[PATCH v8 08/10] tpm: Proxy driver for supporting multiple emulated TPMs

[PATCH v8 08/10] tpm: Proxy driver for supporting multiple emulated TPMs

[Stefan Berger]

This patch implements a proxy driver for supporting multiple emulated TPMs
in a system.

The driver implements a device /dev/vtpmx that is used to created
a client device pair /dev/tpmX (e.g., /dev/tpm10) and a server side that
is accessed using a file descriptor returned by an ioctl.
The device /dev/tpmX is the usual TPM device created by the core TPM
driver. Applications or kernel subsystems can send TPM commands to it
and the corresponding server-side file descriptor receives these
commands and delivers them to an emulated TPM.

Signed-off-by: Stefan Berger <stefanb-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
CC: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
CC: linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
CC: linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
---
 drivers/char/tpm/Kconfig          |  10 +
 drivers/char/tpm/Makefile         |   1 +
 drivers/char/tpm/tpm_vtpm_proxy.c | 572 ++++++++++++++++++++++++++++++++++++++
 include/uapi/linux/Kbuild         |   1 +
 include/uapi/linux/vtpm_proxy.h   |  42 +++
 5 files changed, 626 insertions(+)
 create mode 100644 drivers/char/tpm/tpm_vtpm_proxy.c
 create mode 100644 include/uapi/linux/vtpm_proxy.h

diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig
index 3b84a8b..0eac596 100644
--- a/drivers/char/tpm/Kconfig
+++ b/drivers/char/tpm/Kconfig
@@ -122,5 +122,15 @@ config TCG_CRB
 	  from within Linux.  To compile this driver as a module, choose
 	  M here; the module will be called tpm_crb.
 
+config TCG_VTPM_PROXY
+	tristate "VTPM Proxy Interface"
+	depends on TCG_TPM
+	---help---
+	  This driver proxies for an emulated TPM (vTPM) running in userspace.
+	  A device /dev/vtpmx is provided that creates a device pair
+	  /dev/vtpmX and a server-side file descriptor on which the vTPM
+	  can receive commands.
+
+
 source "drivers/char/tpm/st33zp24/Kconfig"
 endif # TCG_TPM
diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
index 56e8f1f..98de5e6 100644
--- a/drivers/char/tpm/Makefile
+++ b/drivers/char/tpm/Makefile
@@ -23,3 +23,4 @@ obj-$(CONFIG_TCG_IBMVTPM) += tpm_ibmvtpm.o
 obj-$(CONFIG_TCG_TIS_ST33ZP24) += st33zp24/
 obj-$(CONFIG_TCG_XEN) += xen-tpmfront.o
 obj-$(CONFIG_TCG_CRB) += tpm_crb.o
+obj-$(CONFIG_TCG_VTPM_PROXY) += tpm_vtpm_proxy.o
diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c
new file mode 100644
index 0000000..2bb2c8c
--- /dev/null
+++ b/drivers/char/tpm/tpm_vtpm_proxy.c
@@ -0,0 +1,572 @@
+/*
+ * Copyright (C) 2015, 2016 IBM Corporation
+ *
+ * Author: Stefan Berger <stefanb-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
+ *
+ * Maintained by: <tpmdd-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org>
+ *
+ * Device driver for vTPM (vTPM proxy driver)
+ *
+ * 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.
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/spinlock.h>
+#include <linux/uaccess.h>
+#include <linux/wait.h>
+#include <linux/miscdevice.h>
+#include <linux/vtpm_proxy.h>
+#include <linux/file.h>
+#include <linux/anon_inodes.h>
+#include <linux/poll.h>
+#include <linux/compat.h>
+
+#include "tpm.h"
+
+#define VTPM_PROXY_REQ_COMPLETE_FLAG  BIT(0)
+
+struct proxy_dev {
+	struct tpm_chip *chip;
+
+	u32 flags;                   /* public API flags */
+
+	wait_queue_head_t wq;
+
+	struct mutex buf_lock;       /* protect buffer and flags */
+
+	long state;                  /* internal state */
+#define STATE_OPENED_FLAG        BIT(0)
+#define STATE_WAIT_RESPONSE_FLAG BIT(1)  /* waiting for emulator response */
+
+	size_t req_len;              /* length of queued TPM request */
+	size_t resp_len;             /* length of queued TPM response */
+	u8 buffer[TPM_BUFSIZE];      /* request/response buffer */
+};
+
+
+static void vtpm_proxy_delete_device(struct proxy_dev *proxy_dev);
+
+/*
+ * Functions related to 'server side'
+ */
+
+/**
+ * vtpm_proxy_fops_read - Read TPM commands on 'server side'
+ *
+ * Return value:
+ *	Number of bytes read or negative error code
+ */
+static ssize_t vtpm_proxy_fops_read(struct file *filp, char __user *buf,
+				    size_t count, loff_t *off)
+{
+	struct proxy_dev *proxy_dev = filp->private_data;
+	size_t len;
+	int sig, rc;
+
+	sig = wait_event_interruptible(proxy_dev->wq, proxy_dev->req_len != 0);
+	if (sig)
+		return -EINTR;
+
+	mutex_lock(&proxy_dev->buf_lock);
+
+	len = proxy_dev->req_len;
+
+	if (count < len) {
+		mutex_unlock(&proxy_dev->buf_lock);
+		pr_debug("Invalid size in recv: count=%zd, req_len=%zd\n",
+			 count, len);
+		return -EIO;
+	}
+
+	rc = copy_to_user(buf, proxy_dev->buffer, len);
+	memset(proxy_dev->buffer, 0, len);
+	proxy_dev->req_len = 0;
+
+	if (!rc)
+		proxy_dev->state |= STATE_WAIT_RESPONSE_FLAG;
+
+	mutex_unlock(&proxy_dev->buf_lock);
+
+	if (rc)
+		return -EFAULT;
+
+	return len;
+}
+
+/**
+ * vtpm_proxy_fops_write - Write TPM responses on 'server side'
+ *
+ * Return value:
+ *	Number of bytes read or negative error value
+ */
+static ssize_t vtpm_proxy_fops_write(struct file *filp, const char __user *buf,
+				     size_t count, loff_t *off)
+{
+	struct proxy_dev *proxy_dev = filp->private_data;
+
+	mutex_lock(&proxy_dev->buf_lock);
+
+	if (count > sizeof(proxy_dev->buffer) ||
+	    !(proxy_dev->state & STATE_WAIT_RESPONSE_FLAG)) {
+		mutex_unlock(&proxy_dev->buf_lock);
+		return -EIO;
+	}
+
+	proxy_dev->state &= ~STATE_WAIT_RESPONSE_FLAG;
+
+	proxy_dev->req_len = 0;
+
+	if (copy_from_user(proxy_dev->buffer, buf, count)) {
+		mutex_unlock(&proxy_dev->buf_lock);
+		return -EFAULT;
+	}
+
+	proxy_dev->resp_len = count;
+
+	mutex_unlock(&proxy_dev->buf_lock);
+
+	wake_up_interruptible(&proxy_dev->wq);
+
+	return count;
+}
+
+/*
+ * vtpm_proxy_fops_poll: Poll status on 'server side'
+ *
+ * Return value:
+ *      Poll flags
+ */
+static unsigned int vtpm_proxy_fops_poll(struct file *filp, poll_table *wait)
+{
+	struct proxy_dev *proxy_dev = filp->private_data;
+	unsigned ret;
+
+	poll_wait(filp, &proxy_dev->wq, wait);
+
+	ret = POLLOUT;
+
+	mutex_lock(&proxy_dev->buf_lock);
+
+	if (proxy_dev->req_len)
+		ret |= POLLIN | POLLRDNORM;
+
+	mutex_unlock(&proxy_dev->buf_lock);
+
+	return ret;
+}
+
+/*
+ * vtpm_proxy_fops_open - Open vTPM device on 'server side'
+ *
+ * Called when setting up the anonymous file descriptor
+ */
+static void vtpm_proxy_fops_open(struct file *filp)
+{
+	struct proxy_dev *proxy_dev = filp->private_data;
+
+	proxy_dev->state |= STATE_OPENED_FLAG;
+}
+
+/**
+ * vtpm_proxy_fops_undo_open - counter-part to vtpm_fops_open
+ *
+ * Call to undo vtpm_proxy_fops_open
+ */
+static void vtpm_proxy_fops_undo_open(struct proxy_dev *proxy_dev)
+{
+	mutex_lock(&proxy_dev->buf_lock);
+
+	proxy_dev->state &= ~STATE_OPENED_FLAG;
+
+	mutex_unlock(&proxy_dev->buf_lock);
+
+	/* no more TPM responses -- wake up anyone waiting for them */
+	wake_up_interruptible(&proxy_dev->wq);
+}
+
+/*
+ * vtpm_proxy_fops_release: Close 'server side'
+ *
+ * Return value:
+ *      Always returns 0.
+ */
+static int vtpm_proxy_fops_release(struct inode *inode, struct file *filp)
+{
+	struct proxy_dev *proxy_dev = filp->private_data;
+
+	filp->private_data = NULL;
+
+	vtpm_proxy_delete_device(proxy_dev);
+
+	return 0;
+}
+
+static const struct file_operations vtpm_proxy_fops = {
+	.owner = THIS_MODULE,
+	.llseek = no_llseek,
+	.read = vtpm_proxy_fops_read,
+	.write = vtpm_proxy_fops_write,
+	.poll = vtpm_proxy_fops_poll,
+	.release = vtpm_proxy_fops_release,
+};
+
+/*
+ * Functions invoked by the core TPM driver to send TPM commands to
+ * 'server side' and receive responses from there.
+ */
+
+/*
+ * Called when core TPM driver reads TPM responses from 'server side'
+ *
+ * Return value:
+ *      Number of TPM response bytes read, negative error value otherwise
+ */
+static int vtpm_proxy_tpm_op_recv(struct tpm_chip *chip, u8 *buf, size_t count)
+{
+	struct proxy_dev *proxy_dev = chip->vendor.priv;
+	size_t len;
+
+	if (!proxy_dev)
+		return -EIO;
+
+	/* process gone ? */
+	mutex_lock(&proxy_dev->buf_lock);
+
+	if (!(proxy_dev->state & STATE_OPENED_FLAG)) {
+		mutex_unlock(&proxy_dev->buf_lock);
+		return -EPIPE;
+	}
+
+	len = proxy_dev->resp_len;
+	if (count < len) {
+		dev_err(&chip->dev,
+			"Invalid size in recv: count=%zd, resp_len=%zd\n",
+			count, len);
+		len = -EIO;
+		goto out;
+	}
+
+	memcpy(buf, proxy_dev->buffer, len);
+	proxy_dev->resp_len = 0;
+
+out:
+	mutex_unlock(&proxy_dev->buf_lock);
+
+	return len;
+}
+
+/*
+ * Called when core TPM driver forwards TPM requests to 'server side'.
+ *
+ * Return value:
+ *      0 in case of success, negative error value otherwise.
+ */
+static int vtpm_proxy_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t count)
+{
+	struct proxy_dev *proxy_dev = chip->vendor.priv;
+	int rc = 0;
+
+	if (!proxy_dev)
+		return -EIO;
+
+	if (count > sizeof(proxy_dev->buffer)) {
+		dev_err(&chip->dev,
+			"Invalid size in send: count=%zd, buffer size=%zd\n",
+			count, sizeof(proxy_dev->buffer));
+		return -EIO;
+	}
+
+	mutex_lock(&proxy_dev->buf_lock);
+
+	if (!(proxy_dev->state & STATE_OPENED_FLAG)) {
+		mutex_unlock(&proxy_dev->buf_lock);
+		return -EPIPE;
+	}
+
+	proxy_dev->resp_len = 0;
+
+	proxy_dev->req_len = count;
+	memcpy(proxy_dev->buffer, buf, count);
+
+	proxy_dev->state &= ~STATE_WAIT_RESPONSE_FLAG;
+
+	mutex_unlock(&proxy_dev->buf_lock);
+
+	wake_up_interruptible(&proxy_dev->wq);
+
+	return rc;
+}
+
+static void vtpm_proxy_tpm_op_cancel(struct tpm_chip *chip)
+{
+	/* not supported */
+}
+
+static u8 vtpm_proxy_tpm_op_status(struct tpm_chip *chip)
+{
+	struct proxy_dev *proxy_dev = chip->vendor.priv;
+
+	if (proxy_dev->resp_len)
+		return VTPM_PROXY_REQ_COMPLETE_FLAG;
+
+	return 0;
+}
+
+static bool vtpm_proxy_tpm_req_canceled(struct tpm_chip  *chip, u8 status)
+{
+	struct proxy_dev *proxy_dev = chip->vendor.priv;
+	bool ret;
+
+	mutex_lock(&proxy_dev->buf_lock);
+
+	ret = !(proxy_dev->state & STATE_OPENED_FLAG);
+
+	mutex_unlock(&proxy_dev->buf_lock);
+
+	return ret;
+}
+
+static const struct tpm_class_ops vtpm_proxy_tpm_ops = {
+	.recv = vtpm_proxy_tpm_op_recv,
+	.send = vtpm_proxy_tpm_op_send,
+	.cancel = vtpm_proxy_tpm_op_cancel,
+	.status = vtpm_proxy_tpm_op_status,
+	.req_complete_mask = VTPM_PROXY_REQ_COMPLETE_FLAG,
+	.req_complete_val = VTPM_PROXY_REQ_COMPLETE_FLAG,
+	.req_canceled = vtpm_proxy_tpm_req_canceled,
+};
+
+/*
+ * Code related to creation and deletion of device pairs
+ */
+static struct proxy_dev *vtpm_proxy_create_proxy_dev(void)
+{
+	struct proxy_dev *proxy_dev;
+	struct tpm_chip *chip;
+	int err;
+
+	proxy_dev = kzalloc(sizeof(*proxy_dev), GFP_KERNEL);
+	if (proxy_dev == NULL)
+		return ERR_PTR(-ENOMEM);
+
+	init_waitqueue_head(&proxy_dev->wq);
+	mutex_init(&proxy_dev->buf_lock);
+
+	chip = tpm_chip_alloc(NULL, &vtpm_proxy_tpm_ops);
+	if (IS_ERR(chip)) {
+		err = PTR_ERR(chip);
+		goto err_proxy_dev_free;
+	}
+	chip->vendor.priv = proxy_dev;
+
+	proxy_dev->chip = chip;
+
+	return proxy_dev;
+
+err_proxy_dev_free:
+	kfree(proxy_dev);
+
+	return ERR_PTR(err);
+}
+
+/*
+ * Undo what has been done in vtpm_create_proxy_dev
+ */
+static inline void vtpm_proxy_delete_proxy_dev(struct proxy_dev *proxy_dev)
+{
+	put_device(&proxy_dev->chip->dev); /* frees chip */
+	kfree(proxy_dev);
+}
+
+/*
+ * Create a /dev/tpm%d and 'server side' file descriptor pair
+ *
+ * Return value:
+ *      Returns file pointer on success, an error value otherwise
+ */
+static struct file *vtpm_proxy_create_device(
+				 struct vtpm_proxy_new_dev *vtpm_new_dev)
+{
+	struct proxy_dev *proxy_dev;
+	int rc, fd;
+	struct file *file;
+
+	if (vtpm_new_dev->flags & ~VTPM_PROXY_FLAGS_ALL)
+		return ERR_PTR(-EOPNOTSUPP);
+
+	proxy_dev = vtpm_proxy_create_proxy_dev();
+	if (IS_ERR(proxy_dev))
+		return ERR_CAST(proxy_dev);
+
+	proxy_dev->flags = vtpm_new_dev->flags;
+
+	/* setup an anonymous file for the server-side */
+	fd = get_unused_fd_flags(O_RDWR);
+	if (fd < 0) {
+		rc = fd;
+		goto err_delete_proxy_dev;
+	}
+
+	file = anon_inode_getfile("[vtpms]", &vtpm_proxy_fops, proxy_dev,
+				  O_RDWR);
+	if (IS_ERR(file)) {
+		rc = PTR_ERR(file);
+		goto err_put_unused_fd;
+	}
+
+	/* from now on we can unwind with put_unused_fd() + fput() */
+	/* simulate an open() on the server side */
+	vtpm_proxy_fops_open(file);
+
+	if (proxy_dev->flags & VTPM_PROXY_FLAG_TPM2)
+		proxy_dev->chip->flags |= TPM_CHIP_FLAG_TPM2;
+
+	rc = tpm_chip_register(proxy_dev->chip);
+	if (rc)
+		goto err_vtpm_fput;
+
+	vtpm_new_dev->fd = fd;
+	vtpm_new_dev->major = MAJOR(proxy_dev->chip->dev.devt);
+	vtpm_new_dev->minor = MINOR(proxy_dev->chip->dev.devt);
+	vtpm_new_dev->tpm_num = proxy_dev->chip->dev_num;
+
+	return file;
+
+err_vtpm_fput:
+	put_unused_fd(fd);
+	fput(file);
+
+	return ERR_PTR(rc);
+
+err_put_unused_fd:
+	put_unused_fd(fd);
+
+err_delete_proxy_dev:
+	vtpm_proxy_delete_proxy_dev(proxy_dev);
+
+	return ERR_PTR(rc);
+}
+
+/*
+ * Counter part to vtpm_create_device.
+ */
+static void vtpm_proxy_delete_device(struct proxy_dev *proxy_dev)
+{
+	/*
+	 * A client may hold the 'ops' lock, so let it know that the server
+	 * side shuts down before we try to grab the 'ops' lock when
+	 * unregistering the chip.
+	 */
+	vtpm_proxy_fops_undo_open(proxy_dev);
+
+	tpm_chip_unregister(proxy_dev->chip);
+
+	vtpm_proxy_delete_proxy_dev(proxy_dev);
+}
+
+/*
+ * Code related to the control device /dev/vtpmx
+ */
+
+/*
+ * vtpmx_fops_ioctl: ioctl on /dev/vtpmx
+ *
+ * Return value:
+ *      Returns 0 on success, a negative error code otherwise.
+ */
+static long vtpmx_fops_ioctl(struct file *f, unsigned int ioctl,
+				   unsigned long arg)
+{
+	void __user *argp = (void __user *)arg;
+	struct vtpm_proxy_new_dev *vtpm_new_dev_p;
+	struct vtpm_proxy_new_dev vtpm_new_dev;
+	struct file *file;
+
+	switch (ioctl) {
+	case VTPM_PROXY_IOC_NEW_DEV:
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+		vtpm_new_dev_p = argp;
+		if (copy_from_user(&vtpm_new_dev, vtpm_new_dev_p,
+				   sizeof(vtpm_new_dev)))
+			return -EFAULT;
+		file = vtpm_proxy_create_device(&vtpm_new_dev);
+		if (IS_ERR(file))
+			return PTR_ERR(file);
+		if (copy_to_user(vtpm_new_dev_p, &vtpm_new_dev,
+				 sizeof(vtpm_new_dev))) {
+			put_unused_fd(vtpm_new_dev.fd);
+			fput(file);
+			return -EFAULT;
+		}
+
+		fd_install(vtpm_new_dev.fd, file);
+		return 0;
+
+	default:
+		return -ENOIOCTLCMD;
+	}
+}
+
+#ifdef CONFIG_COMPAT
+static long vtpmx_fops_compat_ioctl(struct file *f, unsigned int ioctl,
+					  unsigned long arg)
+{
+	return vtpmx_fops_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
+}
+#endif
+
+static const struct file_operations vtpmx_fops = {
+	.owner = THIS_MODULE,
+	.unlocked_ioctl = vtpmx_fops_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl = vtpmx_fops_compat_ioctl,
+#endif
+	.llseek = noop_llseek,
+};
+
+static struct miscdevice vtpmx_miscdev = {
+	.minor = MISC_DYNAMIC_MINOR,
+	.name = "vtpmx",
+	.fops = &vtpmx_fops,
+};
+
+static int vtpmx_init(void)
+{
+	return misc_register(&vtpmx_miscdev);
+}
+
+static void vtpmx_cleanup(void)
+{
+	misc_deregister(&vtpmx_miscdev);
+}
+
+static int __init vtpm_module_init(void)
+{
+	int rc;
+
+	rc = vtpmx_init();
+	if (rc) {
+		pr_err("couldn't create vtpmx device\n");
+		return rc;
+	}
+
+	return 0;
+}
+
+static void __exit vtpm_module_exit(void)
+{
+	vtpmx_cleanup();
+}
+
+module_init(vtpm_module_init);
+module_exit(vtpm_module_exit);
+
+MODULE_AUTHOR("Stefan Berger (stefanb-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org)");
+MODULE_DESCRIPTION("vTPM Driver");
+MODULE_VERSION("0.1");
+MODULE_LICENSE("GPL");
diff --git a/include/uapi/linux/Kbuild b/include/uapi/linux/Kbuild
index ebd10e6..ac767ce 100644
--- a/include/uapi/linux/Kbuild
+++ b/include/uapi/linux/Kbuild
@@ -449,6 +449,7 @@ header-y += virtio_scsi.h
 header-y += virtio_types.h
 header-y += vm_sockets.h
 header-y += vt.h
+header-y += vtpm_proxy.h
 header-y += wait.h
 header-y += wanrouter.h
 header-y += watchdog.h
diff --git a/include/uapi/linux/vtpm_proxy.h b/include/uapi/linux/vtpm_proxy.h
new file mode 100644
index 0000000..dc73f00
--- /dev/null
+++ b/include/uapi/linux/vtpm_proxy.h
@@ -0,0 +1,42 @@
+/*
+ * Definitions for the VTPM proxy driver
+ * Copyright (c) 2015, 2016, IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#ifndef _UAPI_LINUX_VTPM_PROXY_H
+#define _UAPI_LINUX_VTPM_PROXY_H
+
+#include <linux/types.h>
+#include <linux/ioctl.h>
+
+/* ioctls */
+
+struct vtpm_proxy_new_dev {
+	__u32 flags;         /* input */
+	__u32 tpm_num;       /* output */
+	__u32 fd;            /* output */
+	__u32 major;         /* output */
+	__u32 minor;         /* output */
+};
+
+/* above flags */
+#define VTPM_PROXY_FLAG_TPM2  1  /* emulator is TPM 2 */
+
+/* all supported flags */
+#define VTPM_PROXY_FLAGS_ALL  (VTPM_PROXY_FLAG_TPM2)
+
+#define VTPM_PROXY_MAGIC 0xa1
+
+#define VTPM_PROXY_IOC_NEW_DEV   _IOW(VTPM_PROXY_MAGIC, 0x00, \
+				      struct vtpm_proxy_new_dev)
+
+#endif /* _UAPI_LINUX_VTPM_PROXY_H */
-- 
2.4.3


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Re: [PATCH v8 08/10] tpm: Proxy driver for supporting multiple emulated TPMs

[Jarkko Sakkinen]

On Sun, Mar 13, 2016 at 06:54:38PM -0400, Stefan Berger wrote:
> This patch implements a proxy driver for supporting multiple emulated TPMs
> in a system.
> 
> The driver implements a device /dev/vtpmx that is used to created
> a client device pair /dev/tpmX (e.g., /dev/tpm10) and a server side that
> is accessed using a file descriptor returned by an ioctl.
> The device /dev/tpmX is the usual TPM device created by the core TPM
> driver. Applications or kernel subsystems can send TPM commands to it
> and the corresponding server-side file descriptor receives these
> commands and delivers them to an emulated TPM.

Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

My testing procedure was:

* Wine running TPM 2.0 simulator on the host side. [1]
* QEMU running an OS image with this patch. [2]
* Wrote a script for proxying the simulator: tpm2-simulator-vtpm. [3]
* Run some smoke tests: python -m unittest -v tpm2_smoke. [3]

[1] http://research.microsoft.com/en-us/downloads/35116857-e544-4003-8e7b-584182dc6833/
[2] git://git.infradead.org/users/jjs/buildroot-tpmdd.git
[3] git://git.infradead.org/users/jjs/tpm2-scripts.git

/Jarkko

> Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
> CC: linux-kernel@vger.kernel.org
> CC: linux-doc@vger.kernel.org
> CC: linux-api@vger.kernel.org
> ---
>  drivers/char/tpm/Kconfig          |  10 +
>  drivers/char/tpm/Makefile         |   1 +
>  drivers/char/tpm/tpm_vtpm_proxy.c | 572 ++++++++++++++++++++++++++++++++++++++
>  include/uapi/linux/Kbuild         |   1 +
>  include/uapi/linux/vtpm_proxy.h   |  42 +++
>  5 files changed, 626 insertions(+)
>  create mode 100644 drivers/char/tpm/tpm_vtpm_proxy.c
>  create mode 100644 include/uapi/linux/vtpm_proxy.h

/Jarkko

Re: [PATCH v8 08/10] tpm: Proxy driver for supporting multiple emulated TPMs

[Jarkko Sakkinen]

On Sun, Mar 13, 2016 at 06:54:38PM -0400, Stefan Berger wrote:
> This patch implements a proxy driver for supporting multiple emulated TPMs
> in a system.
> 
> The driver implements a device /dev/vtpmx that is used to created
> a client device pair /dev/tpmX (e.g., /dev/tpm10) and a server side that
> is accessed using a file descriptor returned by an ioctl.
> The device /dev/tpmX is the usual TPM device created by the core TPM
> driver. Applications or kernel subsystems can send TPM commands to it
> and the corresponding server-side file descriptor receives these
> commands and delivers them to an emulated TPM.
> 
> Signed-off-by: Stefan Berger <stefanb-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
> CC: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> CC: linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> CC: linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org

Alternative to this would be to have /dev/vtpmx create:

* /dev/vtpm0 for the server
* /dev/tpm0 for the client

This is how David Howell's PoC worked and that's why I want
to make this alternative visible.

The server could even respawn without container noticing it.
This solution have better availability properties.

/Jarkko

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Re: [PATCH v8 08/10] tpm: Proxy driver for supporting multiple emulated TPMs

[Stefan Berger]

On 03/16/2016 08:09 AM, Jarkko Sakkinen wrote:
> On Sun, Mar 13, 2016 at 06:54:38PM -0400, Stefan Berger wrote:
>> This patch implements a proxy driver for supporting multiple emulated TPMs
>> in a system.
>>
>> The driver implements a device /dev/vtpmx that is used to created
>> a client device pair /dev/tpmX (e.g., /dev/tpm10) and a server side that
>> is accessed using a file descriptor returned by an ioctl.
>> The device /dev/tpmX is the usual TPM device created by the core TPM
>> driver. Applications or kernel subsystems can send TPM commands to it
>> and the corresponding server-side file descriptor receives these
>> commands and delivers them to an emulated TPM.
>>
>> Signed-off-by: Stefan Berger <stefanb-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
>> CC: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
>> CC: linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
>> CC: linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> Alternative to this would be to have /dev/vtpmx create:
>
> * /dev/vtpm0 for the server
> * /dev/tpm0 for the client
>
> This is how David Howell's PoC worked and that's why I want
> to make this alternative visible.

My initial implementation had this as well.

>
> The server could even respawn without container noticing it.
> This solution have better availability properties.

A TPM should be stable enough to not have to be respawned...

     Stefan

Re: [PATCH v8 08/10] tpm: Proxy driver for supporting multiple emulated TPMs

[Jason Gunthorpe]

On Wed, Mar 16, 2016 at 02:09:16PM +0200, Jarkko Sakkinen wrote:
> On Sun, Mar 13, 2016 at 06:54:38PM -0400, Stefan Berger wrote:

> Alternative to this would be to have /dev/vtpmx create:
> 
> * /dev/vtpm0 for the server
> * /dev/tpm0 for the client
> 
> This is how David Howell's PoC worked and that's why I want
> to make this alternative visible.
> 
> The server could even respawn without container noticing it.
> This solution have better availability properties.

Seriously, no, that doesn't make any sense. TPM is stateful, you can't
respawn the server side.

If anyone is ever clever enough to make that workable then they just
go ahead and save the server fd with the other state. systemd for
instance already has everything needed to make that work.

We don't need to have a server dev node and we certainly don't need
the leaking problem that leaves us with.

Jason

Re: [PATCH v8 08/10] tpm: Proxy driver for supporting multiple emulated TPMs

[Jarkko Sakkinen]

On Wed, Mar 16, 2016 at 11:49:04AM -0600, Jason Gunthorpe wrote:
> On Wed, Mar 16, 2016 at 02:09:16PM +0200, Jarkko Sakkinen wrote:
> > On Sun, Mar 13, 2016 at 06:54:38PM -0400, Stefan Berger wrote:
> 
> > Alternative to this would be to have /dev/vtpmx create:
> > 
> > * /dev/vtpm0 for the server
> > * /dev/tpm0 for the client
> > 
> > This is how David Howell's PoC worked and that's why I want
> > to make this alternative visible.
> > 
> > The server could even respawn without container noticing it.
> > This solution have better availability properties.
> 
> Seriously, no, that doesn't make any sense. TPM is stateful, you can't
> respawn the server side.
> 
> If anyone is ever clever enough to make that workable then they just
> go ahead and save the server fd with the other state. systemd for
> instance already has everything needed to make that work.
> 
> We don't need to have a server dev node and we certainly don't need
> the leaking problem that leaves us with.

Fair enough.

> Jason

/Jarkko

Re: [PATCH v8 08/10] tpm: Proxy driver for supporting multiple emulated TPMs

[Jarkko Sakkinen]

On Sun, Mar 13, 2016 at 06:54:38PM -0400, Stefan Berger wrote:
> This patch implements a proxy driver for supporting multiple emulated TPMs
> in a system.
> 
> The driver implements a device /dev/vtpmx that is used to created
> a client device pair /dev/tpmX (e.g., /dev/tpm10) and a server side that
> is accessed using a file descriptor returned by an ioctl.
> The device /dev/tpmX is the usual TPM device created by the core TPM
> driver. Applications or kernel subsystems can send TPM commands to it
> and the corresponding server-side file descriptor receives these
> commands and delivers them to an emulated TPM.
> 
> Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
> CC: linux-kernel@vger.kernel.org
> CC: linux-doc@vger.kernel.org
> CC: linux-api@vger.kernel.org
> ---
>  drivers/char/tpm/Kconfig          |  10 +
>  drivers/char/tpm/Makefile         |   1 +
>  drivers/char/tpm/tpm_vtpm_proxy.c | 572 ++++++++++++++++++++++++++++++++++++++
>  include/uapi/linux/Kbuild         |   1 +
>  include/uapi/linux/vtpm_proxy.h   |  42 +++
>  5 files changed, 626 insertions(+)
>  create mode 100644 drivers/char/tpm/tpm_vtpm_proxy.c
>  create mode 100644 include/uapi/linux/vtpm_proxy.h
> 
> diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig
> index 3b84a8b..0eac596 100644
> --- a/drivers/char/tpm/Kconfig
> +++ b/drivers/char/tpm/Kconfig
> @@ -122,5 +122,15 @@ config TCG_CRB
>  	  from within Linux.  To compile this driver as a module, choose
>  	  M here; the module will be called tpm_crb.
>  
> +config TCG_VTPM_PROXY
> +	tristate "VTPM Proxy Interface"
> +	depends on TCG_TPM
> +	---help---
> +	  This driver proxies for an emulated TPM (vTPM) running in userspace.
> +	  A device /dev/vtpmx is provided that creates a device pair
> +	  /dev/vtpmX and a server-side file descriptor on which the vTPM
> +	  can receive commands.
> +
> +
>  source "drivers/char/tpm/st33zp24/Kconfig"
>  endif # TCG_TPM
> diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
> index 56e8f1f..98de5e6 100644
> --- a/drivers/char/tpm/Makefile
> +++ b/drivers/char/tpm/Makefile
> @@ -23,3 +23,4 @@ obj-$(CONFIG_TCG_IBMVTPM) += tpm_ibmvtpm.o
>  obj-$(CONFIG_TCG_TIS_ST33ZP24) += st33zp24/
>  obj-$(CONFIG_TCG_XEN) += xen-tpmfront.o
>  obj-$(CONFIG_TCG_CRB) += tpm_crb.o
> +obj-$(CONFIG_TCG_VTPM_PROXY) += tpm_vtpm_proxy.o
> diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c
> new file mode 100644
> index 0000000..2bb2c8c
> --- /dev/null
> +++ b/drivers/char/tpm/tpm_vtpm_proxy.c
> @@ -0,0 +1,572 @@
> +/*
> + * Copyright (C) 2015, 2016 IBM Corporation
> + *
> + * Author: Stefan Berger <stefanb@us.ibm.com>
> + *
> + * Maintained by: <tpmdd-devel@lists.sourceforge.net>
> + *
> + * Device driver for vTPM (vTPM proxy driver)
> + *
> + * 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.
> + *
> + */
> +
> +#include <linux/types.h>
> +#include <linux/spinlock.h>
> +#include <linux/uaccess.h>
> +#include <linux/wait.h>
> +#include <linux/miscdevice.h>
> +#include <linux/vtpm_proxy.h>
> +#include <linux/file.h>
> +#include <linux/anon_inodes.h>
> +#include <linux/poll.h>
> +#include <linux/compat.h>
> +
> +#include "tpm.h"
> +
> +#define VTPM_PROXY_REQ_COMPLETE_FLAG  BIT(0)
> +
> +struct proxy_dev {
> +	struct tpm_chip *chip;
> +
> +	u32 flags;                   /* public API flags */
> +
> +	wait_queue_head_t wq;
> +
> +	struct mutex buf_lock;       /* protect buffer and flags */
> +
> +	long state;                  /* internal state */
> +#define STATE_OPENED_FLAG        BIT(0)
> +#define STATE_WAIT_RESPONSE_FLAG BIT(1)  /* waiting for emulator response */
> +
> +	size_t req_len;              /* length of queued TPM request */
> +	size_t resp_len;             /* length of queued TPM response */
> +	u8 buffer[TPM_BUFSIZE];      /* request/response buffer */
> +};
> +
> +
> +static void vtpm_proxy_delete_device(struct proxy_dev *proxy_dev);
> +
> +/*
> + * Functions related to 'server side'
> + */
> +
> +/**
> + * vtpm_proxy_fops_read - Read TPM commands on 'server side'
> + *
> + * Return value:
> + *	Number of bytes read or negative error code
> + */
> +static ssize_t vtpm_proxy_fops_read(struct file *filp, char __user *buf,
> +				    size_t count, loff_t *off)
> +{
> +	struct proxy_dev *proxy_dev = filp->private_data;
> +	size_t len;
> +	int sig, rc;
> +
> +	sig = wait_event_interruptible(proxy_dev->wq, proxy_dev->req_len != 0);
> +	if (sig)
> +		return -EINTR;
> +
> +	mutex_lock(&proxy_dev->buf_lock);
> +
> +	len = proxy_dev->req_len;
> +
> +	if (count < len) {
> +		mutex_unlock(&proxy_dev->buf_lock);
> +		pr_debug("Invalid size in recv: count=%zd, req_len=%zd\n",
> +			 count, len);
> +		return -EIO;
> +	}
> +
> +	rc = copy_to_user(buf, proxy_dev->buffer, len);
> +	memset(proxy_dev->buffer, 0, len);
> +	proxy_dev->req_len = 0;
> +
> +	if (!rc)
> +		proxy_dev->state |= STATE_WAIT_RESPONSE_FLAG;
> +
> +	mutex_unlock(&proxy_dev->buf_lock);
> +
> +	if (rc)
> +		return -EFAULT;
> +
> +	return len;
> +}
> +
> +/**
> + * vtpm_proxy_fops_write - Write TPM responses on 'server side'
> + *
> + * Return value:
> + *	Number of bytes read or negative error value
> + */
> +static ssize_t vtpm_proxy_fops_write(struct file *filp, const char __user *buf,
> +				     size_t count, loff_t *off)
> +{
> +	struct proxy_dev *proxy_dev = filp->private_data;
> +
> +	mutex_lock(&proxy_dev->buf_lock);
> +
> +	if (count > sizeof(proxy_dev->buffer) ||
> +	    !(proxy_dev->state & STATE_WAIT_RESPONSE_FLAG)) {
> +		mutex_unlock(&proxy_dev->buf_lock);
> +		return -EIO;
> +	}
> +
> +	proxy_dev->state &= ~STATE_WAIT_RESPONSE_FLAG;
> +
> +	proxy_dev->req_len = 0;
> +
> +	if (copy_from_user(proxy_dev->buffer, buf, count)) {
> +		mutex_unlock(&proxy_dev->buf_lock);
> +		return -EFAULT;
> +	}
> +
> +	proxy_dev->resp_len = count;
> +
> +	mutex_unlock(&proxy_dev->buf_lock);
> +
> +	wake_up_interruptible(&proxy_dev->wq);
> +
> +	return count;
> +}
> +
> +/*
> + * vtpm_proxy_fops_poll: Poll status on 'server side'
> + *
> + * Return value:
> + *      Poll flags
> + */
> +static unsigned int vtpm_proxy_fops_poll(struct file *filp, poll_table *wait)
> +{
> +	struct proxy_dev *proxy_dev = filp->private_data;
> +	unsigned ret;
> +
> +	poll_wait(filp, &proxy_dev->wq, wait);
> +
> +	ret = POLLOUT;
> +
> +	mutex_lock(&proxy_dev->buf_lock);
> +
> +	if (proxy_dev->req_len)
> +		ret |= POLLIN | POLLRDNORM;
> +
> +	mutex_unlock(&proxy_dev->buf_lock);
> +
> +	return ret;
> +}
> +
> +/*
> + * vtpm_proxy_fops_open - Open vTPM device on 'server side'
> + *
> + * Called when setting up the anonymous file descriptor
> + */
> +static void vtpm_proxy_fops_open(struct file *filp)
> +{
> +	struct proxy_dev *proxy_dev = filp->private_data;
> +
> +	proxy_dev->state |= STATE_OPENED_FLAG;
> +}
> +
> +/**
> + * vtpm_proxy_fops_undo_open - counter-part to vtpm_fops_open
> + *
> + * Call to undo vtpm_proxy_fops_open
> + */
> +static void vtpm_proxy_fops_undo_open(struct proxy_dev *proxy_dev)
> +{
> +	mutex_lock(&proxy_dev->buf_lock);
> +
> +	proxy_dev->state &= ~STATE_OPENED_FLAG;
> +
> +	mutex_unlock(&proxy_dev->buf_lock);
> +
> +	/* no more TPM responses -- wake up anyone waiting for them */
> +	wake_up_interruptible(&proxy_dev->wq);
> +}
> +
> +/*
> + * vtpm_proxy_fops_release: Close 'server side'
> + *
> + * Return value:
> + *      Always returns 0.
> + */
> +static int vtpm_proxy_fops_release(struct inode *inode, struct file *filp)
> +{
> +	struct proxy_dev *proxy_dev = filp->private_data;
> +
> +	filp->private_data = NULL;
> +
> +	vtpm_proxy_delete_device(proxy_dev);
> +
> +	return 0;
> +}
> +
> +static const struct file_operations vtpm_proxy_fops = {
> +	.owner = THIS_MODULE,
> +	.llseek = no_llseek,
> +	.read = vtpm_proxy_fops_read,
> +	.write = vtpm_proxy_fops_write,
> +	.poll = vtpm_proxy_fops_poll,
> +	.release = vtpm_proxy_fops_release,
> +};
> +
> +/*
> + * Functions invoked by the core TPM driver to send TPM commands to
> + * 'server side' and receive responses from there.
> + */
> +
> +/*
> + * Called when core TPM driver reads TPM responses from 'server side'
> + *
> + * Return value:
> + *      Number of TPM response bytes read, negative error value otherwise
> + */
> +static int vtpm_proxy_tpm_op_recv(struct tpm_chip *chip, u8 *buf, size_t count)
> +{
> +	struct proxy_dev *proxy_dev = chip->vendor.priv;
> +	size_t len;
> +
> +	if (!proxy_dev)
> +		return -EIO;
> +
> +	/* process gone ? */
> +	mutex_lock(&proxy_dev->buf_lock);
> +
> +	if (!(proxy_dev->state & STATE_OPENED_FLAG)) {
> +		mutex_unlock(&proxy_dev->buf_lock);
> +		return -EPIPE;
> +	}
> +
> +	len = proxy_dev->resp_len;
> +	if (count < len) {
> +		dev_err(&chip->dev,
> +			"Invalid size in recv: count=%zd, resp_len=%zd\n",
> +			count, len);
> +		len = -EIO;
> +		goto out;
> +	}
> +
> +	memcpy(buf, proxy_dev->buffer, len);
> +	proxy_dev->resp_len = 0;
> +
> +out:
> +	mutex_unlock(&proxy_dev->buf_lock);
> +
> +	return len;
> +}
> +
> +/*
> + * Called when core TPM driver forwards TPM requests to 'server side'.
> + *
> + * Return value:
> + *      0 in case of success, negative error value otherwise.
> + */
> +static int vtpm_proxy_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t count)
> +{
> +	struct proxy_dev *proxy_dev = chip->vendor.priv;
> +	int rc = 0;
> +
> +	if (!proxy_dev)
> +		return -EIO;
> +
> +	if (count > sizeof(proxy_dev->buffer)) {
> +		dev_err(&chip->dev,
> +			"Invalid size in send: count=%zd, buffer size=%zd\n",
> +			count, sizeof(proxy_dev->buffer));
> +		return -EIO;
> +	}
> +
> +	mutex_lock(&proxy_dev->buf_lock);
> +
> +	if (!(proxy_dev->state & STATE_OPENED_FLAG)) {
> +		mutex_unlock(&proxy_dev->buf_lock);
> +		return -EPIPE;
> +	}
> +
> +	proxy_dev->resp_len = 0;
> +
> +	proxy_dev->req_len = count;
> +	memcpy(proxy_dev->buffer, buf, count);
> +
> +	proxy_dev->state &= ~STATE_WAIT_RESPONSE_FLAG;
> +
> +	mutex_unlock(&proxy_dev->buf_lock);
> +
> +	wake_up_interruptible(&proxy_dev->wq);
> +
> +	return rc;
> +}
> +
> +static void vtpm_proxy_tpm_op_cancel(struct tpm_chip *chip)
> +{
> +	/* not supported */
> +}
> +
> +static u8 vtpm_proxy_tpm_op_status(struct tpm_chip *chip)
> +{
> +	struct proxy_dev *proxy_dev = chip->vendor.priv;
> +
> +	if (proxy_dev->resp_len)
> +		return VTPM_PROXY_REQ_COMPLETE_FLAG;
> +
> +	return 0;
> +}
> +
> +static bool vtpm_proxy_tpm_req_canceled(struct tpm_chip  *chip, u8 status)
> +{
> +	struct proxy_dev *proxy_dev = chip->vendor.priv;
> +	bool ret;
> +
> +	mutex_lock(&proxy_dev->buf_lock);
> +
> +	ret = !(proxy_dev->state & STATE_OPENED_FLAG);
> +
> +	mutex_unlock(&proxy_dev->buf_lock);
> +
> +	return ret;
> +}
> +
> +static const struct tpm_class_ops vtpm_proxy_tpm_ops = {
> +	.recv = vtpm_proxy_tpm_op_recv,
> +	.send = vtpm_proxy_tpm_op_send,
> +	.cancel = vtpm_proxy_tpm_op_cancel,
> +	.status = vtpm_proxy_tpm_op_status,
> +	.req_complete_mask = VTPM_PROXY_REQ_COMPLETE_FLAG,
> +	.req_complete_val = VTPM_PROXY_REQ_COMPLETE_FLAG,
> +	.req_canceled = vtpm_proxy_tpm_req_canceled,
> +};
> +
> +/*
> + * Code related to creation and deletion of device pairs
> + */
> +static struct proxy_dev *vtpm_proxy_create_proxy_dev(void)
> +{
> +	struct proxy_dev *proxy_dev;
> +	struct tpm_chip *chip;
> +	int err;
> +
> +	proxy_dev = kzalloc(sizeof(*proxy_dev), GFP_KERNEL);
> +	if (proxy_dev == NULL)
> +		return ERR_PTR(-ENOMEM);
> +
> +	init_waitqueue_head(&proxy_dev->wq);
> +	mutex_init(&proxy_dev->buf_lock);
> +
> +	chip = tpm_chip_alloc(NULL, &vtpm_proxy_tpm_ops);
> +	if (IS_ERR(chip)) {
> +		err = PTR_ERR(chip);
> +		goto err_proxy_dev_free;
> +	}
> +	chip->vendor.priv = proxy_dev;
> +
> +	proxy_dev->chip = chip;
> +
> +	return proxy_dev;
> +
> +err_proxy_dev_free:
> +	kfree(proxy_dev);
> +
> +	return ERR_PTR(err);
> +}
> +
> +/*
> + * Undo what has been done in vtpm_create_proxy_dev
> + */
> +static inline void vtpm_proxy_delete_proxy_dev(struct proxy_dev *proxy_dev)
> +{
> +	put_device(&proxy_dev->chip->dev); /* frees chip */
> +	kfree(proxy_dev);
> +}
> +
> +/*
> + * Create a /dev/tpm%d and 'server side' file descriptor pair
> + *
> + * Return value:
> + *      Returns file pointer on success, an error value otherwise
> + */
> +static struct file *vtpm_proxy_create_device(
> +				 struct vtpm_proxy_new_dev *vtpm_new_dev)
> +{
> +	struct proxy_dev *proxy_dev;
> +	int rc, fd;
> +	struct file *file;
> +
> +	if (vtpm_new_dev->flags & ~VTPM_PROXY_FLAGS_ALL)
> +		return ERR_PTR(-EOPNOTSUPP);
> +
> +	proxy_dev = vtpm_proxy_create_proxy_dev();
> +	if (IS_ERR(proxy_dev))
> +		return ERR_CAST(proxy_dev);
> +
> +	proxy_dev->flags = vtpm_new_dev->flags;
> +
> +	/* setup an anonymous file for the server-side */
> +	fd = get_unused_fd_flags(O_RDWR);
> +	if (fd < 0) {
> +		rc = fd;
> +		goto err_delete_proxy_dev;
> +	}
> +
> +	file = anon_inode_getfile("[vtpms]", &vtpm_proxy_fops, proxy_dev,
> +				  O_RDWR);
> +	if (IS_ERR(file)) {
> +		rc = PTR_ERR(file);
> +		goto err_put_unused_fd;
> +	}
> +
> +	/* from now on we can unwind with put_unused_fd() + fput() */
> +	/* simulate an open() on the server side */
> +	vtpm_proxy_fops_open(file);
> +
> +	if (proxy_dev->flags & VTPM_PROXY_FLAG_TPM2)
> +		proxy_dev->chip->flags |= TPM_CHIP_FLAG_TPM2;
> +
> +	rc = tpm_chip_register(proxy_dev->chip);
> +	if (rc)
> +		goto err_vtpm_fput;
> +
> +	vtpm_new_dev->fd = fd;
> +	vtpm_new_dev->major = MAJOR(proxy_dev->chip->dev.devt);
> +	vtpm_new_dev->minor = MINOR(proxy_dev->chip->dev.devt);
> +	vtpm_new_dev->tpm_num = proxy_dev->chip->dev_num;
> +
> +	return file;
> +
> +err_vtpm_fput:
> +	put_unused_fd(fd);
> +	fput(file);
> +
> +	return ERR_PTR(rc);
> +
> +err_put_unused_fd:
> +	put_unused_fd(fd);
> +
> +err_delete_proxy_dev:
> +	vtpm_proxy_delete_proxy_dev(proxy_dev);
> +
> +	return ERR_PTR(rc);
> +}
> +
> +/*
> + * Counter part to vtpm_create_device.
> + */
> +static void vtpm_proxy_delete_device(struct proxy_dev *proxy_dev)
> +{
> +	/*
> +	 * A client may hold the 'ops' lock, so let it know that the server
> +	 * side shuts down before we try to grab the 'ops' lock when
> +	 * unregistering the chip.
> +	 */
> +	vtpm_proxy_fops_undo_open(proxy_dev);
> +
> +	tpm_chip_unregister(proxy_dev->chip);
> +
> +	vtpm_proxy_delete_proxy_dev(proxy_dev);
> +}
> +
> +/*
> + * Code related to the control device /dev/vtpmx
> + */
> +
> +/*
> + * vtpmx_fops_ioctl: ioctl on /dev/vtpmx
> + *
> + * Return value:
> + *      Returns 0 on success, a negative error code otherwise.
> + */
> +static long vtpmx_fops_ioctl(struct file *f, unsigned int ioctl,
> +				   unsigned long arg)
> +{
> +	void __user *argp = (void __user *)arg;
> +	struct vtpm_proxy_new_dev *vtpm_new_dev_p;
> +	struct vtpm_proxy_new_dev vtpm_new_dev;
> +	struct file *file;
> +
> +	switch (ioctl) {
> +	case VTPM_PROXY_IOC_NEW_DEV:
> +		if (!capable(CAP_SYS_ADMIN))
> +			return -EPERM;
> +		vtpm_new_dev_p = argp;
> +		if (copy_from_user(&vtpm_new_dev, vtpm_new_dev_p,
> +				   sizeof(vtpm_new_dev)))
> +			return -EFAULT;
> +		file = vtpm_proxy_create_device(&vtpm_new_dev);
> +		if (IS_ERR(file))
> +			return PTR_ERR(file);
> +		if (copy_to_user(vtpm_new_dev_p, &vtpm_new_dev,
> +				 sizeof(vtpm_new_dev))) {
> +			put_unused_fd(vtpm_new_dev.fd);
> +			fput(file);
> +			return -EFAULT;
> +		}
> +
> +		fd_install(vtpm_new_dev.fd, file);
> +		return 0;
> +
> +	default:
> +		return -ENOIOCTLCMD;
> +	}
> +}
> +
> +#ifdef CONFIG_COMPAT
> +static long vtpmx_fops_compat_ioctl(struct file *f, unsigned int ioctl,
> +					  unsigned long arg)
> +{
> +	return vtpmx_fops_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
> +}
> +#endif
> +
> +static const struct file_operations vtpmx_fops = {
> +	.owner = THIS_MODULE,
> +	.unlocked_ioctl = vtpmx_fops_ioctl,
> +#ifdef CONFIG_COMPAT
> +	.compat_ioctl = vtpmx_fops_compat_ioctl,
> +#endif
> +	.llseek = noop_llseek,
> +};
> +
> +static struct miscdevice vtpmx_miscdev = {
> +	.minor = MISC_DYNAMIC_MINOR,
> +	.name = "vtpmx",
> +	.fops = &vtpmx_fops,
> +};
> +
> +static int vtpmx_init(void)
> +{
> +	return misc_register(&vtpmx_miscdev);
> +}
> +
> +static void vtpmx_cleanup(void)
> +{
> +	misc_deregister(&vtpmx_miscdev);
> +}
> +
> +static int __init vtpm_module_init(void)
> +{
> +	int rc;
> +
> +	rc = vtpmx_init();
> +	if (rc) {
> +		pr_err("couldn't create vtpmx device\n");
> +		return rc;
> +	}
> +
> +	return 0;
> +}
> +
> +static void __exit vtpm_module_exit(void)
> +{
> +	vtpmx_cleanup();
> +}
> +
> +module_init(vtpm_module_init);
> +module_exit(vtpm_module_exit);
> +
> +MODULE_AUTHOR("Stefan Berger (stefanb@us.ibm.com)");
> +MODULE_DESCRIPTION("vTPM Driver");
> +MODULE_VERSION("0.1");
> +MODULE_LICENSE("GPL");
> diff --git a/include/uapi/linux/Kbuild b/include/uapi/linux/Kbuild
> index ebd10e6..ac767ce 100644
> --- a/include/uapi/linux/Kbuild
> +++ b/include/uapi/linux/Kbuild
> @@ -449,6 +449,7 @@ header-y += virtio_scsi.h
>  header-y += virtio_types.h
>  header-y += vm_sockets.h
>  header-y += vt.h
> +header-y += vtpm_proxy.h
>  header-y += wait.h
>  header-y += wanrouter.h
>  header-y += watchdog.h
> diff --git a/include/uapi/linux/vtpm_proxy.h b/include/uapi/linux/vtpm_proxy.h
> new file mode 100644
> index 0000000..dc73f00
> --- /dev/null
> +++ b/include/uapi/linux/vtpm_proxy.h
> @@ -0,0 +1,42 @@
> +/*
> + * Definitions for the VTPM proxy driver
> + * Copyright (c) 2015, 2016, IBM Corporation
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + */
> +
> +#ifndef _UAPI_LINUX_VTPM_PROXY_H
> +#define _UAPI_LINUX_VTPM_PROXY_H
> +
> +#include <linux/types.h>
> +#include <linux/ioctl.h>
> +
> +/* ioctls */
> +
> +struct vtpm_proxy_new_dev {
> +	__u32 flags;         /* input */
> +	__u32 tpm_num;       /* output */
> +	__u32 fd;            /* output */
> +	__u32 major;         /* output */
> +	__u32 minor;         /* output */
> +};
> +
> +/* above flags */
> +#define VTPM_PROXY_FLAG_TPM2  1  /* emulator is TPM 2 */
> +
> +/* all supported flags */
> +#define VTPM_PROXY_FLAGS_ALL  (VTPM_PROXY_FLAG_TPM2)

This can be moved inside the .c-file?

> +
> +#define VTPM_PROXY_MAGIC 0xa1
> +
> +#define VTPM_PROXY_IOC_NEW_DEV   _IOW(VTPM_PROXY_MAGIC, 0x00, \
> +				      struct vtpm_proxy_new_dev)

Could we simply replace these four lines with one line:

#deifne VTPM_PROXY_IOC_NEW_DEV _IOW('t', 0x00, struct vtpm_proxy_new_dev);

I changed the magic but does it matter?

> +
> +#endif /* _UAPI_LINUX_VTPM_PROXY_H */
> -- 
> 2.4.3

/Jarkko

Re: [PATCH v8 08/10] tpm: Proxy driver for supporting multiple emulated TPMs

[Stefan Berger]

On 03/16/2016 04:42 PM, Jarkko Sakkinen wrote:
> On Sun, Mar 13, 2016 at 06:54:38PM -0400, Stefan Berger wrote:
>> +
>> +/* above flags */
>> +#define VTPM_PROXY_FLAG_TPM2  1  /* emulator is TPM 2 */
>> +
>> +/* all supported flags */
>> +#define VTPM_PROXY_FLAGS_ALL  (VTPM_PROXY_FLAG_TPM2)
> This can be moved inside the .c-file?

I can move that.

>
>> +
>> +#define VTPM_PROXY_MAGIC 0xa1
>> +
>> +#define VTPM_PROXY_IOC_NEW_DEV   _IOW(VTPM_PROXY_MAGIC, 0x00, \
>> +				      struct vtpm_proxy_new_dev)
> Could we simply replace these four lines with one line:
>
> #deifne VTPM_PROXY_IOC_NEW_DEV _IOW('t', 0x00, struct vtpm_proxy_new_dev);

Does this make it better?

>
> I changed the magic but does it matter?

I would keep the magic at '0xa1'. The documentation is written to '0xa1' 
now and seems to be good just as any other.

    Stefan

Re: [PATCH v8 08/10] tpm: Proxy driver for supporting multiple emulated TPMs

[Jarkko Sakkinen]

On Thu, Mar 17, 2016 at 01:45:20PM -0400, Stefan Berger wrote:
> On 03/16/2016 04:42 PM, Jarkko Sakkinen wrote:
> >On Sun, Mar 13, 2016 at 06:54:38PM -0400, Stefan Berger wrote:
> >>+
> >>+/* above flags */
> >>+#define VTPM_PROXY_FLAG_TPM2  1  /* emulator is TPM 2 */
> >>+
> >>+/* all supported flags */
> >>+#define VTPM_PROXY_FLAGS_ALL  (VTPM_PROXY_FLAG_TPM2)
> >This can be moved inside the .c-file?
> 
> I can move that.
> 
> >
> >>+
> >>+#define VTPM_PROXY_MAGIC 0xa1
> >>+
> >>+#define VTPM_PROXY_IOC_NEW_DEV   _IOW(VTPM_PROXY_MAGIC, 0x00, \
> >>+				      struct vtpm_proxy_new_dev)
> >Could we simply replace these four lines with one line:
> >
> >#deifne VTPM_PROXY_IOC_NEW_DEV _IOW('t', 0x00, struct vtpm_proxy_new_dev);
> 
> Does this make it better?
> 
> >
> >I changed the magic but does it matter?
> 
> I would keep the magic at '0xa1'. The documentation is written to '0xa1' now
> and seems to be good just as any other.

OK. Works for me. Keep the ioctl definition as it is.

Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

I can move the constant. You don't have to send a new patch version
anymore. I start keeping this patch in my master but will not merge it
to next before 4.6-rc5 so at the moment it would be scheduled for 4.7.
Does this sound good for you?

Further improvemnts should be sent as separate fixup patches.

>    Stefan

/Jarkko

Re: [PATCH v8 08/10] tpm: Proxy driver for supporting multiple emulated TPMs

[Stefan Berger]

[-- Attachment #1.1: Type: text/plain, Size: 1132 bytes --]

Jarkko Sakkinen <jarkko.sakkinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org> wrote on 03/18/2016 
04:52:00 AM:


> Subject: Re: [tpmdd-devel] [PATCH v8 08/10] tpm: Proxy driver for 
> supporting multiple emulated TPMs
> 
> On Thu, Mar 17, 2016 at 01:45:20PM -0400, Stefan Berger wrote:
> > On 03/16/2016 04:42 PM, Jarkko Sakkinen wrote:
> > >On Sun, Mar 13, 2016 at 06:54:38PM -0400, Stefan Berger wrote:
> > >>+
> > >>+/* above flags */
> > >>+#define VTPM_PROXY_FLAG_TPM2  1  /* emulator is TPM 2 */
> > >>+
> > >>+/* all supported flags */
> > >>+#define VTPM_PROXY_FLAGS_ALL  (VTPM_PROXY_FLAG_TPM2)
> > >This can be moved inside the .c-file?
> > 
> > I can move that.
> > 
> > >
> > >>+
> > >>+#define VTPM_PROXY_MAGIC 0xa1
> > >>+
> > >>+#define VTPM_PROXY_IOC_NEW_DEV   _IOW(VTPM_PROXY_MAGIC, 0x00, \
> > >>+                  struct vtpm_proxy_new_dev)
> > >Could we simply replace these four lines with one line:
> > >
> > >#deifne VTPM_PROXY_IOC_NEW_DEV _IOW('t', 0x00, struct 
vtpm_proxy_new_dev);

Just move the 0xa1 over the 't' and we can get rid of the 
VTPM_PROXY_MAGIC.

   Stefan



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[-- Attachment #2: Type: text/plain, Size: 291 bytes --]

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Re: [PATCH v8 08/10] tpm: Proxy driver for supporting multiple emulated TPMs

[Jarkko Sakkinen]

On Fri, Mar 18, 2016 at 10:52:00AM +0200, Jarkko Sakkinen wrote:
> On Thu, Mar 17, 2016 at 01:45:20PM -0400, Stefan Berger wrote:
> > On 03/16/2016 04:42 PM, Jarkko Sakkinen wrote:
> > >On Sun, Mar 13, 2016 at 06:54:38PM -0400, Stefan Berger wrote:
> > >>+
> > >>+/* above flags */
> > >>+#define VTPM_PROXY_FLAG_TPM2  1  /* emulator is TPM 2 */
> > >>+
> > >>+/* all supported flags */
> > >>+#define VTPM_PROXY_FLAGS_ALL  (VTPM_PROXY_FLAG_TPM2)
> > >This can be moved inside the .c-file?
> > 
> > I can move that.
> > 
> > >
> > >>+
> > >>+#define VTPM_PROXY_MAGIC 0xa1
> > >>+
> > >>+#define VTPM_PROXY_IOC_NEW_DEV   _IOW(VTPM_PROXY_MAGIC, 0x00, \
> > >>+				      struct vtpm_proxy_new_dev)
> > >Could we simply replace these four lines with one line:
> > >
> > >#deifne VTPM_PROXY_IOC_NEW_DEV _IOW('t', 0x00, struct vtpm_proxy_new_dev);
> > 
> > Does this make it better?
> > 
> > >
> > >I changed the magic but does it matter?
> > 
> > I would keep the magic at '0xa1'. The documentation is written to '0xa1' now
> > and seems to be good just as any other.
> 
> OK. Works for me. Keep the ioctl definition as it is.
> 
> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> 
> I can move the constant. You don't have to send a new patch version
> anymore. I start keeping this patch in my master but will not merge it
> to next before 4.6-rc5 so at the moment it would be scheduled for 4.7.
> Does this sound good for you?
> 
> Further improvemnts should be sent as separate fixup patches.

Applied to git://git.infradead.org/users/jjs/linux-tpmdd.git.

/Jarkko

[PATCH v8 09/10] tpm: Initialize TPM and get durations and timeouts

[Stefan Berger]

Add the retrieval of TPM 1.2 durations and timeouts. Since this requires
the startup of the TPM, do this for TPM 1.2 and TPM 2.

Signed-off-by: Stefan Berger <stefanb-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
CC: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
CC: linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
CC: linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
---
 drivers/char/tpm/tpm_vtpm_proxy.c | 95 +++++++++++++++++++++++++++++++++++----
 1 file changed, 86 insertions(+), 9 deletions(-)

diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c
index 2bb2c8c..7fd686b 100644
--- a/drivers/char/tpm/tpm_vtpm_proxy.c
+++ b/drivers/char/tpm/tpm_vtpm_proxy.c
@@ -45,8 +45,11 @@ struct proxy_dev {
 	size_t req_len;              /* length of queued TPM request */
 	size_t resp_len;             /* length of queued TPM response */
 	u8 buffer[TPM_BUFSIZE];      /* request/response buffer */
+
+	struct work_struct work;     /* task that retrieves TPM timeouts */
 };
 
+static struct workqueue_struct *workqueue;
 
 static void vtpm_proxy_delete_device(struct proxy_dev *proxy_dev);
 
@@ -67,6 +70,15 @@ static ssize_t vtpm_proxy_fops_read(struct file *filp, char __user *buf,
 	size_t len;
 	int sig, rc;
 
+	mutex_lock(&proxy_dev->buf_lock);
+
+	if (!(proxy_dev->state & STATE_OPENED_FLAG)) {
+		mutex_unlock(&proxy_dev->buf_lock);
+		return -EPIPE;
+	}
+
+	mutex_unlock(&proxy_dev->buf_lock);
+
 	sig = wait_event_interruptible(proxy_dev->wq, proxy_dev->req_len != 0);
 	if (sig)
 		return -EINTR;
@@ -110,6 +122,11 @@ static ssize_t vtpm_proxy_fops_write(struct file *filp, const char __user *buf,
 
 	mutex_lock(&proxy_dev->buf_lock);
 
+	if (!(proxy_dev->state & STATE_OPENED_FLAG)) {
+		mutex_unlock(&proxy_dev->buf_lock);
+		return -EPIPE;
+	}
+
 	if (count > sizeof(proxy_dev->buffer) ||
 	    !(proxy_dev->state & STATE_WAIT_RESPONSE_FLAG)) {
 		mutex_unlock(&proxy_dev->buf_lock);
@@ -154,6 +171,9 @@ static unsigned int vtpm_proxy_fops_poll(struct file *filp, poll_table *wait)
 	if (proxy_dev->req_len)
 		ret |= POLLIN | POLLRDNORM;
 
+	if (!(proxy_dev->state & STATE_OPENED_FLAG))
+		ret |= POLLHUP;
+
 	mutex_unlock(&proxy_dev->buf_lock);
 
 	return ret;
@@ -341,6 +361,55 @@ static const struct tpm_class_ops vtpm_proxy_tpm_ops = {
 };
 
 /*
+ * Code related to the startup of the TPM 2 and startup of TPM 1.2 +
+ * retrieval of timeouts and durations.
+ */
+
+static void vtpm_proxy_work(struct work_struct *work)
+{
+	struct proxy_dev *proxy_dev = container_of(work, struct proxy_dev,
+						   work);
+	int rc;
+
+	if (proxy_dev->flags & VTPM_PROXY_FLAG_TPM2)
+		rc = tpm2_startup(proxy_dev->chip, TPM2_SU_CLEAR);
+	else
+		rc = tpm_get_timeouts(proxy_dev->chip);
+
+	if (rc)
+		goto err;
+
+	rc = tpm_chip_register(proxy_dev->chip);
+	if (rc)
+		goto err;
+
+	return;
+
+err:
+	vtpm_proxy_fops_undo_open(proxy_dev);
+}
+
+/*
+ * vtpm_proxy_work_stop: make sure the work has finished
+ *
+ * This function is useful when user space closed the fd
+ * while the driver still determines timeouts.
+ */
+static void vtpm_proxy_work_stop(struct proxy_dev *proxy_dev)
+{
+	vtpm_proxy_fops_undo_open(proxy_dev);
+	flush_work(&proxy_dev->work);
+}
+
+/*
+ * vtpm_proxy_work_start: Schedule the work for TPM 1.2 & 2 initialization
+ */
+static inline void vtpm_proxy_work_start(struct proxy_dev *proxy_dev)
+{
+	queue_work(workqueue, &proxy_dev->work);
+}
+
+/*
  * Code related to creation and deletion of device pairs
  */
 static struct proxy_dev *vtpm_proxy_create_proxy_dev(void)
@@ -355,6 +424,7 @@ static struct proxy_dev *vtpm_proxy_create_proxy_dev(void)
 
 	init_waitqueue_head(&proxy_dev->wq);
 	mutex_init(&proxy_dev->buf_lock);
+	INIT_WORK(&proxy_dev->work, vtpm_proxy_work);
 
 	chip = tpm_chip_alloc(NULL, &vtpm_proxy_tpm_ops);
 	if (IS_ERR(chip)) {
@@ -425,9 +495,7 @@ static struct file *vtpm_proxy_create_device(
 	if (proxy_dev->flags & VTPM_PROXY_FLAG_TPM2)
 		proxy_dev->chip->flags |= TPM_CHIP_FLAG_TPM2;
 
-	rc = tpm_chip_register(proxy_dev->chip);
-	if (rc)
-		goto err_vtpm_fput;
+	vtpm_proxy_work_start(proxy_dev);
 
 	vtpm_new_dev->fd = fd;
 	vtpm_new_dev->major = MAJOR(proxy_dev->chip->dev.devt);
@@ -436,12 +504,6 @@ static struct file *vtpm_proxy_create_device(
 
 	return file;
 
-err_vtpm_fput:
-	put_unused_fd(fd);
-	fput(file);
-
-	return ERR_PTR(rc);
-
 err_put_unused_fd:
 	put_unused_fd(fd);
 
@@ -456,6 +518,8 @@ err_delete_proxy_dev:
  */
 static void vtpm_proxy_delete_device(struct proxy_dev *proxy_dev)
 {
+	vtpm_proxy_work_stop(proxy_dev);
+
 	/*
 	 * A client may hold the 'ops' lock, so let it know that the server
 	 * side shuts down before we try to grab the 'ops' lock when
@@ -555,11 +619,24 @@ static int __init vtpm_module_init(void)
 		return rc;
 	}
 
+	workqueue = create_workqueue("tpm-vtpm");
+	if (!workqueue) {
+		pr_err("couldn't create workqueue\n");
+		rc = -ENOMEM;
+		goto err_vtpmx_cleanup;
+	}
+
 	return 0;
+
+err_vtpmx_cleanup:
+	vtpmx_cleanup();
+
+	return rc;
 }
 
 static void __exit vtpm_module_exit(void)
 {
+	destroy_workqueue(workqueue);
 	vtpmx_cleanup();
 }
 
-- 
2.4.3


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Re: [v8,09/10] tpm: Initialize TPM and get durations and timeouts

[Jarkko Sakkinen]

On Sun, Mar 13, 2016 at 06:54:39PM -0400, Stefan Berger wrote:
> Add the retrieval of TPM 1.2 durations and timeouts. Since this requires
> the startup of the TPM, do this for TPM 1.2 and TPM 2.
> 
> Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
> CC: linux-kernel@vger.kernel.org
> CC: linux-doc@vger.kernel.org
> CC: linux-api@vger.kernel.org
> 
> ---
> drivers/char/tpm/tpm_vtpm_proxy.c | 95 +++++++++++++++++++++++++++++++++++----
>  1 file changed, 86 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c
> index 2bb2c8c..7fd686b 100644
> --- a/drivers/char/tpm/tpm_vtpm_proxy.c
> +++ b/drivers/char/tpm/tpm_vtpm_proxy.c
> @@ -45,8 +45,11 @@ struct proxy_dev {
>  	size_t req_len;              /* length of queued TPM request */
>  	size_t resp_len;             /* length of queued TPM response */
>  	u8 buffer[TPM_BUFSIZE];      /* request/response buffer */
> +
> +	struct work_struct work;     /* task that retrieves TPM timeouts */
>  };
>  
> +static struct workqueue_struct *workqueue;
>  
>  static void vtpm_proxy_delete_device(struct proxy_dev *proxy_dev);
>  
> @@ -67,6 +70,15 @@ static ssize_t vtpm_proxy_fops_read(struct file *filp, char __user *buf,
>  	size_t len;
>  	int sig, rc;
>  
> +	mutex_lock(&proxy_dev->buf_lock);
> +
> +	if (!(proxy_dev->state & STATE_OPENED_FLAG)) {
> +		mutex_unlock(&proxy_dev->buf_lock);
> +		return -EPIPE;
> +	}
> +
> +	mutex_unlock(&proxy_dev->buf_lock);
> +
>  	sig = wait_event_interruptible(proxy_dev->wq, proxy_dev->req_len != 0);
>  	if (sig)
>  		return -EINTR;

What if STATE_OPENED_FLAG is set after mutex_unlock()?

Is there some scenario where STATE_OPENED_FLAG would evaluate false
at this point?

Actually I couldn't find a scenario where this check would be needed
because:

* In vtpm_proxy_work() vtpm_proxy_fops_undo_open() is called after
  sending TPM commands.
* vtpm_proxy_delete_device() calls vtpm_proxy_work_stop() as its
  first statement.

Am I ignoring something?

/Jarkko


> @@ -110,6 +122,11 @@ static ssize_t vtpm_proxy_fops_write(struct file *filp, const char __user *buf,
>  
>  	mutex_lock(&proxy_dev->buf_lock);
>  
> +	if (!(proxy_dev->state & STATE_OPENED_FLAG)) {
> +		mutex_unlock(&proxy_dev->buf_lock);
> +		return -EPIPE;
> +	}
> +
>  	if (count > sizeof(proxy_dev->buffer) ||
>  	    !(proxy_dev->state & STATE_WAIT_RESPONSE_FLAG)) {
>  		mutex_unlock(&proxy_dev->buf_lock);
> @@ -154,6 +171,9 @@ static unsigned int vtpm_proxy_fops_poll(struct file *filp, poll_table *wait)
>  	if (proxy_dev->req_len)
>  		ret |= POLLIN | POLLRDNORM;
>  
> +	if (!(proxy_dev->state & STATE_OPENED_FLAG))
> +		ret |= POLLHUP;
> +
>  	mutex_unlock(&proxy_dev->buf_lock);
>  
>  	return ret;
> @@ -341,6 +361,55 @@ static const struct tpm_class_ops vtpm_proxy_tpm_ops = {
>  };
>  
>  /*
> + * Code related to the startup of the TPM 2 and startup of TPM 1.2 +
> + * retrieval of timeouts and durations.
> + */
> +
> +static void vtpm_proxy_work(struct work_struct *work)
> +{
> +	struct proxy_dev *proxy_dev = container_of(work, struct proxy_dev,
> +						   work);
> +	int rc;
> +
> +	if (proxy_dev->flags & VTPM_PROXY_FLAG_TPM2)
> +		rc = tpm2_startup(proxy_dev->chip, TPM2_SU_CLEAR);
> +	else
> +		rc = tpm_get_timeouts(proxy_dev->chip);
> +
> +	if (rc)
> +		goto err;
> +
> +	rc = tpm_chip_register(proxy_dev->chip);
> +	if (rc)
> +		goto err;
> +
> +	return;
> +
> +err:
> +	vtpm_proxy_fops_undo_open(proxy_dev);
> +}
> +
> +/*
> + * vtpm_proxy_work_stop: make sure the work has finished
> + *
> + * This function is useful when user space closed the fd
> + * while the driver still determines timeouts.
> + */
> +static void vtpm_proxy_work_stop(struct proxy_dev *proxy_dev)
> +{
> +	vtpm_proxy_fops_undo_open(proxy_dev);
> +	flush_work(&proxy_dev->work);
> +}
> +
> +/*
> + * vtpm_proxy_work_start: Schedule the work for TPM 1.2 & 2 initialization
> + */
> +static inline void vtpm_proxy_work_start(struct proxy_dev *proxy_dev)
> +{
> +	queue_work(workqueue, &proxy_dev->work);
> +}
> +
> +/*
>   * Code related to creation and deletion of device pairs
>   */
>  static struct proxy_dev *vtpm_proxy_create_proxy_dev(void)
> @@ -355,6 +424,7 @@ static struct proxy_dev *vtpm_proxy_create_proxy_dev(void)
>  
>  	init_waitqueue_head(&proxy_dev->wq);
>  	mutex_init(&proxy_dev->buf_lock);
> +	INIT_WORK(&proxy_dev->work, vtpm_proxy_work);
>  
>  	chip = tpm_chip_alloc(NULL, &vtpm_proxy_tpm_ops);
>  	if (IS_ERR(chip)) {
> @@ -425,9 +495,7 @@ static struct file *vtpm_proxy_create_device(
>  	if (proxy_dev->flags & VTPM_PROXY_FLAG_TPM2)
>  		proxy_dev->chip->flags |= TPM_CHIP_FLAG_TPM2;
>  
> -	rc = tpm_chip_register(proxy_dev->chip);
> -	if (rc)
> -		goto err_vtpm_fput;
> +	vtpm_proxy_work_start(proxy_dev);
>  
>  	vtpm_new_dev->fd = fd;
>  	vtpm_new_dev->major = MAJOR(proxy_dev->chip->dev.devt);
> @@ -436,12 +504,6 @@ static struct file *vtpm_proxy_create_device(
>  
>  	return file;
>  
> -err_vtpm_fput:
> -	put_unused_fd(fd);
> -	fput(file);
> -
> -	return ERR_PTR(rc);
> -
>  err_put_unused_fd:
>  	put_unused_fd(fd);
>  
> @@ -456,6 +518,8 @@ err_delete_proxy_dev:
>   */
>  static void vtpm_proxy_delete_device(struct proxy_dev *proxy_dev)
>  {
> +	vtpm_proxy_work_stop(proxy_dev);
> +
>  	/*
>  	 * A client may hold the 'ops' lock, so let it know that the server
>  	 * side shuts down before we try to grab the 'ops' lock when
> @@ -555,11 +619,24 @@ static int __init vtpm_module_init(void)
>  		return rc;
>  	}
>  
> +	workqueue = create_workqueue("tpm-vtpm");
> +	if (!workqueue) {
> +		pr_err("couldn't create workqueue\n");
> +		rc = -ENOMEM;
> +		goto err_vtpmx_cleanup;
> +	}
> +
>  	return 0;
> +
> +err_vtpmx_cleanup:
> +	vtpmx_cleanup();
> +
> +	return rc;
>  }
>  
>  static void __exit vtpm_module_exit(void)
>  {
> +	destroy_workqueue(workqueue);
>  	vtpmx_cleanup();
>  }
>  

Re: [v8,09/10] tpm: Initialize TPM and get durations and timeouts

[Stefan Berger]

On 03/22/2016 02:34 AM, Jarkko Sakkinen wrote:
> On Sun, Mar 13, 2016 at 06:54:39PM -0400, Stefan Berger wrote:
>> Add the retrieval of TPM 1.2 durations and timeouts. Since this requires
>> the startup of the TPM, do this for TPM 1.2 and TPM 2.
>>
>> Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
>> CC: linux-kernel@vger.kernel.org
>> CC: linux-doc@vger.kernel.org
>> CC: linux-api@vger.kernel.org
>>
>> ---
>> drivers/char/tpm/tpm_vtpm_proxy.c | 95 +++++++++++++++++++++++++++++++++++----
>>   1 file changed, 86 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c
>> index 2bb2c8c..7fd686b 100644
>> --- a/drivers/char/tpm/tpm_vtpm_proxy.c
>> +++ b/drivers/char/tpm/tpm_vtpm_proxy.c
>> @@ -45,8 +45,11 @@ struct proxy_dev {
>>   	size_t req_len;              /* length of queued TPM request */
>>   	size_t resp_len;             /* length of queued TPM response */
>>   	u8 buffer[TPM_BUFSIZE];      /* request/response buffer */
>> +
>> +	struct work_struct work;     /* task that retrieves TPM timeouts */
>>   };
>>   
>> +static struct workqueue_struct *workqueue;
>>   
>>   static void vtpm_proxy_delete_device(struct proxy_dev *proxy_dev);
>>   
>> @@ -67,6 +70,15 @@ static ssize_t vtpm_proxy_fops_read(struct file *filp, char __user *buf,
>>   	size_t len;
>>   	int sig, rc;
>>   
>> +	mutex_lock(&proxy_dev->buf_lock);
>> +
>> +	if (!(proxy_dev->state & STATE_OPENED_FLAG)) {
>> +		mutex_unlock(&proxy_dev->buf_lock);
>> +		return -EPIPE;
>> +	}
>> +
>> +	mutex_unlock(&proxy_dev->buf_lock);
>> +
>>   	sig = wait_event_interruptible(proxy_dev->wq, proxy_dev->req_len != 0);
>>   	if (sig)
>>   		return -EINTR;
> What if STATE_OPENED_FLAG is set after mutex_unlock()?

This flag is only set when the file descriptor for the server side is 
created (vtpm_proxy_fops_open()). After that it can only be cleared 
(vtpm_fops_undo_open()) due to an error condition, which then indicates 
to the server side that the file descriptor is now unusable. One error 
condition can for example be the failure by the TPM emulator to respond 
to the TPM_Startup with a success in the response.


>
> Is there some scenario where STATE_OPENED_FLAG would evaluate false
> at this point?

Yes. The flag is reset in vtpm_fops_undo_open(), which is for example 
called in error conditions detected by the worker thread 
(vtpm_proxy_work()) where the server side for example didn't deliver the 
timeouts and durations or the TPM_Startup() wasn't successful.

>
> Actually I couldn't find a scenario where this check would be needed
> because:
>
> * In vtpm_proxy_work() vtpm_proxy_fops_undo_open() is called after
>    sending TPM commands.
> * vtpm_proxy_delete_device() calls vtpm_proxy_work_stop() as its
>    first statement.
>
> Am I ignoring something?

Does the above explain it? The file descriptor is not closed by any 
failure condition, so it stays around but it becomes 'useless' if the 
work thread detected an error by the TPM emulator.

     Stefan

Re: [v8,09/10] tpm: Initialize TPM and get durations and timeoutsg

[Jarkko Sakkinen]

On Tue, Mar 22, 2016 at 06:54:30AM -0400, Stefan Berger wrote:
> On 03/22/2016 02:34 AM, Jarkko Sakkinen wrote:
> >On Sun, Mar 13, 2016 at 06:54:39PM -0400, Stefan Berger wrote:
> >>Add the retrieval of TPM 1.2 durations and timeouts. Since this requires
> >>the startup of the TPM, do this for TPM 1.2 and TPM 2.
> >>
> >>Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
> >>CC: linux-kernel@vger.kernel.org
> >>CC: linux-doc@vger.kernel.org
> >>CC: linux-api@vger.kernel.org
> >>
> >>---
> >>drivers/char/tpm/tpm_vtpm_proxy.c | 95 +++++++++++++++++++++++++++++++++++----
> >>  1 file changed, 86 insertions(+), 9 deletions(-)
> >>
> >>diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c
> >>index 2bb2c8c..7fd686b 100644
> >>--- a/drivers/char/tpm/tpm_vtpm_proxy.c
> >>+++ b/drivers/char/tpm/tpm_vtpm_proxy.c
> >>@@ -45,8 +45,11 @@ struct proxy_dev {
> >>  	size_t req_len;              /* length of queued TPM request */
> >>  	size_t resp_len;             /* length of queued TPM response */
> >>  	u8 buffer[TPM_BUFSIZE];      /* request/response buffer */
> >>+
> >>+	struct work_struct work;     /* task that retrieves TPM timeouts */
> >>  };
> >>+static struct workqueue_struct *workqueue;
> >>  static void vtpm_proxy_delete_device(struct proxy_dev *proxy_dev);
> >>@@ -67,6 +70,15 @@ static ssize_t vtpm_proxy_fops_read(struct file *filp, char __user *buf,
> >>  	size_t len;
> >>  	int sig, rc;
> >>+	mutex_lock(&proxy_dev->buf_lock);
> >>+
> >>+	if (!(proxy_dev->state & STATE_OPENED_FLAG)) {
> >>+		mutex_unlock(&proxy_dev->buf_lock);
> >>+		return -EPIPE;
> >>+	}
> >>+
> >>+	mutex_unlock(&proxy_dev->buf_lock);
> >>+
> >>  	sig = wait_event_interruptible(proxy_dev->wq, proxy_dev->req_len != 0);
> >>  	if (sig)
> >>  		return -EINTR;
> >What if STATE_OPENED_FLAG is set after mutex_unlock()?
> 
> This flag is only set when the file descriptor for the server side is
> created (vtpm_proxy_fops_open()). After that it can only be cleared
> (vtpm_fops_undo_open()) due to an error condition, which then indicates to
> the server side that the file descriptor is now unusable. One error
> condition can for example be the failure by the TPM emulator to respond to
> the TPM_Startup with a success in the response.

You take the lock two times and OPENED flag could change in-between.

Why couldn't you put the call after wait_event_* after taking the lock?

/Jarkko

Re: [v8,09/10] tpm: Initialize TPM and get durations and timeoutsg

[Stefan Berger]

On 03/29/2016 11:31 AM, Jarkko Sakkinen wrote:
> On Tue, Mar 22, 2016 at 06:54:30AM -0400, Stefan Berger wrote:
>> On 03/22/2016 02:34 AM, Jarkko Sakkinen wrote:
>>> On Sun, Mar 13, 2016 at 06:54:39PM -0400, Stefan Berger wrote:
>>>> Add the retrieval of TPM 1.2 durations and timeouts. Since this requires
>>>> the startup of the TPM, do this for TPM 1.2 and TPM 2.
>>>>
>>>> Signed-off-by: Stefan Berger <stefanb-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
>>>> CC: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
>>>> CC: linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
>>>> CC: linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
>>>>
>>>> ---
>>>> drivers/char/tpm/tpm_vtpm_proxy.c | 95 +++++++++++++++++++++++++++++++++++----
>>>>   1 file changed, 86 insertions(+), 9 deletions(-)
>>>>
>>>> diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c
>>>> index 2bb2c8c..7fd686b 100644
>>>> --- a/drivers/char/tpm/tpm_vtpm_proxy.c
>>>> +++ b/drivers/char/tpm/tpm_vtpm_proxy.c
>>>> @@ -45,8 +45,11 @@ struct proxy_dev {
>>>>   	size_t req_len;              /* length of queued TPM request */
>>>>   	size_t resp_len;             /* length of queued TPM response */
>>>>   	u8 buffer[TPM_BUFSIZE];      /* request/response buffer */
>>>> +
>>>> +	struct work_struct work;     /* task that retrieves TPM timeouts */
>>>>   };
>>>> +static struct workqueue_struct *workqueue;
>>>>   static void vtpm_proxy_delete_device(struct proxy_dev *proxy_dev);
>>>> @@ -67,6 +70,15 @@ static ssize_t vtpm_proxy_fops_read(struct file *filp, char __user *buf,
>>>>   	size_t len;
>>>>   	int sig, rc;
>>>> +	mutex_lock(&proxy_dev->buf_lock);
>>>> +
>>>> +	if (!(proxy_dev->state & STATE_OPENED_FLAG)) {
>>>> +		mutex_unlock(&proxy_dev->buf_lock);
>>>> +		return -EPIPE;
>>>> +	}
>>>> +
>>>> +	mutex_unlock(&proxy_dev->buf_lock);
>>>> +
>>>>   	sig = wait_event_interruptible(proxy_dev->wq, proxy_dev->req_len != 0);
>>>>   	if (sig)
>>>>   		return -EINTR;
>>> What if STATE_OPENED_FLAG is set after mutex_unlock()?
>> This flag is only set when the file descriptor for the server side is
>> created (vtpm_proxy_fops_open()). After that it can only be cleared
>> (vtpm_fops_undo_open()) due to an error condition, which then indicates to
>> the server side that the file descriptor is now unusable. One error
>> condition can for example be the failure by the TPM emulator to respond to
>> the TPM_Startup with a success in the response.
> You take the lock two times and OPENED flag could change in-between.
>
> Why couldn't you put the call after wait_event_* after taking the lock?

Good point. Actually the test for the flag has to go into the 
wait_event_interruptible test (without mutex?!) and we have to look at 
that flag after the wait_event_interruptible again to check whether no 
more requests are coming due to the OPEN flag not being set anymore as 
result of an error condition.

I can post a v9 with that change. However, the dropping of the priv 
field from the vendor struct  in the other patch series, will again 
require changes either here or in that other series.

     Stefan

[PATCH v8 10/10] tpm: Add documentation for the tpm_vtpm device driver

[Stefan Berger]

Add documentation for the tpm_vtpm device driver that implements
support for providing TPM functionality to Linux containers.

Parts of this documentation were recycled from the Xen vTPM
device driver documentation.

Update the documentation for the ioctl numbers.

Signed-off-by: Stefan Berger <stefanb-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
CC: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
CC: linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
CC: linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
---
 Documentation/ioctl/ioctl-number.txt |  1 +
 Documentation/tpm/tpm_vtpm_proxy.txt | 71 ++++++++++++++++++++++++++++++++++++
 2 files changed, 72 insertions(+)
 create mode 100644 Documentation/tpm/tpm_vtpm_proxy.txt

diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt
index 91261a3..7dbec90 100644
--- a/Documentation/ioctl/ioctl-number.txt
+++ b/Documentation/ioctl/ioctl-number.txt
@@ -303,6 +303,7 @@ Code  Seq#(hex)	Include File		Comments
 					<mailto:buk-KMFVLCTwZAcb1SvskN2V4Q@public.gmane.org>
 0xA0	all	linux/sdp/sdp.h		Industrial Device Project
 					<mailto:kenji-/mrfy+mawvNBDgjK7y7TUQ@public.gmane.org>
+0xA1	0	linux/vtpm_proxy.h	TPM Emulator Proxy Driver
 0xA2	00-0F	arch/tile/include/asm/hardwall.h
 0xA3	80-8F	Port ACL		in development:
 					<mailto:tlewis-mn4gwa5WIIQysxA8WJXlww@public.gmane.org>
diff --git a/Documentation/tpm/tpm_vtpm_proxy.txt b/Documentation/tpm/tpm_vtpm_proxy.txt
new file mode 100644
index 0000000..30d1902
--- /dev/null
+++ b/Documentation/tpm/tpm_vtpm_proxy.txt
@@ -0,0 +1,71 @@
+Virtual TPM Proxy Driver for Linux Containers
+
+Authors: Stefan Berger (IBM)
+
+This document describes the virtual Trusted Platform Module (vTPM)
+proxy device driver for Linux containers.
+
+INTRODUCTION
+------------
+
+The goal of this work is to provide TPM functionality to each Linux
+container. This allows programs to interact with a TPM in a container
+the same way they interact with a TPM on the physical system. Each
+container gets its own unique, emulated, software TPM.
+
+
+DESIGN
+------
+
+To make an emulated software TPM available to each container, the container
+management stack needs to create a device pair consisting of a client TPM
+character device /dev/tpmX (with X=0,1,2...) and a 'server side' file
+descriptor. The former is moved into the container by creating a character
+device with the appropriate major and minor numbers while the file descriptor
+is passed to the TPM emulator. Software inside the container can then send
+TPM commands using the character device and the emulator will receive the
+commands via the file descriptor and use it for sending back responses.
+
+To support this, the virtual TPM proxy driver provides a device /dev/vtpmx
+that is used to create device pairs using an ioctl. The ioctl takes as
+an input flags for configuring the device. The flags  for example indicate
+whether TPM 1.2 or TPM 2 functionality is supported by the TPM emulator.
+The result of the ioctl are the file descriptor for the 'server side'
+as well as the major and minor numbers of the character device that was created.
+Besides that the number of the TPM character device is return. If for
+example /dev/tpm10 was created, the number (dev_num) 10 is returned.
+
+The following is the data structure of the TPM_PROXY_IOC_NEW_DEV ioctl:
+
+struct vtpm_proxy_new_dev {
+	__u32 flags;         /* input */
+	__u32 tpm_num;       /* output */
+	__u32 fd;            /* output */
+	__u32 major;         /* output */
+	__u32 minor;         /* output */
+};
+
+Note that if unsupported flags are passed to the device driver, the ioctl will
+fail and errno will be set to EOPNOTSUPP. Similarly, if an unsupported ioctl is
+called on the device driver, the ioctl will fail and errno will be set to
+ENOTTY.
+
+See /usr/include/linux/vtpm_proxy.h for definitions related to the public interface
+of this vTPM device driver.
+
+Once the device has been created, the driver will immediately try to talk
+to the TPM. All commands from the driver can be read from the file descriptor
+returned by the ioctl. The commands should be responded to immediately.
+
+Depending on the version of TPM the following commands will be sent by the
+driver:
+
+- TPM 1.2:
+  - the driver will send a TPM_Startup command to the TPM emulator
+  - the driver will send commands to read the command durations and
+    interface timeouts from the TPM emulator
+- TPM 2:
+  - the driver will send a TPM2_Startup command to the TPM emulator
+
+The TPM device /dev/tpmX will only appear if all of the relevant commands
+were responded to properly.
-- 
2.4.3


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