linux/drivers/hv/connection.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 *
 * Copyright (c) 2009, Microsoft Corporation.
 *
 * Authors:
 *   Haiyang Zhang <[email protected]>
 *   Hank Janssen  <[email protected]>
 */
#define pr_fmt(fmt) …

#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/delay.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/hyperv.h>
#include <linux/export.h>
#include <linux/io.h>
#include <linux/set_memory.h>
#include <asm/mshyperv.h>

#include "hyperv_vmbus.h"


struct vmbus_connection vmbus_connection = …;
EXPORT_SYMBOL_GPL(…);

/*
 * Negotiated protocol version with the host.
 */
__u32 vmbus_proto_version;
EXPORT_SYMBOL_GPL(…);

/*
 * Table of VMBus versions listed from newest to oldest.
 * VERSION_WIN7 and VERSION_WS2008 are no longer supported in
 * Linux guests and are not listed.
 */
static __u32 vmbus_versions[] = …;

/*
 * Maximal VMBus protocol version guests can negotiate.  Useful to cap the
 * VMBus version for testing and debugging purpose.
 */
static uint max_version = …;

module_param(max_version, uint, S_IRUGO);
MODULE_PARM_DESC(…) …;

int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, u32 version)
{ … }

/*
 * vmbus_connect - Sends a connect request on the partition service connection
 */
int vmbus_connect(void)
{ … }

void vmbus_disconnect(void)
{ … }

/*
 * relid2channel - Get the channel object given its
 * child relative id (ie channel id)
 */
struct vmbus_channel *relid2channel(u32 relid)
{ … }

/*
 * vmbus_on_event - Process a channel event notification
 *
 * For batched channels (default) optimize host to guest signaling
 * by ensuring:
 * 1. While reading the channel, we disable interrupts from host.
 * 2. Ensure that we process all posted messages from the host
 *    before returning from this callback.
 * 3. Once we return, enable signaling from the host. Once this
 *    state is set we check to see if additional packets are
 *    available to read. In this case we repeat the process.
 *    If this tasklet has been running for a long time
 *    then reschedule ourselves.
 */
void vmbus_on_event(unsigned long data)
{ … }

/*
 * vmbus_post_msg - Send a msg on the vmbus's message connection
 */
int vmbus_post_msg(void *buffer, size_t buflen, bool can_sleep)
{ … }

/*
 * vmbus_set_event - Send an event notification to the parent
 */
void vmbus_set_event(struct vmbus_channel *channel)
{ … }
EXPORT_SYMBOL_GPL(…);