https://github.com/torvalds/linux
Tip revision: 9cb1fd0efd195590b828b9b865421ad345a4a145 authored by Linus Torvalds on 24 May 2020, 22:32:54 UTC
Linux 5.7-rc7
Linux 5.7-rc7
Tip revision: 9cb1fd0
vmci_driver.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* VMware VMCI Driver
*
* Copyright (C) 2012 VMware, Inc. All rights reserved.
*/
#include <linux/vmw_vmci_defs.h>
#include <linux/vmw_vmci_api.h>
#include <linux/atomic.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include "vmci_driver.h"
#include "vmci_event.h"
static bool vmci_disable_host;
module_param_named(disable_host, vmci_disable_host, bool, 0);
MODULE_PARM_DESC(disable_host,
"Disable driver host personality (default=enabled)");
static bool vmci_disable_guest;
module_param_named(disable_guest, vmci_disable_guest, bool, 0);
MODULE_PARM_DESC(disable_guest,
"Disable driver guest personality (default=enabled)");
static bool vmci_guest_personality_initialized;
static bool vmci_host_personality_initialized;
static DEFINE_MUTEX(vmci_vsock_mutex); /* protects vmci_vsock_transport_cb */
static vmci_vsock_cb vmci_vsock_transport_cb;
static bool vmci_vsock_cb_host_called;
/*
* vmci_get_context_id() - Gets the current context ID.
*
* Returns the current context ID. Note that since this is accessed only
* from code running in the host, this always returns the host context ID.
*/
u32 vmci_get_context_id(void)
{
if (vmci_guest_code_active())
return vmci_get_vm_context_id();
else if (vmci_host_code_active())
return VMCI_HOST_CONTEXT_ID;
return VMCI_INVALID_ID;
}
EXPORT_SYMBOL_GPL(vmci_get_context_id);
/*
* vmci_register_vsock_callback() - Register the VSOCK vmci_transport callback.
*
* The callback will be called when the first host or guest becomes active,
* or if they are already active when this function is called.
* To unregister the callback, call this function with NULL parameter.
*
* Returns 0 on success. -EBUSY if a callback is already registered.
*/
int vmci_register_vsock_callback(vmci_vsock_cb callback)
{
int err = 0;
mutex_lock(&vmci_vsock_mutex);
if (vmci_vsock_transport_cb && callback) {
err = -EBUSY;
goto out;
}
vmci_vsock_transport_cb = callback;
if (!vmci_vsock_transport_cb) {
vmci_vsock_cb_host_called = false;
goto out;
}
if (vmci_guest_code_active())
vmci_vsock_transport_cb(false);
if (vmci_host_users() > 0) {
vmci_vsock_cb_host_called = true;
vmci_vsock_transport_cb(true);
}
out:
mutex_unlock(&vmci_vsock_mutex);
return err;
}
EXPORT_SYMBOL_GPL(vmci_register_vsock_callback);
void vmci_call_vsock_callback(bool is_host)
{
mutex_lock(&vmci_vsock_mutex);
if (!vmci_vsock_transport_cb)
goto out;
/* In the host, this function could be called multiple times,
* but we want to register it only once.
*/
if (is_host) {
if (vmci_vsock_cb_host_called)
goto out;
vmci_vsock_cb_host_called = true;
}
vmci_vsock_transport_cb(is_host);
out:
mutex_unlock(&vmci_vsock_mutex);
}
static int __init vmci_drv_init(void)
{
int vmci_err;
int error;
vmci_err = vmci_event_init();
if (vmci_err < VMCI_SUCCESS) {
pr_err("Failed to initialize VMCIEvent (result=%d)\n",
vmci_err);
return -EINVAL;
}
if (!vmci_disable_guest) {
error = vmci_guest_init();
if (error) {
pr_warn("Failed to initialize guest personality (err=%d)\n",
error);
} else {
vmci_guest_personality_initialized = true;
pr_info("Guest personality initialized and is %s\n",
vmci_guest_code_active() ?
"active" : "inactive");
}
}
if (!vmci_disable_host) {
error = vmci_host_init();
if (error) {
pr_warn("Unable to initialize host personality (err=%d)\n",
error);
} else {
vmci_host_personality_initialized = true;
pr_info("Initialized host personality\n");
}
}
if (!vmci_guest_personality_initialized &&
!vmci_host_personality_initialized) {
vmci_event_exit();
return -ENODEV;
}
return 0;
}
module_init(vmci_drv_init);
static void __exit vmci_drv_exit(void)
{
if (vmci_guest_personality_initialized)
vmci_guest_exit();
if (vmci_host_personality_initialized)
vmci_host_exit();
vmci_event_exit();
}
module_exit(vmci_drv_exit);
MODULE_AUTHOR("VMware, Inc.");
MODULE_DESCRIPTION("VMware Virtual Machine Communication Interface.");
MODULE_VERSION("1.1.6.0-k");
MODULE_LICENSE("GPL v2");