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1/******************************************************************************2 * tpmif.h3 *4 * TPM I/O interface for Xen guest OSes, v25 *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 machine15 *16 * Device open:17 * 1. Both ends start in XenbusStateInitialising18 * 2. Backend transitions to InitWait (frontend does not wait on this step)19 * 3. Frontend populates ring-ref, event-channel, feature-protocol-v220 * 4. Frontend transitions to Initialised21 * 5. Backend maps grant and event channel, verifies feature-protocol-v222 * 6. Backend transitions to Connected23 * 7. Frontend verifies feature-protocol-v2, transitions to Connected24 *25 * Device close:26 * 1. State is changed to XenbusStateClosing27 * 2. Frontend transitions to Closed28 * 3. Backend unmaps grant and event, changes state to InitWait29 */30 31enum 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 the38 * frontend should only change to SUBMIT or CANCEL. */39 40 41struct 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[]; /* grant IDs; length in nr_extra_pages */50};51 52#endif53