include/linux/lguest_launcher.h

   1 #ifndef _LINUX_LGUEST_LAUNCHER
   2 #define _LINUX_LGUEST_LAUNCHER
   3 /* Everything the "lguest" userspace program needs to know. */
   4 #include <linux/types.h>
   5
   6 /*D:010
   7  * Drivers
   8  *
   9  * The Guest needs devices to do anything useful.  Since we don't let it touch
  10  * real devices (think of the damage it could do!) we provide virtual devices.
  11  * We could emulate a PCI bus with various devices on it, but that is a fairly
  12  * complex burden for the Host and suboptimal for the Guest, so we have our own
  13  * "lguest" bus and simple drivers.
  14  *
  15  * Devices are described by a simplified ID, a status byte, and some "config"
  16  * bytes which describe this device's configuration.  This is placed by the
  17  * Launcher just above the top of physical memory:
  18  */
  19 struct lguest_device_desc {
  20         /* The device type: console, network, disk etc.  Type 0 terminates. */
  21         __u8 type;
  22         /* The number of bytes of the config array. */
  23         __u8 config_len;
  24         /* A status byte, written by the Guest. */
  25         __u8 status;
  26         __u8 config[0];
  27 };
  28
  29 /*D:135 This is how we expect the device configuration field for a virtqueue
  30  * (type VIRTIO_CONFIG_F_VIRTQUEUE) to be laid out: */
  31 struct lguest_vqconfig {
  32         /* The number of entries in the virtio_ring */
  33         __u16 num;
  34         /* The interrupt we get when something happens. */
  35         __u16 irq;
  36         /* The page number of the virtio ring for this device. */
  37         __u32 pfn;
  38 };
  39 /*:*/
  40
  41 /* Write command first word is a request. */
  42 enum lguest_req
  43 {
  44         LHREQ_INITIALIZE, /* + base, pfnlimit, pgdir, start */
  45         LHREQ_GETDMA, /* No longer used */
  46         LHREQ_IRQ, /* + irq */
  47         LHREQ_BREAK, /* + on/off flag (on blocks until someone does off) */
  48 };
  49 #endif /* _LINUX_LGUEST_LAUNCHER */