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

[Andra Paraschiv <andraprs@amazon.com>]

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)




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