xen: Add privcmd device driver

Access to arbitrary hypercalls is currently provided via xenfs. This
adds a standard character device to handle this. The support in xenfs
remains for backward compatibility and uses the device driver code.

Signed-off-by: Bastian Blank <waldi@debian.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This commit is contained in:
Bastian Blank 2011-12-16 11:34:33 -05:00 committed by Konrad Rzeszutek Wilk
parent 243082e0d5
commit d8414d3c15
7 changed files with 53 additions and 4 deletions

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@ -86,6 +86,7 @@ config XEN_BACKEND
config XENFS
tristate "Xen filesystem"
select XEN_PRIVCMD
default y
help
The xen filesystem provides a way for domains to share
@ -171,4 +172,10 @@ config XEN_PCIDEV_BACKEND
xen-pciback.hide=(03:00.0)(04:00.0)
If in doubt, say m.
config XEN_PRIVCMD
tristate
depends on XEN
default m
endmenu

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@ -19,7 +19,9 @@ obj-$(CONFIG_XEN_TMEM) += tmem.o
obj-$(CONFIG_SWIOTLB_XEN) += swiotlb-xen.o
obj-$(CONFIG_XEN_DOM0) += pci.o
obj-$(CONFIG_XEN_PCIDEV_BACKEND) += xen-pciback/
obj-$(CONFIG_XEN_PRIVCMD) += xen-privcmd.o
xen-evtchn-y := evtchn.o
xen-gntdev-y := gntdev.o
xen-gntalloc-y := gntalloc.o
xen-privcmd-y := privcmd.o

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@ -7,6 +7,7 @@
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/string.h>
@ -18,6 +19,7 @@
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/seq_file.h>
#include <linux/miscdevice.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
@ -32,6 +34,10 @@
#include <xen/page.h>
#include <xen/xen-ops.h>
#include "privcmd.h"
MODULE_LICENSE("GPL");
#ifndef HAVE_ARCH_PRIVCMD_MMAP
static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma);
#endif
@ -394,7 +400,38 @@ static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma)
}
#endif
const struct file_operations privcmd_file_ops = {
const struct file_operations xen_privcmd_fops = {
.owner = THIS_MODULE,
.unlocked_ioctl = privcmd_ioctl,
.mmap = privcmd_mmap,
};
EXPORT_SYMBOL_GPL(xen_privcmd_fops);
static struct miscdevice privcmd_dev = {
.minor = MISC_DYNAMIC_MINOR,
.name = "xen/privcmd",
.fops = &xen_privcmd_fops,
};
static int __init privcmd_init(void)
{
int err;
if (!xen_domain())
return -ENODEV;
err = misc_register(&privcmd_dev);
if (err != 0) {
printk(KERN_ERR "Could not register Xen privcmd device\n");
return err;
}
return 0;
}
static void __exit privcmd_exit(void)
{
misc_deregister(&privcmd_dev);
}
module_init(privcmd_init);
module_exit(privcmd_exit);

3
drivers/xen/privcmd.h Normal file
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@ -0,0 +1,3 @@
#include <linux/fs.h>
extern const struct file_operations xen_privcmd_fops;

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

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@ -16,6 +16,7 @@
#include <xen/xen.h>
#include "xenfs.h"
#include "../privcmd.h"
#include <asm/xen/hypervisor.h>
@ -84,7 +85,7 @@ static int xenfs_fill_super(struct super_block *sb, void *data, int silent)
[1] = {},
{ "xenbus", &xenbus_file_ops, S_IRUSR|S_IWUSR },
{ "capabilities", &capabilities_file_ops, S_IRUGO },
{ "privcmd", &privcmd_file_ops, S_IRUSR|S_IWUSR },
{ "privcmd", &xen_privcmd_fops, S_IRUSR|S_IWUSR },
{""},
};
int rc;

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@ -2,7 +2,6 @@
#define _XENFS_XENBUS_H
extern const struct file_operations xenbus_file_ops;
extern const struct file_operations privcmd_file_ops;
extern const struct file_operations xsd_kva_file_ops;
extern const struct file_operations xsd_port_file_ops;