From: Alistair Francis <redacted>

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 <redacted>
---
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);