Loading...
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * xenfs.c - a filesystem for passing info between the a domain and
4 * the hypervisor.
5 *
6 * 2008-10-07 Alex Zeffertt Replaced /proc/xen/xenbus with xenfs filesystem
7 * and /proc/xen compatibility mount point.
8 * Turned xenfs into a loadable module.
9 */
10
11#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12
13#include <linux/kernel.h>
14#include <linux/errno.h>
15#include <linux/module.h>
16#include <linux/fs.h>
17#include <linux/fs_context.h>
18#include <linux/magic.h>
19
20#include <xen/xen.h>
21#include <xen/xenbus.h>
22
23#include "xenfs.h"
24#include "../privcmd.h"
25
26#include <asm/xen/hypervisor.h>
27
28MODULE_DESCRIPTION("Xen filesystem");
29MODULE_LICENSE("GPL");
30
31static ssize_t capabilities_read(struct file *file, char __user *buf,
32 size_t size, loff_t *off)
33{
34 char *tmp = "";
35
36 if (xen_initial_domain())
37 tmp = "control_d\n";
38
39 return simple_read_from_buffer(buf, size, off, tmp, strlen(tmp));
40}
41
42static const struct file_operations capabilities_file_ops = {
43 .read = capabilities_read,
44 .llseek = default_llseek,
45};
46
47static int xenfs_fill_super(struct super_block *sb, struct fs_context *fc)
48{
49 static const struct tree_descr xenfs_files[] = {
50 [2] = { "xenbus", &xen_xenbus_fops, S_IRUSR|S_IWUSR },
51 { "capabilities", &capabilities_file_ops, S_IRUGO },
52 { "privcmd", &xen_privcmd_fops, S_IRUSR|S_IWUSR },
53 {""},
54 };
55
56 static const struct tree_descr xenfs_init_files[] = {
57 [2] = { "xenbus", &xen_xenbus_fops, S_IRUSR|S_IWUSR },
58 { "capabilities", &capabilities_file_ops, S_IRUGO },
59 { "privcmd", &xen_privcmd_fops, S_IRUSR|S_IWUSR },
60 { "xsd_kva", &xsd_kva_file_ops, S_IRUSR|S_IWUSR},
61 { "xsd_port", &xsd_port_file_ops, S_IRUSR|S_IWUSR},
62#ifdef CONFIG_XEN_SYMS
63 { "xensyms", &xensyms_ops, S_IRUSR},
64#endif
65 {""},
66 };
67
68 return simple_fill_super(sb, XENFS_SUPER_MAGIC,
69 xen_initial_domain() ? xenfs_init_files : xenfs_files);
70}
71
72static int xenfs_get_tree(struct fs_context *fc)
73{
74 return get_tree_single(fc, xenfs_fill_super);
75}
76
77static const struct fs_context_operations xenfs_context_ops = {
78 .get_tree = xenfs_get_tree,
79};
80
81static int xenfs_init_fs_context(struct fs_context *fc)
82{
83 fc->ops = &xenfs_context_ops;
84 return 0;
85}
86
87static struct file_system_type xenfs_type = {
88 .owner = THIS_MODULE,
89 .name = "xenfs",
90 .init_fs_context = xenfs_init_fs_context,
91 .kill_sb = kill_litter_super,
92};
93MODULE_ALIAS_FS("xenfs");
94
95static int __init xenfs_init(void)
96{
97 if (xen_domain())
98 return register_filesystem(&xenfs_type);
99
100 return 0;
101}
102
103static void __exit xenfs_exit(void)
104{
105 if (xen_domain())
106 unregister_filesystem(&xenfs_type);
107}
108
109module_init(xenfs_init);
110module_exit(xenfs_exit);
111
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 {""},
61 };
62
63 return simple_fill_super(sb, XENFS_SUPER_MAGIC,
64 xen_initial_domain() ? xenfs_init_files : xenfs_files);
65}
66
67static struct dentry *xenfs_mount(struct file_system_type *fs_type,
68 int flags, const char *dev_name,
69 void *data)
70{
71 return mount_single(fs_type, flags, data, xenfs_fill_super);
72}
73
74static struct file_system_type xenfs_type = {
75 .owner = THIS_MODULE,
76 .name = "xenfs",
77 .mount = xenfs_mount,
78 .kill_sb = kill_litter_super,
79};
80MODULE_ALIAS_FS("xenfs");
81
82static int __init xenfs_init(void)
83{
84 if (xen_domain())
85 return register_filesystem(&xenfs_type);
86
87 pr_info("not registering filesystem on non-xen platform\n");
88 return 0;
89}
90
91static void __exit xenfs_exit(void)
92{
93 if (xen_domain())
94 unregister_filesystem(&xenfs_type);
95}
96
97module_init(xenfs_init);
98module_exit(xenfs_exit);
99