xen: add /proc/xen/xsd_{kva,port} to xenfs

These are used by the userspace xenstore daemon, which runs in dom0.
Xenstored is what's behind the xenfs "xenbus" filesystem.

[ Impact: provide mapping and port to usermode for xenstore ]

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
This commit is contained in:
Ian Campbell 2009-02-06 18:46:48 -08:00 committed by Jeremy Fitzhardinge
parent cd07202cc8
commit 655d406a7c
4 changed files with 125 additions and 2 deletions

View File

@ -1,3 +1,4 @@
obj-$(CONFIG_XENFS) += xenfs.o
xenfs-objs = super.o xenbus.o
xenfs-y = super.o xenbus.o
xenfs-$(CONFIG_XEN_DOM0) += xenstored.o

View File

@ -22,6 +22,46 @@
MODULE_DESCRIPTION("Xen filesystem");
MODULE_LICENSE("GPL");
static struct inode *xenfs_make_inode(struct super_block *sb, int mode)
{
struct inode *ret = new_inode(sb);
if (ret) {
ret->i_mode = mode;
ret->i_uid = ret->i_gid = 0;
ret->i_blocks = 0;
ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
}
return ret;
}
static struct dentry *xenfs_create_file(struct super_block *sb,
struct dentry *parent,
const char *name,
const struct file_operations *fops,
void *data,
int mode)
{
struct dentry *dentry;
struct inode *inode;
dentry = d_alloc_name(parent, name);
if (!dentry)
return NULL;
inode = xenfs_make_inode(sb, S_IFREG | mode);
if (!inode) {
dput(dentry);
return NULL;
}
inode->i_fop = fops;
inode->i_private = data;
d_add(dentry, inode);
return dentry;
}
static ssize_t capabilities_read(struct file *file, char __user *buf,
size_t size, loff_t *off)
{
@ -45,8 +85,20 @@ static int xenfs_fill_super(struct super_block *sb, void *data, int silent)
{ "capabilities", &capabilities_file_ops, S_IRUGO },
{""},
};
int rc;
return simple_fill_super(sb, XENFS_SUPER_MAGIC, xenfs_files);
rc = simple_fill_super(sb, XENFS_SUPER_MAGIC, xenfs_files);
if (rc < 0)
return rc;
if (xen_initial_domain()) {
xenfs_create_file(sb, sb->s_root, "xsd_kva",
&xsd_kva_file_ops, NULL, S_IRUSR|S_IWUSR);
xenfs_create_file(sb, sb->s_root, "xsd_port",
&xsd_port_file_ops, NULL, S_IRUSR|S_IWUSR);
}
return rc;
}
static int xenfs_get_sb(struct file_system_type *fs_type,

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@ -2,5 +2,7 @@
#define _XENFS_XENBUS_H
extern const struct file_operations xenbus_file_ops;
extern const struct file_operations xsd_kva_file_ops;
extern const struct file_operations xsd_port_file_ops;
#endif /* _XENFS_XENBUS_H */

View File

@ -0,0 +1,68 @@
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <xen/page.h>
#include "xenfs.h"
#include "../xenbus/xenbus_comms.h"
static ssize_t xsd_read(struct file *file, char __user *buf,
size_t size, loff_t *off)
{
const char *str = (const char *)file->private_data;
return simple_read_from_buffer(buf, size, off, str, strlen(str));
}
static int xsd_release(struct inode *inode, struct file *file)
{
kfree(file->private_data);
return 0;
}
static int xsd_kva_open(struct inode *inode, struct file *file)
{
file->private_data = (void *)kasprintf(GFP_KERNEL, "0x%p",
xen_store_interface);
if (!file->private_data)
return -ENOMEM;
return 0;
}
static int xsd_kva_mmap(struct file *file, struct vm_area_struct *vma)
{
size_t size = vma->vm_end - vma->vm_start;
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 xsd_kva_file_ops = {
.open = xsd_kva_open,
.mmap = xsd_kva_mmap,
.read = xsd_read,
.release = xsd_release,
};
static int xsd_port_open(struct inode *inode, struct file *file)
{
file->private_data = (void *)kasprintf(GFP_KERNEL, "%d",
xen_store_evtchn);
if (!file->private_data)
return -ENOMEM;
return 0;
}
const struct file_operations xsd_port_file_ops = {
.open = xsd_port_open,
.read = xsd_read,
.release = xsd_release,
};