From: Alistair Francis <alistair.francis@wdc.com>

Allow userspace to trigger a KeyUpdate via debugfs. This patch exposes a
key_update file that can be written to with the queue number to trigger
a KeyUpdate on that queue.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
v4:
 - No change
v3:
 - New patch

 drivers/nvme/host/tcp.c | 72 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)

diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index 791e0cc91ad8..f5c7b646d002 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -11,6 +11,7 @@
 #include <linux/crc32.h>
 #include <linux/nvme-tcp.h>
 #include <linux/nvme-keyring.h>
+#include <linux/debugfs.h>
 #include <net/sock.h>
 #include <net/tcp.h>
 #include <net/tls.h>
@@ -1429,6 +1430,75 @@ static void update_tls_keys(struct nvme_tcp_queue *queue)
 	}
 }
 
+#ifdef CONFIG_NVME_TCP_TLS
+#define NVME_DEBUGFS_RW_ATTR(field) \
+	static int field##_open(struct inode *inode, struct file *file) \
+	{ return single_open(file, field##_show, inode->i_private); } \
+	\
+	static const struct file_operations field##_fops = { \
+		.open = field##_open, \
+		.read = seq_read, \
+		.write = field##_write, \
+		.release = single_release, \
+	}
+
+static int nvme_ctrl_key_update_show(struct seq_file *m, void *p)
+{
+	seq_printf(m, "0\n");
+
+	return 0;
+}
+
+static ssize_t nvme_ctrl_key_update_write(struct file *file, const char __user *buf,
+					  size_t count, loff_t *ppos)
+{
+	struct seq_file *m = file->private_data;
+	struct nvme_ctrl *nctrl = m->private;
+	struct nvme_tcp_ctrl *ctrl = to_tcp_ctrl(nctrl);
+	char kbuf[16] = {0};
+	int queue_nr, rc;
+	struct nvme_tcp_queue *queue;
+
+	if (count > sizeof(kbuf) - 1)
+		return -EINVAL;
+	if (copy_from_user(kbuf, buf, count))
+		return -EFAULT;
+	kbuf[count] = 0;
+
+	rc = kstrtouint(kbuf, 10, &queue_nr);
+	if (rc)
+		return rc;
+
+	if (queue_nr >= nctrl->queue_count)
+		return -EINVAL;
+
+	queue = &ctrl->queues[queue_nr];
+
+	update_tls_keys(queue);
+
+	return count;
+}
+NVME_DEBUGFS_RW_ATTR(nvme_ctrl_key_update);
+#endif
+
+static void nvme_tcp_debugfs_init(struct nvme_ctrl *ctrl,
+			    const char *dev_name)
+{
+	struct dentry *parent;
+
+	/* create debugfs directory and attribute */
+	parent = debugfs_create_dir(dev_name, NULL);
+	if (IS_ERR(parent)) {
+		pr_warn("%s: failed to create debugfs directory\n", dev_name);
+		return;
+	}
+
+#ifdef CONFIG_NVME_TCP_TLS
+	debugfs_create_file("key_update", S_IWUSR, parent, ctrl,
+			    &nvme_ctrl_key_update_fops);
+#endif
+}
+
 static void nvme_tcp_io_work(struct work_struct *w)
 {
 	struct nvme_tcp_queue *queue =
@@ -3065,6 +3135,8 @@ static struct nvme_ctrl *nvme_tcp_create_ctrl(struct device *dev,
 	list_add_tail(&ctrl->list, &nvme_tcp_ctrl_list);
 	mutex_unlock(&nvme_tcp_ctrl_mutex);
 
+	nvme_tcp_debugfs_init(&ctrl->ctrl, dev_name(dev));
+
 	return &ctrl->ctrl;
 
 out_uninit_ctrl:
-- 
2.51.0

On 10/17/25 06:23, alistair23@gmail.com wrote:
> From: Alistair Francis <alistair.francis@wdc.com>
> 
> Allow userspace to trigger a KeyUpdate via debugfs. This patch exposes a
> key_update file that can be written to with the queue number to trigger
> a KeyUpdate on that queue.
> 
> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
> ---
> v4:
>   - No change
> v3:
>   - New patch
> 
>   drivers/nvme/host/tcp.c | 72 +++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 72 insertions(+)
> 
> diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
> index 791e0cc91ad8..f5c7b646d002 100644
> --- a/drivers/nvme/host/tcp.c
> +++ b/drivers/nvme/host/tcp.c
> @@ -11,6 +11,7 @@
>   #include <linux/crc32.h>
>   #include <linux/nvme-tcp.h>
>   #include <linux/nvme-keyring.h>
> +#include <linux/debugfs.h>
>   #include <net/sock.h>
>   #include <net/tcp.h>
>   #include <net/tls.h>
> @@ -1429,6 +1430,75 @@ static void update_tls_keys(struct nvme_tcp_queue *queue)
>   	}
>   }
>   
> +#ifdef CONFIG_NVME_TCP_TLS
> +#define NVME_DEBUGFS_RW_ATTR(field) \
> +	static int field##_open(struct inode *inode, struct file *file) \
> +	{ return single_open(file, field##_show, inode->i_private); } \
> +	\
> +	static const struct file_operations field##_fops = { \
> +		.open = field##_open, \
> +		.read = seq_read, \
> +		.write = field##_write, \
> +		.release = single_release, \
> +	}
> +
> +static int nvme_ctrl_key_update_show(struct seq_file *m, void *p)
> +{
> +	seq_printf(m, "0\n");
> +
> +	return 0;
> +}
> +
> +static ssize_t nvme_ctrl_key_update_write(struct file *file, const char __user *buf,
> +					  size_t count, loff_t *ppos)
> +{
> +	struct seq_file *m = file->private_data;
> +	struct nvme_ctrl *nctrl = m->private;
> +	struct nvme_tcp_ctrl *ctrl = to_tcp_ctrl(nctrl);
> +	char kbuf[16] = {0};
> +	int queue_nr, rc;
> +	struct nvme_tcp_queue *queue;
> +
> +	if (count > sizeof(kbuf) - 1)
> +		return -EINVAL;
> +	if (copy_from_user(kbuf, buf, count))
> +		return -EFAULT;
> +	kbuf[count] = 0;
> +
> +	rc = kstrtouint(kbuf, 10, &queue_nr);
> +	if (rc)
> +		return rc;
> +
> +	if (queue_nr >= nctrl->queue_count)
> +		return -EINVAL;
> +
> +	queue = &ctrl->queues[queue_nr];
> +
> +	update_tls_keys(queue);

Are you sure this is correct?

'update_tls_keys' is issuing a handshake request
with 'HANDSHAKE_KEY_UPDATE_TYPE_RECEIVED'.

And the patch introducing it states:
At this time we don't support initiating a KeyUpdate.

So please move this to the patchset implementing support
for initiating KeyUpdates.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
hare@suse.de                                +49 911 74053 688
SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg
HRB 36809 (AG Nürnberg), GF: I. Totev, A. McDonald, W. Knoblich

On Fri, Oct 17, 2025 at 02:23:11PM +1000, alistair23@gmail.com wrote:
> +#ifdef CONFIG_NVME_TCP_TLS
> +#define NVME_DEBUGFS_RW_ATTR(field) \
> +	static int field##_open(struct inode *inode, struct file *file) \
> +	{ return single_open(file, field##_show, inode->i_private); } \

Please use normal indentation in the macro, but do not add an extra
level of indentation just for being inside a macro.

Then again the macro is only used once anyway, so why add it at all?

> +static ssize_t nvme_ctrl_key_update_write(struct file *file, const char __user *buf,

Please avoid the overly long line.

> +					  size_t count, loff_t *ppos)
> +{
> +	struct seq_file *m = file->private_data;
> +	struct nvme_ctrl *nctrl = m->private;
> +	struct nvme_tcp_ctrl *ctrl = to_tcp_ctrl(nctrl);
> +	char kbuf[16] = {0};
> +	int queue_nr, rc;
> +	struct nvme_tcp_queue *queue;
> +
> +	if (count > sizeof(kbuf) - 1)
> +		return -EINVAL;
> +	if (copy_from_user(kbuf, buf, count))
> +		return -EFAULT;
> +	kbuf[count] = 0;
> +
> +	rc = kstrtouint(kbuf, 10, &queue_nr);
> +	if (rc)
> +		return rc;

kstrtoint_from_user?