From patchwork Wed Feb 27 17:47:53 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Berger X-Patchwork-Id: 223668 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id A7B0E2C0040 for ; Thu, 28 Feb 2013 04:52:48 +1100 (EST) Received: from localhost ([::1]:52569 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UAlBL-0000Bv-2G for incoming@patchwork.ozlabs.org; Wed, 27 Feb 2013 12:52:43 -0500 Received: from eggs.gnu.org ([208.118.235.92]:50244) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UAl7Z-00043R-H0 for qemu-devel@nongnu.org; Wed, 27 Feb 2013 12:48:59 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UAl7K-0002SK-1v for qemu-devel@nongnu.org; Wed, 27 Feb 2013 12:48:44 -0500 Received: from e7.ny.us.ibm.com ([32.97.182.137]:51920) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UAl7J-0002QT-Ou for qemu-devel@nongnu.org; Wed, 27 Feb 2013 12:48:33 -0500 Received: from /spool/local by e7.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Wed, 27 Feb 2013 12:48:18 -0500 Received: from d01relay06.pok.ibm.com (d01relay06.pok.ibm.com [9.56.227.116]) by d01dlp03.pok.ibm.com (Postfix) with ESMTP id B3447C9003E for ; Wed, 27 Feb 2013 12:48:17 -0500 (EST) Received: from d01av03.pok.ibm.com (d01av03.pok.ibm.com [9.56.224.217]) by d01relay06.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r1RHmH6j26411204 for ; Wed, 27 Feb 2013 12:48:17 -0500 Received: from d01av03.pok.ibm.com (loopback [127.0.0.1]) by d01av03.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r1RHmDE5003218 for ; Wed, 27 Feb 2013 14:48:14 -0300 Received: from k-d941f-5.watson.ibm.com (k-d941f-5.watson.ibm.com [9.2.141.165]) by d01av03.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id r1RHmDOI003195 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 27 Feb 2013 14:48:13 -0300 Received: from k-d941f-5.watson.ibm.com (localhost.localdomain [127.0.0.1]) by k-d941f-5.watson.ibm.com (8.14.5/8.14.3) with ESMTP id r1RHmB9R026378; Wed, 27 Feb 2013 12:48:12 -0500 Received: (from root@localhost) by k-d941f-5.watson.ibm.com (8.14.5/8.14.5/Submit) id r1RHmBdd026377; Wed, 27 Feb 2013 12:48:11 -0500 From: Stefan Berger To: stefanb@linux.vnet.ibm.com, qemu-devel@nongnu.org, anthony@codemonkey.ws Date: Wed, 27 Feb 2013 12:47:53 -0500 Message-Id: <1361987275-26289-6-git-send-email-stefanb@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.11.7 In-Reply-To: <1361987275-26289-1-git-send-email-stefanb@linux.vnet.ibm.com> References: <1361987275-26289-1-git-send-email-stefanb@linux.vnet.ibm.com> X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13022717-5806-0000-0000-00002020335E X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.4.x-2.6.x [generic] X-Received-From: 32.97.182.137 Cc: andreas.niederl@iaik.tugraz.at, mst@redhat.com Subject: [Qemu-devel] [PATCH V27 5/7] Add a TPM Passthrough backend driver implementation X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From Andreas Niederl's original posting with adaptations where necessary: This patch is based of off version 9 of Stefan Berger's patch series "QEMU Trusted Platform Module (TPM) integration" and adds a new backend driver for it. This patch adds a passthrough backend driver for passing commands sent to the emulated TPM device directly to a TPM device opened on the host machine. Thus it is possible to use a hardware TPM device in a system running on QEMU, providing the ability to access a TPM in a special state (e.g. after a Trusted Boot). This functionality is being used in the acTvSM Trusted Virtualization Platform which is available on [1]. Usage example: qemu-system-x86_64 -tpmdev passthrough,id=tpm0,path=/dev/tpm0 \ -device tpm-tis,tpmdev=tpm0 \ -cdrom test.iso -boot d Some notes about the host TPM: The TPM needs to be enabled and activated. If that's not the case one has to go through the BIOS/UEFI and enable and activate that TPM for TPM commands to work as expected. It may be necessary to boot the kernel using tpm_tis.force=1 in the boot command line or 'modprobe tpm_tis force=1' in case of using it as a module. Regards, Andreas Niederl, Stefan Berger [1] http://trustedjava.sourceforge.net/ Signed-off-by: Andreas Niederl Signed-off-by: Stefan Berger Reviewed-by: Corey Bryant --- include/qemu/sockets.h | 1 + qemu-char.c | 24 +++ qemu-options.hx | 36 ++++- tpm/Makefile.objs | 2 + tpm/tpm.c | 14 ++ tpm/tpm_backend.c | 58 ++++++++ tpm/tpm_backend.h | 45 ++++++ tpm/tpm_int.h | 33 +++++ tpm/tpm_passthrough.c | 387 +++++++++++++++++++++++++++++++++++++++++++++++++ 9 files changed, 599 insertions(+), 1 deletion(-) create mode 100644 tpm/tpm_backend.c create mode 100644 tpm/tpm_backend.h create mode 100644 tpm/tpm_passthrough.c diff --git a/include/qemu/sockets.h b/include/qemu/sockets.h index 803ae17..16569e2 100644 --- a/include/qemu/sockets.h +++ b/include/qemu/sockets.h @@ -37,6 +37,7 @@ int socket_set_cork(int fd, int v); void socket_set_block(int fd); void socket_set_nonblock(int fd); int send_all(int fd, const void *buf, int len1); +int recv_all(int fd, void *buf, int len1, bool single_read); /* callback function for nonblocking connect * valid fd on success, negative error code on failure diff --git a/qemu-char.c b/qemu-char.c index 160decc..a8de655 100644 --- a/qemu-char.c +++ b/qemu-char.c @@ -537,6 +537,30 @@ int send_all(int fd, const void *_buf, int len1) } return len1 - len; } + +int recv_all(int fd, void *_buf, int len1, bool single_read) +{ + int ret, len; + uint8_t *buf = _buf; + + len = len1; + while ((len > 0) && (ret = read(fd, buf, len)) != 0) { + if (ret < 0) { + if (errno != EINTR && errno != EAGAIN) { + return -1; + } + continue; + } else { + if (single_read) { + return ret; + } + buf += ret; + len -= ret; + } + } + return len1 - len; +} + #endif /* !_WIN32 */ #define STDIO_MAX_CLIENTS 1 diff --git a/qemu-options.hx b/qemu-options.hx index 3c31806..97723a7 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -2222,7 +2222,8 @@ DEFHEADING() DEFHEADING(TPM device options:) DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \ - "-tpmdev [],id=str[,option][,option][,...]\n", + "-tpmdev passthrough,id=id[,path=path]\n" + " use path to provide path to a character device; default is /dev/tpm0\n", QEMU_ARCH_ALL) STEXI @@ -2232,6 +2233,7 @@ The general form of a TPM device option is: @item -tpmdev @var{backend} ,id=@var{id} [,@var{options}] @findex -tpmdev Backend type must be: +@option{passthrough}. The specific backend type will determine the applicable options. The @code{-tpmdev} option requires a @code{-device} option. @@ -2243,6 +2245,38 @@ Use 'help' to print all available TPM backend types. qemu -tpmdev help @end example +@item -tpmdev passthrough, id=@var{id}, path=@var{path} + +(Linux-host only) Enable access to the host's TPM using the passthrough +driver. + +@option{path} specifies the path to the host's TPM device, i.e., on +a Linux host this would be @code{/dev/tpm0}. +@option{path} is optional and by default @code{/dev/tpm0} is used. + +Some notes about using the host's TPM with the passthrough driver: + +The TPM device accessed by the passthrough driver must not be +used by any other application on the host. + +Since the host's firmware (BIOS/UEFI) has already initialized the TPM, +the VM's firmware (BIOS/UEFI) will not be able to initialize the +TPM again and may therefore not show a TPM-specific menu that would +otherwise allow the user to configure the TPM, e.g., allow the user to +enable/disable or activate/deactivate the TPM. +Further, if TPM ownership is released from within a VM then the host's TPM +will get disabled and deactivated. To enable and activate the +TPM again afterwards, the host has to be rebooted and the user is +required to enter the firmware's menu to enable and activate the TPM. +If the TPM is left disabled and/or deactivated most TPM commands will fail. + +To create a passthrough TPM use the following two options: +@example +-tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0 +@end example +Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by +@code{tpmdev=tpm0} in the device option. + @end table ETEXI diff --git a/tpm/Makefile.objs b/tpm/Makefile.objs index 94ad2e7..8676824 100644 --- a/tpm/Makefile.objs +++ b/tpm/Makefile.objs @@ -1,4 +1,6 @@ common-obj-y = tpm.o ifeq ($(CONFIG_TPM),y) +common-obj-y += tpm_backend.o common-obj-$(CONFIG_TPM_TIS) += tpm_tis.o +common-obj-$(CONFIG_TPM_PASSTHROUGH) += tpm_passthrough.o endif diff --git a/tpm/tpm.c b/tpm/tpm.c index 0273549..ffd2495 100644 --- a/tpm/tpm.c +++ b/tpm/tpm.c @@ -61,6 +61,20 @@ static bool tpm_model_is_registered(enum TpmModel model) return false; } +/* + * Write an error message in the given output buffer. + */ +void tpm_write_fatal_error_response(uint8_t *out, uint32_t out_len) +{ + if (out_len >= sizeof(struct tpm_resp_hdr)) { + struct tpm_resp_hdr *resp = (struct tpm_resp_hdr *)out; + + resp->tag = cpu_to_be16(TPM_TAG_RSP_COMMAND); + resp->len = cpu_to_be32(sizeof(struct tpm_resp_hdr)); + resp->errcode = cpu_to_be32(TPM_FAIL); + } +} + const TPMDriverOps *tpm_get_backend_driver(const char *type) { int i; diff --git a/tpm/tpm_backend.c b/tpm/tpm_backend.c new file mode 100644 index 0000000..4144ef7 --- /dev/null +++ b/tpm/tpm_backend.c @@ -0,0 +1,58 @@ +/* + * common TPM backend driver functions + * + * Copyright (c) 2012-2013 IBM Corporation + * Authors: + * Stefan Berger + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, see + */ + +#include "tpm/tpm.h" +#include "qemu/thread.h" +#include "tpm_backend.h" + +void tpm_backend_thread_deliver_request(TPMBackendThread *tbt) +{ + g_thread_pool_push(tbt->pool, (gpointer)TPM_BACKEND_CMD_PROCESS_CMD, NULL); +} + +void tpm_backend_thread_create(TPMBackendThread *tbt, + GFunc func, gpointer user_data) +{ + if (!tbt->pool) { + tbt->pool = g_thread_pool_new(func, user_data, 1, TRUE, NULL); + g_thread_pool_push(tbt->pool, (gpointer)TPM_BACKEND_CMD_INIT, NULL); + } +} + +void tpm_backend_thread_end(TPMBackendThread *tbt) +{ + if (tbt->pool) { + g_thread_pool_push(tbt->pool, (gpointer)TPM_BACKEND_CMD_END, NULL); + g_thread_pool_free(tbt->pool, FALSE, TRUE); + tbt->pool = NULL; + } +} + +void tpm_backend_thread_tpm_reset(TPMBackendThread *tbt, + GFunc func, gpointer user_data) +{ + if (!tbt->pool) { + tpm_backend_thread_create(tbt, func, user_data); + } else { + g_thread_pool_push(tbt->pool, (gpointer)TPM_BACKEND_CMD_TPM_RESET, + NULL); + } +} diff --git a/tpm/tpm_backend.h b/tpm/tpm_backend.h new file mode 100644 index 0000000..05d94d0 --- /dev/null +++ b/tpm/tpm_backend.h @@ -0,0 +1,45 @@ +/* + * common TPM backend driver functions + * + * Copyright (c) 2012-2013 IBM Corporation + * Authors: + * Stefan Berger + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, see + */ + +#ifndef TPM_TPM_BACKEND_H +#define TPM_TPM_BACKEND_H + +#include + +typedef struct TPMBackendThread { + GThreadPool *pool; +} TPMBackendThread; + +void tpm_backend_thread_deliver_request(TPMBackendThread *tbt); +void tpm_backend_thread_create(TPMBackendThread *tbt, + GFunc func, gpointer user_data); +void tpm_backend_thread_end(TPMBackendThread *tbt); +void tpm_backend_thread_tpm_reset(TPMBackendThread *tbt, + GFunc func, gpointer user_data); + +typedef enum TPMBackendCmd { + TPM_BACKEND_CMD_INIT = 1, + TPM_BACKEND_CMD_PROCESS_CMD, + TPM_BACKEND_CMD_END, + TPM_BACKEND_CMD_TPM_RESET, +} TPMBackendCmd; + +#endif /* TPM_TPM_BACKEND_H */ diff --git a/tpm/tpm_int.h b/tpm/tpm_int.h index d5358ad..f705643 100644 --- a/tpm/tpm_int.h +++ b/tpm/tpm_int.h @@ -18,6 +18,8 @@ struct TPMDriverOps; typedef struct TPMDriverOps TPMDriverOps; +typedef struct TPMPassthruState TPMPassthruState; + typedef struct TPMBackend { char *id; enum TpmModel fe_model; @@ -25,6 +27,10 @@ typedef struct TPMBackend { char *cancel_path; const TPMDriverOps *ops; + union { + TPMPassthruState *tpm_pt; + } s; + QLIST_ENTRY(TPMBackend) list; } TPMBackend; @@ -74,10 +80,37 @@ struct TPMDriverOps { bool (*get_tpm_established_flag)(TPMBackend *t); }; +struct tpm_req_hdr { + uint16_t tag; + uint32_t len; + uint32_t ordinal; +} QEMU_PACKED; + +struct tpm_resp_hdr { + uint16_t tag; + uint32_t len; + uint32_t errcode; +} QEMU_PACKED; + +#define TPM_TAG_RQU_COMMAND 0xc1 +#define TPM_TAG_RQU_AUTH1_COMMAND 0xc2 +#define TPM_TAG_RQU_AUTH2_COMMAND 0xc3 + +#define TPM_TAG_RSP_COMMAND 0xc4 +#define TPM_TAG_RSP_AUTH1_COMMAND 0xc5 +#define TPM_TAG_RSP_AUTH2_COMMAND 0xc6 + +#define TPM_FAIL 9 + +#define TPM_ORD_GetTicks 0xf1 + TPMBackend *qemu_find_tpm(const char *id); int tpm_register_model(enum TpmModel model); int tpm_register_driver(const TPMDriverOps *tdo); void tpm_display_backend_drivers(void); const TPMDriverOps *tpm_get_backend_driver(const char *type); +void tpm_write_fatal_error_response(uint8_t *out, uint32_t out_len); + +extern const TPMDriverOps tpm_passthrough_driver; #endif /* TPM_TPM_INT_H */ diff --git a/tpm/tpm_passthrough.c b/tpm/tpm_passthrough.c new file mode 100644 index 0000000..760e18f --- /dev/null +++ b/tpm/tpm_passthrough.c @@ -0,0 +1,387 @@ +/* + * passthrough TPM driver + * + * Copyright (c) 2010 - 2013 IBM Corporation + * Authors: + * Stefan Berger + * + * Copyright (C) 2011 IAIK, Graz University of Technology + * Author: Andreas Niederl + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, see + */ + +#include "qemu-common.h" +#include "qapi/error.h" +#include "qemu/sockets.h" +#include "tpm_int.h" +#include "hw/hw.h" +#include "hw/pc.h" +#include "tpm_tis.h" +#include "tpm_backend.h" + +/* #define DEBUG_TPM */ + +#ifdef DEBUG_TPM +#define DPRINTF(fmt, ...) \ + do { fprintf(stderr, fmt, ## __VA_ARGS__); } while (0) +#else +#define DPRINTF(fmt, ...) \ + do { } while (0) +#endif + +/* data structures */ + +typedef struct TPMPassthruThreadParams { + TPMState *tpm_state; + + TPMRecvDataCB *recv_data_callback; + TPMBackend *tb; +} TPMPassthruThreadParams; + +struct TPMPassthruState { + TPMBackendThread tbt; + + TPMPassthruThreadParams tpm_thread_params; + + char *tpm_dev; + int tpm_fd; + bool had_startup_error; +}; + +#define TPM_PASSTHROUGH_DEFAULT_DEVICE "/dev/tpm0" + +static int tpm_passthrough_unix_write(int fd, const uint8_t *buf, uint32_t len) +{ + return send_all(fd, buf, len); +} + +static int tpm_passthrough_unix_read(int fd, uint8_t *buf, uint32_t len) +{ + return recv_all(fd, buf, len, true); +} + +static uint32_t tpm_passthrough_get_size_from_buffer(const uint8_t *buf) +{ + struct tpm_resp_hdr *resp = (struct tpm_resp_hdr *)buf; + + return be32_to_cpu(resp->len); +} + +static int tpm_passthrough_unix_tx_bufs(int tpm_fd, + const uint8_t *in, uint32_t in_len, + uint8_t *out, uint32_t out_len) +{ + int ret; + + ret = tpm_passthrough_unix_write(tpm_fd, in, in_len); + if (ret != in_len) { + error_report("tpm_passthrough: error while transmitting data " + "to TPM: %s (%i)\n", + strerror(errno), errno); + goto err_exit; + } + + ret = tpm_passthrough_unix_read(tpm_fd, out, out_len); + if (ret < 0) { + error_report("tpm_passthrough: error while reading data from " + "TPM: %s (%i)\n", + strerror(errno), errno); + } else if (ret < sizeof(struct tpm_resp_hdr) || + tpm_passthrough_get_size_from_buffer(out) != ret) { + ret = -1; + error_report("tpm_passthrough: received invalid response " + "packet from TPM\n"); + } + +err_exit: + if (ret < 0) { + tpm_write_fatal_error_response(out, out_len); + } + + return ret; +} + +static int tpm_passthrough_unix_transfer(int tpm_fd, + const TPMLocality *locty_data) +{ + return tpm_passthrough_unix_tx_bufs(tpm_fd, + locty_data->w_buffer.buffer, + locty_data->w_offset, + locty_data->r_buffer.buffer, + locty_data->r_buffer.size); +} + +static void tpm_passthrough_worker_thread(gpointer data, + gpointer user_data) +{ + TPMPassthruThreadParams *thr_parms = user_data; + TPMPassthruState *tpm_pt = thr_parms->tb->s.tpm_pt; + TPMBackendCmd cmd = (TPMBackendCmd)data; + + DPRINTF("tpm_passthrough: processing command type %d\n", cmd); + + switch (cmd) { + case TPM_BACKEND_CMD_PROCESS_CMD: + tpm_passthrough_unix_transfer(tpm_pt->tpm_fd, + thr_parms->tpm_state->locty_data); + + thr_parms->recv_data_callback(thr_parms->tpm_state, + thr_parms->tpm_state->locty_number); + break; + case TPM_BACKEND_CMD_INIT: + case TPM_BACKEND_CMD_END: + case TPM_BACKEND_CMD_TPM_RESET: + /* nothing to do */ + break; + } +} + +/* + * Start the TPM (thread). If it had been started before, then terminate + * and start it again. + */ +static int tpm_passthrough_startup_tpm(TPMBackend *tb) +{ + TPMPassthruState *tpm_pt = tb->s.tpm_pt; + + /* terminate a running TPM */ + tpm_backend_thread_end(&tpm_pt->tbt); + + tpm_backend_thread_create(&tpm_pt->tbt, + tpm_passthrough_worker_thread, + &tb->s.tpm_pt->tpm_thread_params); + + return 0; +} + +static void tpm_passthrough_reset(TPMBackend *tb) +{ + TPMPassthruState *tpm_pt = tb->s.tpm_pt; + + DPRINTF("tpm_passthrough: CALL TO TPM_RESET!\n"); + + tpm_backend_thread_end(&tpm_pt->tbt); + + tpm_pt->had_startup_error = false; +} + +static int tpm_passthrough_init(TPMBackend *tb, TPMState *s, + TPMRecvDataCB *recv_data_cb) +{ + TPMPassthruState *tpm_pt = tb->s.tpm_pt; + + tpm_pt->tpm_thread_params.tpm_state = s; + tpm_pt->tpm_thread_params.recv_data_callback = recv_data_cb; + tpm_pt->tpm_thread_params.tb = tb; + + return 0; +} + +static bool tpm_passthrough_get_tpm_established_flag(TPMBackend *tb) +{ + return false; +} + +static bool tpm_passthrough_get_startup_error(TPMBackend *tb) +{ + TPMPassthruState *tpm_pt = tb->s.tpm_pt; + + return tpm_pt->had_startup_error; +} + +static size_t tpm_passthrough_realloc_buffer(TPMSizedBuffer *sb) +{ + size_t wanted_size = 4096; /* Linux tpm.c buffer size */ + + if (sb->size != wanted_size) { + sb->buffer = g_realloc(sb->buffer, wanted_size); + sb->size = wanted_size; + } + return sb->size; +} + +static void tpm_passthrough_deliver_request(TPMBackend *tb) +{ + TPMPassthruState *tpm_pt = tb->s.tpm_pt; + + tpm_backend_thread_deliver_request(&tpm_pt->tbt); +} + +static void tpm_passthrough_cancel_cmd(TPMBackend *tb) +{ + /* cancelling an ongoing command is known not to work with some TPMs */ +} + +static const char *tpm_passthrough_create_desc(void) +{ + return "Passthrough TPM backend driver"; +} + +/* + * A basic test of a TPM device. We expect a well formatted response header + * (error response is fine) within one second. + */ +static int tpm_passthrough_test_tpmdev(int fd) +{ + struct tpm_req_hdr req = { + .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND), + .len = cpu_to_be32(sizeof(req)), + .ordinal = cpu_to_be32(TPM_ORD_GetTicks), + }; + struct tpm_resp_hdr *resp; + fd_set readfds; + int n; + struct timeval tv = { + .tv_sec = 1, + .tv_usec = 0, + }; + unsigned char buf[1024]; + + n = write(fd, &req, sizeof(req)); + if (n < 0) { + return errno; + } + if (n != sizeof(req)) { + return EFAULT; + } + + FD_ZERO(&readfds); + FD_SET(fd, &readfds); + + /* wait for a second */ + n = select(fd + 1, &readfds, NULL, NULL, &tv); + if (n != 1) { + return errno; + } + + n = read(fd, &buf, sizeof(buf)); + if (n < sizeof(struct tpm_resp_hdr)) { + return EFAULT; + } + + resp = (struct tpm_resp_hdr *)buf; + /* check the header */ + if (be16_to_cpu(resp->tag) != TPM_TAG_RSP_COMMAND || + be32_to_cpu(resp->len) != n) { + return EBADMSG; + } + + return 0; +} + +static int tpm_passthrough_handle_device_opts(QemuOpts *opts, TPMBackend *tb) +{ + const char *value; + + value = qemu_opt_get(opts, "path"); + if (!value) { + value = TPM_PASSTHROUGH_DEFAULT_DEVICE; + } + + tb->s.tpm_pt->tpm_dev = g_strdup(value); + + tb->path = g_strdup(tb->s.tpm_pt->tpm_dev); + + tb->s.tpm_pt->tpm_fd = qemu_open(tb->s.tpm_pt->tpm_dev, O_RDWR); + if (tb->s.tpm_pt->tpm_fd < 0) { + error_report("Cannot access TPM device using '%s': %s\n", + tb->s.tpm_pt->tpm_dev, strerror(errno)); + goto err_free_parameters; + } + + if (tpm_passthrough_test_tpmdev(tb->s.tpm_pt->tpm_fd)) { + error_report("'%s' is not a TPM device.\n", + tb->s.tpm_pt->tpm_dev); + goto err_close_tpmdev; + } + + return 0; + + err_close_tpmdev: + qemu_close(tb->s.tpm_pt->tpm_fd); + tb->s.tpm_pt->tpm_fd = -1; + + err_free_parameters: + g_free(tb->path); + tb->path = NULL; + + g_free(tb->s.tpm_pt->tpm_dev); + tb->s.tpm_pt->tpm_dev = NULL; + + return 1; +} + +static TPMBackend *tpm_passthrough_create(QemuOpts *opts, const char *id) +{ + TPMBackend *tb; + + tb = g_new0(TPMBackend, 1); + tb->s.tpm_pt = g_new0(TPMPassthruState, 1); + tb->id = g_strdup(id); + /* let frontend set the fe_model to proper value */ + tb->fe_model = -1; + + tb->ops = &tpm_passthrough_driver; + + if (tpm_passthrough_handle_device_opts(opts, tb)) { + goto err_exit; + } + + return tb; + +err_exit: + g_free(tb->id); + g_free(tb->s.tpm_pt); + g_free(tb); + + return NULL; +} + +static void tpm_passthrough_destroy(TPMBackend *tb) +{ + TPMPassthruState *tpm_pt = tb->s.tpm_pt; + + tpm_backend_thread_end(&tpm_pt->tbt); + + qemu_close(tpm_pt->tpm_fd); + + g_free(tb->id); + g_free(tb->path); + g_free(tb->s.tpm_pt->tpm_dev); + g_free(tb->s.tpm_pt); + g_free(tb); +} + +const TPMDriverOps tpm_passthrough_driver = { + .type = TPM_TYPE_PASSTHROUGH, + .desc = tpm_passthrough_create_desc, + .create = tpm_passthrough_create, + .destroy = tpm_passthrough_destroy, + .init = tpm_passthrough_init, + .startup_tpm = tpm_passthrough_startup_tpm, + .realloc_buffer = tpm_passthrough_realloc_buffer, + .reset = tpm_passthrough_reset, + .had_startup_error = tpm_passthrough_get_startup_error, + .deliver_request = tpm_passthrough_deliver_request, + .cancel_cmd = tpm_passthrough_cancel_cmd, + .get_tpm_established_flag = tpm_passthrough_get_tpm_established_flag, +}; + +static void tpm_passthrough_register(void) +{ + tpm_register_driver(&tpm_passthrough_driver); +} + +type_init(tpm_passthrough_register)