Re: [Qemu-devel] [PATCH v10 19/19] docs: Sample driver to demonstrate how to use Mediated device framework.

[Jonathan Corbet]

On Thu, 27 Oct 2016 02:59:26 +0530
Kirti Wankhede  wrote:

> The Sample driver creates mdev device that simulates serial port over PCI
> card.
> 
> Signed-off-by: Kirti Wankhede 
> Signed-off-by: Neo Jia 
> Change-Id: I857f8f12f8b275f2498dfe8c628a5cdc7193b1b2
> ---
>  Documentation/vfio-mdev/Makefile |   13 +
>  Documentation/vfio-mdev/mtty.c   | 1503 
> ++
>  Documentation/vfio-mdev/vfio-mediated-device.txt |  103 +-

We've been working for a bit to get the buildable code *out* of the
documentation tree.  I think this should go into samples/ instead.

Thanks,

jon

[Qemu-devel] [PATCH v10 19/19] docs: Sample driver to demonstrate how to use Mediated device framework.

[Kirti Wankhede]

The Sample driver creates mdev device that simulates serial port over PCI
card.

Signed-off-by: Kirti Wankhede 
Signed-off-by: Neo Jia 
Change-Id: I857f8f12f8b275f2498dfe8c628a5cdc7193b1b2
---
 Documentation/vfio-mdev/Makefile |   13 +
 Documentation/vfio-mdev/mtty.c   | 1503 ++
 Documentation/vfio-mdev/vfio-mediated-device.txt |  103 +-
 3 files changed, 1618 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/vfio-mdev/Makefile
 create mode 100644 Documentation/vfio-mdev/mtty.c

diff --git a/Documentation/vfio-mdev/Makefile b/Documentation/vfio-mdev/Makefile
new file mode 100644
index ..a932edbe38eb
--- /dev/null
+++ b/Documentation/vfio-mdev/Makefile
@@ -0,0 +1,13 @@
+#
+# Makefile for mtty.c file
+#
+KERNEL_DIR:=/lib/modules/$(shell uname -r)/build
+
+obj-m:=mtty.o
+
+modules clean modules_install:
+   $(MAKE) -C $(KERNEL_DIR) SUBDIRS=$(PWD) $@
+
+default: modules
+
+module: modules
diff --git a/Documentation/vfio-mdev/mtty.c b/Documentation/vfio-mdev/mtty.c
new file mode 100644
index ..6c71d12288d1
--- /dev/null
+++ b/Documentation/vfio-mdev/mtty.c
@@ -0,0 +1,1503 @@
+/*
+ * Mediated virtual PCI serial host device driver
+ *
+ * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
+ * Author: Neo Jia 
+ * Kirti Wankhede 
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Sample driver that creates mdev device that simulates serial port over PCI
+ * card.
+ *
+ */
+
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+/*
+ * #defines
+ */
+
+#define VERSION_STRING  "0.1"
+#define DRIVER_AUTHOR   "NVIDIA Corporation"
+
+#define MTTY_CLASS_NAME "mtty"
+
+#define MTTY_NAME   "mtty"
+
+#define MTTY_STRING_LEN16
+
+#define MTTY_CONFIG_SPACE_SIZE  0xff
+#define MTTY_IO_BAR_SIZE0x8
+#define MTTY_MMIO_BAR_SIZE  0x10
+
+#define STORE_LE16(addr, val)   (*(u16 *)addr = val)
+#define STORE_LE32(addr, val)   (*(u32 *)addr = val)
+
+#define MAX_FIFO_SIZE   16
+
+#define CIRCULAR_BUF_INC_IDX(idx)(idx = (idx + 1) & (MAX_FIFO_SIZE - 1))
+
+#define MTTY_VFIO_PCI_OFFSET_SHIFT   40
+
+#define MTTY_VFIO_PCI_OFFSET_TO_INDEX(off)   (off >> 
MTTY_VFIO_PCI_OFFSET_SHIFT)
+#define MTTY_VFIO_PCI_INDEX_TO_OFFSET(index) \
+   ((u64)(index) << MTTY_VFIO_PCI_OFFSET_SHIFT)
+#define MTTY_VFIO_PCI_OFFSET_MASK\
+   (((u64)(1) << MTTY_VFIO_PCI_OFFSET_SHIFT) - 1)
+#define MAX_MTTYS  24
+
+/*
+ * Global Structures
+ */
+
+struct mtty_dev {
+   dev_t   vd_devt;
+   struct class*vd_class;
+   struct cdev vd_cdev;
+   struct idr  vd_idr;
+   struct device   dev;
+} mtty_dev;
+
+struct mdev_region_info {
+   u64 start;
+   u64 phys_start;
+   u32 size;
+   u64 vfio_offset;
+};
+
+#if defined(DEBUG_REGS)
+const char *wr_reg[] = {
+   "TX",
+   "IER",
+   "FCR",
+   "LCR",
+   "MCR",
+   "LSR",
+   "MSR",
+   "SCR"
+};
+
+const char *rd_reg[] = {
+   "RX",
+   "IER",
+   "IIR",
+   "LCR",
+   "MCR",
+   "LSR",
+   "MSR",
+   "SCR"
+};
+#endif
+
+/* loop back buffer */
+struct rxtx {
+   u8 fifo[MAX_FIFO_SIZE];
+   u8 head, tail;
+   u8 count;
+};
+
+struct serial_port {
+   u8 uart_reg[8]; /* 8 registers */
+   struct rxtx rxtx;   /* loop back buffer */
+   bool dlab;
+   bool overrun;
+   u16 divisor;
+   u8 fcr; /* FIFO control register */
+   u8 max_fifo_size;
+   u8 intr_trigger_level;  /* interrupt trigger level */
+};
+
+/* State of each mdev device */
+struct mdev_state {
+   int irq_fd;
+   struct eventfd_ctx *intx_evtfd;
+   struct eventfd_ctx *msi_evtfd;
+   int irq_index;
+   u8 *vconfig;
+   struct mutex ops_lock;
+   struct mdev_device *mdev;
+   struct mdev_region_info region_info[VFIO_PCI_NUM_REGIONS];
+   u32 bar_mask[VFIO_PCI_NUM_REGIONS];
+   struct list_head next;
+   struct serial_port s[2];
+   struct mutex rxtx_lock;
+   struct vfio_device_info dev_info;
+   int nr_ports;
+};
+
+struct mutex mdev_list_lock;
+struct list_head mdev_devices_list;
+
+static const struct file_operations vd_fops = {
+   .owner  = THIS_MODULE,
+};
+
+/* function prototypes */
+
+static int mtty_trigger_interrupt(uuid_le uuid);
+
+/* Helper functions */
+static struct mdev_state *find_mdev_state_by_uuid(uuid_le uuid)
+{
+   struct mdev_state *mds;
+
+