[PATCH v9 2/4] tpm: Proxy driver for supporting multiple emulated TPMs

[PATCH v9 2/4] 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 | 574 ++++++++++++++++++++++++++++++++++++++
 include/uapi/linux/Kbuild         |   1 +
 include/uapi/linux/vtpm_proxy.h   |  36 +++
 5 files changed, 622 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..81abc4b
--- /dev/null
+++ b/drivers/char/tpm/tpm_vtpm_proxy.c
@@ -0,0 +1,574 @@
+/*
+ * 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 */
+};
+
+/* all supported flags */
+#define VTPM_PROXY_FLAGS_ALL  (VTPM_PROXY_FLAG_TPM2)
+
+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..e8af365
--- /dev/null
+++ b/include/uapi/linux/vtpm_proxy.h
@@ -0,0 +1,36 @@
+/*
+ * 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 */
+
+#define VTPM_PROXY_IOC_NEW_DEV   _IOW(0xa1, 0x00, struct vtpm_proxy_new_dev)
+
+#endif /* _UAPI_LINUX_VTPM_PROXY_H */
-- 
2.4.3


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Re: [PATCH v9 2/4] tpm: Proxy driver for supporting multiple emulated TPMs

[Jarkko Sakkinen]

On Tue, Mar 29, 2016 at 02:19:12PM -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

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

/Jarkko

> ---
>  drivers/char/tpm/Kconfig          |  10 +
>  drivers/char/tpm/Makefile         |   1 +
>  drivers/char/tpm/tpm_vtpm_proxy.c | 574 ++++++++++++++++++++++++++++++++++++++
>  include/uapi/linux/Kbuild         |   1 +
>  include/uapi/linux/vtpm_proxy.h   |  36 +++
>  5 files changed, 622 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..81abc4b
> --- /dev/null
> +++ b/drivers/char/tpm/tpm_vtpm_proxy.c
> @@ -0,0 +1,574 @@
> +/*
> + * 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 */
> +};
> +
> +/* all supported flags */
> +#define VTPM_PROXY_FLAGS_ALL  (VTPM_PROXY_FLAG_TPM2)
> +
> +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..e8af365
> --- /dev/null
> +++ b/include/uapi/linux/vtpm_proxy.h
> @@ -0,0 +1,36 @@
> +/*
> + * 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 */
> +
> +#define VTPM_PROXY_IOC_NEW_DEV   _IOW(0xa1, 0x00, struct vtpm_proxy_new_dev)
> +
> +#endif /* _UAPI_LINUX_VTPM_PROXY_H */
> -- 
> 2.4.3
> 
> --
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> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH v9 2/4] tpm: Proxy driver for supporting multiple emulated TPMs

[Stefan Berger]

On 04/07/2016 08:35 AM, Jarkko Sakkinen wrote:
> On Tue, Mar 29, 2016 at 02:19:12PM -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
> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> Tested-by: Jarkko Sakkinen <jarkko.sakkinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>

Thanks. So I can post a v10 where I have to re-introduce the priv field 
but put it into the tpm_chip struct. Obviously it needs this field. I am 
not sure whether you'll let me take the Reviewed-by and Tested-by, though?

    Stefan

Re: [PATCH v9 2/4] tpm: Proxy driver for supporting multiple emulated TPMs

[Jarkko Sakkinen]

On Thu, Apr 07, 2016 at 11:49:44AM -0400, Stefan Berger wrote:
> On 04/07/2016 08:35 AM, Jarkko Sakkinen wrote:
> >On Tue, Mar 29, 2016 at 02:19:12PM -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
> >Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> >Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> 
> Thanks. So I can post a v10 where I have to re-introduce the priv field but
> put it into the tpm_chip struct. Obviously it needs this field. I am not
> sure whether you'll let me take the Reviewed-by and Tested-by, though?

Lets hold for them then. I'll do retest when I get the new series.

>    Stefan

/Jarkko

Re: [PATCH v9 2/4] tpm: Proxy driver for supporting multiple emulated TPMs

[Jason Gunthorpe]

On Mon, Apr 11, 2016 at 11:43:58AM +0300, Jarkko Sakkinen wrote:
> On Thu, Apr 07, 2016 at 11:49:44AM -0400, Stefan Berger wrote:
> > On 04/07/2016 08:35 AM, Jarkko Sakkinen wrote:
> > >On Tue, Mar 29, 2016 at 02:19:12PM -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
> > >Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> > >Tested-by: Jarkko Sakkinen <jarkko.sakkinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> > 
> > Thanks. So I can post a v10 where I have to re-introduce the priv field but
> > put it into the tpm_chip struct. Obviously it needs this field. I am not
> > sure whether you'll let me take the Reviewed-by and Tested-by, though?
> 
> Lets hold for them then. I'll do retest when I get the new series.

Lets just fix the sysfs stuff the same way we fixed ppi and be done
with this issue.

Something that looks kinda like this untested thing:

diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c
index a7c3473c3421..51e898be4307 100644
--- a/drivers/char/tpm/tpm-sysfs.c
+++ b/drivers/char/tpm/tpm-sysfs.c
@@ -36,7 +36,7 @@ static ssize_t pubek_show(struct device *dev, struct device_attribute *attr,
 	int i, rc;
 	char *str = buf;
 
-	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct tpm_chip *chip = to_tpm_chip(dev);
 
 	tpm_cmd.header.in = tpm_readpubek_header;
 	err = tpm_transmit_cmd(chip, &tpm_cmd, READ_PUBEK_RESULT_SIZE,
@@ -92,7 +92,7 @@ static ssize_t pcrs_show(struct device *dev, struct device_attribute *attr,
 	ssize_t rc;
 	int i, j, num_pcrs;
 	char *str = buf;
-	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct tpm_chip *chip = to_tpm_chip(dev);
 
 	rc = tpm_getcap(dev, TPM_CAP_PROP_PCR, &cap,
 			"attempting to determine the number of PCRS");
@@ -222,7 +222,7 @@ static DEVICE_ATTR_RO(caps);
 static ssize_t cancel_store(struct device *dev, struct device_attribute *attr,
 			    const char *buf, size_t count)
 {
-	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct tpm_chip *chip = to_tpm_chip(dev);
 	if (chip == NULL)
 		return 0;
 
@@ -234,7 +234,7 @@ static DEVICE_ATTR_WO(cancel);
 static ssize_t durations_show(struct device *dev, struct device_attribute *attr,
 			      char *buf)
 {
-	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct tpm_chip *chip = to_tpm_chip(dev);
 
 	if (chip->duration[TPM_LONG] == 0)
 		return 0;
@@ -251,7 +251,7 @@ static DEVICE_ATTR_RO(durations);
 static ssize_t timeouts_show(struct device *dev, struct device_attribute *attr,
 			     char *buf)
 {
-	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct tpm_chip *chip = to_tpm_chip(dev);
 
 	return sprintf(buf, "%d %d %d %d [%s]\n",
 		       jiffies_to_usecs(chip->timeout_a),
@@ -283,22 +283,33 @@ static const struct attribute_group tpm_dev_group = {
 
 int tpm_sysfs_add_device(struct tpm_chip *chip)
 {
-	int err;
-	err = sysfs_create_group(&chip->dev.parent->kobj,
-				 &tpm_dev_group);
+	const struct attribute **i;
 
-	if (err)
-		dev_err(&chip->dev,
-			"failed to create sysfs attributes, %d\n", err);
-	return err;
+	chip->groups[chip->groups_cnt++] = &tpm_dev_group;
+	if (chip->flags & TPM_CHIP_FLAG_TPM2)
+		return 0;
+
+	for (i = tpm_dev_attrs; *i != NULL; ++i) {
+		rc = __compat_only_sysfs_link_entry_to_kobj(
+		    &chip->dev.parent->kobj, &chip->dev.kobj, (*i)->name);
+		if (rc && rc != -ENOENT) {
+			tpm_sysfs_del_device(chip);
+			return rc;
+		}
+	}
+
+	return 0;
 }
 
 void tpm_sysfs_del_device(struct tpm_chip *chip)
 {
-	/* The sysfs routines rely on an implicit tpm_try_get_ops, this
-	 * function is called before ops is null'd and the sysfs core
-	 * synchronizes this removal so that no callbacks are running or can
-	 * run again
+	const struct attribute **i;
+
+	/* The sysfs routines rely on an implicit tpm_try_get_ops, device_del
+	 * is called before ops is null'd and the sysfs core synchronizes this
+	 * removal so that no callbacks are running or can run again
 	 */
-	sysfs_remove_group(&chip->dev.parent->kobj, &tpm_dev_group);
+
+	for (i = tpm_dev_attrs; *i != NULL; ++i)
+		sysfs_remove_link(&chip->dev.parent->kobj, (*i)->name);
 }

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[PATCH v9 3/4] 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@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 | 96 +++++++++++++++++++++++++++++++++++----
 1 file changed, 86 insertions(+), 10 deletions(-)

diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c
index 81abc4b..8936bf3 100644
--- a/drivers/char/tpm/tpm_vtpm_proxy.c
+++ b/drivers/char/tpm/tpm_vtpm_proxy.c
@@ -45,11 +45,15 @@ 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 */
 };
 
 /* all supported flags */
 #define VTPM_PROXY_FLAGS_ALL  (VTPM_PROXY_FLAG_TPM2)
 
+static struct workqueue_struct *workqueue;
+
 static void vtpm_proxy_delete_device(struct proxy_dev *proxy_dev);
 
 /*
@@ -69,12 +73,19 @@ static ssize_t vtpm_proxy_fops_read(struct file *filp, char __user *buf,
 	size_t len;
 	int sig, rc;
 
-	sig = wait_event_interruptible(proxy_dev->wq, proxy_dev->req_len != 0);
+	sig = wait_event_interruptible(proxy_dev->wq,
+		proxy_dev->req_len != 0 ||
+		!(proxy_dev->state & STATE_OPENED_FLAG));
 	if (sig)
 		return -EINTR;
 
 	mutex_lock(&proxy_dev->buf_lock);
 
+	if (!(proxy_dev->state & STATE_OPENED_FLAG)) {
+		mutex_unlock(&proxy_dev->buf_lock);
+		return -EPIPE;
+	}
+
 	len = proxy_dev->req_len;
 
 	if (count < len) {
@@ -112,6 +123,11 @@ 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);
@@ -156,6 +172,9 @@ 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;
@@ -343,6 +362,55 @@ 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)
@@ -357,6 +425,7 @@ 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)) {
@@ -427,9 +496,7 @@ 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);
@@ -438,12 +505,6 @@ 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);
 
@@ -458,6 +519,8 @@ 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
@@ -557,11 +620,24 @@ 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

Re: [v9, 3/4] tpm: Initialize TPM and get durations and timeouts

[Jarkko Sakkinen]

On Tue, Mar 29, 2016 at 02:19:13PM -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 | 96 +++++++++++++++++++++++++++++++++++----
>  1 file changed, 86 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c
> index 81abc4b..8936bf3 100644
> --- a/drivers/char/tpm/tpm_vtpm_proxy.c
> +++ b/drivers/char/tpm/tpm_vtpm_proxy.c
> @@ -45,11 +45,15 @@ 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 */
>  };
>  
>  /* all supported flags */
>  #define VTPM_PROXY_FLAGS_ALL  (VTPM_PROXY_FLAG_TPM2)
>  
> +static struct workqueue_struct *workqueue;
> +
>  static void vtpm_proxy_delete_device(struct proxy_dev *proxy_dev);
>  
>  /*
> @@ -69,12 +73,19 @@ static ssize_t vtpm_proxy_fops_read(struct file *filp, char __user *buf,
>  	size_t len;
>  	int sig, rc;
>  
> -	sig = wait_event_interruptible(proxy_dev->wq, proxy_dev->req_len != 0);
> +	sig = wait_event_interruptible(proxy_dev->wq,
> +		proxy_dev->req_len != 0 ||
> +		!(proxy_dev->state & STATE_OPENED_FLAG));
>  	if (sig)
>  		return -EINTR;
>  
>  	mutex_lock(&proxy_dev->buf_lock);
>  
> +	if (!(proxy_dev->state & STATE_OPENED_FLAG)) {
> +		mutex_unlock(&proxy_dev->buf_lock);
> +		return -EPIPE;
> +	}
> +
>  	len = proxy_dev->req_len;
>  
>  	if (count < len) {
> @@ -112,6 +123,11 @@ 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);
> @@ -156,6 +172,9 @@ 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;
> @@ -343,6 +362,55 @@ 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);

The main proxy driver patch should implement cancel() callback and then
these could be swapped. This whole use of OPENED callback looks like a
hack that is done because cancel is not implemented.

A new flag CANCELED could be added and functions would return -ECANCEL
if it is set. This should be part of original vTPM proxy driver
functionally.

The current solution is unclean and hard to follow. It looks like "it
could work" but the OPENED flag has too many hats that it wears IMHO.

/Jarkko

> +}
> +
> +/*
> + * 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)
> @@ -357,6 +425,7 @@ 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)) {
> @@ -427,9 +496,7 @@ 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);
> @@ -438,12 +505,6 @@ 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);
>  
> @@ -458,6 +519,8 @@ 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
> @@ -557,11 +620,24 @@ 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();
>  }
>  

------------------------------------------------------------------------------
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Re: [v9,3/4] tpm: Initialize TPM and get durations and timeouts

[Stefan Berger]

On 03/31/2016 04:24 AM, Jarkko Sakkinen wrote:
> On Tue, Mar 29, 2016 at 02:19:13PM -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.

>> @@ -343,6 +362,55 @@ 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);
> The main proxy driver patch should implement cancel() callback and then
> these could be swapped. This whole use of OPENED callback looks like a
> hack that is done because cancel is not implemented.

What OPENED callback are you referring to? We have a OPENED flag but not 
a callback.

The above handles the case where the vTPM process for example dies 
[during TPM_Startup()] and the file descriptor is closed. 
vtpm_proxy_fops_undo_open() ensures that the vtpm thread is not stuck 
waiting for the response to the TPM_Startup(). The subsequent 
flush_work() ensures that the thread has finished before we continue 
shutting down the instance. This cannot be swapped.

> A new flag CANCELED could be added and functions would return -ECANCEL
> if it is set. This should be part of original vTPM proxy driver
> functionally.

The above has nothing to do with cancellation from what I can see. We 
have an OPENED flag now which is set when the driver is fully 
operational and cleared when it is not. We could instead use a SHUTDOWN 
or CLOSED flag that works with the reverse meaning, clearing it where 
OPENED is set now and setting it where OPENED is cleared. Would this help?

>
> The current solution is unclean and hard to follow. It looks like "it
> could work" but the OPENED flag has too many hats that it wears IMHO.

It has only one meaning which can be replaced with a flag as indicated 
above.

That it is tested in vtpm_tpm_req_canceled is due to it indicating that 
the driver is not operational for the current command anymore, which 
gets it out of the loop in tpm_transmit. It would probably be worse to 
return a status flag from the status() callback and return a flag in the 
req_complete_mask that would then end up calling the recv() callback 
when there is nothing to receive. So the way it is now it triggers 
-ECANCELED in the tpm_transmit loop, which seems appropriate.

    Stefan



>
> /Jarkko
>
>> +}
>> +
>> +/*
>> + * 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)
>> @@ -357,6 +425,7 @@ 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)) {
>> @@ -427,9 +496,7 @@ 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);
>> @@ -438,12 +505,6 @@ 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);
>>   
>> @@ -458,6 +519,8 @@ 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
>> @@ -557,11 +620,24 @@ 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: [v9, 3/4] tpm: Initialize TPM and get durations and timeouts

[Jarkko Sakkinen]

On Thu, Mar 31, 2016 at 08:58:47AM -0400, Stefan Berger wrote:
> On 03/31/2016 04:24 AM, Jarkko Sakkinen wrote:
> >On Tue, Mar 29, 2016 at 02:19:13PM -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.
> 
> >>@@ -343,6 +362,55 @@ 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);
> >The main proxy driver patch should implement cancel() callback and then
> >these could be swapped. This whole use of OPENED callback looks like a
> >hack that is done because cancel is not implemented.
> 
> What OPENED callback are you referring to? We have a OPENED flag but not a
> callback.
> 
> The above handles the case where the vTPM process for example dies [during
> TPM_Startup()] and the file descriptor is closed.
> vtpm_proxy_fops_undo_open() ensures that the vtpm thread is not stuck
> waiting for the response to the TPM_Startup(). The subsequent flush_work()
> ensures that the thread has finished before we continue shutting down the
> instance. This cannot be swapped.

Got you.


> >A new flag CANCELED could be added and functions would return -ECANCEL
> >if it is set. This should be part of original vTPM proxy driver
> >functionally.
> 
> The above has nothing to do with cancellation from what I can see. We have
> an OPENED flag now which is set when the driver is fully operational and
> cleared when it is not. We could instead use a SHUTDOWN or CLOSED flag that
> works with the reverse meaning, clearing it where OPENED is set now and
> setting it where OPENED is cleared. Would this help?
> 
> >
> >The current solution is unclean and hard to follow. It looks like "it
> >could work" but the OPENED flag has too many hats that it wears IMHO.
> 
> It has only one meaning which can be replaced with a flag as indicated
> above.
> 
> That it is tested in vtpm_tpm_req_canceled is due to it indicating that the
> driver is not operational for the current command anymore, which gets it out
> of the loop in tpm_transmit. It would probably be worse to return a status
> flag from the status() callback and return a flag in the req_complete_mask
> that would then end up calling the recv() callback when there is nothing to
> receive. So the way it is now it triggers -ECANCELED in the tpm_transmit
> loop, which seems appropriate.

Reviewd-by: Jarkko Sakkinen <jarkko.sakkinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>

>    Stefan


/Jarkko

> 
> 
> 
> >
> >/Jarkko
> >
> >>+}
> >>+
> >>+/*
> >>+ * 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)
> >>@@ -357,6 +425,7 @@ 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)) {
> >>@@ -427,9 +496,7 @@ 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);
> >>@@ -438,12 +505,6 @@ 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);
> >>@@ -458,6 +519,8 @@ 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
> >>@@ -557,11 +620,24 @@ 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();
> >>  }
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-security-module" in
> the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

------------------------------------------------------------------------------

Re: [v9,3/4] tpm: Initialize TPM and get durations and timeouts

[Jarkko Sakkinen]

On Tue, Apr 05, 2016 at 12:56:26PM +0300, Jarkko Sakkinen wrote:
> On Thu, Mar 31, 2016 at 08:58:47AM -0400, Stefan Berger wrote:
> > On 03/31/2016 04:24 AM, Jarkko Sakkinen wrote:
> > >On Tue, Mar 29, 2016 at 02:19:13PM -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.
> > 
> > >>@@ -343,6 +362,55 @@ 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);
> > >The main proxy driver patch should implement cancel() callback and then
> > >these could be swapped. This whole use of OPENED callback looks like a
> > >hack that is done because cancel is not implemented.
> > 
> > What OPENED callback are you referring to? We have a OPENED flag but not a
> > callback.
> > 
> > The above handles the case where the vTPM process for example dies [during
> > TPM_Startup()] and the file descriptor is closed.
> > vtpm_proxy_fops_undo_open() ensures that the vtpm thread is not stuck
> > waiting for the response to the TPM_Startup(). The subsequent flush_work()
> > ensures that the thread has finished before we continue shutting down the
> > instance. This cannot be swapped.
> 
> Got you.
> 
> 
> > >A new flag CANCELED could be added and functions would return -ECANCEL
> > >if it is set. This should be part of original vTPM proxy driver
> > >functionally.
> > 
> > The above has nothing to do with cancellation from what I can see. We have
> > an OPENED flag now which is set when the driver is fully operational and
> > cleared when it is not. We could instead use a SHUTDOWN or CLOSED flag that
> > works with the reverse meaning, clearing it where OPENED is set now and
> > setting it where OPENED is cleared. Would this help?
> > 
> > >
> > >The current solution is unclean and hard to follow. It looks like "it
> > >could work" but the OPENED flag has too many hats that it wears IMHO.
> > 
> > It has only one meaning which can be replaced with a flag as indicated
> > above.
> > 
> > That it is tested in vtpm_tpm_req_canceled is due to it indicating that the
> > driver is not operational for the current command anymore, which gets it out
> > of the loop in tpm_transmit. It would probably be worse to return a status
> > flag from the status() callback and return a flag in the req_complete_mask
> > that would then end up calling the recv() callback when there is nothing to
> > receive. So the way it is now it triggers -ECANCELED in the tpm_transmit
> > loop, which seems appropriate.
> 
> Reviewd-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

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

I apply all your remaining patches to my master and I've also run tests
with all of them succesfully (multiple times).

/Jarkko

> >    Stefan
> 
> 
> /Jarkko
> 
> > 
> > 
> > 
> > >
> > >/Jarkko
> > >
> > >>+}
> > >>+
> > >>+/*
> > >>+ * 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)
> > >>@@ -357,6 +425,7 @@ 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)) {
> > >>@@ -427,9 +496,7 @@ 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);
> > >>@@ -438,12 +505,6 @@ 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);
> > >>@@ -458,6 +519,8 @@ 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
> > >>@@ -557,11 +620,24 @@ 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();
> > >>  }
> > 
> > --
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[PATCH v9 4/4] 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@linux.vnet.ibm.com>
CC: linux-kernel@vger.kernel.org
CC: linux-doc@vger.kernel.org
CC: linux-api@vger.kernel.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@buks.ipn.de>
 0xA0	all	linux/sdp/sdp.h		Industrial Device Project
 					<mailto:kenji@bitgate.com>
+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@mindspring.com>
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

Re: [PATCH v9 4/4] tpm: Add documentation for the tpm_vtpm device driver

[Jarkko Sakkinen]

On Tue, Mar 29, 2016 at 02:19:14PM -0400, Stefan Berger wrote:
> 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

Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>

/Jarkko

> ---
>  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
>