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 53