| lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame] | 1 | /****************************************************************************** |
| 2 | * gntalloc.h |
| 3 | * |
| 4 | * Interface to /dev/xen/gntalloc. |
| 5 | * |
| 6 | * Author: Daniel De Graaf <dgdegra@tycho.nsa.gov> |
| 7 | * |
| 8 | * This file is in the public domain. |
| 9 | */ |
| 10 | |
| 11 | #ifndef __LINUX_PUBLIC_GNTALLOC_H__ |
| 12 | #define __LINUX_PUBLIC_GNTALLOC_H__ |
| 13 | |
| 14 | /* |
| 15 | * Allocates a new page and creates a new grant reference. |
| 16 | */ |
| 17 | #define IOCTL_GNTALLOC_ALLOC_GREF \ |
| 18 | _IOC(_IOC_NONE, 'G', 5, sizeof(struct ioctl_gntalloc_alloc_gref)) |
| 19 | struct ioctl_gntalloc_alloc_gref { |
| 20 | /* IN parameters */ |
| 21 | /* The ID of the domain to be given access to the grants. */ |
| 22 | uint16_t domid; |
| 23 | /* Flags for this mapping */ |
| 24 | uint16_t flags; |
| 25 | /* Number of pages to map */ |
| 26 | uint32_t count; |
| 27 | /* OUT parameters */ |
| 28 | /* The offset to be used on a subsequent call to mmap(). */ |
| 29 | uint64_t index; |
| 30 | /* The grant references of the newly created grant, one per page */ |
| 31 | /* Variable size, depending on count */ |
| 32 | uint32_t gref_ids[1]; |
| 33 | }; |
| 34 | |
| 35 | #define GNTALLOC_FLAG_WRITABLE 1 |
| 36 | |
| 37 | /* |
| 38 | * Deallocates the grant reference, allowing the associated page to be freed if |
| 39 | * no other domains are using it. |
| 40 | */ |
| 41 | #define IOCTL_GNTALLOC_DEALLOC_GREF \ |
| 42 | _IOC(_IOC_NONE, 'G', 6, sizeof(struct ioctl_gntalloc_dealloc_gref)) |
| 43 | struct ioctl_gntalloc_dealloc_gref { |
| 44 | /* IN parameters */ |
| 45 | /* The offset returned in the map operation */ |
| 46 | uint64_t index; |
| 47 | /* Number of references to unmap */ |
| 48 | uint32_t count; |
| 49 | }; |
| 50 | |
| 51 | /* |
| 52 | * Sets up an unmap notification within the page, so that the other side can do |
| 53 | * cleanup if this side crashes. Required to implement cross-domain robust |
| 54 | * mutexes or close notification on communication channels. |
| 55 | * |
| 56 | * Each mapped page only supports one notification; multiple calls referring to |
| 57 | * the same page overwrite the previous notification. You must clear the |
| 58 | * notification prior to the IOCTL_GNTALLOC_DEALLOC_GREF if you do not want it |
| 59 | * to occur. |
| 60 | */ |
| 61 | #define IOCTL_GNTALLOC_SET_UNMAP_NOTIFY \ |
| 62 | _IOC(_IOC_NONE, 'G', 7, sizeof(struct ioctl_gntalloc_unmap_notify)) |
| 63 | struct ioctl_gntalloc_unmap_notify { |
| 64 | /* IN parameters */ |
| 65 | /* Offset in the file descriptor for a byte within the page (same as |
| 66 | * used in mmap). If using UNMAP_NOTIFY_CLEAR_BYTE, this is the byte to |
| 67 | * be cleared. Otherwise, it can be any byte in the page whose |
| 68 | * notification we are adjusting. |
| 69 | */ |
| 70 | uint64_t index; |
| 71 | /* Action(s) to take on unmap */ |
| 72 | uint32_t action; |
| 73 | /* Event channel to notify */ |
| 74 | uint32_t event_channel_port; |
| 75 | }; |
| 76 | |
| 77 | /* Clear (set to zero) the byte specified by index */ |
| 78 | #define UNMAP_NOTIFY_CLEAR_BYTE 0x1 |
| 79 | /* Send an interrupt on the indicated event channel */ |
| 80 | #define UNMAP_NOTIFY_SEND_EVENT 0x2 |
| 81 | |
| 82 | #endif /* __LINUX_PUBLIC_GNTALLOC_H__ */ |