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v4.6
  1/*
  2 *  xenfs.c - a filesystem for passing info between the a domain and
  3 *  the hypervisor.
  4 *
  5 * 2008-10-07  Alex Zeffertt    Replaced /proc/xen/xenbus with xenfs filesystem
  6 *                              and /proc/xen compatibility mount point.
  7 *                              Turned xenfs into a loadable module.
  8 */
  9
 10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 11
 12#include <linux/kernel.h>
 13#include <linux/errno.h>
 14#include <linux/module.h>
 15#include <linux/fs.h>
 16#include <linux/magic.h>
 17
 18#include <xen/xen.h>
 19
 20#include "xenfs.h"
 21#include "../privcmd.h"
 22#include "../xenbus/xenbus_comms.h"
 23
 24#include <asm/xen/hypervisor.h>
 25
 26MODULE_DESCRIPTION("Xen filesystem");
 27MODULE_LICENSE("GPL");
 28
 29static ssize_t capabilities_read(struct file *file, char __user *buf,
 30				 size_t size, loff_t *off)
 31{
 32	char *tmp = "";
 33
 34	if (xen_initial_domain())
 35		tmp = "control_d\n";
 36
 37	return simple_read_from_buffer(buf, size, off, tmp, strlen(tmp));
 38}
 39
 40static const struct file_operations capabilities_file_ops = {
 41	.read = capabilities_read,
 42	.llseek = default_llseek,
 43};
 44
 45static int xenfs_fill_super(struct super_block *sb, void *data, int silent)
 46{
 47	static struct tree_descr xenfs_files[] = {
 48		[2] = { "xenbus", &xen_xenbus_fops, S_IRUSR|S_IWUSR },
 49		{ "capabilities", &capabilities_file_ops, S_IRUGO },
 50		{ "privcmd", &xen_privcmd_fops, S_IRUSR|S_IWUSR },
 51		{""},
 52	};
 53
 54	static struct tree_descr xenfs_init_files[] = {
 55		[2] = { "xenbus", &xen_xenbus_fops, S_IRUSR|S_IWUSR },
 56		{ "capabilities", &capabilities_file_ops, S_IRUGO },
 57		{ "privcmd", &xen_privcmd_fops, S_IRUSR|S_IWUSR },
 58		{ "xsd_kva", &xsd_kva_file_ops, S_IRUSR|S_IWUSR},
 59		{ "xsd_port", &xsd_port_file_ops, S_IRUSR|S_IWUSR},
 60#ifdef CONFIG_XEN_SYMS
 61		{ "xensyms", &xensyms_ops, S_IRUSR},
 62#endif
 63		{""},
 64	};
 65
 66	return simple_fill_super(sb, XENFS_SUPER_MAGIC,
 67			xen_initial_domain() ? xenfs_init_files : xenfs_files);
 68}
 69
 70static struct dentry *xenfs_mount(struct file_system_type *fs_type,
 71				  int flags, const char *dev_name,
 72				  void *data)
 73{
 74	return mount_single(fs_type, flags, data, xenfs_fill_super);
 75}
 76
 77static struct file_system_type xenfs_type = {
 78	.owner =	THIS_MODULE,
 79	.name =		"xenfs",
 80	.mount =	xenfs_mount,
 81	.kill_sb =	kill_litter_super,
 82};
 83MODULE_ALIAS_FS("xenfs");
 84
 85static int __init xenfs_init(void)
 86{
 87	if (xen_domain())
 88		return register_filesystem(&xenfs_type);
 89
 90	pr_info("not registering filesystem on non-xen platform\n");
 91	return 0;
 92}
 93
 94static void __exit xenfs_exit(void)
 95{
 96	if (xen_domain())
 97		unregister_filesystem(&xenfs_type);
 98}
 99
100module_init(xenfs_init);
101module_exit(xenfs_exit);
102
v4.10.11
  1/*
  2 *  xenfs.c - a filesystem for passing info between the a domain and
  3 *  the hypervisor.
  4 *
  5 * 2008-10-07  Alex Zeffertt    Replaced /proc/xen/xenbus with xenfs filesystem
  6 *                              and /proc/xen compatibility mount point.
  7 *                              Turned xenfs into a loadable module.
  8 */
  9
 10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 11
 12#include <linux/kernel.h>
 13#include <linux/errno.h>
 14#include <linux/module.h>
 15#include <linux/fs.h>
 16#include <linux/magic.h>
 17
 18#include <xen/xen.h>
 19
 20#include "xenfs.h"
 21#include "../privcmd.h"
 22#include "../xenbus/xenbus_comms.h"
 23
 24#include <asm/xen/hypervisor.h>
 25
 26MODULE_DESCRIPTION("Xen filesystem");
 27MODULE_LICENSE("GPL");
 28
 29static ssize_t capabilities_read(struct file *file, char __user *buf,
 30				 size_t size, loff_t *off)
 31{
 32	char *tmp = "";
 33
 34	if (xen_initial_domain())
 35		tmp = "control_d\n";
 36
 37	return simple_read_from_buffer(buf, size, off, tmp, strlen(tmp));
 38}
 39
 40static const struct file_operations capabilities_file_ops = {
 41	.read = capabilities_read,
 42	.llseek = default_llseek,
 43};
 44
 45static int xenfs_fill_super(struct super_block *sb, void *data, int silent)
 46{
 47	static struct tree_descr xenfs_files[] = {
 48		[2] = { "xenbus", &xen_xenbus_fops, S_IRUSR|S_IWUSR },
 49		{ "capabilities", &capabilities_file_ops, S_IRUGO },
 50		{ "privcmd", &xen_privcmd_fops, S_IRUSR|S_IWUSR },
 51		{""},
 52	};
 53
 54	static struct tree_descr xenfs_init_files[] = {
 55		[2] = { "xenbus", &xen_xenbus_fops, S_IRUSR|S_IWUSR },
 56		{ "capabilities", &capabilities_file_ops, S_IRUGO },
 57		{ "privcmd", &xen_privcmd_fops, S_IRUSR|S_IWUSR },
 58		{ "xsd_kva", &xsd_kva_file_ops, S_IRUSR|S_IWUSR},
 59		{ "xsd_port", &xsd_port_file_ops, S_IRUSR|S_IWUSR},
 60#ifdef CONFIG_XEN_SYMS
 61		{ "xensyms", &xensyms_ops, S_IRUSR},
 62#endif
 63		{""},
 64	};
 65
 66	return simple_fill_super(sb, XENFS_SUPER_MAGIC,
 67			xen_initial_domain() ? xenfs_init_files : xenfs_files);
 68}
 69
 70static struct dentry *xenfs_mount(struct file_system_type *fs_type,
 71				  int flags, const char *dev_name,
 72				  void *data)
 73{
 74	return mount_single(fs_type, flags, data, xenfs_fill_super);
 75}
 76
 77static struct file_system_type xenfs_type = {
 78	.owner =	THIS_MODULE,
 79	.name =		"xenfs",
 80	.mount =	xenfs_mount,
 81	.kill_sb =	kill_litter_super,
 82};
 83MODULE_ALIAS_FS("xenfs");
 84
 85static int __init xenfs_init(void)
 86{
 87	if (xen_domain())
 88		return register_filesystem(&xenfs_type);
 89
 90	pr_info("not registering filesystem on non-xen platform\n");
 91	return 0;
 92}
 93
 94static void __exit xenfs_exit(void)
 95{
 96	if (xen_domain())
 97		unregister_filesystem(&xenfs_type);
 98}
 99
100module_init(xenfs_init);
101module_exit(xenfs_exit);
102