xen/gntdev: allow usermode to map granted pages
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@redhat.com> Signed-off-by: Stefano Stabellini <Stefano.Stabellini@eu.citrix.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>hifive-unleashed-5.1
Gerd Hoffmann
Konrad Rzeszutek Wilk
parent
f07745325c
commit
ab31523c2f
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@ -62,6 +62,13 @@ config XEN_SYS_HYPERVISOR
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virtual environment, /sys/hypervisor will still be present,
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but will have no xen contents.
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config XEN_GNTDEV
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tristate "userspace grant access device driver"
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depends on XEN
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select MMU_NOTIFIER
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help
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Allows userspace processes to use grants.
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config XEN_PLATFORM_PCI
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tristate "xen platform pci device driver"
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depends on XEN_PVHVM
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@ -9,6 +9,7 @@ obj-$(CONFIG_HOTPLUG_CPU) += cpu_hotplug.o
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obj-$(CONFIG_XEN_XENCOMM) += xencomm.o
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obj-$(CONFIG_XEN_BALLOON) += balloon.o
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obj-$(CONFIG_XEN_DEV_EVTCHN) += xen-evtchn.o
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obj-$(CONFIG_XEN_GNTDEV) += xen-gntdev.o
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obj-$(CONFIG_XENFS) += xenfs/
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obj-$(CONFIG_XEN_SYS_HYPERVISOR) += sys-hypervisor.o
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obj-$(CONFIG_XEN_PLATFORM_PCI) += platform-pci.o
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@ -16,4 +17,5 @@ obj-$(CONFIG_SWIOTLB_XEN) += swiotlb-xen.o
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obj-$(CONFIG_XEN_DOM0) += pci.o
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xen-evtchn-y := evtchn.o
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xen-gntdev-y := gntdev.o
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@ -0,0 +1,635 @@
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/******************************************************************************
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* gntdev.c
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*
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* Device for accessing (in user-space) pages that have been granted by other
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* domains.
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*
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* Copyright (c) 2006-2007, D G Murray.
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* (c) 2009 Gerd Hoffmann <kraxel@redhat.com>
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#undef DEBUG
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/miscdevice.h>
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/mman.h>
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#include <linux/mmu_notifier.h>
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#include <linux/types.h>
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#include <linux/uaccess.h>
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#include <linux/sched.h>
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#include <linux/spinlock.h>
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#include <linux/slab.h>
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#include <xen/xen.h>
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#include <xen/grant_table.h>
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#include <xen/gntdev.h>
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#include <asm/xen/hypervisor.h>
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#include <asm/xen/hypercall.h>
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#include <asm/xen/page.h>
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Derek G. Murray <Derek.Murray@cl.cam.ac.uk>, "
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"Gerd Hoffmann <kraxel@redhat.com>");
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MODULE_DESCRIPTION("User-space granted page access driver");
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static int limit = 1024;
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module_param(limit, int, 0644);
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MODULE_PARM_DESC(limit, "Maximum number of grants that may be mapped at "
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"once by a gntdev instance");
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struct gntdev_priv {
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struct list_head maps;
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uint32_t used;
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uint32_t limit;
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/* lock protects maps from concurrent changes */
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spinlock_t lock;
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struct mm_struct *mm;
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struct mmu_notifier mn;
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};
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struct grant_map {
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struct list_head next;
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struct gntdev_priv *priv;
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struct vm_area_struct *vma;
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int index;
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int count;
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int flags;
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int is_mapped;
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struct ioctl_gntdev_grant_ref *grants;
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struct gnttab_map_grant_ref *map_ops;
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struct gnttab_unmap_grant_ref *unmap_ops;
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};
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/* ------------------------------------------------------------------ */
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static void gntdev_print_maps(struct gntdev_priv *priv,
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char *text, int text_index)
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{
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#ifdef DEBUG
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struct grant_map *map;
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pr_debug("maps list (priv %p, usage %d/%d)\n",
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priv, priv->used, priv->limit);
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list_for_each_entry(map, &priv->maps, next)
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pr_debug(" index %2d, count %2d %s\n",
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map->index, map->count,
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map->index == text_index && text ? text : "");
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#endif
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}
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static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count)
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{
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struct grant_map *add;
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add = kzalloc(sizeof(struct grant_map), GFP_KERNEL);
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if (NULL == add)
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return NULL;
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add->grants = kzalloc(sizeof(add->grants[0]) * count, GFP_KERNEL);
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add->map_ops = kzalloc(sizeof(add->map_ops[0]) * count, GFP_KERNEL);
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add->unmap_ops = kzalloc(sizeof(add->unmap_ops[0]) * count, GFP_KERNEL);
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if (NULL == add->grants ||
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NULL == add->map_ops ||
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NULL == add->unmap_ops)
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goto err;
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add->index = 0;
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add->count = count;
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add->priv = priv;
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if (add->count + priv->used > priv->limit)
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goto err;
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return add;
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err:
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kfree(add->grants);
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kfree(add->map_ops);
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kfree(add->unmap_ops);
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kfree(add);
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return NULL;
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}
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static void gntdev_add_map(struct gntdev_priv *priv, struct grant_map *add)
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{
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struct grant_map *map;
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list_for_each_entry(map, &priv->maps, next) {
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if (add->index + add->count < map->index) {
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list_add_tail(&add->next, &map->next);
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goto done;
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}
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add->index = map->index + map->count;
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}
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list_add_tail(&add->next, &priv->maps);
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done:
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priv->used += add->count;
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gntdev_print_maps(priv, "[new]", add->index);
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}
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static struct grant_map *gntdev_find_map_index(struct gntdev_priv *priv,
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int index, int count)
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{
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struct grant_map *map;
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list_for_each_entry(map, &priv->maps, next) {
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if (map->index != index)
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continue;
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if (map->count != count)
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continue;
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return map;
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}
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return NULL;
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}
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static struct grant_map *gntdev_find_map_vaddr(struct gntdev_priv *priv,
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unsigned long vaddr)
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{
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struct grant_map *map;
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list_for_each_entry(map, &priv->maps, next) {
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if (!map->vma)
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continue;
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if (vaddr < map->vma->vm_start)
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continue;
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if (vaddr >= map->vma->vm_end)
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continue;
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return map;
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}
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return NULL;
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}
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static int gntdev_del_map(struct grant_map *map)
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{
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int i;
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if (map->vma)
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return -EBUSY;
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for (i = 0; i < map->count; i++)
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if (map->unmap_ops[i].handle)
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return -EBUSY;
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map->priv->used -= map->count;
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list_del(&map->next);
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return 0;
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}
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static void gntdev_free_map(struct grant_map *map)
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{
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if (!map)
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return;
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kfree(map->grants);
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kfree(map->map_ops);
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kfree(map->unmap_ops);
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kfree(map);
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}
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/* ------------------------------------------------------------------ */
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static int find_grant_ptes(pte_t *pte, pgtable_t token,
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unsigned long addr, void *data)
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{
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struct grant_map *map = data;
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unsigned int pgnr = (addr - map->vma->vm_start) >> PAGE_SHIFT;
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u64 pte_maddr;
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BUG_ON(pgnr >= map->count);
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pte_maddr = (u64)pfn_to_mfn(page_to_pfn(token)) << PAGE_SHIFT;
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pte_maddr += (unsigned long)pte & ~PAGE_MASK;
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gnttab_set_map_op(&map->map_ops[pgnr], pte_maddr, map->flags,
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map->grants[pgnr].ref,
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map->grants[pgnr].domid);
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gnttab_set_unmap_op(&map->unmap_ops[pgnr], pte_maddr, map->flags,
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0 /* handle */);
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return 0;
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}
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static int map_grant_pages(struct grant_map *map)
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{
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int i, err = 0;
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pr_debug("map %d+%d\n", map->index, map->count);
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err = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref,
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map->map_ops, map->count);
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if (err)
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return err;
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for (i = 0; i < map->count; i++) {
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if (map->map_ops[i].status)
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err = -EINVAL;
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map->unmap_ops[i].handle = map->map_ops[i].handle;
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}
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return err;
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}
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static int unmap_grant_pages(struct grant_map *map, int offset, int pages)
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{
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int i, err = 0;
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pr_debug("map %d+%d [%d+%d]\n", map->index, map->count, offset, pages);
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err = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref,
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map->unmap_ops + offset, pages);
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if (err)
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return err;
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for (i = 0; i < pages; i++) {
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if (map->unmap_ops[offset+i].status)
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err = -EINVAL;
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map->unmap_ops[offset+i].handle = 0;
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}
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return err;
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}
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/* ------------------------------------------------------------------ */
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static void gntdev_vma_close(struct vm_area_struct *vma)
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{
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struct grant_map *map = vma->vm_private_data;
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pr_debug("close %p\n", vma);
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map->is_mapped = 0;
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map->vma = NULL;
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vma->vm_private_data = NULL;
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}
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static int gntdev_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
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{
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pr_debug("vaddr %p, pgoff %ld (shouldn't happen)\n",
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vmf->virtual_address, vmf->pgoff);
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vmf->flags = VM_FAULT_ERROR;
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return 0;
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}
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static struct vm_operations_struct gntdev_vmops = {
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.close = gntdev_vma_close,
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.fault = gntdev_vma_fault,
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};
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/* ------------------------------------------------------------------ */
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static void mn_invl_range_start(struct mmu_notifier *mn,
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struct mm_struct *mm,
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unsigned long start, unsigned long end)
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{
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struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn);
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struct grant_map *map;
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unsigned long mstart, mend;
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int err;
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spin_lock(&priv->lock);
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list_for_each_entry(map, &priv->maps, next) {
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if (!map->vma)
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continue;
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if (!map->is_mapped)
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continue;
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if (map->vma->vm_start >= end)
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continue;
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if (map->vma->vm_end <= start)
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continue;
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mstart = max(start, map->vma->vm_start);
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mend = min(end, map->vma->vm_end);
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pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n",
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map->index, map->count,
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map->vma->vm_start, map->vma->vm_end,
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start, end, mstart, mend);
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err = unmap_grant_pages(map,
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(mstart - map->vma->vm_start) >> PAGE_SHIFT,
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(mend - mstart) >> PAGE_SHIFT);
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WARN_ON(err);
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}
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spin_unlock(&priv->lock);
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}
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static void mn_invl_page(struct mmu_notifier *mn,
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struct mm_struct *mm,
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unsigned long address)
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{
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mn_invl_range_start(mn, mm, address, address + PAGE_SIZE);
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}
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static void mn_release(struct mmu_notifier *mn,
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struct mm_struct *mm)
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{
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struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn);
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struct grant_map *map;
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int err;
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spin_lock(&priv->lock);
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list_for_each_entry(map, &priv->maps, next) {
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if (!map->vma)
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continue;
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pr_debug("map %d+%d (%lx %lx)\n",
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map->index, map->count,
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map->vma->vm_start, map->vma->vm_end);
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err = unmap_grant_pages(map, /* offset */ 0, map->count);
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WARN_ON(err);
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}
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spin_unlock(&priv->lock);
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}
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struct mmu_notifier_ops gntdev_mmu_ops = {
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.release = mn_release,
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.invalidate_page = mn_invl_page,
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.invalidate_range_start = mn_invl_range_start,
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};
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/* ------------------------------------------------------------------ */
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static int gntdev_open(struct inode *inode, struct file *flip)
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{
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struct gntdev_priv *priv;
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int ret = 0;
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priv = kzalloc(sizeof(*priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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INIT_LIST_HEAD(&priv->maps);
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spin_lock_init(&priv->lock);
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priv->limit = limit;
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priv->mm = get_task_mm(current);
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if (!priv->mm) {
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kfree(priv);
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return -ENOMEM;
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}
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priv->mn.ops = &gntdev_mmu_ops;
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ret = mmu_notifier_register(&priv->mn, priv->mm);
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mmput(priv->mm);
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if (ret) {
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kfree(priv);
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return ret;
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}
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flip->private_data = priv;
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pr_debug("priv %p\n", priv);
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return 0;
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}
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static int gntdev_release(struct inode *inode, struct file *flip)
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{
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struct gntdev_priv *priv = flip->private_data;
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struct grant_map *map;
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int err;
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pr_debug("priv %p\n", priv);
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spin_lock(&priv->lock);
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while (!list_empty(&priv->maps)) {
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map = list_entry(priv->maps.next, struct grant_map, next);
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err = gntdev_del_map(map);
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if (WARN_ON(err))
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gntdev_free_map(map);
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}
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spin_unlock(&priv->lock);
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mmu_notifier_unregister(&priv->mn, priv->mm);
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kfree(priv);
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return 0;
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}
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static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv,
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struct ioctl_gntdev_map_grant_ref __user *u)
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{
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struct ioctl_gntdev_map_grant_ref op;
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struct grant_map *map;
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int err;
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if (copy_from_user(&op, u, sizeof(op)) != 0)
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return -EFAULT;
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pr_debug("priv %p, add %d\n", priv, op.count);
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if (unlikely(op.count <= 0))
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return -EINVAL;
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if (unlikely(op.count > priv->limit))
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return -EINVAL;
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err = -ENOMEM;
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map = gntdev_alloc_map(priv, op.count);
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if (!map)
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return err;
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if (copy_from_user(map->grants, &u->refs,
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sizeof(map->grants[0]) * op.count) != 0) {
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gntdev_free_map(map);
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return err;
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}
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spin_lock(&priv->lock);
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gntdev_add_map(priv, map);
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op.index = map->index << PAGE_SHIFT;
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spin_unlock(&priv->lock);
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if (copy_to_user(u, &op, sizeof(op)) != 0) {
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spin_lock(&priv->lock);
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gntdev_del_map(map);
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spin_unlock(&priv->lock);
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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 = -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)
|
||||
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;
|
||||
pr_debug("priv %p, offset for vaddr %lx\n", 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;
|
||||
pr_debug("priv %p, limit %d\n", priv, op.count);
|
||||
if (op.count > limit)
|
||||
return -E2BIG;
|
||||
|
||||
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:
|
||||
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 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 (map->vma)
|
||||
goto unlock_out;
|
||||
if (priv->mm != vma->vm_mm) {
|
||||
printk(KERN_WARNING "Huh? Other mm?\n");
|
||||
goto unlock_out;
|
||||
}
|
||||
|
||||
vma->vm_ops = &gntdev_vmops;
|
||||
|
||||
vma->vm_flags |= VM_RESERVED|VM_DONTCOPY|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) {
|
||||
printk(KERN_WARNING "find_grant_ptes() failure.\n");
|
||||
goto unlock_out;
|
||||
}
|
||||
|
||||
err = map_grant_pages(map);
|
||||
if (err) {
|
||||
printk(KERN_WARNING "map_grant_pages() failure.\n");
|
||||
goto unlock_out;
|
||||
}
|
||||
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);
|
||||
|
||||
/* ------------------------------------------------------------------ */
|
||||
|
|
@ -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__ */
|
||||
Loading…
Reference in New Issue