diff options
Diffstat (limited to 'drivers/misc/vmw_vmci/vmci_driver.c')
| -rw-r--r-- | drivers/misc/vmw_vmci/vmci_driver.c | 77 |
1 files changed, 68 insertions, 9 deletions
diff --git a/drivers/misc/vmw_vmci/vmci_driver.c b/drivers/misc/vmw_vmci/vmci_driver.c index 003bfba40758..cbb706dabede 100644 --- a/drivers/misc/vmw_vmci/vmci_driver.c +++ b/drivers/misc/vmw_vmci/vmci_driver.c @@ -1,16 +1,8 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * VMware VMCI Driver * * Copyright (C) 2012 VMware, Inc. All rights reserved. - * - * This program is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License as published by the - * Free Software Foundation version 2 and no later version. - * - * This program is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY - * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License - * for more details. */ #include <linux/vmw_vmci_defs.h> @@ -36,6 +28,10 @@ MODULE_PARM_DESC(disable_guest, 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. * @@ -53,6 +49,69 @@ u32 vmci_get_context_id(void) } 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; |