/****************************************************************************** * tpmif.h * * TPM I/O interface for Xen guest OSes, v2 * * This file is in the public domain. * */ #ifndef __XEN_PUBLIC_IO_TPMIF_H__ #define __XEN_PUBLIC_IO_TPMIF_H__ /* * Xenbus state machine * * Device open: * 1. Both ends start in XenbusStateInitialising * 2. Backend transitions to InitWait (frontend does not wait on this step) * 3. Frontend populates ring-ref, event-channel, feature-protocol-v2 * 4. Frontend transitions to Initialised * 5. Backend maps grant and event channel, verifies feature-protocol-v2 * 6. Backend transitions to Connected * 7. Frontend verifies feature-protocol-v2, transitions to Connected * * Device close: * 1. State is changed to XenbusStateClosing * 2. Frontend transitions to Closed * 3. Backend unmaps grant and event, changes state to InitWait */ enum vtpm_shared_page_state { VTPM_STATE_IDLE, /* no contents / vTPM idle / cancel complete */ VTPM_STATE_SUBMIT, /* request ready / vTPM working */ VTPM_STATE_FINISH, /* response ready / vTPM idle */ VTPM_STATE_CANCEL, /* cancel requested / vTPM working */ }; /* The backend should only change state to IDLE or FINISH, while the * frontend should only change to SUBMIT or CANCEL. */ struct vtpm_shared_page { uint32_t length; /* request/response length in bytes */ uint8_t state; /* enum vtpm_shared_page_state */ uint8_t locality; /* for the current request */ uint8_t pad; uint8_t nr_extra_pages; /* extra pages for long packets; may be zero */ uint32_t extra_pages[]; /* grant IDs; length in nr_extra_pages */ }; #endif