cregit-Linux how code gets into the kernel

Release 4.12 include/uapi/xen/gntalloc.h

Directory: include/uapi/xen
 * gntalloc.h
 * Interface to /dev/xen/gntalloc.
 * Author: Daniel De Graaf <>
 * This file is in the public domain.



#include <linux/types.h>

 * Allocates a new page and creates a new grant reference.

_IOC(_IOC_NONE, 'G', 5, sizeof(struct ioctl_gntalloc_alloc_gref))

struct ioctl_gntalloc_alloc_gref {
	/* IN parameters */
	/* The ID of the domain to be given access to the grants. */
__u16 domid;
	/* Flags for this mapping */
__u16 flags;
	/* Number of pages to map */
__u32 count;
	/* OUT parameters */
	/* The offset to be used on a subsequent call to mmap(). */
__u64 index;
	/* The grant references of the newly created grant, one per page */
	/* Variable size, depending on count */
__u32 gref_ids[1];


 * Deallocates the grant reference, allowing the associated page to be freed if
 * no other domains are using it.

_IOC(_IOC_NONE, 'G', 6, sizeof(struct ioctl_gntalloc_dealloc_gref))

struct ioctl_gntalloc_dealloc_gref {
	/* IN parameters */
	/* The offset returned in the map operation */
__u64 index;
	/* Number of references to unmap */
__u32 count;

 * Sets up an unmap notification within the page, so that the other side can do
 * cleanup if this side crashes. Required to implement cross-domain robust
 * mutexes or close notification on communication channels.
 * Each mapped page only supports one notification; multiple calls referring to
 * the same page overwrite the previous notification. You must clear the
 * notification prior to the IOCTL_GNTALLOC_DEALLOC_GREF if you do not want it
 * to occur.

_IOC(_IOC_NONE, 'G', 7, sizeof(struct ioctl_gntalloc_unmap_notify))

struct ioctl_gntalloc_unmap_notify {
	/* IN parameters */
	/* Offset in the file descriptor for a byte within the page (same as
         * used in mmap). If using UNMAP_NOTIFY_CLEAR_BYTE, this is the byte to
         * be cleared. Otherwise, it can be any byte in the page whose
         * notification we are adjusting.
__u64 index;
	/* Action(s) to take on unmap */
__u32 action;
	/* Event channel to notify */
__u32 event_channel_port;

/* Clear (set to zero) the byte specified by index */

/* Send an interrupt on the indicated event channel */


#endif /* __LINUX_PUBLIC_GNTALLOC_H__ */

Overall Contributors

Daniel De Graaf9587.96%266.67%
Mikko Rapeli1312.04%133.33%
Directory: include/uapi/xen
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.