Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 626 insertions, 0 deletions

diff --git a/drivers/virt/nitro_enclaves/ne_pci_dev.c b/drivers/virt/nitro_enclaves/ne_pci_dev.c
new file mode 100644
index 0000000000..6b81e8f3a5
--- /dev/null
+++ b/drivers/virt/nitro_enclaves/ne_pci_dev.c
@@ -0,0 +1,626 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2020-2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ */
+
+/**
+ * DOC: Nitro Enclaves (NE) PCI device driver.
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/nitro_enclaves.h>
+#include <linux/pci.h>
+#include <linux/types.h>
+#include <linux/wait.h>
+
+#include "ne_misc_dev.h"
+#include "ne_pci_dev.h"
+
+/**
+ * NE_DEFAULT_TIMEOUT_MSECS - Default timeout to wait for a reply from
+ *			      the NE PCI device.
+ */
+#define NE_DEFAULT_TIMEOUT_MSECS	(120000) /* 120 sec */
+
+static const struct pci_device_id ne_pci_ids[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_AMAZON, PCI_DEVICE_ID_NE) },
+	{ 0, }
+};
+
+MODULE_DEVICE_TABLE(pci, ne_pci_ids);
+
+/**
+ * ne_submit_request() - Submit command request to the PCI device based on the
+ *			 command type.
+ * @pdev:		PCI device to send the command to.
+ * @cmd_type:		Command type of the request sent to the PCI device.
+ * @cmd_request:	Command request payload.
+ * @cmd_request_size:	Size of the command request payload.
+ *
+ * Context: Process context. This function is called with the ne_pci_dev mutex held.
+ */
+static void ne_submit_request(struct pci_dev *pdev, enum ne_pci_dev_cmd_type cmd_type,
+			      void *cmd_request, size_t cmd_request_size)
+{
+	struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
+
+	memcpy_toio(ne_pci_dev->iomem_base + NE_SEND_DATA, cmd_request, cmd_request_size);
+
+	iowrite32(cmd_type, ne_pci_dev->iomem_base + NE_COMMAND);
+}
+
+/**
+ * ne_retrieve_reply() - Retrieve reply from the PCI device.
+ * @pdev:		PCI device to receive the reply from.
+ * @cmd_reply:		Command reply payload.
+ * @cmd_reply_size:	Size of the command reply payload.
+ *
+ * Context: Process context. This function is called with the ne_pci_dev mutex held.
+ */
+static void ne_retrieve_reply(struct pci_dev *pdev, struct ne_pci_dev_cmd_reply *cmd_reply,
+			      size_t cmd_reply_size)
+{
+	struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
+
+	memcpy_fromio(cmd_reply, ne_pci_dev->iomem_base + NE_RECV_DATA, cmd_reply_size);
+}
+
+/**
+ * ne_wait_for_reply() - Wait for a reply of a PCI device command.
+ * @pdev:	PCI device for which a reply is waited.
+ *
+ * Context: Process context. This function is called with the ne_pci_dev mutex held.
+ * Return:
+ * * 0 on success.
+ * * Negative return value on failure.
+ */
+static int ne_wait_for_reply(struct pci_dev *pdev)
+{
+	struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
+	int rc = -EINVAL;
+
+	/*
+	 * TODO: Update to _interruptible and handle interrupted wait event
+	 * e.g. -ERESTARTSYS, incoming signals + update timeout, if needed.
+	 */
+	rc = wait_event_timeout(ne_pci_dev->cmd_reply_wait_q,
+				atomic_read(&ne_pci_dev->cmd_reply_avail) != 0,
+				msecs_to_jiffies(NE_DEFAULT_TIMEOUT_MSECS));
+	if (!rc)
+		return -ETIMEDOUT;
+
+	return 0;
+}
+
+int ne_do_request(struct pci_dev *pdev, enum ne_pci_dev_cmd_type cmd_type,
+		  void *cmd_request, size_t cmd_request_size,
+		  struct ne_pci_dev_cmd_reply *cmd_reply, size_t cmd_reply_size)
+{
+	struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
+	int rc = -EINVAL;
+
+	if (cmd_type <= INVALID_CMD || cmd_type >= MAX_CMD) {
+		dev_err_ratelimited(&pdev->dev, "Invalid cmd type=%u\n", cmd_type);
+
+		return -EINVAL;
+	}
+
+	if (!cmd_request) {
+		dev_err_ratelimited(&pdev->dev, "Null cmd request for cmd type=%u\n",
+				    cmd_type);
+
+		return -EINVAL;
+	}
+
+	if (cmd_request_size > NE_SEND_DATA_SIZE) {
+		dev_err_ratelimited(&pdev->dev, "Invalid req size=%zu for cmd type=%u\n",
+				    cmd_request_size, cmd_type);
+
+		return -EINVAL;
+	}
+
+	if (!cmd_reply) {
+		dev_err_ratelimited(&pdev->dev, "Null cmd reply for cmd type=%u\n",
+				    cmd_type);
+
+		return -EINVAL;
+	}
+
+	if (cmd_reply_size > NE_RECV_DATA_SIZE) {
+		dev_err_ratelimited(&pdev->dev, "Invalid reply size=%zu for cmd type=%u\n",
+				    cmd_reply_size, cmd_type);
+
+		return -EINVAL;
+	}
+
+	/*
+	 * Use this mutex so that the PCI device handles one command request at
+	 * a time.
+	 */
+	mutex_lock(&ne_pci_dev->pci_dev_mutex);
+
+	atomic_set(&ne_pci_dev->cmd_reply_avail, 0);
+
+	ne_submit_request(pdev, cmd_type, cmd_request, cmd_request_size);
+
+	rc = ne_wait_for_reply(pdev);
+	if (rc < 0) {
+		dev_err_ratelimited(&pdev->dev, "Error in wait for reply for cmd type=%u [rc=%d]\n",
+				    cmd_type, rc);
+
+		goto unlock_mutex;
+	}
+
+	ne_retrieve_reply(pdev, cmd_reply, cmd_reply_size);
+
+	atomic_set(&ne_pci_dev->cmd_reply_avail, 0);
+
+	if (cmd_reply->rc < 0) {
+		rc = cmd_reply->rc;
+
+		dev_err_ratelimited(&pdev->dev, "Error in cmd process logic, cmd type=%u [rc=%d]\n",
+				    cmd_type, rc);
+
+		goto unlock_mutex;
+	}
+
+	rc = 0;
+
+unlock_mutex:
+	mutex_unlock(&ne_pci_dev->pci_dev_mutex);
+
+	return rc;
+}
+
+/**
+ * ne_reply_handler() - Interrupt handler for retrieving a reply matching a
+ *			request sent to the PCI device for enclave lifetime
+ *			management.
+ * @irq:	Received interrupt for a reply sent by the PCI device.
+ * @args:	PCI device private data structure.
+ *
+ * Context: Interrupt context.
+ * Return:
+ * * IRQ_HANDLED on handled interrupt.
+ */
+static irqreturn_t ne_reply_handler(int irq, void *args)
+{
+	struct ne_pci_dev *ne_pci_dev = (struct ne_pci_dev *)args;
+
+	atomic_set(&ne_pci_dev->cmd_reply_avail, 1);
+
+	/* TODO: Update to _interruptible. */
+	wake_up(&ne_pci_dev->cmd_reply_wait_q);
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * ne_event_work_handler() - Work queue handler for notifying enclaves on a
+ *			     state change received by the event interrupt
+ *			     handler.
+ * @work:	Item containing the NE PCI device for which an out-of-band event
+ *		was issued.
+ *
+ * An out-of-band event is being issued by the Nitro Hypervisor when at least
+ * one enclave is changing state without client interaction.
+ *
+ * Context: Work queue context.
+ */
+static void ne_event_work_handler(struct work_struct *work)
+{
+	struct ne_pci_dev_cmd_reply cmd_reply = {};
+	struct ne_enclave *ne_enclave = NULL;
+	struct ne_pci_dev *ne_pci_dev =
+		container_of(work, struct ne_pci_dev, notify_work);
+	struct pci_dev *pdev = ne_pci_dev->pdev;
+	int rc = -EINVAL;
+	struct slot_info_req slot_info_req = {};
+
+	mutex_lock(&ne_pci_dev->enclaves_list_mutex);
+
+	/*
+	 * Iterate over all enclaves registered for the Nitro Enclaves
+	 * PCI device and determine for which enclave(s) the out-of-band event
+	 * is corresponding to.
+	 */
+	list_for_each_entry(ne_enclave, &ne_pci_dev->enclaves_list, enclave_list_entry) {
+		mutex_lock(&ne_enclave->enclave_info_mutex);
+
+		/*
+		 * Enclaves that were never started cannot receive out-of-band
+		 * events.
+		 */
+		if (ne_enclave->state != NE_STATE_RUNNING)
+			goto unlock;
+
+		slot_info_req.slot_uid = ne_enclave->slot_uid;
+
+		rc = ne_do_request(pdev, SLOT_INFO,
+				   &slot_info_req, sizeof(slot_info_req),
+				   &cmd_reply, sizeof(cmd_reply));
+		if (rc < 0)
+			dev_err(&pdev->dev, "Error in slot info [rc=%d]\n", rc);
+
+		/* Notify enclave process that the enclave state changed. */
+		if (ne_enclave->state != cmd_reply.state) {
+			ne_enclave->state = cmd_reply.state;
+
+			ne_enclave->has_event = true;
+
+			wake_up_interruptible(&ne_enclave->eventq);
+		}
+
+unlock:
+		 mutex_unlock(&ne_enclave->enclave_info_mutex);
+	}
+
+	mutex_unlock(&ne_pci_dev->enclaves_list_mutex);
+}
+
+/**
+ * ne_event_handler() - Interrupt handler for PCI device out-of-band events.
+ *			This interrupt does not supply any data in the MMIO
+ *			region. It notifies a change in the state of any of
+ *			the launched enclaves.
+ * @irq:	Received interrupt for an out-of-band event.
+ * @args:	PCI device private data structure.
+ *
+ * Context: Interrupt context.
+ * Return:
+ * * IRQ_HANDLED on handled interrupt.
+ */
+static irqreturn_t ne_event_handler(int irq, void *args)
+{
+	struct ne_pci_dev *ne_pci_dev = (struct ne_pci_dev *)args;
+
+	queue_work(ne_pci_dev->event_wq, &ne_pci_dev->notify_work);
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * ne_setup_msix() - Setup MSI-X vectors for the PCI device.
+ * @pdev:	PCI device to setup the MSI-X for.
+ *
+ * Context: Process context.
+ * Return:
+ * * 0 on success.
+ * * Negative return value on failure.
+ */
+static int ne_setup_msix(struct pci_dev *pdev)
+{
+	struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
+	int nr_vecs = 0;
+	int rc = -EINVAL;
+
+	nr_vecs = pci_msix_vec_count(pdev);
+	if (nr_vecs < 0) {
+		rc = nr_vecs;
+
+		dev_err(&pdev->dev, "Error in getting vec count [rc=%d]\n", rc);
+
+		return rc;
+	}
+
+	rc = pci_alloc_irq_vectors(pdev, nr_vecs, nr_vecs, PCI_IRQ_MSIX);
+	if (rc < 0) {
+		dev_err(&pdev->dev, "Error in alloc MSI-X vecs [rc=%d]\n", rc);
+
+		return rc;
+	}
+
+	/*
+	 * This IRQ gets triggered every time the PCI device responds to a
+	 * command request. The reply is then retrieved, reading from the MMIO
+	 * space of the PCI device.
+	 */
+	rc = request_irq(pci_irq_vector(pdev, NE_VEC_REPLY), ne_reply_handler,
+			 0, "enclave_cmd", ne_pci_dev);
+	if (rc < 0) {
+		dev_err(&pdev->dev, "Error in request irq reply [rc=%d]\n", rc);
+
+		goto free_irq_vectors;
+	}
+
+	ne_pci_dev->event_wq = create_singlethread_workqueue("ne_pci_dev_wq");
+	if (!ne_pci_dev->event_wq) {
+		rc = -ENOMEM;
+
+		dev_err(&pdev->dev, "Cannot get wq for dev events [rc=%d]\n", rc);
+
+		goto free_reply_irq_vec;
+	}
+
+	INIT_WORK(&ne_pci_dev->notify_work, ne_event_work_handler);
+
+	/*
+	 * This IRQ gets triggered every time any enclave's state changes. Its
+	 * handler then scans for the changes and propagates them to the user
+	 * space.
+	 */
+	rc = request_irq(pci_irq_vector(pdev, NE_VEC_EVENT), ne_event_handler,
+			 0, "enclave_evt", ne_pci_dev);
+	if (rc < 0) {
+		dev_err(&pdev->dev, "Error in request irq event [rc=%d]\n", rc);
+
+		goto destroy_wq;
+	}
+
+	return 0;
+
+destroy_wq:
+	destroy_workqueue(ne_pci_dev->event_wq);
+free_reply_irq_vec:
+	free_irq(pci_irq_vector(pdev, NE_VEC_REPLY), ne_pci_dev);
+free_irq_vectors:
+	pci_free_irq_vectors(pdev);
+
+	return rc;
+}
+
+/**
+ * ne_teardown_msix() - Teardown MSI-X vectors for the PCI device.
+ * @pdev:	PCI device to teardown the MSI-X for.
+ *
+ * Context: Process context.
+ */
+static void ne_teardown_msix(struct pci_dev *pdev)
+{
+	struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
+
+	free_irq(pci_irq_vector(pdev, NE_VEC_EVENT), ne_pci_dev);
+
+	flush_work(&ne_pci_dev->notify_work);
+	destroy_workqueue(ne_pci_dev->event_wq);
+
+	free_irq(pci_irq_vector(pdev, NE_VEC_REPLY), ne_pci_dev);
+
+	pci_free_irq_vectors(pdev);
+}
+
+/**
+ * ne_pci_dev_enable() - Select the PCI device version and enable it.
+ * @pdev:	PCI device to select version for and then enable.
+ *
+ * Context: Process context.
+ * Return:
+ * * 0 on success.
+ * * Negative return value on failure.
+ */
+static int ne_pci_dev_enable(struct pci_dev *pdev)
+{
+	u8 dev_enable_reply = 0;
+	u16 dev_version_reply = 0;
+	struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
+
+	iowrite16(NE_VERSION_MAX, ne_pci_dev->iomem_base + NE_VERSION);
+
+	dev_version_reply = ioread16(ne_pci_dev->iomem_base + NE_VERSION);
+	if (dev_version_reply != NE_VERSION_MAX) {
+		dev_err(&pdev->dev, "Error in pci dev version cmd\n");
+
+		return -EIO;
+	}
+
+	iowrite8(NE_ENABLE_ON, ne_pci_dev->iomem_base + NE_ENABLE);
+
+	dev_enable_reply = ioread8(ne_pci_dev->iomem_base + NE_ENABLE);
+	if (dev_enable_reply != NE_ENABLE_ON) {
+		dev_err(&pdev->dev, "Error in pci dev enable cmd\n");
+
+		return -EIO;
+	}
+
+	return 0;
+}
+
+/**
+ * ne_pci_dev_disable() - Disable the PCI device.
+ * @pdev:	PCI device to disable.
+ *
+ * Context: Process context.
+ */
+static void ne_pci_dev_disable(struct pci_dev *pdev)
+{
+	u8 dev_disable_reply = 0;
+	struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
+	const unsigned int sleep_time = 10; /* 10 ms */
+	unsigned int sleep_time_count = 0;
+
+	iowrite8(NE_ENABLE_OFF, ne_pci_dev->iomem_base + NE_ENABLE);
+
+	/*
+	 * Check for NE_ENABLE_OFF in a loop, to handle cases when the device
+	 * state is not immediately set to disabled and going through a
+	 * transitory state of disabling.
+	 */
+	while (sleep_time_count < NE_DEFAULT_TIMEOUT_MSECS) {
+		dev_disable_reply = ioread8(ne_pci_dev->iomem_base + NE_ENABLE);
+		if (dev_disable_reply == NE_ENABLE_OFF)
+			return;
+
+		msleep_interruptible(sleep_time);
+		sleep_time_count += sleep_time;
+	}
+
+	dev_disable_reply = ioread8(ne_pci_dev->iomem_base + NE_ENABLE);
+	if (dev_disable_reply != NE_ENABLE_OFF)
+		dev_err(&pdev->dev, "Error in pci dev disable cmd\n");
+}
+
+/**
+ * ne_pci_probe() - Probe function for the NE PCI device.
+ * @pdev:	PCI device to match with the NE PCI driver.
+ * @id :	PCI device id table associated with the NE PCI driver.
+ *
+ * Context: Process context.
+ * Return:
+ * * 0 on success.
+ * * Negative return value on failure.
+ */
+static int ne_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
+{
+	struct ne_pci_dev *ne_pci_dev = NULL;
+	int rc = -EINVAL;
+
+	ne_pci_dev = kzalloc(sizeof(*ne_pci_dev), GFP_KERNEL);
+	if (!ne_pci_dev)
+		return -ENOMEM;
+
+	rc = pci_enable_device(pdev);
+	if (rc < 0) {
+		dev_err(&pdev->dev, "Error in pci dev enable [rc=%d]\n", rc);
+
+		goto free_ne_pci_dev;
+	}
+
+	pci_set_master(pdev);
+
+	rc = pci_request_regions_exclusive(pdev, "nitro_enclaves");
+	if (rc < 0) {
+		dev_err(&pdev->dev, "Error in pci request regions [rc=%d]\n", rc);
+
+		goto disable_pci_dev;
+	}
+
+	ne_pci_dev->iomem_base = pci_iomap(pdev, PCI_BAR_NE, 0);
+	if (!ne_pci_dev->iomem_base) {
+		rc = -ENOMEM;
+
+		dev_err(&pdev->dev, "Error in pci iomap [rc=%d]\n", rc);
+
+		goto release_pci_regions;
+	}
+
+	pci_set_drvdata(pdev, ne_pci_dev);
+
+	rc = ne_setup_msix(pdev);
+	if (rc < 0) {
+		dev_err(&pdev->dev, "Error in pci dev msix setup [rc=%d]\n", rc);
+
+		goto iounmap_pci_bar;
+	}
+
+	ne_pci_dev_disable(pdev);
+
+	rc = ne_pci_dev_enable(pdev);
+	if (rc < 0) {
+		dev_err(&pdev->dev, "Error in ne_pci_dev enable [rc=%d]\n", rc);
+
+		goto teardown_msix;
+	}
+
+	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);
+	mutex_init(&ne_pci_dev->enclaves_list_mutex);
+	mutex_init(&ne_pci_dev->pci_dev_mutex);
+	ne_pci_dev->pdev = pdev;
+
+	ne_devs.ne_pci_dev = ne_pci_dev;
+
+	rc = misc_register(ne_devs.ne_misc_dev);
+	if (rc < 0) {
+		dev_err(&pdev->dev, "Error in misc dev register [rc=%d]\n", rc);
+
+		goto disable_ne_pci_dev;
+	}
+
+	return 0;
+
+disable_ne_pci_dev:
+	ne_devs.ne_pci_dev = NULL;
+	ne_pci_dev_disable(pdev);
+teardown_msix:
+	ne_teardown_msix(pdev);
+iounmap_pci_bar:
+	pci_set_drvdata(pdev, NULL);
+	pci_iounmap(pdev, ne_pci_dev->iomem_base);
+release_pci_regions:
+	pci_release_regions(pdev);
+disable_pci_dev:
+	pci_disable_device(pdev);
+free_ne_pci_dev:
+	kfree(ne_pci_dev);
+
+	return rc;
+}
+
+/**
+ * ne_pci_remove() - Remove function for the NE PCI device.
+ * @pdev:	PCI device associated with the NE PCI driver.
+ *
+ * Context: Process context.
+ */
+static void ne_pci_remove(struct pci_dev *pdev)
+{
+	struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
+
+	misc_deregister(ne_devs.ne_misc_dev);
+
+	ne_devs.ne_pci_dev = NULL;
+
+	ne_pci_dev_disable(pdev);
+
+	ne_teardown_msix(pdev);
+
+	pci_set_drvdata(pdev, NULL);
+
+	pci_iounmap(pdev, ne_pci_dev->iomem_base);
+
+	pci_release_regions(pdev);
+
+	pci_disable_device(pdev);
+
+	kfree(ne_pci_dev);
+}
+
+/**
+ * ne_pci_shutdown() - Shutdown function for the NE PCI device.
+ * @pdev:	PCI device associated with the NE PCI driver.
+ *
+ * Context: Process context.
+ */
+static void ne_pci_shutdown(struct pci_dev *pdev)
+{
+	struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
+
+	if (!ne_pci_dev)
+		return;
+
+	misc_deregister(ne_devs.ne_misc_dev);
+
+	ne_devs.ne_pci_dev = NULL;
+
+	ne_pci_dev_disable(pdev);
+
+	ne_teardown_msix(pdev);
+
+	pci_set_drvdata(pdev, NULL);
+
+	pci_iounmap(pdev, ne_pci_dev->iomem_base);
+
+	pci_release_regions(pdev);
+
+	pci_disable_device(pdev);
+
+	kfree(ne_pci_dev);
+}
+
+/*
+ * TODO: Add suspend / resume functions for power management w/ CONFIG_PM, if
+ * needed.
+ */
+/* NE PCI device driver. */
+struct pci_driver ne_pci_driver = {
+	.name		= "nitro_enclaves",
+	.id_table	= ne_pci_ids,
+	.probe		= ne_pci_probe,
+	.remove		= ne_pci_remove,
+	.shutdown	= ne_pci_shutdown,
+};