![Daniel De Graaf](/assets/img/avatar_default.png)
Add support for mappings without GNTMAP_contains_pte. This was not supported because the unmap operation assumed that this flag was being used; adding a parameter to the unmap operation to allow the PTE clearing to be disabled is sufficient to make unmap capable of supporting either mapping type. Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> [v1: Fix cleanpatch warnings] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
824 lines
20 KiB
C
824 lines
20 KiB
C
/******************************************************************************
|
|
* gntdev.c
|
|
*
|
|
* Device for accessing (in user-space) pages that have been granted by other
|
|
* domains.
|
|
*
|
|
* Copyright (c) 2006-2007, D G Murray.
|
|
* (c) 2009 Gerd Hoffmann <kraxel@redhat.com>
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*/
|
|
|
|
#undef DEBUG
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/init.h>
|
|
#include <linux/miscdevice.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/mman.h>
|
|
#include <linux/mmu_notifier.h>
|
|
#include <linux/types.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/highmem.h>
|
|
|
|
#include <xen/xen.h>
|
|
#include <xen/grant_table.h>
|
|
#include <xen/balloon.h>
|
|
#include <xen/gntdev.h>
|
|
#include <xen/events.h>
|
|
#include <asm/xen/hypervisor.h>
|
|
#include <asm/xen/hypercall.h>
|
|
#include <asm/xen/page.h>
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Derek G. Murray <Derek.Murray@cl.cam.ac.uk>, "
|
|
"Gerd Hoffmann <kraxel@redhat.com>");
|
|
MODULE_DESCRIPTION("User-space granted page access driver");
|
|
|
|
static int limit = 1024*1024;
|
|
module_param(limit, int, 0644);
|
|
MODULE_PARM_DESC(limit, "Maximum number of grants that may be mapped by "
|
|
"the gntdev device");
|
|
|
|
static atomic_t pages_mapped = ATOMIC_INIT(0);
|
|
|
|
static int use_ptemod;
|
|
|
|
struct gntdev_priv {
|
|
struct list_head maps;
|
|
/* lock protects maps from concurrent changes */
|
|
spinlock_t lock;
|
|
struct mm_struct *mm;
|
|
struct mmu_notifier mn;
|
|
};
|
|
|
|
struct unmap_notify {
|
|
int flags;
|
|
/* Address relative to the start of the grant_map */
|
|
int addr;
|
|
int event;
|
|
};
|
|
|
|
struct grant_map {
|
|
struct list_head next;
|
|
struct vm_area_struct *vma;
|
|
int index;
|
|
int count;
|
|
int flags;
|
|
atomic_t users;
|
|
struct unmap_notify notify;
|
|
struct ioctl_gntdev_grant_ref *grants;
|
|
struct gnttab_map_grant_ref *map_ops;
|
|
struct gnttab_unmap_grant_ref *unmap_ops;
|
|
struct gnttab_map_grant_ref *kmap_ops;
|
|
struct page **pages;
|
|
};
|
|
|
|
static int unmap_grant_pages(struct grant_map *map, int offset, int pages);
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
|
|
static void gntdev_print_maps(struct gntdev_priv *priv,
|
|
char *text, int text_index)
|
|
{
|
|
#ifdef DEBUG
|
|
struct grant_map *map;
|
|
|
|
pr_debug("%s: maps list (priv %p)\n", __func__, priv);
|
|
list_for_each_entry(map, &priv->maps, next)
|
|
pr_debug(" index %2d, count %2d %s\n",
|
|
map->index, map->count,
|
|
map->index == text_index && text ? text : "");
|
|
#endif
|
|
}
|
|
|
|
static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count)
|
|
{
|
|
struct grant_map *add;
|
|
int i;
|
|
|
|
add = kzalloc(sizeof(struct grant_map), GFP_KERNEL);
|
|
if (NULL == add)
|
|
return NULL;
|
|
|
|
add->grants = kcalloc(count, sizeof(add->grants[0]), GFP_KERNEL);
|
|
add->map_ops = kcalloc(count, sizeof(add->map_ops[0]), GFP_KERNEL);
|
|
add->unmap_ops = kcalloc(count, sizeof(add->unmap_ops[0]), GFP_KERNEL);
|
|
add->kmap_ops = kcalloc(count, sizeof(add->kmap_ops[0]), GFP_KERNEL);
|
|
add->pages = kcalloc(count, sizeof(add->pages[0]), GFP_KERNEL);
|
|
if (NULL == add->grants ||
|
|
NULL == add->map_ops ||
|
|
NULL == add->unmap_ops ||
|
|
NULL == add->kmap_ops ||
|
|
NULL == add->pages)
|
|
goto err;
|
|
|
|
if (alloc_xenballooned_pages(count, add->pages, false /* lowmem */))
|
|
goto err;
|
|
|
|
for (i = 0; i < count; i++) {
|
|
add->map_ops[i].handle = -1;
|
|
add->unmap_ops[i].handle = -1;
|
|
add->kmap_ops[i].handle = -1;
|
|
}
|
|
|
|
add->index = 0;
|
|
add->count = count;
|
|
atomic_set(&add->users, 1);
|
|
|
|
return add;
|
|
|
|
err:
|
|
kfree(add->pages);
|
|
kfree(add->grants);
|
|
kfree(add->map_ops);
|
|
kfree(add->unmap_ops);
|
|
kfree(add->kmap_ops);
|
|
kfree(add);
|
|
return NULL;
|
|
}
|
|
|
|
static void gntdev_add_map(struct gntdev_priv *priv, struct grant_map *add)
|
|
{
|
|
struct grant_map *map;
|
|
|
|
list_for_each_entry(map, &priv->maps, next) {
|
|
if (add->index + add->count < map->index) {
|
|
list_add_tail(&add->next, &map->next);
|
|
goto done;
|
|
}
|
|
add->index = map->index + map->count;
|
|
}
|
|
list_add_tail(&add->next, &priv->maps);
|
|
|
|
done:
|
|
gntdev_print_maps(priv, "[new]", add->index);
|
|
}
|
|
|
|
static struct grant_map *gntdev_find_map_index(struct gntdev_priv *priv,
|
|
int index, int count)
|
|
{
|
|
struct grant_map *map;
|
|
|
|
list_for_each_entry(map, &priv->maps, next) {
|
|
if (map->index != index)
|
|
continue;
|
|
if (count && map->count != count)
|
|
continue;
|
|
return map;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static void gntdev_put_map(struct grant_map *map)
|
|
{
|
|
if (!map)
|
|
return;
|
|
|
|
if (!atomic_dec_and_test(&map->users))
|
|
return;
|
|
|
|
atomic_sub(map->count, &pages_mapped);
|
|
|
|
if (map->notify.flags & UNMAP_NOTIFY_SEND_EVENT) {
|
|
notify_remote_via_evtchn(map->notify.event);
|
|
evtchn_put(map->notify.event);
|
|
}
|
|
|
|
if (map->pages) {
|
|
if (!use_ptemod)
|
|
unmap_grant_pages(map, 0, map->count);
|
|
|
|
free_xenballooned_pages(map->count, map->pages);
|
|
}
|
|
kfree(map->pages);
|
|
kfree(map->grants);
|
|
kfree(map->map_ops);
|
|
kfree(map->unmap_ops);
|
|
kfree(map);
|
|
}
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
|
|
static int find_grant_ptes(pte_t *pte, pgtable_t token,
|
|
unsigned long addr, void *data)
|
|
{
|
|
struct grant_map *map = data;
|
|
unsigned int pgnr = (addr - map->vma->vm_start) >> PAGE_SHIFT;
|
|
int flags = map->flags | GNTMAP_application_map | GNTMAP_contains_pte;
|
|
u64 pte_maddr;
|
|
|
|
BUG_ON(pgnr >= map->count);
|
|
pte_maddr = arbitrary_virt_to_machine(pte).maddr;
|
|
|
|
gnttab_set_map_op(&map->map_ops[pgnr], pte_maddr, flags,
|
|
map->grants[pgnr].ref,
|
|
map->grants[pgnr].domid);
|
|
gnttab_set_unmap_op(&map->unmap_ops[pgnr], pte_maddr, flags,
|
|
-1 /* handle */);
|
|
return 0;
|
|
}
|
|
|
|
static int map_grant_pages(struct grant_map *map)
|
|
{
|
|
int i, err = 0;
|
|
|
|
if (!use_ptemod) {
|
|
/* Note: it could already be mapped */
|
|
if (map->map_ops[0].handle != -1)
|
|
return 0;
|
|
for (i = 0; i < map->count; i++) {
|
|
unsigned long addr = (unsigned long)
|
|
pfn_to_kaddr(page_to_pfn(map->pages[i]));
|
|
gnttab_set_map_op(&map->map_ops[i], addr, map->flags,
|
|
map->grants[i].ref,
|
|
map->grants[i].domid);
|
|
gnttab_set_unmap_op(&map->unmap_ops[i], addr,
|
|
map->flags, -1 /* handle */);
|
|
}
|
|
} else {
|
|
/*
|
|
* Setup the map_ops corresponding to the pte entries pointing
|
|
* to the kernel linear addresses of the struct pages.
|
|
* These ptes are completely different from the user ptes dealt
|
|
* with find_grant_ptes.
|
|
*/
|
|
for (i = 0; i < map->count; i++) {
|
|
unsigned level;
|
|
unsigned long address = (unsigned long)
|
|
pfn_to_kaddr(page_to_pfn(map->pages[i]));
|
|
pte_t *ptep;
|
|
u64 pte_maddr = 0;
|
|
BUG_ON(PageHighMem(map->pages[i]));
|
|
|
|
ptep = lookup_address(address, &level);
|
|
pte_maddr = arbitrary_virt_to_machine(ptep).maddr;
|
|
gnttab_set_map_op(&map->kmap_ops[i], pte_maddr,
|
|
map->flags |
|
|
GNTMAP_host_map |
|
|
GNTMAP_contains_pte,
|
|
map->grants[i].ref,
|
|
map->grants[i].domid);
|
|
}
|
|
}
|
|
|
|
pr_debug("map %d+%d\n", map->index, map->count);
|
|
err = gnttab_map_refs(map->map_ops, use_ptemod ? map->kmap_ops : NULL,
|
|
map->pages, map->count);
|
|
if (err)
|
|
return err;
|
|
|
|
for (i = 0; i < map->count; i++) {
|
|
if (map->map_ops[i].status)
|
|
err = -EINVAL;
|
|
else {
|
|
BUG_ON(map->map_ops[i].handle == -1);
|
|
map->unmap_ops[i].handle = map->map_ops[i].handle;
|
|
pr_debug("map handle=%d\n", map->map_ops[i].handle);
|
|
}
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static int __unmap_grant_pages(struct grant_map *map, int offset, int pages)
|
|
{
|
|
int i, err = 0;
|
|
|
|
if (map->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) {
|
|
int pgno = (map->notify.addr >> PAGE_SHIFT);
|
|
if (pgno >= offset && pgno < offset + pages && use_ptemod) {
|
|
void __user *tmp = (void __user *)
|
|
map->vma->vm_start + map->notify.addr;
|
|
err = copy_to_user(tmp, &err, 1);
|
|
if (err)
|
|
return -EFAULT;
|
|
map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE;
|
|
} else if (pgno >= offset && pgno < offset + pages) {
|
|
uint8_t *tmp = kmap(map->pages[pgno]);
|
|
tmp[map->notify.addr & (PAGE_SIZE-1)] = 0;
|
|
kunmap(map->pages[pgno]);
|
|
map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE;
|
|
}
|
|
}
|
|
|
|
err = gnttab_unmap_refs(map->unmap_ops + offset, map->pages + offset,
|
|
pages, true);
|
|
if (err)
|
|
return err;
|
|
|
|
for (i = 0; i < pages; i++) {
|
|
if (map->unmap_ops[offset+i].status)
|
|
err = -EINVAL;
|
|
pr_debug("unmap handle=%d st=%d\n",
|
|
map->unmap_ops[offset+i].handle,
|
|
map->unmap_ops[offset+i].status);
|
|
map->unmap_ops[offset+i].handle = -1;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static int unmap_grant_pages(struct grant_map *map, int offset, int pages)
|
|
{
|
|
int range, err = 0;
|
|
|
|
pr_debug("unmap %d+%d [%d+%d]\n", map->index, map->count, offset, pages);
|
|
|
|
/* It is possible the requested range will have a "hole" where we
|
|
* already unmapped some of the grants. Only unmap valid ranges.
|
|
*/
|
|
while (pages && !err) {
|
|
while (pages && map->unmap_ops[offset].handle == -1) {
|
|
offset++;
|
|
pages--;
|
|
}
|
|
range = 0;
|
|
while (range < pages) {
|
|
if (map->unmap_ops[offset+range].handle == -1) {
|
|
range--;
|
|
break;
|
|
}
|
|
range++;
|
|
}
|
|
err = __unmap_grant_pages(map, offset, range);
|
|
offset += range;
|
|
pages -= range;
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
|
|
static void gntdev_vma_open(struct vm_area_struct *vma)
|
|
{
|
|
struct grant_map *map = vma->vm_private_data;
|
|
|
|
pr_debug("gntdev_vma_open %p\n", vma);
|
|
atomic_inc(&map->users);
|
|
}
|
|
|
|
static void gntdev_vma_close(struct vm_area_struct *vma)
|
|
{
|
|
struct grant_map *map = vma->vm_private_data;
|
|
|
|
pr_debug("gntdev_vma_close %p\n", vma);
|
|
map->vma = NULL;
|
|
vma->vm_private_data = NULL;
|
|
gntdev_put_map(map);
|
|
}
|
|
|
|
static struct vm_operations_struct gntdev_vmops = {
|
|
.open = gntdev_vma_open,
|
|
.close = gntdev_vma_close,
|
|
};
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
|
|
static void mn_invl_range_start(struct mmu_notifier *mn,
|
|
struct mm_struct *mm,
|
|
unsigned long start, unsigned long end)
|
|
{
|
|
struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn);
|
|
struct grant_map *map;
|
|
unsigned long mstart, mend;
|
|
int err;
|
|
|
|
spin_lock(&priv->lock);
|
|
list_for_each_entry(map, &priv->maps, next) {
|
|
if (!map->vma)
|
|
continue;
|
|
if (map->vma->vm_start >= end)
|
|
continue;
|
|
if (map->vma->vm_end <= start)
|
|
continue;
|
|
mstart = max(start, map->vma->vm_start);
|
|
mend = min(end, map->vma->vm_end);
|
|
pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n",
|
|
map->index, map->count,
|
|
map->vma->vm_start, map->vma->vm_end,
|
|
start, end, mstart, mend);
|
|
err = unmap_grant_pages(map,
|
|
(mstart - map->vma->vm_start) >> PAGE_SHIFT,
|
|
(mend - mstart) >> PAGE_SHIFT);
|
|
WARN_ON(err);
|
|
}
|
|
spin_unlock(&priv->lock);
|
|
}
|
|
|
|
static void mn_invl_page(struct mmu_notifier *mn,
|
|
struct mm_struct *mm,
|
|
unsigned long address)
|
|
{
|
|
mn_invl_range_start(mn, mm, address, address + PAGE_SIZE);
|
|
}
|
|
|
|
static void mn_release(struct mmu_notifier *mn,
|
|
struct mm_struct *mm)
|
|
{
|
|
struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn);
|
|
struct grant_map *map;
|
|
int err;
|
|
|
|
spin_lock(&priv->lock);
|
|
list_for_each_entry(map, &priv->maps, next) {
|
|
if (!map->vma)
|
|
continue;
|
|
pr_debug("map %d+%d (%lx %lx)\n",
|
|
map->index, map->count,
|
|
map->vma->vm_start, map->vma->vm_end);
|
|
err = unmap_grant_pages(map, /* offset */ 0, map->count);
|
|
WARN_ON(err);
|
|
}
|
|
spin_unlock(&priv->lock);
|
|
}
|
|
|
|
struct mmu_notifier_ops gntdev_mmu_ops = {
|
|
.release = mn_release,
|
|
.invalidate_page = mn_invl_page,
|
|
.invalidate_range_start = mn_invl_range_start,
|
|
};
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
|
|
static int gntdev_open(struct inode *inode, struct file *flip)
|
|
{
|
|
struct gntdev_priv *priv;
|
|
int ret = 0;
|
|
|
|
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
|
|
if (!priv)
|
|
return -ENOMEM;
|
|
|
|
INIT_LIST_HEAD(&priv->maps);
|
|
spin_lock_init(&priv->lock);
|
|
|
|
if (use_ptemod) {
|
|
priv->mm = get_task_mm(current);
|
|
if (!priv->mm) {
|
|
kfree(priv);
|
|
return -ENOMEM;
|
|
}
|
|
priv->mn.ops = &gntdev_mmu_ops;
|
|
ret = mmu_notifier_register(&priv->mn, priv->mm);
|
|
mmput(priv->mm);
|
|
}
|
|
|
|
if (ret) {
|
|
kfree(priv);
|
|
return ret;
|
|
}
|
|
|
|
flip->private_data = priv;
|
|
pr_debug("priv %p\n", priv);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int gntdev_release(struct inode *inode, struct file *flip)
|
|
{
|
|
struct gntdev_priv *priv = flip->private_data;
|
|
struct grant_map *map;
|
|
|
|
pr_debug("priv %p\n", priv);
|
|
|
|
while (!list_empty(&priv->maps)) {
|
|
map = list_entry(priv->maps.next, struct grant_map, next);
|
|
list_del(&map->next);
|
|
gntdev_put_map(map);
|
|
}
|
|
|
|
if (use_ptemod)
|
|
mmu_notifier_unregister(&priv->mn, priv->mm);
|
|
kfree(priv);
|
|
return 0;
|
|
}
|
|
|
|
static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv,
|
|
struct ioctl_gntdev_map_grant_ref __user *u)
|
|
{
|
|
struct ioctl_gntdev_map_grant_ref op;
|
|
struct grant_map *map;
|
|
int err;
|
|
|
|
if (copy_from_user(&op, u, sizeof(op)) != 0)
|
|
return -EFAULT;
|
|
pr_debug("priv %p, add %d\n", priv, op.count);
|
|
if (unlikely(op.count <= 0))
|
|
return -EINVAL;
|
|
|
|
err = -ENOMEM;
|
|
map = gntdev_alloc_map(priv, op.count);
|
|
if (!map)
|
|
return err;
|
|
|
|
if (unlikely(atomic_add_return(op.count, &pages_mapped) > limit)) {
|
|
pr_debug("can't map: over limit\n");
|
|
gntdev_put_map(map);
|
|
return err;
|
|
}
|
|
|
|
if (copy_from_user(map->grants, &u->refs,
|
|
sizeof(map->grants[0]) * op.count) != 0) {
|
|
gntdev_put_map(map);
|
|
return err;
|
|
}
|
|
|
|
spin_lock(&priv->lock);
|
|
gntdev_add_map(priv, map);
|
|
op.index = map->index << PAGE_SHIFT;
|
|
spin_unlock(&priv->lock);
|
|
|
|
if (copy_to_user(u, &op, sizeof(op)) != 0)
|
|
return -EFAULT;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv,
|
|
struct ioctl_gntdev_unmap_grant_ref __user *u)
|
|
{
|
|
struct ioctl_gntdev_unmap_grant_ref op;
|
|
struct grant_map *map;
|
|
int err = -ENOENT;
|
|
|
|
if (copy_from_user(&op, u, sizeof(op)) != 0)
|
|
return -EFAULT;
|
|
pr_debug("priv %p, del %d+%d\n", priv, (int)op.index, (int)op.count);
|
|
|
|
spin_lock(&priv->lock);
|
|
map = gntdev_find_map_index(priv, op.index >> PAGE_SHIFT, op.count);
|
|
if (map) {
|
|
list_del(&map->next);
|
|
err = 0;
|
|
}
|
|
spin_unlock(&priv->lock);
|
|
if (map)
|
|
gntdev_put_map(map);
|
|
return err;
|
|
}
|
|
|
|
static long gntdev_ioctl_get_offset_for_vaddr(struct gntdev_priv *priv,
|
|
struct ioctl_gntdev_get_offset_for_vaddr __user *u)
|
|
{
|
|
struct ioctl_gntdev_get_offset_for_vaddr op;
|
|
struct vm_area_struct *vma;
|
|
struct grant_map *map;
|
|
|
|
if (copy_from_user(&op, u, sizeof(op)) != 0)
|
|
return -EFAULT;
|
|
pr_debug("priv %p, offset for vaddr %lx\n", priv, (unsigned long)op.vaddr);
|
|
|
|
vma = find_vma(current->mm, op.vaddr);
|
|
if (!vma || vma->vm_ops != &gntdev_vmops)
|
|
return -EINVAL;
|
|
|
|
map = vma->vm_private_data;
|
|
if (!map)
|
|
return -EINVAL;
|
|
|
|
op.offset = map->index << PAGE_SHIFT;
|
|
op.count = map->count;
|
|
|
|
if (copy_to_user(u, &op, sizeof(op)) != 0)
|
|
return -EFAULT;
|
|
return 0;
|
|
}
|
|
|
|
static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u)
|
|
{
|
|
struct ioctl_gntdev_unmap_notify op;
|
|
struct grant_map *map;
|
|
int rc;
|
|
int out_flags;
|
|
unsigned int out_event;
|
|
|
|
if (copy_from_user(&op, u, sizeof(op)))
|
|
return -EFAULT;
|
|
|
|
if (op.action & ~(UNMAP_NOTIFY_CLEAR_BYTE|UNMAP_NOTIFY_SEND_EVENT))
|
|
return -EINVAL;
|
|
|
|
/* We need to grab a reference to the event channel we are going to use
|
|
* to send the notify before releasing the reference we may already have
|
|
* (if someone has called this ioctl twice). This is required so that
|
|
* it is possible to change the clear_byte part of the notification
|
|
* without disturbing the event channel part, which may now be the last
|
|
* reference to that event channel.
|
|
*/
|
|
if (op.action & UNMAP_NOTIFY_SEND_EVENT) {
|
|
if (evtchn_get(op.event_channel_port))
|
|
return -EINVAL;
|
|
}
|
|
|
|
out_flags = op.action;
|
|
out_event = op.event_channel_port;
|
|
|
|
spin_lock(&priv->lock);
|
|
|
|
list_for_each_entry(map, &priv->maps, next) {
|
|
uint64_t begin = map->index << PAGE_SHIFT;
|
|
uint64_t end = (map->index + map->count) << PAGE_SHIFT;
|
|
if (op.index >= begin && op.index < end)
|
|
goto found;
|
|
}
|
|
rc = -ENOENT;
|
|
goto unlock_out;
|
|
|
|
found:
|
|
if ((op.action & UNMAP_NOTIFY_CLEAR_BYTE) &&
|
|
(map->flags & GNTMAP_readonly)) {
|
|
rc = -EINVAL;
|
|
goto unlock_out;
|
|
}
|
|
|
|
out_flags = map->notify.flags;
|
|
out_event = map->notify.event;
|
|
|
|
map->notify.flags = op.action;
|
|
map->notify.addr = op.index - (map->index << PAGE_SHIFT);
|
|
map->notify.event = op.event_channel_port;
|
|
|
|
rc = 0;
|
|
|
|
unlock_out:
|
|
spin_unlock(&priv->lock);
|
|
|
|
/* Drop the reference to the event channel we did not save in the map */
|
|
if (out_flags & UNMAP_NOTIFY_SEND_EVENT)
|
|
evtchn_put(out_event);
|
|
|
|
return rc;
|
|
}
|
|
|
|
static long gntdev_ioctl(struct file *flip,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
struct gntdev_priv *priv = flip->private_data;
|
|
void __user *ptr = (void __user *)arg;
|
|
|
|
switch (cmd) {
|
|
case IOCTL_GNTDEV_MAP_GRANT_REF:
|
|
return gntdev_ioctl_map_grant_ref(priv, ptr);
|
|
|
|
case IOCTL_GNTDEV_UNMAP_GRANT_REF:
|
|
return gntdev_ioctl_unmap_grant_ref(priv, ptr);
|
|
|
|
case IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR:
|
|
return gntdev_ioctl_get_offset_for_vaddr(priv, ptr);
|
|
|
|
case IOCTL_GNTDEV_SET_UNMAP_NOTIFY:
|
|
return gntdev_ioctl_notify(priv, ptr);
|
|
|
|
default:
|
|
pr_debug("priv %p, unknown cmd %x\n", priv, cmd);
|
|
return -ENOIOCTLCMD;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
|
|
{
|
|
struct gntdev_priv *priv = flip->private_data;
|
|
int index = vma->vm_pgoff;
|
|
int count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
|
|
struct grant_map *map;
|
|
int i, err = -EINVAL;
|
|
|
|
if ((vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_SHARED))
|
|
return -EINVAL;
|
|
|
|
pr_debug("map %d+%d at %lx (pgoff %lx)\n",
|
|
index, count, vma->vm_start, vma->vm_pgoff);
|
|
|
|
spin_lock(&priv->lock);
|
|
map = gntdev_find_map_index(priv, index, count);
|
|
if (!map)
|
|
goto unlock_out;
|
|
if (use_ptemod && map->vma)
|
|
goto unlock_out;
|
|
if (use_ptemod && priv->mm != vma->vm_mm) {
|
|
printk(KERN_WARNING "Huh? Other mm?\n");
|
|
goto unlock_out;
|
|
}
|
|
|
|
atomic_inc(&map->users);
|
|
|
|
vma->vm_ops = &gntdev_vmops;
|
|
|
|
vma->vm_flags |= VM_RESERVED|VM_DONTEXPAND;
|
|
|
|
if (use_ptemod)
|
|
vma->vm_flags |= VM_DONTCOPY|VM_PFNMAP;
|
|
|
|
vma->vm_private_data = map;
|
|
|
|
if (use_ptemod)
|
|
map->vma = vma;
|
|
|
|
if (map->flags) {
|
|
if ((vma->vm_flags & VM_WRITE) &&
|
|
(map->flags & GNTMAP_readonly))
|
|
goto out_unlock_put;
|
|
} else {
|
|
map->flags = GNTMAP_host_map;
|
|
if (!(vma->vm_flags & VM_WRITE))
|
|
map->flags |= GNTMAP_readonly;
|
|
}
|
|
|
|
spin_unlock(&priv->lock);
|
|
|
|
if (use_ptemod) {
|
|
err = apply_to_page_range(vma->vm_mm, vma->vm_start,
|
|
vma->vm_end - vma->vm_start,
|
|
find_grant_ptes, map);
|
|
if (err) {
|
|
printk(KERN_WARNING "find_grant_ptes() failure.\n");
|
|
goto out_put_map;
|
|
}
|
|
}
|
|
|
|
err = map_grant_pages(map);
|
|
if (err)
|
|
goto out_put_map;
|
|
|
|
if (!use_ptemod) {
|
|
for (i = 0; i < count; i++) {
|
|
err = vm_insert_page(vma, vma->vm_start + i*PAGE_SIZE,
|
|
map->pages[i]);
|
|
if (err)
|
|
goto out_put_map;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
|
|
unlock_out:
|
|
spin_unlock(&priv->lock);
|
|
return err;
|
|
|
|
out_unlock_put:
|
|
spin_unlock(&priv->lock);
|
|
out_put_map:
|
|
if (use_ptemod)
|
|
map->vma = NULL;
|
|
gntdev_put_map(map);
|
|
return err;
|
|
}
|
|
|
|
static const struct file_operations gntdev_fops = {
|
|
.owner = THIS_MODULE,
|
|
.open = gntdev_open,
|
|
.release = gntdev_release,
|
|
.mmap = gntdev_mmap,
|
|
.unlocked_ioctl = gntdev_ioctl
|
|
};
|
|
|
|
static struct miscdevice gntdev_miscdev = {
|
|
.minor = MISC_DYNAMIC_MINOR,
|
|
.name = "xen/gntdev",
|
|
.fops = &gntdev_fops,
|
|
};
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
|
|
static int __init gntdev_init(void)
|
|
{
|
|
int err;
|
|
|
|
if (!xen_domain())
|
|
return -ENODEV;
|
|
|
|
use_ptemod = xen_pv_domain();
|
|
|
|
err = misc_register(&gntdev_miscdev);
|
|
if (err != 0) {
|
|
printk(KERN_ERR "Could not register gntdev device\n");
|
|
return err;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void __exit gntdev_exit(void)
|
|
{
|
|
misc_deregister(&gntdev_miscdev);
|
|
}
|
|
|
|
module_init(gntdev_init);
|
|
module_exit(gntdev_exit);
|
|
|
|
/* ------------------------------------------------------------------ */
|