mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-29 23:53:32 +00:00
88ce642492
This implements synchronized time-travel mode which - using a special application on a unix socket - lets multiple machines take part in a time-travelling simulation together. The protocol for the unix domain socket is defined in the new file include/uapi/linux/um_timetravel.h. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at>
128 lines
3.9 KiB
C
128 lines
3.9 KiB
C
/*
|
|
* Permission to use, copy, modify, and/or distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
|
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
|
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
|
|
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
*
|
|
* Copyright (C) 2019 Intel Corporation
|
|
*/
|
|
#ifndef _UAPI_LINUX_UM_TIMETRAVEL_H
|
|
#define _UAPI_LINUX_UM_TIMETRAVEL_H
|
|
#include <linux/types.h>
|
|
|
|
/**
|
|
* struct um_timetravel_msg - UM time travel message
|
|
*
|
|
* This is the basic message type, going in both directions.
|
|
*
|
|
* This is the message passed between the host (user-mode Linux instance)
|
|
* and the calendar (the application on the other side of the socket) in
|
|
* order to implement common scheduling.
|
|
*
|
|
* Whenever UML has an event it will request runtime for it from the
|
|
* calendar, and then wait for its turn until it can run, etc. Note
|
|
* that it will only ever request the single next runtime, i.e. multiple
|
|
* REQUEST messages override each other.
|
|
*/
|
|
struct um_timetravel_msg {
|
|
/**
|
|
* @op: operation value from &enum um_timetravel_ops
|
|
*/
|
|
__u32 op;
|
|
|
|
/**
|
|
* @seq: sequence number for the message - shall be reflected in
|
|
* the ACK response, and should be checked while processing
|
|
* the response to see if it matches
|
|
*/
|
|
__u32 seq;
|
|
|
|
/**
|
|
* @time: time in nanoseconds
|
|
*/
|
|
__u64 time;
|
|
};
|
|
|
|
/**
|
|
* enum um_timetravel_ops - Operation codes
|
|
*/
|
|
enum um_timetravel_ops {
|
|
/**
|
|
* @UM_TIMETRAVEL_ACK: response (ACK) to any previous message,
|
|
* this usually doesn't carry any data in the 'time' field
|
|
* unless otherwise specified below
|
|
*/
|
|
UM_TIMETRAVEL_ACK = 0,
|
|
|
|
/**
|
|
* @UM_TIMETRAVEL_START: initialize the connection, the time
|
|
* field contains an (arbitrary) ID to possibly be able
|
|
* to distinguish the connections.
|
|
*/
|
|
UM_TIMETRAVEL_START = 1,
|
|
|
|
/**
|
|
* @UM_TIMETRAVEL_REQUEST: request to run at the given time
|
|
* (host -> calendar)
|
|
*/
|
|
UM_TIMETRAVEL_REQUEST = 2,
|
|
|
|
/**
|
|
* @UM_TIMETRAVEL_WAIT: Indicate waiting for the previously requested
|
|
* runtime, new requests may be made while waiting (e.g. due to
|
|
* interrupts); the time field is ignored. The calendar must process
|
|
* this message and later send a %UM_TIMETRAVEL_RUN message when
|
|
* the host can run again.
|
|
* (host -> calendar)
|
|
*/
|
|
UM_TIMETRAVEL_WAIT = 3,
|
|
|
|
/**
|
|
* @UM_TIMETRAVEL_GET: return the current time from the calendar in the
|
|
* ACK message, the time in the request message is ignored
|
|
* (host -> calendar)
|
|
*/
|
|
UM_TIMETRAVEL_GET = 4,
|
|
|
|
/**
|
|
* @UM_TIMETRAVEL_UPDATE: time update to the calendar, must be sent e.g.
|
|
* before kicking an interrupt to another calendar
|
|
* (host -> calendar)
|
|
*/
|
|
UM_TIMETRAVEL_UPDATE = 5,
|
|
|
|
/**
|
|
* @UM_TIMETRAVEL_RUN: run time request granted, current time is in
|
|
* the time field
|
|
* (calendar -> host)
|
|
*/
|
|
UM_TIMETRAVEL_RUN = 6,
|
|
|
|
/**
|
|
* @UM_TIMETRAVEL_FREE_UNTIL: Enable free-running until the given time,
|
|
* this is a message from the calendar telling the host that it can
|
|
* freely do its own scheduling for anything before the indicated
|
|
* time.
|
|
* Note that if a calendar sends this message once, the host may
|
|
* assume that it will also do so in the future, if it implements
|
|
* wraparound semantics for the time field.
|
|
* (calendar -> host)
|
|
*/
|
|
UM_TIMETRAVEL_FREE_UNTIL = 7,
|
|
|
|
/**
|
|
* @UM_TIMETRAVEL_GET_TOD: Return time of day, typically used once at
|
|
* boot by the virtual machines to get a synchronized time from
|
|
* the simulation.
|
|
*/
|
|
UM_TIMETRAVEL_GET_TOD = 8,
|
|
};
|
|
|
|
#endif /* _UAPI_LINUX_UM_TIMETRAVEL_H */
|