436 lines
8.8 KiB
C
436 lines
8.8 KiB
C
|
/******************************************************************************
|
||
|
|
* privcmd.c
|
||
|
|
*
|
||
|
|
* Interface to privileged domain-0 commands.
|
||
|
|
*
|
||
|
|
* Copyright (c) 2002-2004, K A Fraser, B Dragovic
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/kernel.h>
|
||
|
|
#include <linux/module.h>
|
||
|
|
#include <linux/sched.h>
|
||
|
|
#include <linux/slab.h>
|
||
|
|
#include <linux/string.h>
|
||
|
|
#include <linux/errno.h>
|
||
|
|
#include <linux/mm.h>
|
||
|
|
#include <linux/mman.h>
|
||
|
|
#include <linux/uaccess.h>
|
||
|
|
#include <linux/swap.h>
|
||
|
|
#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>
|
||
|
|
#include <asm/tlb.h>
|
||
|
|
#include <asm/xen/hypervisor.h>
|
||
|
|
#include <asm/xen/hypercall.h>
|
||
|
|
|
||
|
|
#include <xen/xen.h>
|
||
|
|
#include <xen/privcmd.h>
|
||
|
|
#include <xen/interface/xen.h>
|
||
|
|
#include <xen/features.h>
|
||
|
|
#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
|
||
|
|
|
||
|
|
static long privcmd_ioctl_hypercall(void __user *udata)
|
||
|
|
{
|
||
|
|
struct privcmd_hypercall hypercall;
|
||
|
|
long ret;
|
||
|
|
|
||
|
|
if (copy_from_user(&hypercall, udata, sizeof(hypercall)))
|
||
|
|
return -EFAULT;
|
||
|
|
|
||
|
|
ret = privcmd_call(hypercall.op,
|
||
|
|
hypercall.arg[0], hypercall.arg[1],
|
||
|
|
hypercall.arg[2], hypercall.arg[3],
|
||
|
|
hypercall.arg[4]);
|
||
|
|
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
static void free_page_list(struct list_head *pages)
|
||
|
|
{
|
||
|
|
struct page *p, *n;
|
||
|
|
|
||
|
|
list_for_each_entry_safe(p, n, pages, lru)
|
||
|
|
__free_page(p);
|
||
|
|
|
||
|
|
INIT_LIST_HEAD(pages);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Given an array of items in userspace, return a list of pages
|
||
|
|
* containing the data. If copying fails, either because of memory
|
||
|
|
* allocation failure or a problem reading user memory, return an
|
||
|
|
* error code; its up to the caller to dispose of any partial list.
|
||
|
|
*/
|
||
|
|
static int gather_array(struct list_head *pagelist,
|
||
|
|
unsigned nelem, size_t size,
|
||
|
|
void __user *data)
|
||
|
|
{
|
||
|
|
unsigned pageidx;
|
||
|
|
void *pagedata;
|
||
|
|
int ret;
|
||
|
|
|
||
|
|
if (size > PAGE_SIZE)
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
pageidx = PAGE_SIZE;
|
||
|
|
pagedata = NULL; /* quiet, gcc */
|
||
|
|
while (nelem--) {
|
||
|
|
if (pageidx > PAGE_SIZE-size) {
|
||
|
|
struct page *page = alloc_page(GFP_KERNEL);
|
||
|
|
|
||
|
|
ret = -ENOMEM;
|
||
|
|
if (page == NULL)
|
||
|
|
goto fail;
|
||
|
|
|
||
|
|
pagedata = page_address(page);
|
||
|
|
|
||
|
|
list_add_tail(&page->lru, pagelist);
|
||
|
|
pageidx = 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
ret = -EFAULT;
|
||
|
|
if (copy_from_user(pagedata + pageidx, data, size))
|
||
|
|
goto fail;
|
||
|
|
|
||
|
|
data += size;
|
||
|
|
pageidx += size;
|
||
|
|
}
|
||
|
|
|
||
|
|
ret = 0;
|
||
|
|
|
||
|
|
fail:
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Call function "fn" on each element of the array fragmented
|
||
|
|
* over a list of pages.
|
||
|
|
*/
|
||
|
|
static int traverse_pages(unsigned nelem, size_t size,
|
||
|
|
struct list_head *pos,
|
||
|
|
int (*fn)(void *data, void *state),
|
||
|
|
void *state)
|
||
|
|
{
|
||
|
|
void *pagedata;
|
||
|
|
unsigned pageidx;
|
||
|
|
int ret = 0;
|
||
|
|
|
||
|
|
BUG_ON(size > PAGE_SIZE);
|
||
|
|
|
||
|
|
pageidx = PAGE_SIZE;
|
||
|
|
pagedata = NULL; /* hush, gcc */
|
||
|
|
|
||
|
|
while (nelem--) {
|
||
|
|
if (pageidx > PAGE_SIZE-size) {
|
||
|
|
struct page *page;
|
||
|
|
pos = pos->next;
|
||
|
|
page = list_entry(pos, struct page, lru);
|
||
|
|
pagedata = page_address(page);
|
||
|
|
pageidx = 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
ret = (*fn)(pagedata + pageidx, state);
|
||
|
|
if (ret)
|
||
|
|
break;
|
||
|
|
pageidx += size;
|
||
|
|
}
|
||
|
|
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
struct mmap_mfn_state {
|
||
|
|
unsigned long va;
|
||
|
|
struct vm_area_struct *vma;
|
||
|
|
domid_t domain;
|
||
|
|
};
|
||
|
|
|
||
|
|
static int mmap_mfn_range(void *data, void *state)
|
||
|
|
{
|
||
|
|
struct privcmd_mmap_entry *msg = data;
|
||
|
|
struct mmap_mfn_state *st = state;
|
||
|
|
struct vm_area_struct *vma = st->vma;
|
||
|
|
int rc;
|
||
|
|
|
||
|
|
/* Do not allow range to wrap the address space. */
|
||
|
|
if ((msg->npages > (LONG_MAX >> PAGE_SHIFT)) ||
|
||
|
|
((unsigned long)(msg->npages << PAGE_SHIFT) >= -st->va))
|
||
|
|
return -EINVAL;
|
||
|
|
|
||
|
|
/* Range chunks must be contiguous in va space. */
|
||
|
|
if ((msg->va != st->va) ||
|
||
|
|
((msg->va+(msg->npages<<PAGE_SHIFT)) > vma->vm_end))
|
||
|
|
return -EINVAL;
|
||
|
|
|
||
|
|
rc = xen_remap_domain_mfn_range(vma,
|
||
|
|
msg->va & PAGE_MASK,
|
||
|
|
msg->mfn, msg->npages,
|
||
|
|
vma->vm_page_prot,
|
||
|
|
st->domain);
|
||
|
|
if (rc < 0)
|
||
|
|
return rc;
|
||
|
|
|
||
|
|
st->va += msg->npages << PAGE_SHIFT;
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static long privcmd_ioctl_mmap(void __user *udata)
|
||
|
|
{
|
||
|
|
struct privcmd_mmap mmapcmd;
|
||
|
|
struct mm_struct *mm = current->mm;
|
||
|
|
struct vm_area_struct *vma;
|
||
|
|
int rc;
|
||
|
|
LIST_HEAD(pagelist);
|
||
|
|
struct mmap_mfn_state state;
|
||
|
|
|
||
|
|
if (!xen_initial_domain())
|
||
|
|
return -EPERM;
|
||
|
|
|
||
|
|
if (copy_from_user(&mmapcmd, udata, sizeof(mmapcmd)))
|
||
|
|
return -EFAULT;
|
||
|
|
|
||
|
|
rc = gather_array(&pagelist,
|
||
|
|
mmapcmd.num, sizeof(struct privcmd_mmap_entry),
|
||
|
|
mmapcmd.entry);
|
||
|
|
|
||
|
|
if (rc || list_empty(&pagelist))
|
||
|
|
goto out;
|
||
|
|
|
||
|
|
down_write(&mm->mmap_sem);
|
||
|
|
|
||
|
|
{
|
||
|
|
struct page *page = list_first_entry(&pagelist,
|
||
|
|
struct page, lru);
|
||
|
|
struct privcmd_mmap_entry *msg = page_address(page);
|
||
|
|
|
||
|
|
vma = find_vma(mm, msg->va);
|
||
|
|
rc = -EINVAL;
|
||
|
|
|
||
|
|
if (!vma || (msg->va != vma->vm_start) ||
|
||
|
|
!privcmd_enforce_singleshot_mapping(vma))
|
||
|
|
goto out_up;
|
||
|
|
}
|
||
|
|
|
||
|
|
state.va = vma->vm_start;
|
||
|
|
state.vma = vma;
|
||
|
|
state.domain = mmapcmd.dom;
|
||
|
|
|
||
|
|
rc = traverse_pages(mmapcmd.num, sizeof(struct privcmd_mmap_entry),
|
||
|
|
&pagelist,
|
||
|
|
mmap_mfn_range, &state);
|
||
|
|
|
||
|
|
|
||
|
|
out_up:
|
||
|
|
up_write(&mm->mmap_sem);
|
||
|
|
|
||
|
|
out:
|
||
|
|
free_page_list(&pagelist);
|
||
|
|
|
||
|
|
return rc;
|
||
|
|
}
|
||
|
|
|
||
|
|
struct mmap_batch_state {
|
||
|
|
domid_t domain;
|
||
|
|
unsigned long va;
|
||
|
|
struct vm_area_struct *vma;
|
||
|
|
int err;
|
||
|
|
|
||
|
|
xen_pfn_t __user *user;
|
||
|
|
};
|
||
|
|
|
||
|
|
static int mmap_batch_fn(void *data, void *state)
|
||
|
|
{
|
||
|
|
xen_pfn_t *mfnp = data;
|
||
|
|
struct mmap_batch_state *st = state;
|
||
|
|
|
||
|
|
if (xen_remap_domain_mfn_range(st->vma, st->va & PAGE_MASK, *mfnp, 1,
|
||
|
|
st->vma->vm_page_prot, st->domain) < 0) {
|
||
|
|
*mfnp |= 0xf0000000U;
|
||
|
|
st->err++;
|
||
|
|
}
|
||
|
|
st->va += PAGE_SIZE;
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int mmap_return_errors(void *data, void *state)
|
||
|
|
{
|
||
|
|
xen_pfn_t *mfnp = data;
|
||
|
|
struct mmap_batch_state *st = state;
|
||
|
|
|
||
|
|
return put_user(*mfnp, st->user++);
|
||
|
|
}
|
||
|
|
|
||
|
|
static struct vm_operations_struct privcmd_vm_ops;
|
||
|
|
|
||
|
|
static long privcmd_ioctl_mmap_batch(void __user *udata)
|
||
|
|
{
|
||
|
|
int ret;
|
||
|
|
struct privcmd_mmapbatch m;
|
||
|
|
struct mm_struct *mm = current->mm;
|
||
|
|
struct vm_area_struct *vma;
|
||
|
|
unsigned long nr_pages;
|
||
|
|
LIST_HEAD(pagelist);
|
||
|
|
struct mmap_batch_state state;
|
||
|
|
|
||
|
|
if (!xen_initial_domain())
|
||
|
|
return -EPERM;
|
||
|
|
|
||
|
|
if (copy_from_user(&m, udata, sizeof(m)))
|
||
|
|
return -EFAULT;
|
||
|
|
|
||
|
|
nr_pages = m.num;
|
||
|
|
if ((m.num <= 0) || (nr_pages > (LONG_MAX >> PAGE_SHIFT)))
|
||
|
|
return -EINVAL;
|
||
|
|
|
||
|
|
ret = gather_array(&pagelist, m.num, sizeof(xen_pfn_t),
|
||
|
|
m.arr);
|
||
|
|
|
||
|
|
if (ret || list_empty(&pagelist))
|
||
|
|
goto out;
|
||
|
|
|
||
|
|
down_write(&mm->mmap_sem);
|
||
|
|
|
||
|
|
vma = find_vma(mm, m.addr);
|
||
|
|
ret = -EINVAL;
|
||
|
|
if (!vma ||
|
||
|
|
vma->vm_ops != &privcmd_vm_ops ||
|
||
|
|
(m.addr != vma->vm_start) ||
|
||
|
|
((m.addr + (nr_pages << PAGE_SHIFT)) != vma->vm_end) ||
|
||
|
|
!privcmd_enforce_singleshot_mapping(vma)) {
|
||
|
|
up_write(&mm->mmap_sem);
|
||
|
|
goto out;
|
||
|
|
}
|
||
|
|
|
||
|
|
state.domain = m.dom;
|
||
|
|
state.vma = vma;
|
||
|
|
state.va = m.addr;
|
||
|
|
state.err = 0;
|
||
|
|
|
||
|
|
ret = traverse_pages(m.num, sizeof(xen_pfn_t),
|
||
|
|
&pagelist, mmap_batch_fn, &state);
|
||
|
|
|
||
|
|
up_write(&mm->mmap_sem);
|
||
|
|
|
||
|
|
if (state.err > 0) {
|
||
|
|
state.user = m.arr;
|
||
|
|
ret = traverse_pages(m.num, sizeof(xen_pfn_t),
|
||
|
|
&pagelist,
|
||
|
|
mmap_return_errors, &state);
|
||
|
|
}
|
||
|
|
|
||
|
|
out:
|
||
|
|
free_page_list(&pagelist);
|
||
|
|
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
static long privcmd_ioctl(struct file *file,
|
||
|
|
unsigned int cmd, unsigned long data)
|
||
|
|
{
|
||
|
|
int ret = -ENOSYS;
|
||
|
|
void __user *udata = (void __user *) data;
|
||
|
|
|
||
|
|
switch (cmd) {
|
||
|
|
case IOCTL_PRIVCMD_HYPERCALL:
|
||
|
|
ret = privcmd_ioctl_hypercall(udata);
|
||
|
|
break;
|
||
|
|
|
||
|
|
case IOCTL_PRIVCMD_MMAP:
|
||
|
|
ret = privcmd_ioctl_mmap(udata);
|
||
|
|
break;
|
||
|
|
|
||
|
|
case IOCTL_PRIVCMD_MMAPBATCH:
|
||
|
|
ret = privcmd_ioctl_mmap_batch(udata);
|
||
|
|
break;
|
||
|
|
|
||
|
|
default:
|
||
|
|
ret = -EINVAL;
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int privcmd_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
|
||
|
|
{
|
||
|
|
printk(KERN_DEBUG "privcmd_fault: vma=%p %lx-%lx, pgoff=%lx, uv=%p\n",
|
||
|
|
vma, vma->vm_start, vma->vm_end,
|
||
|
|
vmf->pgoff, vmf->virtual_address);
|
||
|
|
|
||
|
|
return VM_FAULT_SIGBUS;
|
||
|
|
}
|
||
|
|
|
||
|
|
static struct vm_operations_struct privcmd_vm_ops = {
|
||
|
|
.fault = privcmd_fault
|
||
|
|
};
|
||
|
|
|
||
|
|
static int privcmd_mmap(struct file *file, struct vm_area_struct *vma)
|
||
|
|
{
|
||
|
|
/* Unsupported for auto-translate guests. */
|
||
|
|
if (xen_feature(XENFEAT_auto_translated_physmap))
|
||
|
|
return -ENOSYS;
|
||
|
|
|
||
|
|
/* DONTCOPY is essential for Xen because copy_page_range doesn't know
|
||
|
|
* how to recreate these mappings */
|
||
|
|
vma->vm_flags |= VM_RESERVED | VM_IO | VM_DONTCOPY | VM_PFNMAP;
|
||
|
|
vma->vm_ops = &privcmd_vm_ops;
|
||
|
|
vma->vm_private_data = NULL;
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma)
|
||
|
|
{
|
||
|
|
return (xchg(&vma->vm_private_data, (void *)1) == NULL);
|
||
|
|
}
|
||
|
|
|
||
|
|
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);
|