Re: [Qemu-devel] [PATCH 1/3] Add TPM 1.2 host device passthrough interface

[Anthony Liguori <anthony@codemonkey.ws>]

On 08/25/2010 11:33 AM, Andreas Niederl wrote:
> This implementation is based on the TPM 1.2 interface for virtualized TPM
> devices from the Xen-4.0.0 ioemu-qemu-xen fork.
>
> A separate thread is used for I/O to the host TPM device because the Linux TPM
> driver does not allow for non-blocking I/O.
>
> Signed-off-by: Andreas Niederl<andreas.niederl@iaik.tugraz.at>
>    

Interesting.  A few high level comments.

You need to make the device qdev-aware and VMState aware.

It would be better to use the generic thread pool series floating around 
on the list than to introduce a device specific thread.

The command line interface should separate our the host passthrough from 
a future vTPM interface.  IOW, something like a -tpm 
host,path=/dev/tpm0,id=vtpm0 -device tpm,driver=vtpm0

Regards,

Anthony Liguori

> ---
>   Makefile.target |    3 +
>   configure       |    9 +
>   hw/pc_piix.c    |    8 +
>   hw/tpm_tis.c    |  831 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>   4 files changed, 851 insertions(+), 0 deletions(-)
>   create mode 100644 hw/tpm_tis.c
>
> diff --git a/Makefile.target b/Makefile.target
> index c8281e9..2226c75 100644
> --- a/Makefile.target
> +++ b/Makefile.target
> @@ -193,6 +193,9 @@ obj-y += e1000.o
>   # Inter-VM PCI shared memory
>   obj-$(CONFIG_KVM) += ivshmem.o
>
> +# TPM passthrough device
> +obj-$(CONFIG_TPM) += tpm_tis.o qemu-thread.o
> +
>   # Hardware support
>   obj-i386-y += vga.o
>   obj-i386-y += mc146818rtc.o i8259.o pc.o
> diff --git a/configure b/configure
> index a20371c..e1b55a8 100755
> --- a/configure
> +++ b/configure
> @@ -315,6 +315,7 @@ pkgversion=""
>   check_utests="no"
>   user_pie="no"
>   zero_malloc=""
> +tpm="no"
>
>   # OS specific
>   if check_define __linux__ ; then
> @@ -448,6 +449,7 @@ AIX)
>     usb="linux"
>     if [ "$cpu" = "i386" -o "$cpu" = "x86_64" ] ; then
>       audio_possible_drivers="$audio_possible_drivers fmod"
> +    tpm="yes"
>     fi
>   ;;
>   esac
> @@ -707,6 +709,8 @@ for opt do
>     ;;
>     --enable-vhost-net) vhost_net="yes"
>     ;;
> +  --disable-tpm) tpm="no"
> +  ;;
>     --*dir)
>     ;;
>     *) echo "ERROR: unknown option $opt"; show_help="yes"
> @@ -895,6 +899,7 @@ echo "  --enable-docs            enable documentation build"
>   echo "  --disable-docs           disable documentation build"
>   echo "  --disable-vhost-net      disable vhost-net acceleration support"
>   echo "  --enable-vhost-net       enable vhost-net acceleration support"
> +echo "  --disable-tpm            disable tpm passthrough device emulation"
>   echo ""
>   echo "NOTE: The object files are built at the place where configure is launched"
>   exit 1
> @@ -2187,6 +2192,7 @@ echo "preadv support    $preadv"
>   echo "fdatasync         $fdatasync"
>   echo "uuid support      $uuid"
>   echo "vhost-net support $vhost_net"
> +echo "tpm support       $tpm"
>
>   if test $sdl_too_old = "yes"; then
>   echo "->  Your SDL version is too old - please upgrade to have SDL support"
> @@ -2423,6 +2429,9 @@ fi
>   if test "$fdatasync" = "yes" ; then
>     echo "CONFIG_FDATASYNC=y">>  $config_host_mak
>   fi
> +if test "$tpm" = "yes" ; then
> +  echo "CONFIG_TPM=y">>  $config_host_mak
> +fi
>
>   # XXX: suppress that
>   if [ "$bsd" = "yes" ] ; then
> diff --git a/hw/pc_piix.c b/hw/pc_piix.c
> index 32a1057..ebc3478 100644
> --- a/hw/pc_piix.c
> +++ b/hw/pc_piix.c
> @@ -38,6 +38,10 @@
>
>   #define MAX_IDE_BUS 2
>
> +#ifdef CONFIG_TPM
> +void tpm_tis_init(qemu_irq irq);
> +#endif
> +
>   static const int ide_iobase[MAX_IDE_BUS] = { 0x1f0, 0x170 };
>   static const int ide_iobase2[MAX_IDE_BUS] = { 0x3f6, 0x376 };
>   static const int ide_irq[MAX_IDE_BUS] = { 14, 15 };
> @@ -147,6 +151,10 @@ static void pc_init1(ram_addr_t ram_size,
>           }
>       }
>
> +#ifdef CONFIG_TPM
> +    tpm_tis_init(isa_reserve_irq(11));
> +#endif
> +
>       pc_audio_init(pci_enabled ? pci_bus : NULL, isa_irq);
>
>       pc_cmos_init(below_4g_mem_size, above_4g_mem_size, boot_device,
> diff --git a/hw/tpm_tis.c b/hw/tpm_tis.c
> new file mode 100644
> index 0000000..e109e1a
> --- /dev/null
> +++ b/hw/tpm_tis.c
> @@ -0,0 +1,831 @@
> +/*
> + * tpm_tis.c - QEMU emulator for a 1.2 TPM with TIS interface
> + *
> + * Copyright (C) 2006 IBM Corporation
> + * Copyright (C) 2010 IAIK, Graz University of Technology
> + *
> + * Author: Stefan Berger<stefanb@us.ibm.com>
> + *         David Safford<safford@us.ibm.com>
> + *
> + * Author: Andreas Niederl<andreas.niederl@iaik.tugraz.at>
> + * Pass through a TPM device rather than using the emulator
> + * Modified to use a separate thread for IO to/from TPM as the Linux TPM driver
> + * framework does not allow non-blocking IO
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License as
> + * published by the Free Software Foundation, version 2 of the
> + * License.
> + *
> + *
> + * Implementation of the TIS interface according to specs at
> + * https://www.trustedcomputinggroup.org/groups/pc_client/TCG_PCClientTPMSpecification_1-20_1-00_FINAL.pdf
> + *
> + */
> +
> +#include<sys/types.h>
> +#include<sys/stat.h>
> +#include<errno.h>
> +#include<string.h>
> +
> +#include "qemu-option.h"
> +#include "qemu-config.h"
> +#include "hw/hw.h"
> +#include "hw/pc.h"
> +#include "hw/pci.h"
> +#include "hw/pci_ids.h"
> +#include "qemu-thread.h"
> +
> +//#define TPM_DEBUG
> +
> +#define TPM_MAX_PKT            4096
> +
> +#define TIS_ADDR_BASE                 0xFED40000
> +
> +/* tis registers */
> +#define TPM_REG_ACCESS                0x00
> +#define TPM_REG_INT_ENABLE            0x08
> +#define TPM_REG_INT_VECTOR            0x0c
> +#define TPM_REG_INT_STATUS            0x10
> +#define TPM_REG_INTF_CAPABILITY       0x14
> +#define TPM_REG_STS                   0x18
> +#define TPM_REG_DATA_FIFO             0x24
> +#define TPM_REG_DID_VID               0xf00
> +#define TPM_REG_RID                   0xf04
> +
> +#define STS_VALID                    (1<<  7)
> +#define STS_COMMAND_READY            (1<<  6)
> +#define STS_TPM_GO                   (1<<  5)
> +#define STS_DATA_AVAILABLE           (1<<  4)
> +#define STS_EXPECT                   (1<<  3)
> +#define STS_RESPONSE_RETRY           (1<<  1)
> +
> +#define ACCESS_TPM_REG_VALID_STS     (1<<  7)
> +#define ACCESS_ACTIVE_LOCALITY       (1<<  5)
> +#define ACCESS_BEEN_SEIZED           (1<<  4)
> +#define ACCESS_SEIZE                 (1<<  3)
> +#define ACCESS_PENDING_REQUEST       (1<<  2)
> +#define ACCESS_REQUEST_USE           (1<<  1)
> +#define ACCESS_TPM_ESTABLISHMENT     (1<<  0)
> +
> +#define INT_ENABLED                  (1<<  31)
> +#define INT_DATA_AVAILABLE           (1<<  0)
> +#define INT_LOCALITY_CHANGED         (1<<  2)
> +#define INT_COMMAND_READY            (1<<  7)
> +
> +#define INTERRUPTS_SUPPORTED         (INT_LOCALITY_CHANGED | \
> +                                      INT_DATA_AVAILABLE   | \
> +                                      INT_COMMAND_READY)
> +#define CAPABILITIES_SUPPORTED       ((1<<  4) |            \
> +                                      INTERRUPTS_SUPPORTED)
> +
> +enum {
> +  STATE_IDLE = 0,
> +  STATE_READY,
> +  STATE_COMPLETION,
> +  STATE_EXECUTION,
> +  STATE_RECEPTION
> +};
> +
> +#define NUM_LOCALITIES   5
> +#define NO_LOCALITY      0xff
> +
> +#define IS_VALID_LOC(x) ((x)<  NUM_LOCALITIES)
> +
> +#define TPM_DID          0x0001
> +#define TPM_VID          0x0001
> +#define TPM_RID          0x0001
> +
> +
> +const char *tpm_device = NULL;
> +
> +/* locality data */
> +typedef struct TPMLocal {
> +    uint32_t state;
> +    uint8_t access;
> +    uint8_t sts;
> +    uint32_t inte;
> +    uint32_t ints;
> +} tpmLoc;
> +
> +/* overall state of the TPM interface; 's' marks as save upon suspension */
> +typedef struct TPMState {
> +    uint8_t    transmit;   /* boolean value */
> +                           /* set when tpm transmit in progress */
> +    uint8_t    aborting;   /* boolean value */
> +    uint32_t   offset;           /* s */
> +    uint8_t    buf[TPM_MAX_PKT]; /* s */
> +    int        tpmfd;            /* s */
> +
> +    /* path to host tpm device */
> +    const char *path;            /* s */
> +    uint32_t    path_len;        /* s */
> +
> +    QemuMutex  tpm_thread_lock;
> +    QemuMutex  tpm_thread_abort_lock;
> +    QemuCond   tpm_thread_cond_data_avail;
> +    QemuThread tpm_thread_id;
> +
> +    uint8_t active_loc;         /* s */
> +    uint8_t aborting_locty;
> +    uint8_t next_locty;
> +    uint8_t irq_pending;        /* s */
> +    tpmLoc loc[NUM_LOCALITIES]; /* s */
> +    qemu_irq_handler set_irq;
> +    void *irq_opaque;
> +    int irq;
> +} tpmState;
> +
> +
> +/* local prototypes */
> +static void tis_raise_irq(tpmState *s, uint8_t locty, uint32_t irqmask);
> +static void tis_abort(tpmState *s);
> +
> +#ifdef TPM_DEBUG
> +static void showBuff(unsigned char *buff, const char *string);
> +#endif
> +
> +
> +/**********************************************************************
> + helper functions
> + *********************************************************************/
> +
> +static inline uint32_t tpm_get_size_from_buffer(const uint8_t *buffer)
> +{
> +    uint32_t len = (buffer[4]<<  8) + buffer[5];
> +    return len;
> +}
> +
> +static inline uint8_t locality_from_addr(target_phys_addr_t addr)
> +{
> +    return (uint8_t)((addr>>  12)&  0x7);
> +}
> +
> +
> +static void die2(int err, const char *what)
> +{
> +    fprintf(stderr, "%s failed: %s\n", what, strerror(err));
> +    abort();
> +}
> +
> +static void die(const char *what)
> +{
> +    die2(errno, what);
> +}
> +
> +
> +/* borrowed from qemu-char.c */
> +static int unix_write(int fd, const uint8_t *buf, uint32_t len1)
> +{
> +    int ret, len;
> +
> +    len = len1;
> +    while (len>  0) {
> +        ret = write(fd, buf, len);
> +        if (ret<  0) {
> +            if (errno != EINTR&&  errno != EAGAIN)
> +                return -1;
> +        } else if (ret == 0) {
> +            break;
> +        } else {
> +            buf += ret;
> +            len -= ret;
> +        }
> +    }
> +    return len1 - len;
> +}
> +
> +static int unix_tpm_read(int fd, uint8_t *buf)
> +{
> +    int ret, len, len1;
> +    uint8_t *buf1;
> +
> +    buf1 = buf;
> +    len  = sizeof(buf) + TPM_MAX_PKT;
> +    while ((buf1 - buf)<  6) {
> +        ret = read(fd, buf1, len);
> +        if (ret<  0) {
> +            if (errno != EINTR&&  errno != EAGAIN)
> +                return -1;
> +        } else {
> +            buf1 += ret;
> +        }
> +    }
> +
> +    len1 = tpm_get_size_from_buffer(buf);
> +    if (len1>  TPM_MAX_PKT) {
> +        fprintf(stderr, "Error: received invalid tpm response size: %d\n",
> +                len1);
> +        return -1;
> +    }
> +
> +    /* response size minus already read data */
> +    len  = len1 - (buf1 - buf);
> +    while (len>  0) {
> +        ret = read(fd, buf, len);
> +        if (ret<  0) {
> +            if (errno != EINTR&&  errno != EAGAIN)
> +                return -1;
> +        } else if (ret == 0) {
> +            break;
> +        } else {
> +            buf += ret;
> +            len -= ret;
> +        }
> +    }
> +    return len1 - len;
> +}
> +
> +/****************************************************************************/
> +/* Transmit request to TPM and read Response                                */
> +/****************************************************************************/
> +
> +static void *tpm_thread(void *opaque)
> +{
> +    tpmState *s = opaque;
> +    sigset_t  set;
> +    uint32_t  size = 0;
> +    /* hardcode locality 0 */
> +    uint8_t   locty = 0;
> +#ifdef TPM_DEBUG
> +    uint32_t  ret;
> +#endif
> +
> +    /* block all signals */
> +    if (sigfillset(&set)) die("sigfillset");
> +    if (sigprocmask(SIG_BLOCK,&set, NULL)) die("sigprocmask");
> +
> +    qemu_mutex_lock(&s->tpm_thread_lock);
> +    while(1) {
> +        if(!s->transmit)
> +            qemu_cond_wait(&s->tpm_thread_cond_data_avail,&s->tpm_thread_lock);
> +        qemu_mutex_unlock(&s->tpm_thread_lock);
> +
> +#ifdef TPM_DEBUG
> +        showBuff(s->buf, "To TPM");
> +#endif
> +        size = tpm_get_size_from_buffer(s->buf);
> +
> +        if(unix_write(s->tpmfd, s->buf, size)<  0) {
> +            fprintf(stderr, "Error: while transmitting data to host tpm"
> +                    ": %s (%i)\n",
> +                    strerror(errno), errno);
> +            tis_abort(s);
> +            qemu_mutex_lock(&s->tpm_thread_lock);
> +            continue;
> +        }
> +
> +        if(unix_tpm_read(s->tpmfd, s->buf)<  0) {
> +            fprintf(stderr, "Error: while reading data from host tpm"
> +                    ": %s (%i)\n",
> +                    strerror(errno), errno);
> +            tis_abort(s);
> +            qemu_mutex_lock(&s->tpm_thread_lock);
> +            continue;
> +        }
> +
> +        qemu_mutex_lock(&s->tpm_thread_abort_lock);
> +        if(!s->aborting) {
> +#ifdef TPM_DEBUG
> +            showBuff(s->buf, "From TPM");
> +
> +            ret = (s->buf[8])*256 + s->buf[9];
> +            if (ret)
> +                printf("tpm command failed with error %d\n", ret);
> +            else
> +                printf("tpm command succeeded\n");
> +#endif
> +
> +            qemu_mutex_lock(&s->tpm_thread_lock);
> +            s->loc[locty].sts = STS_VALID | STS_DATA_AVAILABLE;
> +            s->loc[locty].state = STATE_COMPLETION;
> +            s->transmit = 0;
> +            tis_raise_irq(s, locty, INT_DATA_AVAILABLE);
> +        } else {
> +            qemu_mutex_lock(&s->tpm_thread_lock);
> +            tis_abort(s);
> +#ifdef TPM_DEBUG
> +            printf("Abort is complete.\n");
> +#endif
> +            s->transmit  = 0;
> +        }
> +        qemu_mutex_unlock(&s->tpm_thread_abort_lock);
> +    }
> +
> +    return NULL;
> +}
> +
> +
> +/**********************************************************************/
> +
> +/*
> + * read a byte of response data
> + */
> +static uint32_t tpm_data_read(tpmState *s, uint8_t locty)
> +{
> +    uint32_t ret, len;
> +
> +    if (s->loc[locty].state != STATE_COMPLETION) {
> +#ifdef TPM_DEBUG
> +        printf("tpm_data_read with no data available!\n");
> +#endif
> +        return 0xff;
> +    }
> +
> +    len = tpm_get_size_from_buffer(s->buf);
> +    ret = s->buf[s->offset++];
> +    if (s->offset>= len) {
> +        s->loc[locty].sts = STS_VALID ;
> +        s->offset = 0;
> +    }
> +#ifdef TPM_DEBUG
> +    printf("tpm_data_read byte x%02x   [%d]\n",ret,s->offset-1);
> +#endif
> +    return ret;
> +}
> +
> +/* raise an interrupt if allowed */
> +static void tis_raise_irq(tpmState *s, uint8_t locty, uint32_t irqmask)
> +{
> +    if (!s->irq_pending&&
> +        (s->loc[locty].inte&  INT_ENABLED)&&
> +        (s->loc[locty].inte&  irqmask)) {
> +        if ((irqmask&  s->loc[locty].ints) == 0) {
> +#ifdef TPM_DEBUG
> +            printf("Raising IRQ for flag %08x\n",irqmask);
> +#endif
> +            s->set_irq(s->irq_opaque, s->irq, 1);
> +            s->irq_pending = 1;
> +            s->loc[locty].ints |= irqmask;
> +        }
> +    }
> +}
> +
> +/* abort execution of command */
> +static void tis_abort(tpmState *s)
> +{
> +    s->offset = 0;
> +    s->active_loc = s->next_locty;
> +    qemu_mutex_lock(&s->tpm_thread_lock);
> +    s->transmit  = 0;
> +    qemu_mutex_unlock(&s->tpm_thread_lock);
> +
> +    /*
> +     * Need to react differently depending on who's aborting now and
> +     * which locality will become active afterwards.
> +     */
> +    if (s->aborting_locty == s->next_locty) {
> +        s->loc[s->aborting_locty].state = STATE_READY;
> +        s->loc[s->aborting_locty].sts   = STS_COMMAND_READY;
> +        tis_raise_irq(s, s->aborting_locty, INT_COMMAND_READY);
> +    }
> +
> +    /* locality after abort is another one than the current one */
> +    if (s->aborting_locty != s->next_locty&&  s->next_locty != NO_LOCALITY) {
> +        s->loc[s->aborting_locty].access&= ~ACCESS_ACTIVE_LOCALITY;
> +        s->loc[s->next_locty].access     |=  ACCESS_ACTIVE_LOCALITY;
> +        tis_raise_irq(s, s->next_locty, INT_LOCALITY_CHANGED);
> +    }
> +
> +    s->aborting_locty = NO_LOCALITY; /* nobody's aborting a command anymore */
> +}
> +
> +/* abort current command */
> +static void tis_prep_abort(tpmState *s, uint8_t locty, uint8_t newlocty)
> +{
> +    s->aborting_locty = locty; /* current locality */
> +    s->next_locty = newlocty;  /* locality after successful abort */
> +
> +    s->next_locty = 0;  /* only locality 0 available */
> +
> +    /*
> +     * only abort a command using an interrupt if currently executing
> +     * a command AND if there's a valid connection to the vTPM.
> +     */
> +    if (s->loc[locty].state == STATE_EXECUTION) {
> +        qemu_mutex_lock(&s->tpm_thread_abort_lock);
> +        s->aborting = 1;
> +        qemu_mutex_unlock(&s->tpm_thread_abort_lock);
> +    } else {
> +        tis_abort(s);
> +    }
> +}
> +
> +
> +/*
> + * Read a register of the TIS interface
> + * See specs pages 33-63 for description of the registers
> + */
> +static uint32_t tis_mem_readl(void *opaque, target_phys_addr_t addr)
> +{
> +    tpmState *s = (tpmState *)opaque;
> +    uint16_t offset = addr&  0xffc;
> +    uint8_t shift = (addr&  0x3) * 8;
> +    uint32_t val = 0;
> +    uint8_t locty = locality_from_addr(addr);
> +
> +    if (offset == TPM_REG_ACCESS) {
> +        if (locty>  0) {
> +            /* no access to localities other than 0 possible */
> +            val = 0;
> +        } else {
> +            if (s->active_loc == locty) {
> +                s->loc[locty].access |= (1<<  5);
> +            } else {
> +                s->loc[locty].access&= ~(1<<  5);
> +            }
> +            val = s->loc[locty].access;
> +        }
> +    } else
> +    if (locty>  0) {
> +        /* higher localities deactivated */
> +        val = 0xffff;
> +    } else
> +    if (offset == TPM_REG_INT_ENABLE) {
> +        val = s->loc[locty].inte;
> +    } else
> +    if (offset == TPM_REG_INT_VECTOR) {
> +        val = s->irq;
> +    } else
> +    if (offset == TPM_REG_INT_STATUS) {
> +        val = s->loc[locty].ints;
> +    } else
> +    if (offset == TPM_REG_INTF_CAPABILITY) {
> +        val = CAPABILITIES_SUPPORTED;
> +    } else
> +    if (offset == TPM_REG_STS) { /* status register */
> +        /* ??? - appears to be just some value as we aren't a hardware TPM */
> +        val = (sizeof(s->buf) - s->offset)<<  8 | s->loc[locty].sts;
> +    } else
> +    if (offset == TPM_REG_DATA_FIFO) {
> +      val = tpm_data_read(s, locty);
> +    } else
> +    if (offset == TPM_REG_DID_VID) {
> +        val = (TPM_DID<<  16) | TPM_VID;
> +    } else
> +    if (offset == TPM_REG_RID) {
> +         val = TPM_RID;
> +    }
> +
> +    if (shift&&  locty == 0) {
> +        val>>= shift;
> +    }
> +
> +#ifdef TPM_DEBUG
> +    printf(" read(%08x) = %08x\n",
> +           (int)addr,
> +           val);
> +#endif
> +
> +    return val;
> +}
> +
> +/*
> + * Write a value to a register of the TIS interface
> + * See specs pages 33-63 for description of the registers
> + */
> +static void tis_mem_writel(void *opaque, target_phys_addr_t addr, uint32_t val)
> +{
> +    tpmState* s=(tpmState*)opaque;
> +    uint16_t off = addr&  0xfff;
> +    uint8_t locty = locality_from_addr(addr);
> +    uint32_t len;
> +
> +#ifdef TPM_DEBUG
> +    printf("write(%08x) = %08x\n",
> +           (int)addr,
> +           val);
> +#endif
> +
> +    /* linux tpm_tis driver only uses locality 0 */
> +    if (locty>  0) {
> +        fprintf(stderr, "Warning: Write to unavailable locality: %d \n", locty);
> +        return;
> +    }
> +#ifdef TPM_DEBUG
> +    if(s->transmit) {
> +        fprintf(stderr, "Warning: tpm received data while transmit"
> +                " in progress.\n");
> +        printf("WARN: write(%08x) = %08x\n",
> +                (int)addr,
> +                val);
> +    }
> +#endif
> +
> +    if (off == TPM_REG_ACCESS) {
> +        if (val&  ACCESS_ACTIVE_LOCALITY) {
> +            /* give up locality if currently owned */
> +            if (s->active_loc == locty) {
> +                /*uint8_t newlocty = NO_LOCALITY;*/
> +                s->loc[locty].access&= ~(ACCESS_PENDING_REQUEST);
> +                /* anybody wants the locality ? */
> +                if (s->loc[locty].access&  ACCESS_REQUEST_USE) {
> +                    s->loc[locty].access |= ACCESS_TPM_REG_VALID_STS;
> +                    s->loc[locty].access&= ~ACCESS_REQUEST_USE;
> +                }
> +                tis_prep_abort(s, locty, locty);
> +            }
> +        }
> +        if (val&  ACCESS_BEEN_SEIZED) {
> +            /* clear the flag */
> +            s->loc[locty].access&= ~ACCESS_BEEN_SEIZED;
> +        }
> +        if (val&  ACCESS_SEIZE) {
> +            if (locty>  s->active_loc&&  IS_VALID_LOC(s->active_loc)) {
> +                s->loc[s->active_loc].access |= ACCESS_BEEN_SEIZED;
> +                s->loc[locty].access = ACCESS_TPM_REG_VALID_STS;
> +                tis_prep_abort(s, s->active_loc, locty);
> +            }
> +        }
> +        if (val&  ACCESS_REQUEST_USE) {
> +            if (IS_VALID_LOC(s->active_loc)) {
> +                /* locality election */
> +                s->loc[s->active_loc].access |= ACCESS_PENDING_REQUEST;
> +            } else {
> +                /* no locality active ->  make this one active now */
> +                s->loc[locty].access |= ACCESS_ACTIVE_LOCALITY;
> +                s->active_loc = locty;
> +                tis_raise_irq(s, locty, INT_LOCALITY_CHANGED);
> +            }
> +        }
> +    } else
> +    if (off == TPM_REG_INT_ENABLE) {
> +        s->loc[locty].inte = (val&  (INT_ENABLED | (0x3<<  3) |
> +                                     INTERRUPTS_SUPPORTED));
> +    } else
> +    if (off == TPM_REG_INT_STATUS) {
> +        /* clearing of interrupt flags */
> +        if ((val&  INTERRUPTS_SUPPORTED)&&
> +            (s->loc[locty].ints&  INTERRUPTS_SUPPORTED)) {
> +            s->set_irq(s->irq_opaque, s->irq, 0);
> +            s->irq_pending = 0;
> +        }
> +        s->loc[locty].ints&= ~(val&  INTERRUPTS_SUPPORTED);
> +    } else
> +    if (off == TPM_REG_STS) {
> +        if (val&  STS_COMMAND_READY) {
> +            if (s->loc[locty].state == STATE_IDLE) {
> +                s->loc[locty].sts   = STS_COMMAND_READY;
> +                s->loc[locty].state = STATE_READY;
> +                tis_raise_irq(s, locty, INT_COMMAND_READY);
> +            } else if (s->loc[locty].state == STATE_COMPLETION ||
> +                       s->loc[locty].state == STATE_EXECUTION  ||
> +                       s->loc[locty].state == STATE_RECEPTION) {
> +                /* abort currently running command */
> +                tis_prep_abort(s, locty, locty);
> +            }
> +        }
> +        if (val&  STS_TPM_GO) {
> +            s->offset   = 0;
> +
> +            if (s->transmit != 1) {
> +                qemu_mutex_lock(&s->tpm_thread_lock);
> +                s->transmit = 1;
> +                s->loc[locty].state = STATE_EXECUTION;
> +                qemu_mutex_unlock(&s->tpm_thread_lock);
> +                qemu_cond_signal(&s->tpm_thread_cond_data_avail);
> +            }
> +        }
> +        if (val&  STS_RESPONSE_RETRY) {
> +            s->offset = 0;
> +        }
> +    } else if (off == TPM_REG_DATA_FIFO) {
> +        /* data fifo */
> +        if (s->loc[locty].state == STATE_IDLE ||
> +            s->loc[locty].state == STATE_EXECUTION ||
> +            s->loc[locty].state == STATE_COMPLETION) {
> +            /* drop the byte */
> +        } else {
> +#ifdef TPM_DEBUG
> +        printf("Byte to send to TPM: %02x at offset: %03d\n", val, s->offset);
> +#endif
> +            s->loc[locty].state = STATE_RECEPTION;
> +            s->loc[locty].sts   = STS_EXPECT | STS_VALID;
> +
> +            if (s->offset<  TPM_MAX_PKT)
> +                s->buf[s->offset++] = (uint8_t)val;
> +
> +            if (s->offset>  5) {
> +                /* we have a packet length - see if we have all of it */
> +                len = tpm_get_size_from_buffer(s->buf);
> +                if (s->offset>= len) {
> +#ifdef TPM_DEBUG
> +                    printf("We have a complete packet of %u bytes\n", len);
> +#endif
> +                    s->offset   = 0;
> +
> +                    qemu_mutex_lock(&s->tpm_thread_lock);
> +                    s->transmit = 1;
> +                    qemu_mutex_unlock(&s->tpm_thread_lock);
> +                    qemu_cond_signal(&s->tpm_thread_cond_data_avail);
> +                    s->loc[locty].sts = STS_VALID;
> +                }
> +            }
> +        }
> +    }
> +}
> +
> +
> +static CPUReadMemoryFunc *tis_readfn[3]={
> +    tis_mem_readl,
> +    tis_mem_readl,
> +    tis_mem_readl
> +};
> +
> +static CPUWriteMemoryFunc *tis_writefn[3]={
> +    tis_mem_writel,
> +    tis_mem_writel,
> +    tis_mem_writel
> +};
> +
> +/*
> + * Save the internal state of this interface for later resumption.
> + * Need to get any outstanding responses from the vTPM back, so
> + * this might delay the suspend for a while.
> + */
> +static void tpm_save(QEMUFile* f,void* opaque)
> +{
> +    tpmState* s=(tpmState*)opaque;
> +    uint8_t locty = s->active_loc;
> +    int c;
> +
> +    /* need to wait for outstanding requests to complete */
> +    if (s->loc[locty].state == STATE_EXECUTION) {
> +        int repeats = 30; /* 30 seconds; really should be infty */
> +        while (repeats>  0&&
> +               !(s->loc[s->active_loc].sts&  STS_DATA_AVAILABLE)) {
> +            sleep(1);
> +        }
> +    }
> +
> +    close(s->tpmfd);
> +
> +    qemu_put_be32s(f,&s->offset);
> +    qemu_put_buffer(f, s->buf, TPM_MAX_PKT);
> +    qemu_put_8s(f,&s->active_loc);
> +    qemu_put_8s(f,&s->irq_pending);
> +    for (c = 0; c<  NUM_LOCALITIES; c++) {
> +        qemu_put_be32s(f,&s->loc[c].state);
> +        qemu_put_8s(f,&s->loc[c].access);
> +        qemu_put_8s(f,&s->loc[c].sts);
> +        qemu_put_be32s(f,&s->loc[c].inte);
> +        qemu_put_be32s(f,&s->loc[c].ints);
> +    }
> +    qemu_put_buffer(f,  (uint8_t*) s->path, s->path_len);
> +    qemu_put_be32s(f,&s->path_len);
> +}
> +
> +
> +/*
> + * load TIS interface state
> + */
> +static int tpm_load(QEMUFile* f,void* opaque,int version_id)
> +{
> +    tpmState* s=(tpmState*)opaque;
> +    int c;
> +
> +    if (version_id != 1)
> +        return -EINVAL;
> +
> +    qemu_get_be32s(f,&s->offset);
> +    qemu_get_buffer(f, s->buf, TPM_MAX_PKT);
> +    qemu_get_8s(f,&s->active_loc);
> +    qemu_get_8s(f,&s->irq_pending);
> +    for (c = 0; c<  NUM_LOCALITIES; c++) {
> +        qemu_get_be32s(f,&s->loc[c].state);
> +        qemu_get_8s(f,&s->loc[c].access);
> +        qemu_get_8s(f,&s->loc[c].sts);
> +        qemu_get_be32s(f,&s->loc[c].inte);
> +        qemu_get_be32s(f,&s->loc[c].ints);
> +    }
> +    qemu_get_be32s(f,&s->path_len);
> +    qemu_get_buffer(f,  (uint8_t*) s->path, s->path_len);
> +
> +    s->tpmfd = open(s->path, O_RDWR);
> +
> +    if(s->tpmfd<  0)
> +        hw_error("Cannot open %s: %s (%i)\n", s->path, strerror(errno), errno);
> +
> +    qemu_mutex_init(&s->tpm_thread_lock);
> +    qemu_cond_init(&s->tpm_thread_cond_data_avail);
> +    qemu_mutex_init(&s->tpm_thread_abort_lock);
> +
> +    qemu_thread_create(&s->tpm_thread_id,&tpm_thread, s);
> +
> +    return 0;
> +}
> +
> +
> +typedef struct LPCtpmState {
> +    tpmState tpm;
> +    int mem;
> +} LPCtpmState;
> +
> +
> +/*
> + * initialize TIS interface
> + */
> +
> +struct IRQState {
> +    qemu_irq_handler handler;
> +    void *opaque;
> +    int n;
> +};
> +
> +void tpm_tis_init(qemu_irq irq);
> +
> +void tpm_tis_init(qemu_irq irq)
> +{
> +    LPCtpmState *d;
> +    tpmState *s;
> +    int c = 0;
> +    int tpmfd = -1;
> +
> +    if(tpm_device == NULL) {
> +        return;
> +    }
> +
> +    tpmfd = open(tpm_device, O_RDWR);
> +    if(tpmfd<  0) {
> +        fprintf(stderr, "Cannot open %s: %s (%i)\n", tpm_device,
> +                strerror(errno), errno);
> +        return;
> +    }
> +
> +    d = qemu_mallocz(sizeof(LPCtpmState));
> +    d->mem = cpu_register_io_memory(tis_readfn, tis_writefn, d);
> +
> +    if (d->mem == -1) {
> +        fprintf(stderr, "Failed to register IO memory TPM TIS\n");
> +        return;
> +    }
> +
> +    cpu_register_physical_memory(TIS_ADDR_BASE,
> +                                 0x1000 * NUM_LOCALITIES, d->mem);
> +
> +    /* initialize tpmState */
> +    s =&d->tpm;
> +
> +    s->offset     = 0;
> +    s->transmit   = 0;
> +    s->aborting   = 0;
> +    s->active_loc = NO_LOCALITY;
> +
> +    while (c<  NUM_LOCALITIES) {
> +        s->loc[c].access = (1<<  7);
> +        s->loc[c].sts = 0;
> +        s->loc[c].inte = (1<<  3);
> +        s->loc[c].ints = 0;
> +        s->loc[c].state = STATE_IDLE;
> +        c++;
> +    }
> +    s->set_irq    = irq->handler;
> +    s->irq_opaque = irq->opaque;
> +    s->irq        = irq->n;
> +    s->aborting_locty = NO_LOCALITY;
> +    s->tpmfd      = tpmfd;
> +    s->path_len   = strlen(tpm_device);
> +    s->path       = tpm_device;
> +
> +    memset(s->buf,0,sizeof(s->buf));
> +
> +    qemu_mutex_init(&s->tpm_thread_lock);
> +    qemu_cond_init(&s->tpm_thread_cond_data_avail);
> +    qemu_mutex_init(&s->tpm_thread_abort_lock);
> +
> +    qemu_thread_create(&s->tpm_thread_id,&tpm_thread, s);
> +
> +    register_savevm(NULL, "tpm-tis", 0, 1, tpm_save, tpm_load, s);
> +}
> +
> +
> +int tpm_init(QemuOpts *opts) {
> +    if(tpm_device == NULL) {
> +        tpm_device = qemu_opt_get(opts, "dev");
> +    }
> +    return 0;
> +}
> +
> +/****************************************************************************/
> +/*                                                                          */
> +/* optional verbose logging of data to/from tpm chip                        */
> +/*                                                                          */
> +/****************************************************************************/
> +#ifdef TPM_DEBUG
> +static void showBuff(unsigned char *buff, const char *string)
> +{
> +    uint32_t i, len;
> +
> +    len = tpm_get_size_from_buffer(buff);
> +    printf("%s length=%d\n", string, len);
> +    for (i = 0; i<  len; i++) {
> +        if (i&&  !(i % 16)) {
> +            printf("\n");
> +        }
> +        printf("%.2X ", buff[i]);
> +    }
> +    printf("\n");
> +}
> +#endif
> +
> +
>