diff options
| -rw-r--r-- | drivers/virt/nitro_enclaves/ne_misc_dev.c | 695 |
1 files changed, 695 insertions, 0 deletions
diff --git a/drivers/virt/nitro_enclaves/ne_misc_dev.c b/drivers/virt/nitro_enclaves/ne_misc_dev.c index 3515b163ad0e..24e4270d181d 100644 --- a/drivers/virt/nitro_enclaves/ne_misc_dev.c +++ b/drivers/virt/nitro_enclaves/ne_misc_dev.c @@ -83,8 +83,11 @@ struct ne_devs ne_devs = { * TODO: Update logic to create new sysfs entries instead of using * a kernel parameter e.g. if multiple sysfs files needed. */ +static int ne_set_kernel_param(const char *val, const struct kernel_param *kp); + static const struct kernel_param_ops ne_cpu_pool_ops = { .get = param_get_string, + .set = ne_set_kernel_param, }; static char ne_cpus[NE_CPUS_SIZE]; @@ -123,6 +126,695 @@ struct ne_cpu_pool { static struct ne_cpu_pool ne_cpu_pool; /** + * ne_check_enclaves_created() - Verify if at least one enclave has been created. + * @void: No parameters provided. + * + * Context: Process context. + * Return: + * * True if at least one enclave is created. + * * False otherwise. + */ +static bool ne_check_enclaves_created(void) +{ + struct ne_pci_dev *ne_pci_dev = ne_devs.ne_pci_dev; + bool ret = false; + + if (!ne_pci_dev) + return ret; + + mutex_lock(&ne_pci_dev->enclaves_list_mutex); + + if (!list_empty(&ne_pci_dev->enclaves_list)) + ret = true; + + mutex_unlock(&ne_pci_dev->enclaves_list_mutex); + + return ret; +} + +/** + * ne_setup_cpu_pool() - Set the NE CPU pool after handling sanity checks such + * as not sharing CPU cores with the primary / parent VM + * or not using CPU 0, which should remain available for + * the primary / parent VM. Offline the CPUs from the + * pool after the checks passed. + * @ne_cpu_list: The CPU list used for setting NE CPU pool. + * + * Context: Process context. + * Return: + * * 0 on success. + * * Negative return value on failure. + */ +static int ne_setup_cpu_pool(const char *ne_cpu_list) +{ + int core_id = -1; + unsigned int cpu = 0; + cpumask_var_t cpu_pool; + unsigned int cpu_sibling = 0; + unsigned int i = 0; + int numa_node = -1; + int rc = -EINVAL; + + if (!zalloc_cpumask_var(&cpu_pool, GFP_KERNEL)) + return -ENOMEM; + + mutex_lock(&ne_cpu_pool.mutex); + + rc = cpulist_parse(ne_cpu_list, cpu_pool); + if (rc < 0) { + pr_err("%s: Error in cpulist parse [rc=%d]\n", ne_misc_dev.name, rc); + + goto free_pool_cpumask; + } + + cpu = cpumask_any(cpu_pool); + if (cpu >= nr_cpu_ids) { + pr_err("%s: No CPUs available in CPU pool\n", ne_misc_dev.name); + + rc = -EINVAL; + + goto free_pool_cpumask; + } + + /* + * Check if the CPUs are online, to further get info about them + * e.g. numa node, core id, siblings. + */ + for_each_cpu(cpu, cpu_pool) + if (cpu_is_offline(cpu)) { + pr_err("%s: CPU %d is offline, has to be online to get its metadata\n", + ne_misc_dev.name, cpu); + + rc = -EINVAL; + + goto free_pool_cpumask; + } + + /* + * Check if the CPUs from the NE CPU pool are from the same NUMA node. + */ + for_each_cpu(cpu, cpu_pool) + if (numa_node < 0) { + numa_node = cpu_to_node(cpu); + if (numa_node < 0) { + pr_err("%s: Invalid NUMA node %d\n", + ne_misc_dev.name, numa_node); + + rc = -EINVAL; + + goto free_pool_cpumask; + } + } else { + if (numa_node != cpu_to_node(cpu)) { + pr_err("%s: CPUs with different NUMA nodes\n", + ne_misc_dev.name); + + rc = -EINVAL; + + goto free_pool_cpumask; + } + } + + /* + * Check if CPU 0 and its siblings are included in the provided CPU pool + * They should remain available for the primary / parent VM. + */ + if (cpumask_test_cpu(0, cpu_pool)) { + pr_err("%s: CPU 0 has to remain available\n", ne_misc_dev.name); + + rc = -EINVAL; + + goto free_pool_cpumask; + } + + for_each_cpu(cpu_sibling, topology_sibling_cpumask(0)) { + if (cpumask_test_cpu(cpu_sibling, cpu_pool)) { + pr_err("%s: CPU sibling %d for CPU 0 is in CPU pool\n", + ne_misc_dev.name, cpu_sibling); + + rc = -EINVAL; + + goto free_pool_cpumask; + } + } + + /* + * Check if CPU siblings are included in the provided CPU pool. The + * expectation is that full CPU cores are made available in the CPU pool + * for enclaves. + */ + for_each_cpu(cpu, cpu_pool) { + for_each_cpu(cpu_sibling, topology_sibling_cpumask(cpu)) { + if (!cpumask_test_cpu(cpu_sibling, cpu_pool)) { + pr_err("%s: CPU %d is not in CPU pool\n", + ne_misc_dev.name, cpu_sibling); + + rc = -EINVAL; + + goto free_pool_cpumask; + } + } + } + + /* Calculate the number of threads from a full CPU core. */ + cpu = cpumask_any(cpu_pool); + for_each_cpu(cpu_sibling, topology_sibling_cpumask(cpu)) + ne_cpu_pool.nr_threads_per_core++; + + ne_cpu_pool.nr_parent_vm_cores = nr_cpu_ids / ne_cpu_pool.nr_threads_per_core; + + ne_cpu_pool.avail_threads_per_core = kcalloc(ne_cpu_pool.nr_parent_vm_cores, + sizeof(*ne_cpu_pool.avail_threads_per_core), + GFP_KERNEL); + if (!ne_cpu_pool.avail_threads_per_core) { + rc = -ENOMEM; + + goto free_pool_cpumask; + } + + for (i = 0; i < ne_cpu_pool.nr_parent_vm_cores; i++) + if (!zalloc_cpumask_var(&ne_cpu_pool.avail_threads_per_core[i], GFP_KERNEL)) { + rc = -ENOMEM; + + goto free_cores_cpumask; + } + + /* + * Split the NE CPU pool in threads per core to keep the CPU topology + * after offlining the CPUs. + */ + for_each_cpu(cpu, cpu_pool) { + core_id = topology_core_id(cpu); + if (core_id < 0 || core_id >= ne_cpu_pool.nr_parent_vm_cores) { + pr_err("%s: Invalid core id %d for CPU %d\n", + ne_misc_dev.name, core_id, cpu); + + rc = -EINVAL; + + goto clear_cpumask; + } + + cpumask_set_cpu(cpu, ne_cpu_pool.avail_threads_per_core[core_id]); + } + + /* + * CPUs that are given to enclave(s) should not be considered online + * by Linux anymore, as the hypervisor will degrade them to floating. + * The physical CPUs (full cores) are carved out of the primary / parent + * VM and given to the enclave VM. The same number of vCPUs would run + * on less pCPUs for the primary / parent VM. + * + * We offline them here, to not degrade performance and expose correct + * topology to Linux and user space. + */ + for_each_cpu(cpu, cpu_pool) { + rc = remove_cpu(cpu); + if (rc != 0) { + pr_err("%s: CPU %d is not offlined [rc=%d]\n", + ne_misc_dev.name, cpu, rc); + + goto online_cpus; + } + } + + free_cpumask_var(cpu_pool); + + ne_cpu_pool.numa_node = numa_node; + + mutex_unlock(&ne_cpu_pool.mutex); + + return 0; + +online_cpus: + for_each_cpu(cpu, cpu_pool) + add_cpu(cpu); +clear_cpumask: + for (i = 0; i < ne_cpu_pool.nr_parent_vm_cores; i++) + cpumask_clear(ne_cpu_pool.avail_threads_per_core[i]); +free_cores_cpumask: + for (i = 0; i < ne_cpu_pool.nr_parent_vm_cores; i++) + free_cpumask_var(ne_cpu_pool.avail_threads_per_core[i]); + kfree(ne_cpu_pool.avail_threads_per_core); +free_pool_cpumask: + free_cpumask_var(cpu_pool); + ne_cpu_pool.nr_parent_vm_cores = 0; + ne_cpu_pool.nr_threads_per_core = 0; + ne_cpu_pool.numa_node = -1; + mutex_unlock(&ne_cpu_pool.mutex); + + return rc; +} + +/** + * ne_teardown_cpu_pool() - Online the CPUs from the NE CPU pool and cleanup the + * CPU pool. + * @void: No parameters provided. + * + * Context: Process context. + */ +static void ne_teardown_cpu_pool(void) +{ + unsigned int cpu = 0; + unsigned int i = 0; + int rc = -EINVAL; + + mutex_lock(&ne_cpu_pool.mutex); + + if (!ne_cpu_pool.nr_parent_vm_cores) { + mutex_unlock(&ne_cpu_pool.mutex); + + return; + } + + for (i = 0; i < ne_cpu_pool.nr_parent_vm_cores; i++) { + for_each_cpu(cpu, ne_cpu_pool.avail_threads_per_core[i]) { + rc = add_cpu(cpu); + if (rc != 0) + pr_err("%s: CPU %d is not onlined [rc=%d]\n", + ne_misc_dev.name, cpu, rc); + } + + cpumask_clear(ne_cpu_pool.avail_threads_per_core[i]); + + free_cpumask_var(ne_cpu_pool.avail_threads_per_core[i]); + } + + kfree(ne_cpu_pool.avail_threads_per_core); + ne_cpu_pool.nr_parent_vm_cores = 0; + ne_cpu_pool.nr_threads_per_core = 0; + ne_cpu_pool.numa_node = -1; + + mutex_unlock(&ne_cpu_pool.mutex); +} + +/** + * ne_set_kernel_param() - Set the NE CPU pool value via the NE kernel parameter. + * @val: NE CPU pool string value. + * @kp : NE kernel parameter associated with the NE CPU pool. + * + * Context: Process context. + * Return: + * * 0 on success. + * * Negative return value on failure. + */ +static int ne_set_kernel_param(const char *val, const struct kernel_param *kp) +{ + char error_val[] = ""; + int rc = -EINVAL; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + if (ne_check_enclaves_created()) { + pr_err("%s: The CPU pool is used by enclave(s)\n", ne_misc_dev.name); + + return -EPERM; + } + + ne_teardown_cpu_pool(); + + rc = ne_setup_cpu_pool(val); + if (rc < 0) { + pr_err("%s: Error in setup CPU pool [rc=%d]\n", ne_misc_dev.name, rc); + + param_set_copystring(error_val, kp); + + return rc; + } + + rc = param_set_copystring(val, kp); + if (rc < 0) { + pr_err("%s: Error in param set copystring [rc=%d]\n", ne_misc_dev.name, rc); + + ne_teardown_cpu_pool(); + + param_set_copystring(error_val, kp); + + return rc; + } + + return 0; +} + +/** + * ne_donated_cpu() - Check if the provided CPU is already used by the enclave. + * @ne_enclave : Private data associated with the current enclave. + * @cpu: CPU to check if already used. + * + * Context: Process context. This function is called with the ne_enclave mutex held. + * Return: + * * True if the provided CPU is already used by the enclave. + * * False otherwise. + */ +static bool ne_donated_cpu(struct ne_enclave *ne_enclave, unsigned int cpu) +{ + if (cpumask_test_cpu(cpu, ne_enclave->vcpu_ids)) + return true; + + return false; +} + +/** + * ne_get_unused_core_from_cpu_pool() - Get the id of a full core from the + * NE CPU pool. + * @void: No parameters provided. + * + * Context: Process context. This function is called with the ne_enclave and + * ne_cpu_pool mutexes held. + * Return: + * * Core id. + * * -1 if no CPU core available in the pool. + */ +static int ne_get_unused_core_from_cpu_pool(void) +{ + int core_id = -1; + unsigned int i = 0; + + for (i = 0; i < ne_cpu_pool.nr_parent_vm_cores; i++) + if (!cpumask_empty(ne_cpu_pool.avail_threads_per_core[i])) { + core_id = i; + + break; + } + + return core_id; +} + +/** + * ne_set_enclave_threads_per_core() - Set the threads of the provided core in + * the enclave data structure. + * @ne_enclave : Private data associated with the current enclave. + * @core_id: Core id to get its threads from the NE CPU pool. + * @vcpu_id: vCPU id part of the provided core. + * + * Context: Process context. This function is called with the ne_enclave and + * ne_cpu_pool mutexes held. + * Return: + * * 0 on success. + * * Negative return value on failure. + */ +static int ne_set_enclave_threads_per_core(struct ne_enclave *ne_enclave, + int core_id, u32 vcpu_id) +{ + unsigned int cpu = 0; + + if (core_id < 0 && vcpu_id == 0) { + dev_err_ratelimited(ne_misc_dev.this_device, + "No CPUs available in NE CPU pool\n"); + + return -NE_ERR_NO_CPUS_AVAIL_IN_POOL; + } + + if (core_id < 0) { + dev_err_ratelimited(ne_misc_dev.this_device, + "CPU %d is not in NE CPU pool\n", vcpu_id); + + return -NE_ERR_VCPU_NOT_IN_CPU_POOL; + } + + if (core_id >= ne_enclave->nr_parent_vm_cores) { + dev_err_ratelimited(ne_misc_dev.this_device, + "Invalid core id %d - ne_enclave\n", core_id); + + return -NE_ERR_VCPU_INVALID_CPU_CORE; + } + + for_each_cpu(cpu, ne_cpu_pool.avail_threads_per_core[core_id]) + cpumask_set_cpu(cpu, ne_enclave->threads_per_core[core_id]); + + cpumask_clear(ne_cpu_pool.avail_threads_per_core[core_id]); + + return 0; +} + +/** + * ne_get_cpu_from_cpu_pool() - Get a CPU from the NE CPU pool, either from the + * remaining sibling(s) of a CPU core or the first + * sibling of a new CPU core. + * @ne_enclave : Private data associated with the current enclave. + * @vcpu_id: vCPU to get from the NE CPU pool. + * + * Context: Process context. This function is called with the ne_enclave mutex held. + * Return: + * * 0 on success. + * * Negative return value on failure. + */ +static int ne_get_cpu_from_cpu_pool(struct ne_enclave *ne_enclave, u32 *vcpu_id) +{ + int core_id = -1; + unsigned int cpu = 0; + unsigned int i = 0; + int rc = -EINVAL; + + /* + * If previously allocated a thread of a core to this enclave, first + * check remaining sibling(s) for new CPU allocations, so that full + * CPU cores are used for the enclave. + */ + for (i = 0; i < ne_enclave->nr_parent_vm_cores; i++) + for_each_cpu(cpu, ne_enclave->threads_per_core[i]) + if (!ne_donated_cpu(ne_enclave, cpu)) { + *vcpu_id = cpu; + + return 0; + } + + mutex_lock(&ne_cpu_pool.mutex); + + /* + * If no remaining siblings, get a core from the NE CPU pool and keep + * track of all the threads in the enclave threads per core data structure. + */ + core_id = ne_get_unused_core_from_cpu_pool(); + + rc = ne_set_enclave_threads_per_core(ne_enclave, core_id, *vcpu_id); + if (rc < 0) + goto unlock_mutex; + + *vcpu_id = cpumask_any(ne_enclave->threads_per_core[core_id]); + + rc = 0; + +unlock_mutex: + mutex_unlock(&ne_cpu_pool.mutex); + + return rc; +} + +/** + * ne_get_vcpu_core_from_cpu_pool() - Get from the NE CPU pool the id of the + * core associated with the provided vCPU. + * @vcpu_id: Provided vCPU id to get its associated core id. + * + * Context: Process context. This function is called with the ne_enclave and + * ne_cpu_pool mutexes held. + * Return: + * * Core id. + * * -1 if the provided vCPU is not in the pool. + */ +static int ne_get_vcpu_core_from_cpu_pool(u32 vcpu_id) +{ + int core_id = -1; + unsigned int i = 0; + + for (i = 0; i < ne_cpu_pool.nr_parent_vm_cores; i++) + if (cpumask_test_cpu(vcpu_id, ne_cpu_pool.avail_threads_per_core[i])) { + core_id = i; + + break; + } + + return core_id; +} + +/** + * ne_check_cpu_in_cpu_pool() - Check if the given vCPU is in the available CPUs + * from the pool. + * @ne_enclave : Private data associated with the current enclave. + * @vcpu_id: ID of the vCPU to check if available in the NE CPU pool. + * + * Context: Process context. This function is called with the ne_enclave mutex held. + * Return: + * * 0 on success. + * * Negative return value on failure. + */ +static int ne_check_cpu_in_cpu_pool(struct ne_enclave *ne_enclave, u32 vcpu_id) +{ + int core_id = -1; + unsigned int i = 0; + int rc = -EINVAL; + + if (ne_donated_cpu(ne_enclave, vcpu_id)) { + dev_err_ratelimited(ne_misc_dev.this_device, + "CPU %d already used\n", vcpu_id); + + return -NE_ERR_VCPU_ALREADY_USED; + } + + /* + * If previously allocated a thread of a core to this enclave, but not + * the full core, first check remaining sibling(s). + */ + for (i = 0; i < ne_enclave->nr_parent_vm_cores; i++) + if (cpumask_test_cpu(vcpu_id, ne_enclave->threads_per_core[i])) + return 0; + + mutex_lock(&ne_cpu_pool.mutex); + + /* + * If no remaining siblings, get from the NE CPU pool the core + * associated with the vCPU and keep track of all the threads in the + * enclave threads per core data structure. + */ + core_id = ne_get_vcpu_core_from_cpu_pool(vcpu_id); + + rc = ne_set_enclave_threads_per_core(ne_enclave, core_id, vcpu_id); + if (rc < 0) + goto unlock_mutex; + + rc = 0; + +unlock_mutex: + mutex_unlock(&ne_cpu_pool.mutex); + + return rc; +} + +/** + * ne_add_vcpu_ioctl() - Add a vCPU to the slot associated with the current + * enclave. + * @ne_enclave : Private data associated with the current enclave. + * @vcpu_id: ID of the CPU to be associated with the given slot, + * apic id on x86. + * + * Context: Process context. This function is called with the ne_enclave mutex held. + * Return: + * * 0 on success. + * * Negative return value on failure. + */ +static int ne_add_vcpu_ioctl(struct ne_enclave *ne_enclave, u32 vcpu_id) +{ + struct ne_pci_dev_cmd_reply cmd_reply = {}; + struct pci_dev *pdev = ne_devs.ne_pci_dev->pdev; + int rc = -EINVAL; + struct slot_add_vcpu_req slot_add_vcpu_req = {}; + + if (ne_enclave->mm != current->mm) + return -EIO; + + slot_add_vcpu_req.slot_uid = ne_enclave->slot_uid; + slot_add_vcpu_req.vcpu_id = vcpu_id; + + rc = ne_do_request(pdev, SLOT_ADD_VCPU, + &slot_add_vcpu_req, sizeof(slot_add_vcpu_req), + &cmd_reply, sizeof(cmd_reply)); + if (rc < 0) { + dev_err_ratelimited(ne_misc_dev.this_device, + "Error in slot add vCPU [rc=%d]\n", rc); + + return rc; + } + + cpumask_set_cpu(vcpu_id, ne_enclave->vcpu_ids); + + ne_enclave->nr_vcpus++; + + return 0; +} + +/** + * ne_enclave_ioctl() - Ioctl function provided by the enclave file. + * @file: File associated with this ioctl function. + * @cmd: The command that is set for the ioctl call. + * @arg: The argument that is provided for the ioctl call. + * + * Context: Process context. + * Return: + * * 0 on success. + * * Negative return value on failure. + */ +static long ne_enclave_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct ne_enclave *ne_enclave = file->private_data; + + switch (cmd) { + case NE_ADD_VCPU: { + int rc = -EINVAL; + u32 vcpu_id = 0; + + if (copy_from_user(&vcpu_id, (void __user *)arg, sizeof(vcpu_id))) + return -EFAULT; + + mutex_lock(&ne_enclave->enclave_info_mutex); + + if (ne_enclave->state != NE_STATE_INIT) { + dev_err_ratelimited(ne_misc_dev.this_device, + "Enclave is not in init state\n"); + + mutex_unlock(&ne_enclave->enclave_info_mutex); + + return -NE_ERR_NOT_IN_INIT_STATE; + } + + if (vcpu_id >= (ne_enclave->nr_parent_vm_cores * + ne_enclave->nr_threads_per_core)) { + dev_err_ratelimited(ne_misc_dev.this_device, + "vCPU id higher than max CPU id\n"); + + mutex_unlock(&ne_enclave->enclave_info_mutex); + + return -NE_ERR_INVALID_VCPU; + } + + if (!vcpu_id) { + /* Use the CPU pool for choosing a CPU for the enclave. */ + rc = ne_get_cpu_from_cpu_pool(ne_enclave, &vcpu_id); + if (rc < 0) { + dev_err_ratelimited(ne_misc_dev.this_device, + "Error in get CPU from pool [rc=%d]\n", + rc); + + mutex_unlock(&ne_enclave->enclave_info_mutex); + + return rc; + } + } else { + /* Check if the provided vCPU is available in the NE CPU pool. */ + rc = ne_check_cpu_in_cpu_pool(ne_enclave, vcpu_id); + if (rc < 0) { + dev_err_ratelimited(ne_misc_dev.this_device, + "Error in check CPU %d in pool [rc=%d]\n", + vcpu_id, rc); + + mutex_unlock(&ne_enclave->enclave_info_mutex); + + return rc; + } + } + + rc = ne_add_vcpu_ioctl(ne_enclave, vcpu_id); + if (rc < 0) { + mutex_unlock(&ne_enclave->enclave_info_mutex); + + return rc; + } + + mutex_unlock(&ne_enclave->enclave_info_mutex); + + if (copy_to_user((void __user *)arg, &vcpu_id, sizeof(vcpu_id))) + return -EFAULT; + + return 0; + } + + default: + return -ENOTTY; + } + + return 0; +} + +/** * ne_enclave_poll() - Poll functionality used for enclave out-of-band events. * @file: File associated with this poll function. * @wait: Poll table data structure. @@ -150,6 +842,7 @@ static const struct file_operations ne_enclave_fops = { .owner = THIS_MODULE, .llseek = noop_llseek, .poll = ne_enclave_poll, + .unlocked_ioctl = ne_enclave_ioctl, }; /** @@ -352,6 +1045,8 @@ static int __init ne_init(void) static void __exit ne_exit(void) { pci_unregister_driver(&ne_pci_driver); + + ne_teardown_cpu_pool(); } module_init(ne_init); |