diff options
| -rw-r--r-- | drivers/xen/xenbus/Makefile | 1 | ||||
| -rw-r--r-- | drivers/xen/xenbus/xenbus_dev_backend.c | 89 | ||||
| -rw-r--r-- | include/xen/xenbus_dev.h | 41 |
3 files changed, 131 insertions, 0 deletions
diff --git a/drivers/xen/xenbus/Makefile b/drivers/xen/xenbus/Makefile index a2ea363b9f3..31e2e9050c7 100644 --- a/drivers/xen/xenbus/Makefile +++ b/drivers/xen/xenbus/Makefile @@ -10,4 +10,5 @@ xenbus-objs += xenbus_probe.o xenbus-be-objs-$(CONFIG_XEN_BACKEND) += xenbus_probe_backend.o xenbus-objs += $(xenbus-be-objs-y) +obj-$(CONFIG_XEN_BACKEND) += xenbus_dev_backend.o obj-$(CONFIG_XEN_XENBUS_FRONTEND) += xenbus_probe_frontend.o diff --git a/drivers/xen/xenbus/xenbus_dev_backend.c b/drivers/xen/xenbus/xenbus_dev_backend.c new file mode 100644 index 00000000000..a2092bd9769 --- /dev/null +++ b/drivers/xen/xenbus/xenbus_dev_backend.c @@ -0,0 +1,89 @@ +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/mm.h> +#include <linux/fs.h> +#include <linux/miscdevice.h> +#include <linux/module.h> +#include <linux/capability.h> + +#include <xen/page.h> +#include <xen/xenbus_dev.h> + +#include "xenbus_comms.h" + +MODULE_LICENSE("GPL"); + +static int xenbus_backend_open(struct inode *inode, struct file *filp) +{ + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + return nonseekable_open(inode, filp); +} + +static long xenbus_backend_ioctl(struct file *file, unsigned int cmd, unsigned long data) +{ + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + switch (cmd) { + case IOCTL_XENBUS_BACKEND_EVTCHN: + if (xen_store_evtchn > 0) + return xen_store_evtchn; + return -ENODEV; + + default: + return -ENOTTY; + } +} + +static int xenbus_backend_mmap(struct file *file, struct vm_area_struct *vma) +{ + size_t size = vma->vm_end - vma->vm_start; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + if ((size > PAGE_SIZE) || (vma->vm_pgoff != 0)) + return -EINVAL; + + if (remap_pfn_range(vma, vma->vm_start, + virt_to_pfn(xen_store_interface), + size, vma->vm_page_prot)) + return -EAGAIN; + + return 0; +} + +const struct file_operations xenbus_backend_fops = { + .open = xenbus_backend_open, + .mmap = xenbus_backend_mmap, + .unlocked_ioctl = xenbus_backend_ioctl, +}; + +static struct miscdevice xenbus_backend_dev = { + .minor = MISC_DYNAMIC_MINOR, + .name = "xen/xenbus_backend", + .fops = &xenbus_backend_fops, +}; + +static int __init xenbus_backend_init(void) +{ + int err; + + if (!xen_initial_domain()) + return -ENODEV; + + err = misc_register(&xenbus_backend_dev); + if (err) + printk(KERN_ERR "Could not register xenbus backend device\n"); + return err; +} + +static void __exit xenbus_backend_exit(void) +{ + misc_deregister(&xenbus_backend_dev); +} + +module_init(xenbus_backend_init); +module_exit(xenbus_backend_exit); diff --git a/include/xen/xenbus_dev.h b/include/xen/xenbus_dev.h new file mode 100644 index 00000000000..ac5f0fe47ed --- /dev/null +++ b/include/xen/xenbus_dev.h @@ -0,0 +1,41 @@ +/****************************************************************************** + * evtchn.h + * + * Interface to /dev/xen/xenbus_backend. + * + * Copyright (c) 2011 Bastian Blank <waldi@debian.org> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation; or, when distributed + * separately from the Linux kernel or incorporated into other + * software packages, subject to the following license: + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this source file (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, modify, + * merge, publish, distribute, sublicense, and/or sell copies of the Software, + * and to permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + */ + +#ifndef __LINUX_XEN_XENBUS_DEV_H__ +#define __LINUX_XEN_XENBUS_DEV_H__ + +#include <linux/ioctl.h> + +#define IOCTL_XENBUS_BACKEND_EVTCHN \ + _IOC(_IOC_NONE, 'B', 0, 0) + +#endif /* __LINUX_XEN_XENBUS_DEV_H__ */ |