[PATCH v1 07/15] nitro_enclaves: Init misc device providing the ioctl interface

Andra Paraschiv
2020-04-21T18:43:11Z

The Nitro Enclaves driver provides an ioctl interface to the user space
for enclave lifetime management e.g. enclave creation / termination and
setting enclave resources such as memory and CPU.

This ioctl interface is mapped to a Nitro Enclaves misc device.

Signed-off-by: Andra Paraschiv <andraprs@amazon.com>
---
.../virt/amazon/nitro_enclaves/ne_misc_dev.c | 174 ++++++++++++++++++
.../virt/amazon/nitro_enclaves/ne_pci_dev.c | 13 ++
2 files changed, 187 insertions(+)
create mode 100644 drivers/virt/amazon/nitro_enclaves/ne_misc_dev.c

diff --git a/drivers/virt/amazon/nitro_enclaves/ne_misc_dev.c b/drivers/virt/amazon/nitro_enclaves/ne_misc_dev.c
new file mode 100644
index 000000000000..d22a76ed07e5
--- /dev/null
+++ b/drivers/virt/amazon/nitro_enclaves/ne_misc_dev.c
@@ -0,0 +1,174 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * Enclave lifetime management driver for Nitro Enclaves (NE).
+ * Nitro is a hypervisor that has been developed by Amazon.
+ */
+
+#include <linux/anon_inodes.h>
+#include <linux/bug.h>
+#include <linux/cpu.h>
+#include <linux/device.h>
+#include <linux/file.h>
+#include <linux/hugetlb.h>
+#include <linux/kvm_host.h>
+#include <linux/list.h>
+#include <linux/miscdevice.h>
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/nitro_enclaves.h>
+#include <linux/pci.h>
+#include <linux/poll.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include "ne_misc_dev.h"
+#include "ne_pci_dev.h"
+
+#define NE_DEV_NAME "nitro_enclaves"
+
+#define MIN_MEM_REGION_SIZE (2 * 1024UL * 1024UL)
+
+static char *ne_cpus;
+module_param(ne_cpus, charp, 0644);
+MODULE_PARM_DESC(ne_cpus, "<cpu-list> - CPU pool used for Nitro Enclaves");
+
+/* CPU pool used for Nitro Enclaves. */
+struct ne_cpu_pool {
+ /* Available CPUs in the pool. */
+ cpumask_var_t avail;
+};
+
+static struct ne_cpu_pool ne_cpu_pool;
+
+static struct mutex ne_cpu_pool_mutex;
+
+static int ne_open(struct inode *node, struct file *file)
+{
+ return 0;
+}
+
+static long ne_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ switch (cmd) {
+
+ default:
+ return -ENOTTY;
+ }
+
+ return 0;
+}
+
+static int ne_release(struct inode *inode, struct file *file)
+{
+ return 0;
+}
+
+static const struct file_operations ne_fops = {
+ .owner = THIS_MODULE,
+ .llseek = noop_llseek,
+ .unlocked_ioctl = ne_ioctl,
+ .open = ne_open,
+ .release = ne_release,
+};
+
+struct miscdevice ne_miscdevice = {
+ .minor = MISC_DYNAMIC_MINOR,
+ .name = NE_DEV_NAME,
+ .fops = &ne_fops,
+ .mode = 0664,
+};
+
+static int __init ne_init(void)
+{
+ unsigned int cpu = 0;
+ int rc = -EINVAL;
+
+ memset(&ne_cpu_pool, 0, sizeof(ne_cpu_pool));
+
+ if (!zalloc_cpumask_var(&ne_cpu_pool.avail, GFP_KERNEL))
+ return -ENOMEM;
+
+ mutex_init(&ne_cpu_pool_mutex);
+
+ rc = cpulist_parse(ne_cpus, ne_cpu_pool.avail);
+ if (rc < 0) {
+ pr_err_ratelimited("Failure in cpulist parse [rc=%d]\n", rc);
+
+ goto err_cpulist_parse;
+ }
+
+ for_each_cpu(cpu, ne_cpu_pool.avail) {
+ rc = remove_cpu(cpu);
+ if (rc != 0) {
+ pr_err_ratelimited("Failure in cpu=%d remove [rc=%d]\n",
+ cpu, rc);
+
+ goto err_remove_cpu;
+ }
+ }
+
+ rc = pci_register_driver(&ne_pci_driver);
+ if (rc < 0) {
+ pr_err_ratelimited("Failure in pci register driver [rc=%d]\n",
+ rc);
+
+ goto err_pci_register_driver;
+ }
+
+ return 0;
+
+err_pci_register_driver:
+err_remove_cpu:
+ for_each_cpu(cpu, ne_cpu_pool.avail)
+ add_cpu(cpu);
+err_cpulist_parse:
+ free_cpumask_var(ne_cpu_pool.avail);
+ return rc;
+}
+
+static void __exit ne_exit(void)
+{
+ unsigned int cpu = 0;
+ int rc = -EINVAL;
+
+ pci_unregister_driver(&ne_pci_driver);
+
+ if (!ne_cpu_pool.avail)
+ return;
+
+ for_each_cpu(cpu, ne_cpu_pool.avail) {
+ rc = add_cpu(cpu);
+ if (WARN_ON(rc != 0))
+ pr_err_ratelimited("Failure in cpu=%d add [rc=%d]\n",
+ cpu, rc);
+ }
+
+ free_cpumask_var(ne_cpu_pool.avail);
+}
+
+/* TODO: Handle actions such as reboot, kexec. */
+
+module_init(ne_init);
+module_exit(ne_exit);
+
+MODULE_AUTHOR("Amazon.com, Inc. or its affiliates");
+MODULE_DESCRIPTION("Nitro Enclaves Driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/virt/amazon/nitro_enclaves/ne_pci_dev.c b/drivers/virt/amazon/nitro_enclaves/ne_pci_dev.c
index 884acbb92305..19b3836b08f4 100644
--- a/drivers/virt/amazon/nitro_enclaves/ne_pci_dev.c
+++ b/drivers/virt/amazon/nitro_enclaves/ne_pci_dev.c
@@ -593,6 +593,15 @@ static int ne_probe(struct pci_dev *pdev, const struct pci_device_id *id)
goto err_ne_pci_dev_enable;
}

+ rc = misc_register(&ne_miscdevice);
+ if (rc < 0) {
+ dev_err_ratelimited(&pdev->dev,
+ "Failure in misc dev register [rc=%d]\n",
+ rc);
+
+ goto err_misc_register;
+ }
+
atomic_set(&ne_pci_dev->cmd_reply_avail, 0);
init_waitqueue_head(&ne_pci_dev->cmd_reply_wait_q);
INIT_LIST_HEAD(&ne_pci_dev->enclaves_list);
@@ -603,6 +612,8 @@ static int ne_probe(struct pci_dev *pdev, const struct pci_device_id *id)

return 0;

+err_misc_register:
+ ne_pci_dev_disable(pdev, ne_pci_dev);
err_ne_pci_dev_enable:
err_ne_pci_dev_disable:
free_irq(pci_irq_vector(pdev, NE_VEC_EVENT), ne_pci_dev);
@@ -627,6 +638,8 @@ static void ne_remove(struct pci_dev *pdev)
if (!ne_pci_dev || !ne_pci_dev->iomem_base)
return;

+ misc_deregister(&ne_miscdevice);
+
ne_pci_dev_disable(pdev, ne_pci_dev);

pci_set_drvdata(pdev, NULL);
--
2.20.1 (Apple Git-117)