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Commit 655d406a authored by Ian Campbell's avatar Ian Campbell Committed by Jeremy Fitzhardinge
Browse files

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: default avatarIan Campbell <ian.campbell@citrix.com>
Signed-off-by: default avatarJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
parent cd07202c

drivers/xen/xenfs/Makefile

+2 −1
Original line number Diff line number Diff line 
obj-$(CONFIG_XENFS) += xenfs.o



xenfs-objs = super.o xenbus.o
 
 No newline at end of file
 
xenfs-y			  = super.o xenbus.o

xenfs-$(CONFIG_XEN_DOM0) += xenstored.o

drivers/xen/xenfs/super.c

+53 −1
Original line number Diff line number Diff line
@@ -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;



	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 simple_fill_super(sb, XENFS_SUPER_MAGIC, xenfs_files);

	return rc;

}



static int xenfs_get_sb(struct file_system_type *fs_type,

drivers/xen/xenfs/xenfs.h

+2 −0
Original line number Diff line number Diff line
@@ -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 */

drivers/xen/xenfs/xenstored.c

0 → 100644
+68 −0
Original line number Diff line number Diff line 
#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,

};