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nitro_enclaves: Init misc device providing the ioctl interface
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. Changelog v9 -> v10 * Update commit message to include the changelog before the SoB tag(s). v8 -> v9 * Use the ne_devs data structure to get the refs for the NE misc device in the NE PCI device driver logic. v7 -> v8 * Add define for the CID of the primary / parent VM. * Update the NE PCI driver shutdown logic to include misc device deregister. v6 -> v7 * Set the NE PCI device the parent of the NE misc device to be able to use it in the ioctl logic. * Update the naming and add more comments to make more clear the logic of handling full CPU cores and dedicating them to the enclave. v5 -> v6 * Remove the ioctl to query API version. * Update documentation to kernel-doc format. v4 -> v5 * Update the size of the NE CPU pool string from 4096 to 512 chars. v3 -> v4 * Use dev_err instead of custom NE log pattern. * Remove the NE CPU pool init during kernel module loading, as the CPU pool is now setup at runtime, via a sysfs file for the kernel parameter. * Add minimum enclave memory size definition. v2 -> v3 * Remove the GPL additional wording as SPDX-License-Identifier is already in place. * Remove the WARN_ON calls. * Remove linux/bug and linux/kvm_host includes that are not needed. * Remove "ratelimited" from the logs that are not in the ioctl call paths. * Remove file ops that do nothing for now - open and release. v1 -> v2 * Add log pattern for NE. * Update goto labels to match their purpose. * Update ne_cpu_pool data structure to include the global mutex. * Update NE misc device mode to 0660. * Check if the CPU siblings are included in the NE CPU pool, as full CPU cores are given for the enclave(s). Reviewed-by: Alexander Graf <graf@amazon.com> Signed-off-by: Andra Paraschiv <andraprs@amazon.com> Link: https://lore.kernel.org/r/20200921121732.44291-8-andraprs@amazon.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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‎drivers/virt/nitro_enclaves/ne_misc_dev.c‎

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// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
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*/
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/**
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* DOC: Enclave lifetime management driver for Nitro Enclaves (NE).
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* Nitro is a hypervisor that has been developed by Amazon.
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*/
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#include <linux/anon_inodes.h>
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#include <linux/capability.h>
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#include <linux/cpu.h>
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#include <linux/device.h>
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#include <linux/file.h>
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#include <linux/hugetlb.h>
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#include <linux/limits.h>
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#include <linux/list.h>
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#include <linux/miscdevice.h>
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#include <linux/mm.h>
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#include <linux/mman.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/nitro_enclaves.h>
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#include <linux/pci.h>
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#include <linux/poll.h>
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#include <linux/slab.h>
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#include <linux/types.h>
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#include <uapi/linux/vm_sockets.h>
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#include "ne_misc_dev.h"
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#include "ne_pci_dev.h"
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/**
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* NE_CPUS_SIZE - Size for max 128 CPUs, for now, in a cpu-list string, comma
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* separated. The NE CPU pool includes CPUs from a single NUMA
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* node.
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*/
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#define NE_CPUS_SIZE (512)
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/**
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* NE_EIF_LOAD_OFFSET - The offset where to copy the Enclave Image Format (EIF)
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* image in enclave memory.
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*/
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#define NE_EIF_LOAD_OFFSET (8 * 1024UL * 1024UL)
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/**
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* NE_MIN_ENCLAVE_MEM_SIZE - The minimum memory size an enclave can be launched
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* with.
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*/
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#define NE_MIN_ENCLAVE_MEM_SIZE (64 * 1024UL * 1024UL)
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/**
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* NE_MIN_MEM_REGION_SIZE - The minimum size of an enclave memory region.
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*/
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#define NE_MIN_MEM_REGION_SIZE (2 * 1024UL * 1024UL)
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/**
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* NE_PARENT_VM_CID - The CID for the vsock device of the primary / parent VM.
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*/
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#define NE_PARENT_VM_CID (3)
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static const struct file_operations ne_fops = {
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.owner = THIS_MODULE,
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.llseek = noop_llseek,
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};
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static struct miscdevice ne_misc_dev = {
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.minor = MISC_DYNAMIC_MINOR,
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.name = "nitro_enclaves",
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.fops = &ne_fops,
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.mode = 0660,
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};
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struct ne_devs ne_devs = {
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.ne_misc_dev = &ne_misc_dev,
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};
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/*
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* TODO: Update logic to create new sysfs entries instead of using
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* a kernel parameter e.g. if multiple sysfs files needed.
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*/
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static const struct kernel_param_ops ne_cpu_pool_ops = {
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.get = param_get_string,
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};
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static char ne_cpus[NE_CPUS_SIZE];
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static struct kparam_string ne_cpus_arg = {
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.maxlen = sizeof(ne_cpus),
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.string = ne_cpus,
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};
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module_param_cb(ne_cpus, &ne_cpu_pool_ops, &ne_cpus_arg, 0644);
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/* https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html#cpu-lists */
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MODULE_PARM_DESC(ne_cpus, "<cpu-list> - CPU pool used for Nitro Enclaves");
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/**
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* struct ne_cpu_pool - CPU pool used for Nitro Enclaves.
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* @avail_threads_per_core: Available full CPU cores to be dedicated to
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* enclave(s). The cpumasks from the array, indexed
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* by core id, contain all the threads from the
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* available cores, that are not set for created
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* enclave(s). The full CPU cores are part of the
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* NE CPU pool.
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* @mutex: Mutex for the access to the NE CPU pool.
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* @nr_parent_vm_cores : The size of the available threads per core array.
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* The total number of CPU cores available on the
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* primary / parent VM.
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* @nr_threads_per_core: The number of threads that a full CPU core has.
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* @numa_node: NUMA node of the CPUs in the pool.
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*/
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struct ne_cpu_pool {
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cpumask_var_t *avail_threads_per_core;
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struct mutex mutex;
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unsigned int nr_parent_vm_cores;
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unsigned int nr_threads_per_core;
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int numa_node;
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};
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static struct ne_cpu_pool ne_cpu_pool;
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static int __init ne_init(void)
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{
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mutex_init(&ne_cpu_pool.mutex);
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return pci_register_driver(&ne_pci_driver);
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}
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static void __exit ne_exit(void)
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{
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pci_unregister_driver(&ne_pci_driver);
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}
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module_init(ne_init);
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module_exit(ne_exit);
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MODULE_AUTHOR("Amazon.com, Inc. or its affiliates");
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MODULE_DESCRIPTION("Nitro Enclaves Driver");
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MODULE_LICENSE("GPL v2");

‎drivers/virt/nitro_enclaves/ne_pci_dev.c‎

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@@ -523,8 +523,18 @@ static int ne_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
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ne_devs.ne_pci_dev = ne_pci_dev;
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rc = misc_register(ne_devs.ne_misc_dev);
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if (rc < 0) {
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dev_err(&pdev->dev, "Error in misc dev register [rc=%d]\n", rc);
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goto disable_ne_pci_dev;
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}
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return 0;
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disable_ne_pci_dev:
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ne_devs.ne_pci_dev = NULL;
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ne_pci_dev_disable(pdev);
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teardown_msix:
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ne_teardown_msix(pdev);
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iounmap_pci_bar:
@@ -550,6 +560,8 @@ static void ne_pci_remove(struct pci_dev *pdev)
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{
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struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
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misc_deregister(ne_devs.ne_misc_dev);
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ne_devs.ne_pci_dev = NULL;
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ne_pci_dev_disable(pdev);
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if (!ne_pci_dev)
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return;
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misc_deregister(ne_devs.ne_misc_dev);
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ne_devs.ne_pci_dev = NULL;
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ne_pci_dev_disable(pdev);

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