The Nitro Enclaves PCI device exposes a MMIO space that this driver
uses to submit command requests and to receive command replies e.g. for
enclave creation / termination or setting enclave resources.
Add logic for handling PCI device command requests based on the given
command type.
Register an MSI-X interrupt vector for command reply notifications to
handle this type of communication events.
Signed-off-by: Alexandru-Catalin Vasile <[email protected]>
Signed-off-by: Andra Paraschiv <[email protected]>
Fix issue reported in:
https://lore.kernel.org/lkml/202004231644.xTmN4Z1z%[email protected]/
Reported-by: kbuild test robot <[email protected]>
Signed-off-by: Andra Paraschiv <[email protected]>
---
Changelog
v4 -> v5
* Remove sanity checks for situations that shouldn't happen, only if
buggy system or broken logic at all.
v3 -> v4
* Use dev_err instead of custom NE log pattern.
* Return IRQ_NONE when interrupts are not handled.
v2 -> v3
* Remove the WARN_ON calls.
* Update static calls sanity checks.
* Remove "ratelimited" from the logs that are not in the ioctl call
paths.
v1 -> v2
* Add log pattern for NE.
* Remove the BUG_ON calls.
* Update goto labels to match their purpose.
* Add fix for kbuild report.
---
drivers/virt/nitro_enclaves/ne_pci_dev.c | 202 +++++++++++++++++++++++
1 file changed, 202 insertions(+)
diff --git a/drivers/virt/nitro_enclaves/ne_pci_dev.c b/drivers/virt/nitro_enclaves/ne_pci_dev.c
index dd23caecd57d..738b8f4d8faf 100644
--- a/drivers/virt/nitro_enclaves/ne_pci_dev.c
+++ b/drivers/virt/nitro_enclaves/ne_pci_dev.c
@@ -27,6 +27,185 @@ static const struct pci_device_id ne_pci_ids[] = {
MODULE_DEVICE_TABLE(pci, ne_pci_ids);
+/**
+ * ne_submit_request - Submit command request to the PCI device based on the
+ * command type.
+ *
+ * This function gets called with the ne_pci_dev mutex held.
+ *
+ * @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.
+ *
+ * @returns: 0 on success, negative return value on failure.
+ */
+static int 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);
+
+ return 0;
+}
+
+/**
+ * ne_retrieve_reply - Retrieve reply from the PCI device.
+ *
+ * This function gets called with the ne_pci_dev mutex held.
+ *
+ * @pdev: PCI device to receive the reply from.
+ * @cmd_reply: command reply payload.
+ * @cmd_reply_size: size of the command reply payload.
+ *
+ * @returns: 0 on success, negative return value on failure.
+ */
+static int 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);
+
+ return 0;
+}
+
+/**
+ * ne_wait_for_reply - Wait for a reply of a PCI command.
+ *
+ * This function gets called with the ne_pci_dev mutex held.
+ *
+ * @pdev: PCI device for which a reply is waited.
+ *
+ * @returns: 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 + add / update timeout.
+ */
+ 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\n");
+
+ 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\n");
+
+ return -EINVAL;
+ }
+
+ if (cmd_reply_size > NE_RECV_DATA_SIZE) {
+ dev_err_ratelimited(&pdev->dev, "Invalid reply size=%zu\n", cmd_reply_size);
+
+ 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);
+
+ rc = ne_submit_request(pdev, cmd_type, cmd_request, cmd_request_size);
+ if (rc < 0) {
+ dev_err_ratelimited(&pdev->dev, "Error in submit request [rc=%d]\n", rc);
+
+ goto unlock_mutex;
+ }
+
+ rc = ne_wait_for_reply(pdev);
+ if (rc < 0) {
+ dev_err_ratelimited(&pdev->dev, "Error in wait for reply [rc=%d]\n", rc);
+
+ goto unlock_mutex;
+ }
+
+ rc = ne_retrieve_reply(pdev, cmd_reply, cmd_reply_size);
+ if (rc < 0) {
+ dev_err_ratelimited(&pdev->dev, "Error in retrieve reply [rc=%d]\n", rc);
+
+ goto unlock_mutex;
+ }
+
+ 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 [rc=%d]\n", 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.
+ *
+ * @returns: IRQ_HANDLED on handled interrupt, IRQ_NONE otherwise.
+ */
+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_setup_msix - Setup MSI-X vectors for the PCI device.
*
@@ -36,6 +215,7 @@ MODULE_DEVICE_TABLE(pci, ne_pci_ids);
*/
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;
@@ -55,7 +235,25 @@ static int ne_setup_msix(struct pci_dev *pdev)
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;
+ }
+
return 0;
+
+free_irq_vectors:
+ pci_free_irq_vectors(pdev);
+
+ return rc;
}
/**
@@ -65,6 +263,10 @@ static int ne_setup_msix(struct pci_dev *pdev)
*/
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_REPLY), ne_pci_dev);
+
pci_free_irq_vectors(pdev);
}
--
2.20.1 (Apple Git-117)
Amazon Development Center (Romania) S.R.L. registered office: 27A Sf. Lazar Street, UBC5, floor 2, Iasi, Iasi County, 700045, Romania. Registered in Romania. Registration number J22/2621/2005.
On 15.07.20 21:45, Andra Paraschiv wrote:
> The Nitro Enclaves PCI device exposes a MMIO space that this driver
> uses to submit command requests and to receive command replies e.g. for
> enclave creation / termination or setting enclave resources.
>
> Add logic for handling PCI device command requests based on the given
> command type.
>
> Register an MSI-X interrupt vector for command reply notifications to
> handle this type of communication events.
>
> Signed-off-by: Alexandru-Catalin Vasile <[email protected]>
> Signed-off-by: Andra Paraschiv <[email protected]>
>
> Fix issue reported in:
> https://lore.kernel.org/lkml/202004231644.xTmN4Z1z%[email protected]/
>
> Reported-by: kbuild test robot <[email protected]>
This means that the overall patch is a fix that was reported by the test
rebot. I doubt that's what you mean. Just remove the line.
> Signed-off-by: Andra Paraschiv <[email protected]>
Reviewed-by: Alexander Graf <[email protected]>
Alex
Amazon Development Center Germany GmbH
Krausenstr. 38
10117 Berlin
Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss
Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B
Sitz: Berlin
Ust-ID: DE 289 237 879
On 21/07/2020 13:17, Alexander Graf wrote:
>
>
> On 15.07.20 21:45, Andra Paraschiv wrote:
>> The Nitro Enclaves PCI device exposes a MMIO space that this driver
>> uses to submit command requests and to receive command replies e.g. for
>> enclave creation / termination or setting enclave resources.
>>
>> Add logic for handling PCI device command requests based on the given
>> command type.
>>
>> Register an MSI-X interrupt vector for command reply notifications to
>> handle this type of communication events.
>>
>> Signed-off-by: Alexandru-Catalin Vasile <[email protected]>
>> Signed-off-by: Andra Paraschiv <[email protected]>
>>
>> Fix issue reported in:
>> https://lore.kernel.org/lkml/202004231644.xTmN4Z1z%[email protected]/
>>
>> Reported-by: kbuild test robot <[email protected]>
>
> This means that the overall patch is a fix that was reported by the
> test rebot. I doubt that's what you mean. Just remove the line.
I wanted to mention that the patch includes also the fix for the report.
I moved these details to the changelog.
>
>> Signed-off-by: Andra Paraschiv <[email protected]>
>
> Reviewed-by: Alexander Graf <[email protected]>
Thanks for review.
Andra
Amazon Development Center (Romania) S.R.L. registered office: 27A Sf. Lazar Street, UBC5, floor 2, Iasi, Iasi County, 700045, Romania. Registered in Romania. Registration number J22/2621/2005.