include/linux/lguest_launcher.h

   1 #ifndef _ASM_LGUEST_USER
   2 #define _ASM_LGUEST_USER
   3 /* Everything the "lguest" userspace program needs to know. */
   4 #include <linux/types.h>
   5 /* They can register up to 32 arrays of lguest_dma. */
   6 #define LGUEST_MAX_DMA          32
   7 /* At most we can dma 16 lguest_dma in one op. */
   8 #define LGUEST_MAX_DMA_SECTIONS 16
   9
  10 /* How many devices?  Assume each one wants up to two dma arrays per device. */
  11 #define LGUEST_MAX_DEVICES (LGUEST_MAX_DMA/2)
  12
  13 /* Where the Host expects the Guest to SEND_DMA console output to. */
  14 #define LGUEST_CONSOLE_DMA_KEY 0
  15
  16 /*D:010
  17  * Drivers
  18  *
  19  * The Guest needs devices to do anything useful.  Since we don't let it touch
  20  * real devices (think of the damage it could do!) we provide virtual devices.
  21  * We could emulate a PCI bus with various devices on it, but that is a fairly
  22  * complex burden for the Host and suboptimal for the Guest, so we have our own
  23  * "lguest" bus and simple drivers.
  24  *
  25  * Devices are described by a simplified ID, a status byte, and some "config"
  26  * bytes which describe this device's configuration.  This is placed by the
  27  * Launcher just above the top of physical memory:
  28  */
  29 struct lguest_device_desc {
  30         /* The device type: console, network, disk etc.  Type 0 terminates. */
  31         __u8 type;
  32         /* The number of bytes of the config array. */
  33         __u8 config_len;
  34         /* A status byte, written by the Guest. */
  35         __u8 status;
  36         __u8 config[0];
  37 };
  38
  39 /*D:135 This is how we expect the device configuration field for a virtqueue
  40  * (type VIRTIO_CONFIG_F_VIRTQUEUE) to be laid out: */
  41 struct lguest_vqconfig {
  42         /* The number of entries in the virtio_ring */
  43         __u16 num;
  44         /* The interrupt we get when something happens. */
  45         __u16 irq;
  46         /* The page number of the virtio ring for this device. */
  47         __u32 pfn;
  48 };
  49 /*:*/
  50
  51 /* Write command first word is a request. */
  52 enum lguest_req
  53 {
  54         LHREQ_INITIALIZE, /* + pfnlimit, pgdir, start, pageoffset */
  55         LHREQ_GETDMA, /* No longer used */
  56         LHREQ_IRQ, /* + irq */
  57         LHREQ_BREAK, /* + on/off flag (on blocks until someone does off) */
  58 };
  59 #endif /* _ASM_LGUEST_USER */