| Daniel De Graaf | e268395 | 2013-07-30 13:29:47 -0400 | [diff] [blame] | 1 | /****************************************************************************** |
| 2 | * tpmif.h |
| 3 | * |
| 4 | * TPM I/O interface for Xen guest OSes, v2 |
| 5 | * |
| 6 | * This file is in the public domain. |
| 7 | * |
| 8 | */ |
| 9 | |
| 10 | #ifndef __XEN_PUBLIC_IO_TPMIF_H__ |
| 11 | #define __XEN_PUBLIC_IO_TPMIF_H__ |
| 12 | |
| 13 | /* |
| 14 | * Xenbus state machine |
| 15 | * |
| 16 | * Device open: |
| 17 | * 1. Both ends start in XenbusStateInitialising |
| 18 | * 2. Backend transitions to InitWait (frontend does not wait on this step) |
| 19 | * 3. Frontend populates ring-ref, event-channel, feature-protocol-v2 |
| 20 | * 4. Frontend transitions to Initialised |
| 21 | * 5. Backend maps grant and event channel, verifies feature-protocol-v2 |
| 22 | * 6. Backend transitions to Connected |
| 23 | * 7. Frontend verifies feature-protocol-v2, transitions to Connected |
| 24 | * |
| 25 | * Device close: |
| 26 | * 1. State is changed to XenbusStateClosing |
| 27 | * 2. Frontend transitions to Closed |
| 28 | * 3. Backend unmaps grant and event, changes state to InitWait |
| 29 | */ |
| 30 | |
| 31 | enum vtpm_shared_page_state { |
| 32 | VTPM_STATE_IDLE, /* no contents / vTPM idle / cancel complete */ |
| 33 | VTPM_STATE_SUBMIT, /* request ready / vTPM working */ |
| 34 | VTPM_STATE_FINISH, /* response ready / vTPM idle */ |
| 35 | VTPM_STATE_CANCEL, /* cancel requested / vTPM working */ |
| 36 | }; |
| 37 | /* The backend should only change state to IDLE or FINISH, while the |
| 38 | * frontend should only change to SUBMIT or CANCEL. */ |
| 39 | |
| 40 | |
| 41 | struct vtpm_shared_page { |
| 42 | uint32_t length; /* request/response length in bytes */ |
| 43 | |
| 44 | uint8_t state; /* enum vtpm_shared_page_state */ |
| 45 | uint8_t locality; /* for the current request */ |
| 46 | uint8_t pad; |
| 47 | |
| 48 | uint8_t nr_extra_pages; /* extra pages for long packets; may be zero */ |
| 49 | uint32_t extra_pages[0]; /* grant IDs; length in nr_extra_pages */ |
| 50 | }; |
| 51 | |
| 52 | #endif |