ENOMEM;
}
rc = ioctl(enclave_fd, NE_GET_IMAGE_LOAD_INFO, &image_load_info);
if (rc < 0) {
switch (errno) {
case NE_ERR_NOT_IN_INIT_STATE: {
printf("Error in get image load info, enclave not in init state\n");
break;
}
case NE_ERR_INVALID_FLAG_VALUE: {
printf("Error in get image load info, provided invalid flag\n");
break;
}
default:
printf("Error in get image load info [%m]\n");
}
return rc;
}
printf("Enclave image offset in enclave memory is %lld\n",
image_load_info.memory_offset);
enclave_image_fd = open(enclave_image_path, O_RDONLY);
if (enclave_image_fd < 0) {
printf("Error in open enclave image file [%m]\n");
return enclave_image_fd;
}
enclave_image = mmap(NULL, enclave_image_size, PROT_READ,
MAP_PRIVATE, enclave_image_fd, 0);
if (enclave_image == MAP_FAILED) {
printf("Error in mmap enclave image [%m]\n");
return -1;
}
temp_image_offset = image_load_info.memory_offset;
for (i = 0; i < NE_DEFAULT_NR_MEM_REGIONS; i++) {
size_t bytes_to_write = 0;
size_t memory_offset = 0;
size_t memory_size = ne_user_mem_regions[i].memory_size;
size_t remaining_bytes = 0;
void *userspace_addr = ne_user_mem_regions[i].userspace_addr;
if (temp_image_offset >= memory_size) {
temp_image_offset -= memory_size;
continue;
} else if (temp_image_offset != 0) {
memory_offset = temp_image_offset;
memory_size -= temp_image_offset;
temp_image_offset = 0;
}
remaining_bytes = enclave_image_size - image_written_bytes;
bytes_to_write = memory_size < remaining_bytes ?
memory_size : remaining_bytes;
memcpy(userspace_addr + memory_offset,
enclave_image + image_written_bytes, bytes_to_write);
image_written_bytes += bytes_to_write;
if (image_written_bytes == enclave_image_size)
break;
}
munmap(enclave_image, enclave_image_size);
close(enclave_image_fd);
return 0;
}
/**
* ne_set_user_mem_region() - Set a user space memory region for the given enclave.
* @enclave_fd : The file descriptor associated with the enclave.
* @ne_user_mem_region : User space memory region to be set for the enclave.
*
* Context: Process context.
* Return:
* * 0 on success.
* * Negative return value on failure.
*/
static int ne_set_user_mem_region(int enclave_fd, struct ne_user_mem_region ne_user_mem_region)
{
struct ne_user_memory_region mem_region = {
.flags = NE_DEFAULT_MEMORY_REGION,
.memory_size = ne_user_mem_region.memory_size,
.userspace_addr = (__u64)ne_user_mem_region.userspace_addr,
};
int rc = -EINVAL;
rc = ioctl(enclave_fd, NE_SET_USER_MEMORY_REGION, &mem_region);
if (rc < 0) {
switch (errno) {
case NE_ERR_NOT_IN_INIT_STATE: {
printf("Error in set user memory region, enclave not in init state\n");
break;
}
case NE_ERR_INVALID_MEM_REGION_SIZE: {
printf("Error in set user memory region, mem size not multiple of 2 MiB\n");
break;
}
case NE_ERR_INVALID_MEM_REGION_ADDR: {
printf("Error in set user memory region, invalid user space address\n");
break;
}
case NE_ERR_UNALIGNED_MEM_REGION_ADDR: {
printf("Error in set user memory region, unaligned user space address\n");
break;
}
case NE_ERR_MEM_REGION_ALREADY_USED: {
printf("Error in set user memory region, memory region already used\n");
break;
}
case NE_ERR_MEM_NOT_HUGE_PAGE: {
printf("Error in set user memory region, not backed by huge pages\n");
break;
}
case NE_ERR_MEM_DIFFERENT_NUMA_NODE: {
printf("Error in set user memory region, different NUMA node than CPUs\n");
break;
}
case NE_ERR_MEM_MAX_REGIONS: {
printf("Error in set user memory region, max memory regions reached\n");
break;
}
case NE_ERR_INVALID_PAGE_SIZE: {
printf("Error in set user memory region, has page not multiple of 2 MiB\n");
break;
}
case NE_ERR_INVALID_FLAG_VALUE: {
printf("Error in set user memory region, provided invalid flag\n");
break;
}
default:
printf("Error in set user memory region [%m]\n");
}
return rc;
}
return 0;
}
/**
* ne_free_mem_regions() - Unmap all the user space memory regions that were set
* aside for the enclave.
* @ne_user_mem_regions: The user space memory regions associated with an enclave.
*
* Context: Process context.
*/
static void ne_free_mem_regions(struct ne_user_mem_region ne_user_mem_regions[])
{
unsigned int i = 0;
for (i = 0; i < NE_DEFAULT_NR_MEM_REGIONS; i++)
munmap(ne_user_mem_regions[i].userspace_addr,
ne_user_mem_regions[i].memory_size);
}
/**
* ne_add_vcpu() - Add a vCPU to the given enclave.
* @enclave_fd : The file descriptor associated with the enclave.
* @vcpu_id: vCPU id to be set for the enclave, either provided or
* auto-generated (if provided vCPU id is 0).
*
* Context: Process context.
* Return:
* * 0 on success.
* * Negative return value on failure.
*/
static int ne_add_vcpu(int enclave_fd, unsigned int *vcpu_id)
{
int rc = -EINVAL;
rc = ioctl(enclave_fd, NE_ADD_VCPU, vcpu_id);
if (rc < 0) {
switch (errno) {
case NE_ERR_NO_CPUS_AVAIL_IN_POOL: {
printf("Error in add vcpu, no CPUs available in the NE CPU pool\n");
break;
}
case NE_ERR_VCPU_ALREADY_USED: {
printf("Error in add vcpu, the provided vCPU is already used\n");
break;
}
case NE_ERR_VCPU_NOT_IN_CPU_POOL: {
printf("Error in add vcpu, the provided vCPU is not in the NE CPU pool\n");
break;
}
case NE_ERR_VCPU_INVALID_CPU_CORE: {
printf("Error in add vcpu, the core id of the provided vCPU is invalid\n");
break;
}
case NE_ERR_NOT_IN_INIT_STATE: {
printf("Error in add vcpu, enclave not in init state\n");
break;
}
case NE_ERR_INVALID_VCPU: {
printf("Error in add vcpu, the provided vCPU is out of avail CPUs range\n");
break;
}
default:
printf("Error in add vcpu [%m]\n");
}
return rc;
}
return 0;
}
/**
* ne_start_enclave() - Start the given enclave.
* @enclave_fd : The file descriptor associated with the enclave.
* @enclave_start_info : Enclave metadata used for starting e.g. vsock CID.
*
* Context: Process context.
* Return:
* * 0 on success.
* * Negative return value on failure.
*/
static int ne_start_enclave(int enclave_fd, struct ne_enclave_start_info *enclave_start_info)
{
int rc = -EINVAL;
rc = ioctl(enclave_fd, NE_START_ENCLAVE, enclave_start_info);
if (rc < 0) {
switch (errno) {
case NE_ERR_NOT_IN_INIT_STATE: {
printf("Error in start enclave, enclave not in init state\n");
break;
}
case NE_ERR_NO_MEM_REGIONS_ADDED: {
printf("Error in start enclave, no memory regions have been added\n");
break;
}
case NE_ERR_NO_VCPUS_ADDED: {
printf("Error in start enclave, no vCPUs have been added\n");
break;
}
case NE_ERR_FULL_CORES_NOT_USED: {
printf("Error in start enclave, enclave has no full cores set\n");
break;
}
case NE_ERR_ENCLAVE_MEM_MIN_SIZE: {
printf("Error in start enclave, enclave memory is less than min size\n");
break;
}
case NE_ERR_INVALID_FLAG_VALUE: {
printf("Error in start enclave, provided invalid flag\n");
break;
}
case NE_ERR_INVALID_ENCLAVE_CID: {
printf("Error in start enclave, provided invalid enclave CID\n");
break;
}
default:
printf("Error in start enclave [%m]\n");
}
return rc;
}
return 0;
}
/**
* ne_start_enclave_check_booted() - Start the enclave and wait for a heartbeat
* from it, on a newly created vsock channel,
* to check it has booted.
* @enclave_fd : The file descriptor associated with the enclave.
*
* Context: Process context.
* Return:
* * 0 on success.
* * Negative return value on failure.
*/
static int ne_start_enclave_check_booted(int enclave_fd)
{
struct sockaddr_vm client_vsock_addr = {};
int client_vsock_fd = -1;
socklen_t client_vsock_len = sizeof(client_vsock_addr);
struct ne_enclave_start_info enclave_start_info = {};
struct pollfd fds[1] = {};
int rc = -EINVAL;
unsigned char recv_buf = 0;
struct sockaddr_vm server_vsock_addr = {
.svm_family = AF_VSOCK,
.svm_cid = NE_IMAGE_LOAD_HEARTBEAT_CID,
.svm_port = NE_IMAGE_LOAD_HEARTBEAT_PORT,
};
int server_vsock_fd = -1;
server_vsock_fd = socket(AF_VSOCK, SOCK_STREAM, 0);
if (server_vsock_fd < 0) {
rc = server_vsock_fd;
printf("Error in socket [%m]\n");
return rc;
}
rc = bind(server_vsock_fd, (struct sockaddr *)&server_vsock_addr,
sizeof(server_vsock_addr));
if (rc < 0) {
printf("Error in bind [%m]\n");
goto out;
}
rc = listen(server_vsock_fd, 1);
if (rc < 0) {
printf("Error in listen [%m]\n");
goto out;
}
rc = ne_start_enclave(enclave_fd, &enclave_start_info);
if (rc < 0)
goto out;
printf("Enclave started, CID %llu\n", enclave_start_info.enclave_cid);
fds[0].fd = server_vsock_fd;
fds[0].events = POLLIN;
rc = poll(fds, 1, NE_POLL_WAIT_TIME_MS);
if (rc < 0) {
printf("Error in poll [%m]\n");
goto out;
}
if (!rc) {
printf("Poll timeout, %d seconds elapsed\n", NE_POLL_WAIT_TIME);
rc = -ETIMEDOUT;
goto out;
}
if ((fds[0].revents & POLLIN) == 0) {
printf("Poll received value %d\n", fds[0].revents);
rc = -EINVAL;
goto out;
}
rc = accept(server_vsock_fd, (struct sockaddr *)&client_vsock_addr,
&client_vsock_len);
if (rc < 0) {
printf("Error in accept [%m]\n");
goto out;
}
client_vsock_fd = rc;
/*
* Read the heartbeat value that the init process in the enclave sends
* after vsock connect.
*/
rc = read(client_vsock_fd, &recv_buf, sizeof(recv_buf));
if (rc < 0) {
printf("Error in read [%m]\n");
goto out;
}
if (rc != sizeof(recv_buf) || recv_buf != NE_IMAGE_LOAD_HEARTBEAT_VALUE) {
printf("Read %d instead of %d\n", recv_buf,
NE_IMAGE_LOAD_HEARTBEAT_VALUE);
goto out;
}
/* Write the heartbeat value back. */
rc = write(client_vsock_fd, &recv_buf, sizeof(recv_buf));
if (rc < 0) {
printf("Error in write [%m]\n");
goto out;
}
rc = 0;
out:
close(server_vsock_fd);
return rc;
}
int main(int argc, char *argv[])
{
int enclave_fd = -1;
unsigned int i = 0;
int ne_dev_fd = -1;
struct ne_user_mem_region ne_user_mem_regions[NE_DEFAULT_NR_MEM_REGIONS] = {};
unsigned int ne_vcpus[NE_DEFAULT_NR_VCPUS] = {};
int rc = -EINVAL;
pthread_t thread_id = 0;
unsigned long slot_uid = 0;
if (argc != 2) {
printf("Usage: %s <path_to_enclave_image>\n", argv[0]);
exit(EXIT_FAILURE);
}
if (strlen(argv[1]) >= PATH_MAX) {
printf("The size of the path to enclave image is higher than max path\n");
exit(EXIT_FAILURE);
}
ne_dev_fd = open(NE_DEV_NAME, O_RDWR | O_CLOEXEC);
if (ne_dev_fd < 0) {
printf("Error in open NE device [%m]\n");
exit(EXIT_FAILURE);
}
printf("Creating enclave slot ...\n");
rc = ne_create_vm(ne_dev_fd, &slot_uid, &enclave_fd);
close(ne_dev_fd);
if (rc < 0)
exit(EXIT_FAILURE);
printf("Enclave fd %d\n", enclave_fd);
rc = pthread_create(&thread_id, NULL, ne_poll_enclave_fd, (void *)&enclave_fd);
if (rc < 0) {
printf("Error in thread create [%m]\n");
close(enclave_fd);
exit(EXIT_FAILURE);
}
for (i = 0; i < NE_DEFAULT_NR_MEM_REGIONS; i++) {
ne_user_mem_regions[i].memory_size = NE_MIN_MEM_REGION_SIZE;
rc = ne_alloc_user_mem_region(&ne_user_mem_regions[i]);
if (rc < 0) {
printf("Error in alloc userspace memory region, iter %d\n", i);
goto release_enclave_fd;
}
}
rc = ne_load_enclave_image(enclave_fd, ne_user_mem_regions, argv[1]);
if (rc < 0)
goto release_enclave_fd;
for (i = 0; i < NE_DEFAULT_NR_MEM_REGIONS; i++) {
rc = ne_set_user_mem_region(enclave_fd, ne_user_mem_regions[i]);
if (rc < 0) {
printf("Error in set memory region, iter %d\n", i);
goto release_enclave_fd;
}
}
printf("Enclave memory regions were added\n");
for (i = 0; i < NE_DEFAULT_NR_VCPUS; i++) {
/*
* The vCPU is chosen from the enclave vCPU pool, if the value
* of the vcpu_id is 0.
*/
ne_vcpus[i] = 0;
rc = ne_add_vcpu(enclave_fd, &ne_vcpus[i]);
if (rc < 0) {
printf("Error in add vcpu, iter %d\n", i);
goto release_enclave_fd;
}
printf("Added vCPU %d to the enclave\n", ne_vcpus[i]);
}
printf("Enclave vCPUs were added\n");
rc = ne_start_enclave_check_booted(enclave_fd);
if (rc < 0) {
printf("Error in the enclave start / image loading heartbeat logic [rc=%d]\n", rc);
goto release_enclave_fd;
}
printf("Entering sleep for %d seconds ...\n", NE_SLEEP_TIME);
sleep(NE_SLEEP_TIME);
close(enclave_fd);
ne_free_mem_regions(ne_user_mem_regions);
exit(EXIT_SUCCESS);
release_enclave_fd:
close(enclave_fd);
ne_free_mem_regions(ne_user_mem_regions);
exit(EXIT_FAILURE);
}
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