diff options
Diffstat (limited to 'include/xen/gntalloc.h')
-rw-r--r-- | include/xen/gntalloc.h | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/include/xen/gntalloc.h b/include/xen/gntalloc.h new file mode 100644 index 0000000..76bd580 --- /dev/null +++ b/include/xen/gntalloc.h @@ -0,0 +1,82 @@ +/****************************************************************************** + * gntalloc.h + * + * Interface to /dev/xen/gntalloc. + * + * Author: Daniel De Graaf <dgdegra@tycho.nsa.gov> + * + * This file is in the public domain. + */ + +#ifndef __LINUX_PUBLIC_GNTALLOC_H__ +#define __LINUX_PUBLIC_GNTALLOC_H__ + +/* + * Allocates a new page and creates a new grant reference. + */ +#define IOCTL_GNTALLOC_ALLOC_GREF \ +_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. */ + uint16_t domid; + /* Flags for this mapping */ + uint16_t flags; + /* Number of pages to map */ + uint32_t count; + /* OUT parameters */ + /* The offset to be used on a subsequent call to mmap(). */ + uint64_t index; + /* The grant references of the newly created grant, one per page */ + /* Variable size, depending on count */ + uint32_t gref_ids[1]; +}; + +#define GNTALLOC_FLAG_WRITABLE 1 + +/* + * Deallocates the grant reference, allowing the associated page to be freed if + * no other domains are using it. + */ +#define IOCTL_GNTALLOC_DEALLOC_GREF \ +_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 */ + uint64_t index; + /* Number of references to unmap */ + uint32_t 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. + */ +#define IOCTL_GNTALLOC_SET_UNMAP_NOTIFY \ +_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. + */ + uint64_t index; + /* Action(s) to take on unmap */ + uint32_t action; + /* Event channel to notify */ + uint32_t event_channel_port; +}; + +/* Clear (set to zero) the byte specified by index */ +#define UNMAP_NOTIFY_CLEAR_BYTE 0x1 +/* Send an interrupt on the indicated event channel */ +#define UNMAP_NOTIFY_SEND_EVENT 0x2 + +#endif /* __LINUX_PUBLIC_GNTALLOC_H__ */ |