An enclave, before being started, has its resources set. One of its
resources is CPU.
Add ioctl command logic for enclave vCPU creation. Return as result a
file descriptor that is associated with the enclave vCPU.
Signed-off-by: Alexandru Vasile <le...@amazon.com>
Signed-off-by: Andra Paraschiv <andra...@amazon.com>
---
Changelog
v2 -> v3
* Remove the WARN_ON calls.
* Update static calls sanity checks.
* Update kzfree() calls to kfree().
* Remove file ops that do nothing for now - open, ioctl and release.
v1 -> v2
* Add log pattern for NE.
* Update goto labels to match their purpose.
* Remove the BUG_ON calls.
* Check if enclave state is init when setting enclave vcpu.
---
drivers/virt/nitro_enclaves/ne_misc_dev.c | 190 ++++++++++++++++++++++
1 file changed, 190 insertions(+)
diff --git a/drivers/virt/nitro_enclaves/ne_misc_dev.c
b/drivers/virt/nitro_enclaves/ne_misc_dev.c
index 8cf1c4ee1812..6db88e128d1f 100644
--- a/drivers/virt/nitro_enclaves/ne_misc_dev.c
+++ b/drivers/virt/nitro_enclaves/ne_misc_dev.c
@@ -49,10 +49,200 @@ struct ne_cpu_pool {
static struct ne_cpu_pool ne_cpu_pool;
+static const struct file_operations ne_enclave_vcpu_fops = {
+ .owner = THIS_MODULE,
+ .llseek = noop_llseek,
+};
+
+/**
+ * ne_get_cpu_from_cpu_pool - Get a CPU from the CPU pool, if it is set.
+ *
+ * This function gets called with the ne_enclave mutex held.
+ *
+ * @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.
+ *
+ * @returns: 0 on success, negative return value on failure.
+ */
+static int ne_get_cpu_from_cpu_pool(struct ne_enclave *ne_enclave, u32
*vcpu_id)
+{
+ unsigned int cpu = 0;
+ unsigned int cpu_sibling = 0;
+
+ /* There are CPU siblings available to choose from. */
+ cpu = cpumask_any(ne_enclave->cpu_siblings);
+ if (cpu < nr_cpu_ids) {
+ cpumask_clear_cpu(cpu, ne_enclave->cpu_siblings);
+
+ *vcpu_id = cpu;
+
+ return 0;
+ }
+
+ mutex_lock(&ne_cpu_pool.mutex);
+
+ /* Choose any CPU from the available CPU pool. */
+ cpu = cpumask_any(ne_cpu_pool.avail);
+ if (cpu >= nr_cpu_ids) {
+ pr_err_ratelimited(NE "No CPUs available in CPU pool\n");
+
+ mutex_unlock(&ne_cpu_pool.mutex);
+
+ return -EINVAL;
+ }
+
+ cpumask_clear_cpu(cpu, ne_cpu_pool.avail);
+
+ /*
+ * Make sure the CPU siblings are not marked as
+ * available anymore.
+ */
+ for_each_cpu(cpu_sibling, topology_sibling_cpumask(cpu)) {
+ if (cpu_sibling != cpu) {
+ cpumask_clear_cpu(cpu_sibling, ne_cpu_pool.avail);
+
+ cpumask_set_cpu(cpu_sibling, ne_enclave->cpu_siblings);
+ }
+ }
+
+ mutex_unlock(&ne_cpu_pool.mutex);
+
+ *vcpu_id = cpu;
+
+ return 0;
+}
+
+/**
+ * ne_create_vcpu_ioctl - Add vCPU to the slot associated with the current
+ * enclave. Create vCPU file descriptor to be further used for CPU handling.
+ *
+ * This function gets called with the ne_enclave mutex held.
+ *
+ * @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.
+ *
+ * @returns: vCPU fd on success, negative return value on failure.
+ */
+static int ne_create_vcpu_ioctl(struct ne_enclave *ne_enclave, u32 vcpu_id)
+{
+ struct ne_pci_dev_cmd_reply cmd_reply = {};
+ int fd = 0;
+ struct file *file = NULL;
+ struct ne_vcpu_id *ne_vcpu_id = NULL;
+ int rc = -EINVAL;
+ struct slot_add_vcpu_req slot_add_vcpu_req = {};
+
+ if (ne_enclave->mm != current->mm)
+ return -EIO;
+
+ ne_vcpu_id = kzalloc(sizeof(*ne_vcpu_id), GFP_KERNEL);
+ if (!ne_vcpu_id)
+ return -ENOMEM;
+
+ fd = get_unused_fd_flags(O_CLOEXEC);
+ if (fd < 0) {
+ rc = fd;
+
+ pr_err_ratelimited(NE "Error in getting unused fd [rc=%d]\n",
+ rc);
+
+ goto free_ne_vcpu_id;
+ }
+
+ /* TODO: Include (vcpu) id in the ne-vm-vcpu naming. */
+ file = anon_inode_getfile("ne-vm-vcpu", &ne_enclave_vcpu_fops,
+ ne_enclave, O_RDWR);
+ if (IS_ERR(file)) {
+ rc = PTR_ERR(file);
+
+ pr_err_ratelimited(NE "Error in anon inode get file [rc=%d]\n",
+ rc);
+
+ goto put_fd;
+ }
+
+ slot_add_vcpu_req.slot_uid = ne_enclave->slot_uid;
+ slot_add_vcpu_req.vcpu_id = vcpu_id;
+
+ rc = ne_do_request(ne_enclave->pdev, SLOT_ADD_VCPU, &slot_add_vcpu_req,
+ sizeof(slot_add_vcpu_req), &cmd_reply,
+ sizeof(cmd_reply));
+ if (rc < 0) {
+ pr_err_ratelimited(NE "Error in slot add vcpu [rc=%d]\n", rc);
+
+ goto put_file;
+ }
+
+ ne_vcpu_id->vcpu_id = vcpu_id;
+
+ list_add(&ne_vcpu_id->vcpu_id_list_entry, &ne_enclave->vcpu_ids_list);
+
+ ne_enclave->nr_vcpus++;
+
+ fd_install(fd, file);
+
+ return fd;
+
+put_file:
+ fput(file);
+put_fd:
+ put_unused_fd(fd);
+free_ne_vcpu_id:
+ kfree(ne_vcpu_id);
+
+ return rc;
+}
+
static long ne_enclave_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
+ struct ne_enclave *ne_enclave = file->private_data;
+
+ if (!ne_enclave || !ne_enclave->pdev)
+ return -EINVAL;
+
switch (cmd) {
+ case KVM_CREATE_VCPU: {
+ int rc = -EINVAL;
+ u32 vcpu_id = 0;
+
+ if (copy_from_user(&vcpu_id, (void *)arg, sizeof(vcpu_id))) {
+ pr_err_ratelimited(NE "Error in copy from user\n");
+
+ return -EFAULT;
+ }
+
+ mutex_lock(&ne_enclave->enclave_info_mutex);
+
+ if (ne_enclave->state != NE_STATE_INIT) {
+ pr_err_ratelimited(NE "Enclave isn't in init state\n");
+
+ mutex_unlock(&ne_enclave->enclave_info_mutex);
+
+ return -EINVAL;
+ }
+
+ /* 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) {
+ pr_err_ratelimited(NE "Error in get CPU from pool\n");
+
+ mutex_unlock(&ne_enclave->enclave_info_mutex);
+
+ return -EINVAL;
+ }
+
+ rc = ne_create_vcpu_ioctl(ne_enclave, vcpu_id);
+
+ /* Put back the CPU in enclave cpu pool, if add vcpu error. */
+ if (rc < 0)
+ cpumask_set_cpu(vcpu_id, ne_enclave->cpu_siblings);
+
+ mutex_unlock(&ne_enclave->enclave_info_mutex);
+
+ return rc;
+ }
+
default:
return -ENOTTY;
}
--
2.20.1 (Apple Git-117)
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