Re: [PATCH v4 04/18] nitro_enclaves: Init PCI device driver
From: Paraschiv, Andra-Irina
Date: Sat Jul 04 2020 - 06:00:35 EST
On 02/07/2020 18:09, Alexander Graf wrote:
On 22.06.20 22:03, Andra Paraschiv wrote:
The Nitro Enclaves PCI device is used by the kernel driver as a means of
communication with the hypervisor on the host where the primary VM and
the enclaves run. It handles requests with regard to enclave lifetime.
Setup the PCI device driver and add support for MSI-X interrupts.
Signed-off-by: Alexandru-Catalin Vasile <lexnv@xxxxxxxxxx>
Signed-off-by: Alexandru Ciobotaru <alcioa@xxxxxxxxxx>
Signed-off-by: Andra Paraschiv <andraprs@xxxxxxxxxx>
---
Changelog
v3 -> v4
* Use dev_err instead of custom NE log pattern.
* Update NE PCI driver name to "nitro_enclaves".
v2 -> v3
* Remove the GPL additional wording as SPDX-License-Identifier is
already in place.
* Remove the WARN_ON calls.
* Remove linux/bug include that is not needed.
* Update static calls sanity checks.
* Remove "ratelimited" from the logs that are not in the ioctl call
paths.
* Update kzfree() calls to kfree().
v1 -> v2
* Add log pattern for NE.
* Update PCI device setup functions to receive PCI device data
structure and
then get private data from it inside the functions logic.
* Remove the BUG_ON calls.
* Add teardown function for MSI-X setup.
* Update goto labels to match their purpose.
* Implement TODO for NE PCI device disable state check.
* Update function name for NE PCI device probe / remove.
---
drivers/virt/nitro_enclaves/ne_pci_dev.c | 261 +++++++++++++++++++++++
1 file changed, 261 insertions(+)
create mode 100644 drivers/virt/nitro_enclaves/ne_pci_dev.c
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 000000000000..235fa3ecbee2
--- /dev/null
+++ b/drivers/virt/nitro_enclaves/ne_pci_dev.c
@@ -0,0 +1,261 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2020 Amazon.com, Inc. or its affiliates. All Rights
Reserved.
+ */
+
+/* Nitro Enclaves (NE) PCI device driver. */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/module.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"
+
+#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_setup_msix - Setup MSI-X vectors for the PCI device.
+ *
+ * @pdev: PCI device to setup the MSI-X for.
+ *
+ * @returns: 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;
+
+ if (!ne_pci_dev)
+ return -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;
+ }
+
+ return 0;
+}
+
+/**
+ * ne_teardown_msix - Teardown MSI-X vectors for the PCI device.
+ *
+ * @pdev: PCI device to teardown the MSI-X for.
+ */
+static void ne_teardown_msix(struct pci_dev *pdev)
+{
+ struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
+
+ if (!ne_pci_dev)
+ return;
+
+ pci_free_irq_vectors(pdev);
+}
+
+/**
+ * ne_pci_dev_enable - Select PCI device version and enable it.
+ *
+ * @pdev: PCI device to select version for and then enable.
+ *
+ * @returns: 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);
+
+ if (!ne_pci_dev || !ne_pci_dev->iomem_base)
+ return -EINVAL;
How can this ever happen?
This check and the following one are part of that checks added before
for the situations that shouldn't happen, only if buggy system or broken
logic at all. Removed the checks.
Thanks,
Andra
+
+ 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 PCI device.
+ *
+ * @pdev: PCI device to disable.
+ */
+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;
+
+ if (!ne_pci_dev || !ne_pci_dev->iomem_base)
+ return;
How can this ever happen?
Alex
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.