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[PATCH v10 0/5] Multi-instance vTPM proxy driver

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  [PATCH v10 0/5] Multi-instance vTPM proxy driver Stefan Berger <stefanb@linux.vnet.ibm.com> - 2016-04-15 16:00 +0200
    [PATCH v10 4/5] tpm: Initialize TPM and get durations and timeouts Stefan Berger <stefanb@linux.vnet.ibm.com> - 2016-04-15 16:00 +0200
      Re: [PATCH v10 4/5] tpm: Initialize TPM and get durations and  timeouts Jason Gunthorpe <jgunthorpe@obsidianresearch.com> - 2016-04-15 19:20 +0200

#1379833 — [PATCH v10 0/5] Multi-instance vTPM proxy driver

The following series of patches implements a multi-instance vTPM 
proxy driver that can dynamically create TPM 'server' and client device
pairs.

Using an ioctl on the provided /dev/vtpmx, a client-side vTPM device
and a server side file descriptor is created. The file descriptor must
be passed to a TPM emulator. The device driver will initialize the
emulated TPM using TPM 1.2 or TPM 2 startup commands and it will read
the command durations from the device in case of a TPM 1.2. The choice
of emulated TPM device (1.2 or 2) must be provided with a flag in
the ioctl.

The patches are based on the tip of a recent checkout of Jarkko's tree
(master branch).

   Stefan

v9->v10:
 - add new patch 1 with sysfs related rework; reworked patch 2 as a consequence
 - patch 3: fixed ioctl from using _IOW to using _IOWR (reinstall headers
   and rebuild test tools)
 - patch 3: do not use priv field anymore but uses dev_set_drvdata /
   dev_get_drvdata instead now

v8->v9:
 - move constant from public header into tpm_vtpm_proxy.c
 - Replaced VTPM_PROXY_MAGIC in ioctl definition with its value (0xa1)
 - Check for the STATE_OPEN_FLAG in wait_event_interruptable and after
   returning from it

v7->v8:
 - minor tweaks on the documentation
 - Reordered function calls in the VTPM proxy driver's server side release
   function so that a client holding the 'ops' lock releases it before the
   driver tries to grab the lock when unregistering the device.

v6->v7:
 - Adjusted name of driver to tpm_vtpm_proxy from tpm_vtpm. Adjust function
   names, names of structures, and names of constants.
 - Adjusted IOCTL to use magic 0xa1 rather than the completely used 0xa0.
 - Extended driver documentation and added documentation of ioctl.
 - Moved test program to own project (dropped patch 11).

v5->v6:
 - Adapted errno's for unsupported flags and ioctls following Jason's
   comments

v4->v5:
 - Introduced different error codes for unsupported flags and ioctls
 - Added documentation patch




Jason Gunthorpe (1):
  tpm: Remove all uses of drvdata from the TPM Core

Stefan Berger (4):
  tpm: Introduce TPM_CHIP_FLAG_VIRTUAL
  tpm: Proxy driver for supporting multiple emulated TPMs
  tpm: Initialize TPM and get durations and timeouts
  tpm: Add documentation for the tpm_vtpm_proxy device driver

 Documentation/ioctl/ioctl-number.txt |   1 +
 Documentation/tpm/tpm_vtpm_proxy.txt |  71 ++++
 drivers/char/tpm/Kconfig             |  10 +
 drivers/char/tpm/Makefile            |   1 +
 drivers/char/tpm/tpm-chip.c          |  76 ++--
 drivers/char/tpm/tpm-interface.c     |   7 +-
 drivers/char/tpm/tpm-sysfs.c         |  61 ++--
 drivers/char/tpm/tpm.h               |  11 +-
 drivers/char/tpm/tpm_vtpm_proxy.c    | 650 +++++++++++++++++++++++++++++++++++
 include/uapi/linux/Kbuild            |   1 +
 include/uapi/linux/vtpm_proxy.h      |  36 ++
 11 files changed, 858 insertions(+), 67 deletions(-)
 create mode 100644 Documentation/tpm/tpm_vtpm_proxy.txt
 create mode 100644 drivers/char/tpm/tpm_vtpm_proxy.c
 create mode 100644 include/uapi/linux/vtpm_proxy.h

-- 
2.4.3

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#1379837 — [PATCH v10 4/5] tpm: Initialize TPM and get durations and timeouts

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 a81e814..3b09458 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

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#1380047 — Re: [PATCH v10 4/5] tpm: Initialize TPM and get durations and timeouts

On Fri, Apr 15, 2016 at 09:50:15AM -0400, Stefan Berger wrote:

> @@ -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;

This hunk and related doesn't look like it belongs in this patch?

Suggest just merging this into the prior patch and be done with it, not
really any reason to have two patches anymore.

I think everything that was brought up is taken care of now..

One last read through..

> static int vtpm_proxy_tpm_op_recv(struct tpm_chip *chip, u8 *buf, size_t count)
> {
>	struct proxy_dev *proxy_dev = dev_get_drvdata(&chip->dev);
>	if (!proxy_dev)
>		return -EIO;

Is that actually possible? It shouldn't be. If not please drop it an
related.

For both:
Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>

Jason

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