numam-dpdk/examples/vm_power_manager/channel_monitor.h
Alan Carew e8ae9b6625 examples/vm_power: channel manager and monitor in host
The manager is responsible for adding communications channels to the Monitor
thread, tracking and reporting VM state and employs the libvirt API for
synchronization with the KVM Hypervisor. The manager interacts with the
Hypervisor to discover the mapping of virtual CPUS(vCPUs) to the host
physical CPUS(pCPUs) and to inspect the VM running state.

The manager provides the following functionality to the CLI:
1) Connect to a libvirtd instance, default: qemu:///system
2) Add a VM to an internal list, each VM is identified by a "name" which must
   correspond a valid libvirt Domain Name.
3) Add communication channels associated with a VM to the epoll based Monitor
   thread.
   The channels must exist and be in the form of:
   /tmp/powermonitor/<vm_name>.<channel_number>. Each channel is a
   Virtio-Serial endpoint configured as an AF_UNIX file socket and opened in
   non-blocking mode.
   Each VM can have a maximum of 64 channels associated with it.
4) Disable or re-enable VM communication channels, channels once added to the
   Monitor thread remain in that threads control, however acting on channel
   requests can be disabled and renabled via CLI.

The monitor is an epoll based infinite loop running in a separate thread that
waits on channel events from VMs and calls the corresponding functions. Channel
definitions from the manager are registered via the epoll event opaque pointer
when calling epoll_ctl(EPOLL_CTL_ADD), this allows for obtaining the channels
file descriptor for reading EPOLLIN events and mapping the vCPU to pCPU(s)
associated with a request from a particular VM.

Signed-off-by: Alan Carew <alan.carew@intel.com>
Signed-off-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>
2014-11-26 17:27:03 +01:00

103 lines
2.9 KiB
C

/*-
* BSD LICENSE
*
* Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef CHANNEL_MONITOR_H_
#define CHANNEL_MONITOR_H_
#include "channel_manager.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* Setup the Channel Monitor resources required to initialize epoll.
* Must be called first before calling other functions.
*
* @return
* - 0 on success.
* - Negative on error.
*/
int channel_monitor_init(void);
/**
* Run the channel monitor, loops forever on on epoll_wait.
*
*
* @return
* None
*/
void run_channel_monitor(void);
/**
* Exit the Channel Monitor, exiting the epoll_wait loop and events processing.
*
* @return
* - 0 on success.
* - Negative on error.
*/
void channel_monitor_exit(void);
/**
* Add an open channel to monitor via epoll. A pointer to struct channel_info
* will be registered with epoll for event processing.
* It is thread-safe.
*
* @param chan_info
* Pointer to struct channel_info pointer.
*
* @return
* - 0 on success.
* - Negative on error.
*/
int add_channel_to_monitor(struct channel_info **chan_info);
/**
* Remove a previously added channel from epoll control.
*
* @param chan_info
* Pointer to struct channel_info.
*
* @return
* - 0 on success.
* - Negative on error.
*/
int remove_channel_from_monitor(struct channel_info *chan_info);
#ifdef __cplusplus
}
#endif
#endif /* CHANNEL_MONITOR_H_ */