[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v3] drivers/tpm: add xen tpmfront interface
On Tue, May 28, 2013 at 11:40:32AM -0400, Daniel De Graaf wrote: > This is a complete rewrite of the Xen TPM frontend driver, taking > advantage of a simplified frontend/backend interface and adding support > for cancellation and timeouts. The backend for this driver is provided > by a vTPM stub domain using the interface in Xen 4.3. > > Signed-off-by: Daniel De Graaf <dgdegra@xxxxxxxxxxxxx> > Acked-by: Matthew Fioravante <matthew.fioravante@xxxxxxxxxx> I am OK with it and you can stick the Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> Did the maintainers of the tpm subsystem have any questions? > > --- > > Changes since v1: > * Added some wmb()s for clarity > * Removed a few magic numbers > * Fix a misused length in memcpy > * Style/comment fixes > > Documentation/xen-tpmfront.txt | 116 ++++++++++ > drivers/char/tpm/Kconfig | 11 + > drivers/char/tpm/Makefile | 1 + > drivers/char/tpm/xen-tpmfront.c | 470 > +++++++++++++++++++++++++++++++++++++++ > include/xen/interface/io/tpmif.h | 50 +++++ > 5 files changed, 648 insertions(+) > create mode 100644 Documentation/xen-tpmfront.txt > create mode 100644 drivers/char/tpm/xen-tpmfront.c > create mode 100644 include/xen/interface/io/tpmif.h > > diff --git a/Documentation/xen-tpmfront.txt b/Documentation/xen-tpmfront.txt > new file mode 100644 > index 0000000..8a61d6f > --- /dev/null > +++ b/Documentation/xen-tpmfront.txt > @@ -0,0 +1,116 @@ > +Copyright (c) 2010-2012 United States Government, as represented by > +the Secretary of Defense. All rights reserved. > +November 12 2012 > +Authors: Matthew Fioravante (JHUAPL), Daniel De Graaf (NSA) > + > +This document describes the virtual Trusted Platform Module (vTPM) subsystem > for > +Xen. The reader is assumed to have familiarity with building and installing > Xen, > +Linux, and a basic understanding of the TPM and vTPM concepts. > + > +------------------------------ > +INTRODUCTION > +------------------------------ > + > +The goal of this work is to provide a TPM functionality to a virtual guest > +operating system (in Xen terms, a DomU). This allows programs to interact > with > +a TPM in a virtual system the same way they interact with a TPM on the > physical > +system. Each guest gets its own unique, emulated, software TPM. However, > each > +of the vTPM's secrets (Keys, NVRAM, etc) are managed by a vTPM Manager > domain, > +which seals the secrets to the Physical TPM. If the process of creating > each of > +these domains (manager, vTPM, and guest) is trusted, the vTPM subsystem > extends > +the chain of trust rooted in the hardware TPM to virtual machines in Xen. > Each > +major component of vTPM is implemented as a separate domain, providing secure > +separation guaranteed by the hypervisor. The vTPM domains are implemented in > +mini-os to reduce memory and processor overhead. > + > +This mini-os vTPM subsystem was built on top of the previous vTPM work done > by > +IBM and Intel corporation. > + > +------------------------------ > +DESIGN OVERVIEW > +------------------------------ > + > +The architecture of vTPM is described below: > + > ++------------------+ > +| Linux DomU | ... > +| | ^ | > +| v | | > +| xen-tpmfront | > ++------------------+ > + | ^ > + v | > ++------------------+ > +| mini-os/tpmback | > +| | ^ | > +| v | | > +| vtpm-stubdom | ... > +| | ^ | > +| v | | > +| mini-os/tpmfront | > ++------------------+ > + | ^ > + v | > ++------------------+ > +| mini-os/tpmback | > +| | ^ | > +| v | | > +| vtpmmgr-stubdom | > +| | ^ | > +| v | | > +| mini-os/tpm_tis | > ++------------------+ > + | ^ > + v | > ++------------------+ > +| Hardware TPM | > ++------------------+ > + > + * Linux DomU: The Linux based guest that wants to use a vTPM. There many be > + more than one of these. > + > + * xen-tpmfront.ko: Linux kernel virtual TPM frontend driver. This driver > + provides vTPM access to a Linux-based DomU. > + > + * mini-os/tpmback: Mini-os TPM backend driver. The Linux frontend driver > + connects to this backend driver to facilitate communications > + between the Linux DomU and its vTPM. This driver is also > + used by vtpmmgr-stubdom to communicate with vtpm-stubdom. > + > + * vtpm-stubdom: A mini-os stub domain that implements a vTPM. There is a > + one to one mapping between running vtpm-stubdom instances and > + logical vtpms on the system. The vTPM Platform Configuration > + Registers (PCRs) are normally all initialized to zero. > + > + * mini-os/tpmfront: Mini-os TPM frontend driver. The vTPM mini-os domain > + vtpm-stubdom uses this driver to communicate with > + vtpmmgr-stubdom. This driver is also used in mini-os > + domains such as pv-grub that talk to the vTPM domain. > + > + * vtpmmgr-stubdom: A mini-os domain that implements the vTPM manager. There > is > + only one vTPM manager and it should be running during the > + entire lifetime of the machine. This domain regulates > + access to the physical TPM on the system and secures the > + persistent state of each vTPM. > + > + * mini-os/tpm_tis: Mini-os TPM version 1.2 TPM Interface Specification (TIS) > + driver. This driver used by vtpmmgr-stubdom to talk > directly to > + the hardware TPM. Communication is facilitated by mapping > + hardware memory pages into vtpmmgr-stubdom. > + > + * Hardware TPM: The physical TPM that is soldered onto the motherboard. > + > +------------------------------ > +INTEGRATION WITH XEN > +------------------------------ > + > +Support for the vTPM driver was added in Xen using the libxl toolstack in Xen > +4.3. See the Xen documentation (docs/misc/vtpm.txt) for details on setting > up > +the vTPM and vTPM Manager stub domains. Once the stub domains are running, a > +vTPM device is set up in the same manner as a disk or network device in the > +domain's configuration file. > + > +In order to use features such as IMA that require a TPM to be loaded prior to > +the initrd, the xen-tpmfront driver must be compiled in to the kernel. If > not > +using such features, the driver can be compiled as a module and will be > loaded > +as usual. > diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig > index dbfd564..205ed35 100644 > --- a/drivers/char/tpm/Kconfig > +++ b/drivers/char/tpm/Kconfig > @@ -91,4 +91,15 @@ config TCG_ST33_I2C > To compile this driver as a module, choose M here; the module will be > called tpm_stm_st33_i2c. > > +config TCG_XEN > + tristate "XEN TPM Interface" > + depends on TCG_TPM && XEN > + ---help--- > + If you want to make TPM support available to a Xen user domain, > + say Yes and it will be accessible from within Linux. See > + the manpages for xl, xl.conf, and docs/misc/vtpm.txt in > + the Xen source repository for more details. > + To compile this driver as a module, choose M here; the module > + will be called xen-tpmfront. > + > endif # TCG_TPM > diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile > index a3736c9..eb41ff9 100644 > --- a/drivers/char/tpm/Makefile > +++ b/drivers/char/tpm/Makefile > @@ -18,3 +18,4 @@ obj-$(CONFIG_TCG_ATMEL) += tpm_atmel.o > obj-$(CONFIG_TCG_INFINEON) += tpm_infineon.o > obj-$(CONFIG_TCG_IBMVTPM) += tpm_ibmvtpm.o > obj-$(CONFIG_TCG_ST33_I2C) += tpm_i2c_stm_st33.o > +obj-$(CONFIG_TCG_XEN) += xen-tpmfront.o > diff --git a/drivers/char/tpm/xen-tpmfront.c b/drivers/char/tpm/xen-tpmfront.c > new file mode 100644 > index 0000000..4c0fb12 > --- /dev/null > +++ b/drivers/char/tpm/xen-tpmfront.c > @@ -0,0 +1,470 @@ > +/* > + * Implementation of the Xen vTPM device frontend > + * > + * Author: Daniel De Graaf <dgdegra@xxxxxxxxxxxxx> > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2, > + * as published by the Free Software Foundation. > + */ > +#include <linux/errno.h> > +#include <linux/err.h> > +#include <linux/interrupt.h> > +#include <xen/events.h> > +#include <xen/interface/io/tpmif.h> > +#include <xen/grant_table.h> > +#include <xen/xenbus.h> > +#include <xen/page.h> > +#include "tpm.h" > + > +struct tpm_private { > + struct tpm_chip *chip; > + struct xenbus_device *dev; > + > + struct vtpm_shared_page *shr; > + > + unsigned int evtchn; > + int ring_ref; > + domid_t backend_id; > +}; > + > +enum status_bits { > + VTPM_STATUS_RUNNING = 0x1, > + VTPM_STATUS_IDLE = 0x2, > + VTPM_STATUS_RESULT = 0x4, > + VTPM_STATUS_CANCELED = 0x8, > +}; > + > +static u8 vtpm_status(struct tpm_chip *chip) > +{ > + struct tpm_private *priv = TPM_VPRIV(chip); > + switch (priv->shr->state) { > + case VTPM_STATE_IDLE: > + return VTPM_STATUS_IDLE | VTPM_STATUS_CANCELED; > + case VTPM_STATE_FINISH: > + return VTPM_STATUS_IDLE | VTPM_STATUS_RESULT; > + case VTPM_STATE_SUBMIT: > + case VTPM_STATE_CANCEL: /* cancel requested, not yet canceled */ > + return VTPM_STATUS_RUNNING; > + default: > + return 0; > + } > +} > + > +static bool vtpm_req_canceled(struct tpm_chip *chip, u8 status) > +{ > + return status & VTPM_STATUS_CANCELED; > +} > + > +static void vtpm_cancel(struct tpm_chip *chip) > +{ > + struct tpm_private *priv = TPM_VPRIV(chip); > + priv->shr->state = VTPM_STATE_CANCEL; > + wmb(); > + notify_remote_via_evtchn(priv->evtchn); > +} > + > +static unsigned int shr_data_offset(struct vtpm_shared_page *shr) > +{ > + return sizeof(*shr) + sizeof(u32) * shr->nr_extra_pages; > +} > + > +static int vtpm_send(struct tpm_chip *chip, u8 *buf, size_t count) > +{ > + struct tpm_private *priv = TPM_VPRIV(chip); > + struct vtpm_shared_page *shr = priv->shr; > + unsigned int offset = shr_data_offset(shr); > + > + u32 ordinal; > + unsigned long duration; > + > + if (offset > PAGE_SIZE) > + return -EIO; > + > + if (offset + count > PAGE_SIZE) > + return -EIO; > + > + /* Wait for completion of any existing command or cancellation */ > + if (wait_for_tpm_stat(chip, VTPM_STATUS_IDLE, chip->vendor.timeout_c, > + &chip->vendor.read_queue, true) < 0) { > + vtpm_cancel(chip); > + return -ETIME; > + } > + > + memcpy(offset + (u8 *)shr, buf, count); > + shr->length = count; > + barrier(); > + shr->state = VTPM_STATE_SUBMIT; > + wmb(); > + notify_remote_via_evtchn(priv->evtchn); > + > + ordinal = be32_to_cpu(((struct tpm_input_header*)buf)->ordinal); > + duration = tpm_calc_ordinal_duration(chip, ordinal); > + > + if (wait_for_tpm_stat(chip, VTPM_STATUS_IDLE, duration, > + &chip->vendor.read_queue, true) < 0) { > + /* got a signal or timeout, try to cancel */ > + vtpm_cancel(chip); > + return -ETIME; > + } > + > + return count; > +} > + > +static int vtpm_recv(struct tpm_chip *chip, u8 *buf, size_t count) > +{ > + struct tpm_private *priv = TPM_VPRIV(chip); > + struct vtpm_shared_page *shr = priv->shr; > + unsigned int offset = shr_data_offset(shr); > + size_t length = shr->length; > + > + if (shr->state == VTPM_STATE_IDLE) > + return -ECANCELED; > + > + /* In theory the wait at the end of _send makes this one unnecessary */ > + if (wait_for_tpm_stat(chip, VTPM_STATUS_RESULT, chip->vendor.timeout_c, > + &chip->vendor.read_queue, true) < 0) { > + vtpm_cancel(chip); > + return -ETIME; > + } > + > + if (offset > PAGE_SIZE) > + return -EIO; > + > + if (offset + length > PAGE_SIZE) > + length = PAGE_SIZE - offset; > + > + if (length > count) > + length = count; > + > + memcpy(buf, offset + (u8 *)shr, length); > + > + return length; > +} > + > +ssize_t tpm_show_locality(struct device *dev, struct device_attribute *attr, > + char *buf) > +{ > + struct tpm_chip *chip = dev_get_drvdata(dev); > + struct tpm_private *priv = TPM_VPRIV(chip); > + u8 locality = priv->shr->locality; > + > + return sprintf(buf, "%d\n", locality); > +} > + > +ssize_t tpm_store_locality(struct device *dev, struct device_attribute *attr, > + const char *buf, size_t len) > +{ > + struct tpm_chip *chip = dev_get_drvdata(dev); > + struct tpm_private *priv = TPM_VPRIV(chip); > + u8 val; > + > + int rv = kstrtou8(buf, 0, &val); > + if (rv) > + return rv; > + > + priv->shr->locality = val; > + > + return len; > +} > + > +static const struct file_operations vtpm_ops = { > + .owner = THIS_MODULE, > + .llseek = no_llseek, > + .open = tpm_open, > + .read = tpm_read, > + .write = tpm_write, > + .release = tpm_release, > +}; > + > +static DEVICE_ATTR(pubek, S_IRUGO, tpm_show_pubek, NULL); > +static DEVICE_ATTR(pcrs, S_IRUGO, tpm_show_pcrs, NULL); > +static DEVICE_ATTR(enabled, S_IRUGO, tpm_show_enabled, NULL); > +static DEVICE_ATTR(active, S_IRUGO, tpm_show_active, NULL); > +static DEVICE_ATTR(owned, S_IRUGO, tpm_show_owned, NULL); > +static DEVICE_ATTR(temp_deactivated, S_IRUGO, tpm_show_temp_deactivated, > + NULL); > +static DEVICE_ATTR(caps, S_IRUGO, tpm_show_caps, NULL); > +static DEVICE_ATTR(cancel, S_IWUSR | S_IWGRP, NULL, tpm_store_cancel); > +static DEVICE_ATTR(durations, S_IRUGO, tpm_show_durations, NULL); > +static DEVICE_ATTR(timeouts, S_IRUGO, tpm_show_timeouts, NULL); > +static DEVICE_ATTR(locality, S_IRUGO | S_IWUSR, tpm_show_locality, > + tpm_store_locality); > + > +static struct attribute *vtpm_attrs[] = { > + &dev_attr_pubek.attr, > + &dev_attr_pcrs.attr, > + &dev_attr_enabled.attr, > + &dev_attr_active.attr, > + &dev_attr_owned.attr, > + &dev_attr_temp_deactivated.attr, > + &dev_attr_caps.attr, > + &dev_attr_cancel.attr, > + &dev_attr_durations.attr, > + &dev_attr_timeouts.attr, > + &dev_attr_locality.attr, > + NULL, > +}; > + > +static struct attribute_group vtpm_attr_grp = { > + .attrs = vtpm_attrs, > +}; > + > +#define TPM_LONG_TIMEOUT (10 * 60 * HZ) > + > +static const struct tpm_vendor_specific tpm_vtpm = { > + .status = vtpm_status, > + .recv = vtpm_recv, > + .send = vtpm_send, > + .cancel = vtpm_cancel, > + .req_complete_mask = VTPM_STATUS_IDLE | VTPM_STATUS_RESULT, > + .req_complete_val = VTPM_STATUS_IDLE | VTPM_STATUS_RESULT, > + .req_canceled = vtpm_req_canceled, > + .attr_group = &vtpm_attr_grp, > + .miscdev = { > + .fops = &vtpm_ops, > + }, > + .duration = { > + TPM_LONG_TIMEOUT, > + TPM_LONG_TIMEOUT, > + TPM_LONG_TIMEOUT, > + }, > +}; > + > +static irqreturn_t tpmif_interrupt(int dummy, void *dev_id) > +{ > + struct tpm_private *priv = dev_id; > + > + switch (priv->shr->state) { > + case VTPM_STATE_IDLE: > + case VTPM_STATE_FINISH: > + wake_up_interruptible(&priv->chip->vendor.read_queue); > + break; > + case VTPM_STATE_SUBMIT: > + case VTPM_STATE_CANCEL: > + default: > + break; > + } > + return IRQ_HANDLED; > +} > + > +static int setup_chip(struct device *dev, struct tpm_private *priv) > +{ > + struct tpm_chip *chip; > + > + chip = tpm_register_hardware(dev, &tpm_vtpm); > + if (!chip) > + return -ENODEV; > + > + init_waitqueue_head(&chip->vendor.read_queue); > + > + priv->chip = chip; > + TPM_VPRIV(chip) = priv; > + > + return 0; > +} > + > +/* caller must clean up in case of errors */ > +static int setup_ring(struct xenbus_device *dev, struct tpm_private *priv) > +{ > + struct xenbus_transaction xbt; > + const char *message = NULL; > + int rv; > + > + priv->shr = (void *)__get_free_page(GFP_KERNEL|__GFP_ZERO); > + if (!priv->shr) { > + xenbus_dev_fatal(dev, -ENOMEM, "allocating shared ring"); > + return -ENOMEM; > + } > + > + rv = xenbus_grant_ring(dev, virt_to_mfn(priv->shr)); > + if (rv < 0) > + return rv; > + > + priv->ring_ref = rv; > + > + rv = xenbus_alloc_evtchn(dev, &priv->evtchn); > + if (rv) > + return rv; > + > + rv = bind_evtchn_to_irqhandler(priv->evtchn, tpmif_interrupt, 0, > + "tpmif", priv); > + if (rv <= 0) { > + xenbus_dev_fatal(dev, rv, "allocating TPM irq"); > + return rv; > + } > + priv->chip->vendor.irq = rv; > + > + again: > + rv = xenbus_transaction_start(&xbt); > + if (rv) { > + xenbus_dev_fatal(dev, rv, "starting transaction"); > + return rv; > + } > + > + rv = xenbus_printf(xbt, dev->nodename, > + "ring-ref", "%u", priv->ring_ref); > + if (rv) { > + message = "writing ring-ref"; > + goto abort_transaction; > + } > + > + rv = xenbus_printf(xbt, dev->nodename, "event-channel", "%u", > + priv->evtchn); > + if (rv) { > + message = "writing event-channel"; > + goto abort_transaction; > + } > + > + rv = xenbus_printf(xbt, dev->nodename, "feature-protocol-v2", "1"); > + if (rv) { > + message = "writing feature-protocol-v2"; > + goto abort_transaction; > + } > + > + rv = xenbus_transaction_end(xbt, 0); > + if (rv == -EAGAIN) > + goto again; > + if (rv) { > + xenbus_dev_fatal(dev, rv, "completing transaction"); > + return rv; > + } > + > + xenbus_switch_state(dev, XenbusStateInitialised); > + > + return 0; > + > + abort_transaction: > + xenbus_transaction_end(xbt, 1); > + if (message) > + xenbus_dev_error(dev, rv, "%s", message); > + > + return rv; > +} > + > +static void ring_free(struct tpm_private *priv) > +{ > + if (!priv) > + return; > + > + if (priv->ring_ref) > + gnttab_end_foreign_access(priv->ring_ref, 0, > + (unsigned long)priv->shr); > + else > + free_page((unsigned long)priv->shr); > + > + if (priv->chip && priv->chip->vendor.irq) > + unbind_from_irqhandler(priv->chip->vendor.irq, priv); > + > + kfree(priv); > +} > + > +static int tpmfront_probe(struct xenbus_device *dev, > + const struct xenbus_device_id *id) > +{ > + struct tpm_private *priv; > + int rv; > + > + priv = kzalloc(sizeof(*priv), GFP_KERNEL); > + if (!priv) { > + xenbus_dev_fatal(dev, -ENOMEM, "allocating priv structure"); > + return -ENOMEM; > + } > + > + rv = setup_chip(&dev->dev, priv); > + if (rv) { > + kfree(priv); > + return rv; > + } > + > + rv = setup_ring(dev, priv); > + if (rv) { > + tpm_remove_hardware(&dev->dev); > + ring_free(priv); > + return rv; > + } > + > + tpm_get_timeouts(priv->chip); > + > + dev_set_drvdata(&dev->dev, priv->chip); > + > + return rv; > +} > + > +static int tpmfront_remove(struct xenbus_device *dev) > +{ > + struct tpm_chip *chip = dev_get_drvdata(&dev->dev); > + struct tpm_private *priv = TPM_VPRIV(chip); > + tpm_remove_hardware(&dev->dev); > + ring_free(priv); > + TPM_VPRIV(chip) = NULL; > + return 0; > +} > + > +static int tpmfront_resume(struct xenbus_device *dev) > +{ > + /* A suspend/resume/migrate will interrupt a vTPM anyway */ > + tpmfront_remove(dev); > + return tpmfront_probe(dev, NULL); > +} > + > +static void backend_changed(struct xenbus_device *dev, > + enum xenbus_state backend_state) > +{ > + int val; > + > + switch (backend_state) { > + case XenbusStateInitialised: > + case XenbusStateConnected: > + if (xenbus_scanf(XBT_NIL, dev->otherend, > + "feature-protocol-v2", "%d", &val) < 0) > + val = 0; > + if (!val) { > + xenbus_dev_fatal(dev, -EINVAL, > + "vTPM protocol 2 required"); > + return; > + } > + xenbus_switch_state(dev, XenbusStateConnected); > + break; > + > + case XenbusStateClosing: > + case XenbusStateClosed: > + device_unregister(&dev->dev); > + xenbus_frontend_closed(dev); > + break; > + default: > + break; > + } > +} > + > +static const struct xenbus_device_id tpmfront_ids[] = { > + { "vtpm" }, > + { "" } > +}; > +MODULE_ALIAS("xen:vtpm"); > + > +static DEFINE_XENBUS_DRIVER(tpmfront, , > + .probe = tpmfront_probe, > + .remove = tpmfront_remove, > + .resume = tpmfront_resume, > + .otherend_changed = backend_changed, > + ); > + > +static int __init xen_tpmfront_init(void) > +{ > + if (!xen_domain()) > + return -ENODEV; > + > + return xenbus_register_frontend(&tpmfront_driver); > +} > +module_init(xen_tpmfront_init); > + > +static void __exit xen_tpmfront_exit(void) > +{ > + xenbus_unregister_driver(&tpmfront_driver); > +} > +module_exit(xen_tpmfront_exit); > + > +MODULE_AUTHOR("Daniel De Graaf <dgdegra@xxxxxxxxxxxxx>"); > +MODULE_DESCRIPTION("Xen vTPM Driver"); > +MODULE_LICENSE("GPL"); > diff --git a/include/xen/interface/io/tpmif.h > b/include/xen/interface/io/tpmif.h > new file mode 100644 > index 0000000..92522a4 > --- /dev/null > +++ b/include/xen/interface/io/tpmif.h > @@ -0,0 +1,50 @@ > +/****************************************************************************** > + * tpmif.h > + * > + * TPM I/O interface for Xen guest OSes, v2 > + * > + * Permission is hereby granted, free of charge, to any person obtaining a > copy > + * of this software and associated documentation files (the "Software"), to > + * deal in the Software without restriction, including without limitation the > + * rights to use, copy, modify, merge, publish, distribute, sublicense, > and/or > + * sell copies of the Software, and to permit persons to whom the Software is > + * furnished to do so, subject to the following conditions: > + * > + * The above copyright notice and this permission notice shall be included in > + * all copies or substantial portions of the Software. > + * > + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR > + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, > + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL > THE > + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER > + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING > + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER > + * DEALINGS IN THE SOFTWARE. > + * > + */ > + > +#ifndef __XEN_PUBLIC_IO_TPMIF_H__ > +#define __XEN_PUBLIC_IO_TPMIF_H__ > + > +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[0]; /* grant IDs; length in nr_extra_pages */ > +}; > + > +#endif > -- > 1.8.1.4 > _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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