Documentation

LVE userland API

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currently LVE userland API consist two files lve-ctl.h and liblve.a for static linking.

Check ability 

• int lve_is_available(void);
  return 1 if lve is available
  0 otherwise.

Admin functions 

• int lve_set_default(uint32_t cpu, uint32_t io);
  set default parameters for newly created light weight virtual environments.
  args:
  cpu - default CPU power
  io - default IO priority
  return codes:
  0 OK, otherwise is error.

• int lve_create(uint32_t ve_id);
  create custom configured virtual environment
  args:
  ve_id = id associated with new created LVE

• int lve_destroy(uint32_t ve_id);
  destroy configured virtual environment
  args:
  ve_id = id associated with LVE

• int lve_setup(uint32_t ve_id, int32_t cpu, int32_t io)
  adjust parameters for virtual environment
  args:
  ve_id = id associated with LVE
  cpu - CPU power, -1 if don't adjust
  io - IO priority, -1 if don't set

application functions 

• int lve_instance_init(struct liblve *lve);
  create lve library instance
  args 
  libvlve - pointer to allocated memory to store per instance info
  or NULL to return how many memory need for per
  instance structure.
  return codes:
  > 0, size of lve instance structure, if liblve == NULL.
  0 = if instance is correctly init.
  < 0, if any error is hit

• int lve_instance_destroy(struct liblve *lve)
  destroy lve library instance
  args:
  lve = fully init liblve instance

• int lve_enter(struct liblve *lve, uint32_t ve_id,uint32_t uid, uint32_t gid, uint32_t *cookie);
  enter into virtual environment (puts current process in LVE)
  args:
  lve = pointer to fully init lve library instance.
  ve_id = id associated with LVE
  uid = user id to switch, -1 if switch not need. (NOT USED, should always be -1)
  gid = group id to switch, -1 if switch not need. (NOT USED, should always be -1)
  cookie = pointer to cookie, which returned if task correctly migrated
  in LVE and used to leave from this LVE

  return codes:
  0 = none error,
  all less zero is errors:
  -EPERM - don't have permission to call, or called from outside root VE
  -ENOMEM - don't have memory to allocate new VE
  -EFAULT - cookie is bad pointer

• int lve_leave(struct liblve *lve, uint32_t *cookie);
  leave from virtual environment, if fatal error is occurred task will be killed.
  arguments:
  lve = pointer to fully init lve library instance.
  cookie - pointer to cookie returned from lve_enter.
  return codes:
  0 = none error, all less zero is errors:
  -ESRCH = task not in virtual environment