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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 02/11] xen/gntdev: allow usermode to map granted pages
From: Gerd Hoffmann <kraxel@xxxxxxxxxx>
The gntdev driver allows usermode to map granted pages from other
domains. This is typically used to implement a Xen backend driver
in user mode.
Signed-off-by: Gerd Hoffmann <kraxel@xxxxxxxxxx>
Signed-off-by: Stefano Stabellini <Stefano.Stabellini@xxxxxxxxxxxxx>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
---
drivers/xen/Kconfig | 7 +
drivers/xen/Makefile | 2 +
drivers/xen/gntdev.c | 646 ++++++++++++++++++++++++++++++++++++++++++++++++++
include/xen/gntdev.h | 119 +++++++++
4 files changed, 774 insertions(+), 0 deletions(-)
create mode 100644 drivers/xen/gntdev.c
create mode 100644 include/xen/gntdev.h
diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
index 6e6180c..0c6d2a1 100644
--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -62,6 +62,13 @@ config XEN_SYS_HYPERVISOR
virtual environment, /sys/hypervisor will still be present,
but will have no xen contents.
+config XEN_GNTDEV
+ tristate "userspace grant access device driver"
+ depends on XEN
+ select MMU_NOTIFIER
+ help
+ Allows userspace processes use grants.
+
config XEN_PLATFORM_PCI
tristate "xen platform pci device driver"
depends on XEN_PVHVM
diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
index 533a199..674fdb5 100644
--- a/drivers/xen/Makefile
+++ b/drivers/xen/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_HOTPLUG_CPU) += cpu_hotplug.o
obj-$(CONFIG_XEN_XENCOMM) += xencomm.o
obj-$(CONFIG_XEN_BALLOON) += balloon.o
obj-$(CONFIG_XEN_DEV_EVTCHN) += xen-evtchn.o
+obj-$(CONFIG_XEN_GNTDEV) += xen-gntdev.o
obj-$(CONFIG_XENFS) += xenfs/
obj-$(CONFIG_XEN_SYS_HYPERVISOR) += sys-hypervisor.o
obj-$(CONFIG_XEN_PLATFORM_PCI) += platform-pci.o
@@ -16,4 +17,5 @@ obj-$(CONFIG_SWIOTLB_XEN) += swiotlb-xen.o
obj-$(CONFIG_XEN_DOM0) += pci.o
xen-evtchn-y := evtchn.o
+xen-gntdev-y := gntdev.o
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
new file mode 100644
index 0000000..45898d4
--- /dev/null
+++ b/drivers/xen/gntdev.c
@@ -0,0 +1,646 @@
+/******************************************************************************
+ * 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@xxxxxxxxxx>
+ *
+ * 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
+ */
+
+#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 <xen/xen.h>
+#include <xen/grant_table.h>
+#include <xen/gntdev.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@xxxxxxxxxxxx>, "
+ "Gerd Hoffmann <kraxel@xxxxxxxxxx>");
+MODULE_DESCRIPTION("User-space granted page access driver");
+
+static int debug = 0;
+module_param(debug, int, 0644);
+static int limit = 1024;
+module_param(limit, int, 0644);
+
+struct gntdev_priv {
+ struct list_head maps;
+ uint32_t used;
+ uint32_t limit;
+ spinlock_t lock;
+ struct mm_struct *mm;
+ struct mmu_notifier mn;
+};
+
+struct grant_map {
+ struct list_head next;
+ struct gntdev_priv *priv;
+ struct vm_area_struct *vma;
+ int index;
+ int count;
+ int flags;
+ int is_mapped;
+ struct ioctl_gntdev_grant_ref *grants;
+ struct gnttab_map_grant_ref *map_ops;
+ struct gnttab_unmap_grant_ref *unmap_ops;
+};
+
+/* ------------------------------------------------------------------ */
+
+static void gntdev_print_maps(struct gntdev_priv *priv,
+ char *text, int text_index)
+{
+ struct grant_map *map;
+
+ printk("%s: maps list (priv %p, usage %d/%d)\n",
+ __FUNCTION__, priv, priv->used, priv->limit);
+ list_for_each_entry(map, &priv->maps, next)
+ printk(" index %2d, count %2d %s\n",
+ map->index, map->count,
+ map->index == text_index && text ? text : "");
+}
+
+static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count)
+{
+ struct grant_map *add;
+
+ add = kzalloc(sizeof(struct grant_map), GFP_KERNEL);
+ if (NULL == add)
+ return NULL;
+
+ add->grants = kzalloc(sizeof(add->grants[0]) * count, GFP_KERNEL);
+ add->map_ops = kzalloc(sizeof(add->map_ops[0]) * count, GFP_KERNEL);
+ add->unmap_ops = kzalloc(sizeof(add->unmap_ops[0]) * count, GFP_KERNEL);
+ if (NULL == add->grants ||
+ NULL == add->map_ops ||
+ NULL == add->unmap_ops)
+ goto err;
+
+ add->index = 0;
+ add->count = count;
+ add->priv = priv;
+
+ if (add->count + priv->used > priv->limit)
+ goto err;
+
+ return add;
+
+err:
+ kfree(add->grants);
+ kfree(add->map_ops);
+ kfree(add->unmap_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:
+ priv->used += add->count;
+ if (debug)
+ 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 (map->count != count)
+ continue;
+ return map;
+ }
+ return NULL;
+}
+
+static struct grant_map *gntdev_find_map_vaddr(struct gntdev_priv *priv,
+ unsigned long vaddr)
+{
+ struct grant_map *map;
+
+ list_for_each_entry(map, &priv->maps, next) {
+ if (!map->vma)
+ continue;
+ if (vaddr < map->vma->vm_start)
+ continue;
+ if (vaddr >= map->vma->vm_end)
+ continue;
+ return map;
+ }
+ return NULL;
+}
+
+static int gntdev_del_map(struct grant_map *map)
+{
+ int i;
+
+ if (map->vma)
+ return -EBUSY;
+ for (i = 0; i < map->count; i++)
+ if (map->unmap_ops[i].handle)
+ return -EBUSY;
+
+ map->priv->used -= map->count;
+ list_del(&map->next);
+ return 0;
+}
+
+static void gntdev_free_map(struct grant_map *map)
+{
+ if (!map)
+ return;
+ 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;
+ u64 pte_maddr;
+
+ BUG_ON(pgnr >= map->count);
+ pte_maddr = (u64)pfn_to_mfn(page_to_pfn(token)) << PAGE_SHIFT;
+ pte_maddr += (unsigned long)pte & ~PAGE_MASK;
+ gnttab_set_map_op(&map->map_ops[pgnr], pte_maddr, map->flags,
+ map->grants[pgnr].ref,
+ map->grants[pgnr].domid);
+ gnttab_set_unmap_op(&map->unmap_ops[pgnr], pte_maddr, map->flags,
+ 0 /* handle */);
+ return 0;
+}
+
+static int map_grant_pages(struct grant_map *map)
+{
+ int i, err = 0;
+
+ if (debug)
+ printk("%s: map %d+%d\n", __FUNCTION__, map->index, map->count);
+ err = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref,
+ map->map_ops, map->count);
+ if (WARN_ON(err))
+ return err;
+
+ for (i = 0; i < map->count; i++) {
+ if (map->map_ops[i].status)
+ err = -EINVAL;
+ map->unmap_ops[i].handle = 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 (debug)
+ printk("%s: map %d+%d [%d+%d]\n", __FUNCTION__,
+ map->index, map->count, offset, pages);
+ err = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref,
+ map->unmap_ops + offset, pages);
+ if (WARN_ON(err))
+ return err;
+
+ for (i = 0; i < pages; i++) {
+ if (map->unmap_ops[offset+i].status)
+ err = -EINVAL;
+ map->unmap_ops[offset+i].handle = 0;
+ }
+ return err;
+}
+
+/* ------------------------------------------------------------------ */
+
+static void gntdev_vma_close(struct vm_area_struct *vma)
+{
+ struct grant_map *map = vma->vm_private_data;
+
+ if (debug)
+ printk("%s\n", __FUNCTION__);
+ map->is_mapped = 0;
+ map->vma = NULL;
+ vma->vm_private_data = NULL;
+}
+
+static int gntdev_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+ if (debug)
+ printk("%s: vaddr %p, pgoff %ld (shouldn't happen)\n",
+ __FUNCTION__, vmf->virtual_address, vmf->pgoff);
+ vmf->flags = VM_FAULT_ERROR;
+ return 0;
+}
+
+static struct vm_operations_struct gntdev_vmops = {
+ .close = gntdev_vma_close,
+ .fault = gntdev_vma_fault,
+};
+
+/* ------------------------------------------------------------------ */
+
+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->is_mapped)
+ 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);
+ if (debug)
+ printk("%s: map %d+%d (%lx %lx), range %lx %lx, mrange
%lx %lx\n",
+ __FUNCTION__, 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;
+ if (debug)
+ printk("%s: map %d+%d (%lx %lx)\n",
+ __FUNCTION__, map->index, map->count,
+ map->vma->vm_start, map->vma->vm_end);
+ err = unmap_grant_pages(map, 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;
+
+ priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ INIT_LIST_HEAD(&priv->maps);
+ spin_lock_init(&priv->lock);
+ priv->limit = limit;
+
+ priv->mm = get_task_mm(current);
+ if (!priv->mm) {
+ kfree(priv);
+ return -ENOMEM;
+ }
+ priv->mn.ops = &gntdev_mmu_ops;
+ mmu_notifier_register(&priv->mn, priv->mm);
+ mmput(priv->mm);
+
+ flip->private_data = priv;
+ if (debug)
+ printk("%s: priv %p\n", __FUNCTION__, priv);
+
+ return 0;
+}
+
+static int gntdev_release(struct inode *inode, struct file *flip)
+{
+ struct gntdev_priv *priv = flip->private_data;
+ struct grant_map *map;
+ int err;
+
+ if (debug)
+ printk("%s: priv %p\n", __FUNCTION__, priv);
+
+ spin_lock(&priv->lock);
+ while (!list_empty(&priv->maps)) {
+ map = list_entry(priv->maps.next, struct grant_map, next);
+ err = gntdev_del_map(map);
+ if (WARN_ON(err))
+ gntdev_free_map(map);
+
+ }
+ spin_unlock(&priv->lock);
+
+ 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;
+ if (debug)
+ printk("%s: priv %p, add %d\n", __FUNCTION__, priv,
+ op.count);
+ if (unlikely(op.count <= 0))
+ return -EINVAL;
+ if (unlikely(op.count > priv->limit))
+ return -EINVAL;
+
+ err = -ENOMEM;
+ map = gntdev_alloc_map(priv, op.count);
+ if (!map)
+ return err;
+ if (copy_from_user(map->grants, &u->refs,
+ sizeof(map->grants[0]) * op.count) != 0) {
+ gntdev_free_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) {
+ spin_lock(&priv->lock);
+ gntdev_del_map(map);
+ spin_unlock(&priv->lock);
+ gntdev_free_map(map);
+ return err;
+ }
+ 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 = -EINVAL;
+
+ if (copy_from_user(&op, u, sizeof(op)) != 0)
+ return -EFAULT;
+ if (debug)
+ printk("%s: priv %p, del %d+%d\n", __FUNCTION__, 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)
+ err = gntdev_del_map(map);
+ spin_unlock(&priv->lock);
+ if (!err)
+ gntdev_free_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 grant_map *map;
+
+ if (copy_from_user(&op, u, sizeof(op)) != 0)
+ return -EFAULT;
+ if (debug)
+ printk("%s: priv %p, offset for vaddr %lx\n", __FUNCTION__,
priv,
+ (unsigned long)op.vaddr);
+
+ spin_lock(&priv->lock);
+ map = gntdev_find_map_vaddr(priv, op.vaddr);
+ if (map == NULL ||
+ map->vma->vm_start != op.vaddr) {
+ spin_unlock(&priv->lock);
+ return -EINVAL;
+ }
+ op.offset = map->index << PAGE_SHIFT;
+ op.count = map->count;
+ spin_unlock(&priv->lock);
+
+ if (copy_to_user(u, &op, sizeof(op)) != 0)
+ return -EFAULT;
+ return 0;
+}
+
+static long gntdev_ioctl_set_max_grants(struct gntdev_priv *priv,
+ struct ioctl_gntdev_set_max_grants
__user *u)
+{
+ struct ioctl_gntdev_set_max_grants op;
+
+ if (copy_from_user(&op, u, sizeof(op)) != 0)
+ return -EFAULT;
+ if (debug)
+ printk("%s: priv %p, limit %d\n", __FUNCTION__, priv, op.count);
+ if (op.count > limit)
+ return -EINVAL;
+
+ spin_lock(&priv->lock);
+ priv->limit = op.count;
+ spin_unlock(&priv->lock);
+ return 0;
+}
+
+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_MAX_GRANTS:
+ return gntdev_ioctl_set_max_grants(priv, ptr);
+
+ default:
+ if (debug)
+ printk("%s: priv %p, unknown cmd %x\n",
+ __FUNCTION__, 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 err = -EINVAL;
+
+ if ((vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_SHARED))
+ return -EINVAL;
+
+ if (debug)
+ printk("%s: map %d+%d at %lx (pgoff %lx)\n", __FUNCTION__,
+ 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 (map->vma)
+ goto unlock_out;
+ if (priv->mm != vma->vm_mm) {
+ printk("%s: Huh? Other mm?\n", __FUNCTION__);
+ goto unlock_out;
+ }
+
+ vma->vm_ops = &gntdev_vmops;
+
+ vma->vm_flags |= VM_RESERVED;
+ vma->vm_flags |= VM_DONTCOPY;
+ vma->vm_flags |= VM_DONTEXPAND;
+
+ vma->vm_private_data = map;
+ map->vma = vma;
+
+ map->flags = GNTMAP_host_map | GNTMAP_application_map |
GNTMAP_contains_pte;
+ if (!(vma->vm_flags & VM_WRITE))
+ map->flags |= GNTMAP_readonly;
+
+ err = apply_to_page_range(vma->vm_mm, vma->vm_start,
+ vma->vm_end - vma->vm_start,
+ find_grant_ptes, map);
+ if (err) {
+ goto unlock_out;
+ if (debug)
+ printk("%s: find_grant_ptes() failure.\n",
__FUNCTION__);
+ }
+
+ err = map_grant_pages(map);
+ if (err) {
+ goto unlock_out;
+ if (debug)
+ printk("%s: map_grant_pages() failure.\n",
__FUNCTION__);
+ }
+ map->is_mapped = 1;
+
+unlock_out:
+ spin_unlock(&priv->lock);
+ 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;
+
+ 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);
+
+/* ------------------------------------------------------------------ */
diff --git a/include/xen/gntdev.h b/include/xen/gntdev.h
new file mode 100644
index 0000000..8bd1467
--- /dev/null
+++ b/include/xen/gntdev.h
@@ -0,0 +1,119 @@
+/******************************************************************************
+ * gntdev.h
+ *
+ * Interface to /dev/xen/gntdev.
+ *
+ * Copyright (c) 2007, D G Murray
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#ifndef __LINUX_PUBLIC_GNTDEV_H__
+#define __LINUX_PUBLIC_GNTDEV_H__
+
+struct ioctl_gntdev_grant_ref {
+ /* The domain ID of the grant to be mapped. */
+ uint32_t domid;
+ /* The grant reference of the grant to be mapped. */
+ uint32_t ref;
+};
+
+/*
+ * Inserts the grant references into the mapping table of an instance
+ * of gntdev. N.B. This does not perform the mapping, which is deferred
+ * until mmap() is called with @index as the offset.
+ */
+#define IOCTL_GNTDEV_MAP_GRANT_REF \
+_IOC(_IOC_NONE, 'G', 0, sizeof(struct ioctl_gntdev_map_grant_ref))
+struct ioctl_gntdev_map_grant_ref {
+ /* IN parameters */
+ /* The number of grants to be mapped. */
+ uint32_t count;
+ uint32_t pad;
+ /* OUT parameters */
+ /* The offset to be used on a subsequent call to mmap(). */
+ uint64_t index;
+ /* Variable IN parameter. */
+ /* Array of grant references, of size @count. */
+ struct ioctl_gntdev_grant_ref refs[1];
+};
+
+/*
+ * Removes the grant references from the mapping table of an instance of
+ * of gntdev. N.B. munmap() must be called on the relevant virtual address(es)
+ * before this ioctl is called, or an error will result.
+ */
+#define IOCTL_GNTDEV_UNMAP_GRANT_REF \
+_IOC(_IOC_NONE, 'G', 1, sizeof(struct ioctl_gntdev_unmap_grant_ref))
+struct ioctl_gntdev_unmap_grant_ref {
+ /* IN parameters */
+ /* The offset was returned by the corresponding map operation. */
+ uint64_t index;
+ /* The number of pages to be unmapped. */
+ uint32_t count;
+ uint32_t pad;
+};
+
+/*
+ * Returns the offset in the driver's address space that corresponds
+ * to @vaddr. This can be used to perform a munmap(), followed by an
+ * UNMAP_GRANT_REF ioctl, where no state about the offset is retained by
+ * the caller. The number of pages that were allocated at the same time as
+ * @vaddr is returned in @count.
+ *
+ * N.B. Where more than one page has been mapped into a contiguous range, the
+ * supplied @vaddr must correspond to the start of the range; otherwise
+ * an error will result. It is only possible to munmap() the entire
+ * contiguously-allocated range at once, and not any subrange thereof.
+ */
+#define IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR \
+_IOC(_IOC_NONE, 'G', 2, sizeof(struct ioctl_gntdev_get_offset_for_vaddr))
+struct ioctl_gntdev_get_offset_for_vaddr {
+ /* IN parameters */
+ /* The virtual address of the first mapped page in a range. */
+ uint64_t vaddr;
+ /* OUT parameters */
+ /* The offset that was used in the initial mmap() operation. */
+ uint64_t offset;
+ /* The number of pages mapped in the VM area that begins at @vaddr. */
+ uint32_t count;
+ uint32_t pad;
+};
+
+/*
+ * Sets the maximum number of grants that may mapped at once by this gntdev
+ * instance.
+ *
+ * N.B. This must be called before any other ioctl is performed on the device.
+ */
+#define IOCTL_GNTDEV_SET_MAX_GRANTS \
+_IOC(_IOC_NONE, 'G', 3, sizeof(struct ioctl_gntdev_set_max_grants))
+struct ioctl_gntdev_set_max_grants {
+ /* IN parameter */
+ /* The maximum number of grants that may be mapped at once. */
+ uint32_t count;
+};
+
+#endif /* __LINUX_PUBLIC_GNTDEV_H__ */
--
1.5.6.5
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