From 6188bfb86c5520a1e85f7a1b4f0e445851aaf30d Mon Sep 17 00:00:00 2001
From: Ciro Santilli <ciro.santilli@gmail.com>
Date: Sun, 9 Jul 2017 08:30:08 +0100
Subject: [PATCH] pcimin

---
 kernel_module/pci_min.c | 96 +++++++++++++++++++++++++++++++++++++++++
 qemu                    |  2 +-
 2 files changed, 97 insertions(+), 1 deletion(-)
 create mode 100644 kernel_module/pci_min.c

diff --git a/kernel_module/pci_min.c b/kernel_module/pci_min.c
new file mode 100644
index 0000000..54481a7
--- /dev/null
+++ b/kernel_module/pci_min.c
@@ -0,0 +1,96 @@
+/*
+Only tested in x86.
+
+PCI driver for our minimal pci_min.c QEMU fork device.
+*/
+
+#include <asm/uaccess.h>
+#include <linux/cdev.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+
+#define BAR 0
+#define CDEV_NAME "lkmc_hw_pci_min"
+#define EDU_DEVICE_ID 0x11e9
+#define QEMU_VENDOR_ID 0x1234
+
+MODULE_LICENSE("GPL");
+
+static struct pci_device_id id_table[] = {
+    { PCI_DEVICE(QEMU_VENDOR_ID, EDU_DEVICE_ID), },
+    { 0, }
+};
+MODULE_DEVICE_TABLE(pci, id_table);
+static int major;
+static struct pci_dev *pdev;
+static void __iomem *mmio;
+static struct file_operations fops = {
+    .owner   = THIS_MODULE,
+};
+
+static irqreturn_t irq_handler(int irq, void *dev)
+{
+    pr_info("irq_handler irq = %d dev = %d\n", irq, *(int *)dev);
+    iowrite32(0, mmio + 4);
+    return IRQ_HANDLED;
+}
+
+static int probe(struct pci_dev *dev, const struct pci_device_id *id)
+{
+    pr_info("probe\n");
+    major = register_chrdev(0, CDEV_NAME, &fops);
+    pdev = dev;
+    if (pci_enable_device(dev) < 0) {
+        dev_err(&(pdev->dev), "pci_enable_device\n");
+        goto error;
+    }
+    if (pci_request_region(dev, BAR, "myregion0")) {
+        dev_err(&(pdev->dev), "pci_request_region\n");
+        goto error;
+    }
+    mmio = pci_iomap(pdev, BAR, pci_resource_len(pdev, BAR));
+    pr_info("dev->irq = %u\n", dev->irq);
+    if (request_irq(dev->irq, irq_handler, IRQF_SHARED, "pci_irq_handler0", &major) < 0) {
+        dev_err(&(dev->dev), "request_irq\n");
+        goto error;
+    }
+    iowrite32(0x12345678, mmio);
+    return 0;
+error:
+    return 1;
+}
+
+static void remove(struct pci_dev *dev)
+{
+    pr_info("remove\n");
+    free_irq(dev->irq, &major);
+    pci_release_region(dev, BAR);
+    unregister_chrdev(major, CDEV_NAME);
+}
+
+static struct pci_driver pci_driver = {
+    .name     = CDEV_NAME,
+    .id_table = id_table,
+    .probe    = probe,
+    .remove   = remove,
+};
+
+static int myinit(void)
+{
+    if (pci_register_driver(&pci_driver) < 0) {
+        return 1;
+    }
+    return 0;
+}
+
+static void myexit(void)
+{
+    pci_unregister_driver(&pci_driver);
+}
+
+module_init(myinit);
+module_exit(myexit);
diff --git a/qemu b/qemu
index 144ea94..577f463 160000
--- a/qemu
+++ b/qemu
@@ -1 +1 @@
-Subproject commit 144ea94d710c666babd06ed733007377e132ed4a
+Subproject commit 577f4633f156c263aae9855c2f06328831e05ccd