From e66cb3294f3aa815ae6741b7030dfeb2ea801284 Mon Sep 17 00:00:00 2001 From: Daniel De Graaf Date: Thu, 21 Mar 2013 16:11:19 -0400 Subject: mini-os/tpm{back, front}: Allow device repoens Allow the vtpm device to be disconnected and reconnected so that a bootloader (like pv-grub) can submit measurements and return the vtpm device to its initial state before booting the target kernel. Signed-off-by: Daniel De Graaf --- extras/mini-os/tpmback.c | 23 ++++++++++++++++++++++- extras/mini-os/tpmfront.c | 14 ++++++++++++-- 2 files changed, 34 insertions(+), 3 deletions(-) (limited to 'extras') diff --git a/extras/mini-os/tpmback.c b/extras/mini-os/tpmback.c index d68ad2b876..9917765133 100644 --- a/extras/mini-os/tpmback.c +++ b/extras/mini-os/tpmback.c @@ -645,6 +645,24 @@ error_post_map: return -1; } +static void disconnect_fe(tpmif_t* tpmif) +{ + if (tpmif->status == CONNECTED) { + tpmif->status = DISCONNECTING; + mask_evtchn(tpmif->evtchn); + + if(gntmap_munmap(>pmdev.map, (unsigned long)tpmif->page, 1)) { + TPMBACK_ERR("%u/%u Error occured while trying to unmap shared page\n", (unsigned int) tpmif->domid, tpmif->handle); + } + + unbind_evtchn(tpmif->evtchn); + } + tpmif->status = DISCONNECTED; + tpmif_change_state(tpmif, XenbusStateInitWait); + + TPMBACK_LOG("Frontend %u/%u disconnected\n", (unsigned int) tpmif->domid, tpmif->handle); +} + static int frontend_changed(tpmif_t* tpmif) { int state = xenbus_read_integer(tpmif->fe_state_path); @@ -671,8 +689,11 @@ static int frontend_changed(tpmif_t* tpmif) tpmif_change_state(tpmif, XenbusStateClosing); break; - case XenbusStateUnknown: /* keep it here */ case XenbusStateClosed: + disconnect_fe(tpmif); + break; + + case XenbusStateUnknown: /* keep it here */ free_tpmif(tpmif); break; diff --git a/extras/mini-os/tpmfront.c b/extras/mini-os/tpmfront.c index 9f930b5c6f..95d86f6fcc 100644 --- a/extras/mini-os/tpmfront.c +++ b/extras/mini-os/tpmfront.c @@ -156,6 +156,9 @@ static int wait_for_backend_closed(xenbus_event_queue* events, char* path) case XenbusStateClosed: TPMFRONT_LOG("Backend Closed\n"); return 0; + case XenbusStateInitWait: + TPMFRONT_LOG("Backend Closed (waiting for reconnect)\n"); + return 0; default: xenbus_wait_for_watch(events); } @@ -339,10 +342,10 @@ void shutdown_tpmfront(struct tpmfront_dev* dev) TPMFRONT_LOG("Shutting down tpmfront\n"); /* disconnect */ if(dev->state == XenbusStateConnected) { - dev->state = XenbusStateClosing; - //FIXME: Transaction for this? /* Tell backend we are closing */ + dev->state = XenbusStateClosing; if((err = xenbus_printf(XBT_NIL, dev->nodename, "state", "%u", (unsigned int) dev->state))) { + TPMFRONT_ERR("Unable to write to %s, error was %s", dev->nodename, err); free(err); } @@ -366,6 +369,13 @@ void shutdown_tpmfront(struct tpmfront_dev* dev) /* Wait for the backend to close and unmap shared pages, ignore any errors */ wait_for_backend_state_changed(dev, XenbusStateClosed); + /* Prepare for a later reopen (possibly by a kexec'd kernel) */ + dev->state = XenbusStateInitialising; + if((err = xenbus_printf(XBT_NIL, dev->nodename, "state", "%u", (unsigned int) dev->state))) { + TPMFRONT_ERR("Unable to write to %s, error was %s", dev->nodename, err); + free(err); + } + /* Close event channel and unmap shared page */ mask_evtchn(dev->evtchn); unbind_evtchn(dev->evtchn); -- cgit v1.2.3