* [PATCH v2] nvmet: Add traffic based keep alive support to configfs
@ 2026-09-23 20:20 Jesse Taube
2026-09-23 21:45 ` Mohamed Khalfella
0 siblings, 1 reply; 2+ messages in thread
From: Jesse Taube @ 2026-09-23 20:20 UTC (permalink / raw)
To: linux-nvme
Cc: Christoph Hellwig, Sagi Grimberg, Chaitanya Kulkarni,
Martin K. Petersen, John Meneghini, Chris Leech, linux-kernel,
Mohamed Khalfella, Jesse Taube
Add the ability to turn on and off tbkas (traffic based keep alive
support) via configfs. This is useful for testing and debugging.
Signed-off-by: Jesse Taube <jtaubepe@redhat.com>
V1 -> V2:
- Add tbkas to nvmet_ctrl
- Force reconnect controllers when tbkas is set
- Use ctrl->tbkas in nvmet_execute_identify_ctrl and nvmet_req_init
---
drivers/nvme/target/admin-cmd.c | 4 +++-
drivers/nvme/target/configfs.c | 29 +++++++++++++++++++++++++++++
drivers/nvme/target/core.c | 4 +++-
drivers/nvme/target/nvmet.h | 2 ++
4 files changed, 37 insertions(+), 2 deletions(-)
diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index 7764a3c0195c..26028be8fe4d 100644
--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -696,7 +696,9 @@ static void nvmet_execute_identify_ctrl(struct nvmet_req *req)
/* XXX: figure out what to do about RTD3R/RTD3 */
id->oaes = cpu_to_le32(NVMET_AEN_CFG_OPTIONAL);
- ctratt = NVME_CTRL_ATTR_HID_128_BIT | NVME_CTRL_ATTR_TBKAS;
+ ctratt = NVME_CTRL_ATTR_HID_128_BIT;
+ if (ctrl->tbkas)
+ ctratt |= NVME_CTRL_ATTR_TBKAS;
if (nvmet_is_pci_ctrl(ctrl))
ctratt |= NVME_CTRL_ATTR_RHII;
id->ctratt = cpu_to_le32(ctratt);
diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
index 6286e38436dd..2b879b1d4c3c 100644
--- a/drivers/nvme/target/configfs.c
+++ b/drivers/nvme/target/configfs.c
@@ -1369,6 +1369,34 @@ static ssize_t nvmet_subsys_attr_serial_store(struct config_item *item,
}
CONFIGFS_ATTR(nvmet_subsys_, attr_serial);
+static ssize_t nvmet_subsys_attr_tbkas_show(struct config_item *item,
+ char *page)
+{
+ return snprintf(page, PAGE_SIZE, "%d\n", to_subsys(item)->tbkas);
+}
+
+static ssize_t nvmet_subsys_attr_tbkas_store(struct config_item *item,
+ const char *page, size_t count)
+{
+ struct nvmet_subsys *subsys = to_subsys(item);
+ struct nvmet_ctrl *ctrl;
+ bool tbkas;
+
+ if (kstrtobool(page, &tbkas))
+ return -EINVAL;
+
+ down_write(&nvmet_config_sem);
+ subsys->tbkas = tbkas;
+
+ /* Force reconnect */
+ list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry)
+ ctrl->ops->delete_ctrl(ctrl);
+ up_write(&nvmet_config_sem);
+
+ return count;
+}
+CONFIGFS_ATTR(nvmet_subsys_, attr_tbkas);
+
static ssize_t nvmet_subsys_attr_cntlid_min_show(struct config_item *item,
char *page)
{
@@ -1706,6 +1734,7 @@ static struct configfs_attribute *nvmet_subsys_attrs[] = {
&nvmet_subsys_attr_attr_qid_max,
&nvmet_subsys_attr_attr_ieee_oui,
&nvmet_subsys_attr_attr_firmware,
+ &nvmet_subsys_attr_attr_tbkas,
#ifdef CONFIG_BLK_DEV_INTEGRITY
&nvmet_subsys_attr_attr_pi_enable,
#endif
diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index 43871a8f56ca..6b4bda231bd9 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -1227,7 +1227,7 @@ bool nvmet_req_init(struct nvmet_req *req, struct nvmet_sq *sq,
goto fail;
}
- if (sq->ctrl)
+ if (sq->ctrl && sq->ctrl->tbkas)
sq->ctrl->reset_tbkas = true;
return true;
@@ -1677,6 +1677,7 @@ struct nvmet_ctrl *nvmet_alloc_ctrl(struct nvmet_alloc_ctrl_args *args)
mutex_lock(&subsys->lock);
ctrl->max_qid = subsys->max_qid;
+ ctrl->tbkas = subsys->tbkas;
ctrl->sqs = kzalloc_objs(struct nvmet_sq *, ctrl->max_qid + 1);
if (!ctrl->sqs)
@@ -1865,6 +1866,7 @@ struct nvmet_subsys *nvmet_subsys_alloc(const char *subsysnqn,
}
subsys->ieee_oui = 0;
+ subsys->tbkas = true;
subsys->firmware_rev = kstrndup(UTS_RELEASE, NVMET_FR_MAX_SIZE, GFP_KERNEL);
if (!subsys->firmware_rev) {
diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index dbda55895f4f..2bc0e87ea981 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -270,6 +270,7 @@ struct nvmet_ctrl {
u16 cntlid;
u16 max_qid;
u32 kato;
+ bool tbkas;
struct nvmet_port *port;
@@ -343,6 +344,7 @@ struct nvmet_subsys {
bool subsys_discovered;
char *subsysnqn;
bool pi_support;
+ bool tbkas;
struct config_group group;
--
2.55.0
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH v2] nvmet: Add traffic based keep alive support to configfs
2026-09-23 20:20 [PATCH v2] nvmet: Add traffic based keep alive support to configfs Jesse Taube
@ 2026-09-23 21:45 ` Mohamed Khalfella
0 siblings, 0 replies; 2+ messages in thread
From: Mohamed Khalfella @ 2026-09-23 21:45 UTC (permalink / raw)
To: Jesse Taube
Cc: linux-nvme, Christoph Hellwig, Sagi Grimberg, Chaitanya Kulkarni,
Martin K. Petersen, John Meneghini, Chris Leech, linux-kernel
On Wed 2026-09-23 16:20:03 -0400, Jesse Taube wrote:
> Add the ability to turn on and off tbkas (traffic based keep alive
> support) via configfs. This is useful for testing and debugging.
>
> Signed-off-by: Jesse Taube <jtaubepe@redhat.com>
Reviewed-by: Mohamed Khalfella <mkhalfella@purestorage.com>
> V1 -> V2:
> - Add tbkas to nvmet_ctrl
> - Force reconnect controllers when tbkas is set
> - Use ctrl->tbkas in nvmet_execute_identify_ctrl and nvmet_req_init
> ---
> drivers/nvme/target/admin-cmd.c | 4 +++-
> drivers/nvme/target/configfs.c | 29 +++++++++++++++++++++++++++++
> drivers/nvme/target/core.c | 4 +++-
> drivers/nvme/target/nvmet.h | 2 ++
> 4 files changed, 37 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
> index 7764a3c0195c..26028be8fe4d 100644
> --- a/drivers/nvme/target/admin-cmd.c
> +++ b/drivers/nvme/target/admin-cmd.c
> @@ -696,7 +696,9 @@ static void nvmet_execute_identify_ctrl(struct nvmet_req *req)
>
> /* XXX: figure out what to do about RTD3R/RTD3 */
> id->oaes = cpu_to_le32(NVMET_AEN_CFG_OPTIONAL);
> - ctratt = NVME_CTRL_ATTR_HID_128_BIT | NVME_CTRL_ATTR_TBKAS;
> + ctratt = NVME_CTRL_ATTR_HID_128_BIT;
> + if (ctrl->tbkas)
> + ctratt |= NVME_CTRL_ATTR_TBKAS;
> if (nvmet_is_pci_ctrl(ctrl))
> ctratt |= NVME_CTRL_ATTR_RHII;
> id->ctratt = cpu_to_le32(ctratt);
> diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
> index 6286e38436dd..2b879b1d4c3c 100644
> --- a/drivers/nvme/target/configfs.c
> +++ b/drivers/nvme/target/configfs.c
> @@ -1369,6 +1369,34 @@ static ssize_t nvmet_subsys_attr_serial_store(struct config_item *item,
> }
> CONFIGFS_ATTR(nvmet_subsys_, attr_serial);
>
> +static ssize_t nvmet_subsys_attr_tbkas_show(struct config_item *item,
> + char *page)
> +{
> + return snprintf(page, PAGE_SIZE, "%d\n", to_subsys(item)->tbkas);
> +}
> +
> +static ssize_t nvmet_subsys_attr_tbkas_store(struct config_item *item,
> + const char *page, size_t count)
> +{
> + struct nvmet_subsys *subsys = to_subsys(item);
> + struct nvmet_ctrl *ctrl;
> + bool tbkas;
> +
> + if (kstrtobool(page, &tbkas))
> + return -EINVAL;
> +
> + down_write(&nvmet_config_sem);
> + subsys->tbkas = tbkas;
> +
> + /* Force reconnect */
> + list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry)
> + ctrl->ops->delete_ctrl(ctrl);
> + up_write(&nvmet_config_sem);
> +
> + return count;
> +}
> +CONFIGFS_ATTR(nvmet_subsys_, attr_tbkas);
> +
> static ssize_t nvmet_subsys_attr_cntlid_min_show(struct config_item *item,
> char *page)
> {
> @@ -1706,6 +1734,7 @@ static struct configfs_attribute *nvmet_subsys_attrs[] = {
> &nvmet_subsys_attr_attr_qid_max,
> &nvmet_subsys_attr_attr_ieee_oui,
> &nvmet_subsys_attr_attr_firmware,
> + &nvmet_subsys_attr_attr_tbkas,
> #ifdef CONFIG_BLK_DEV_INTEGRITY
> &nvmet_subsys_attr_attr_pi_enable,
> #endif
> diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
> index 43871a8f56ca..6b4bda231bd9 100644
> --- a/drivers/nvme/target/core.c
> +++ b/drivers/nvme/target/core.c
> @@ -1227,7 +1227,7 @@ bool nvmet_req_init(struct nvmet_req *req, struct nvmet_sq *sq,
> goto fail;
> }
>
> - if (sq->ctrl)
> + if (sq->ctrl && sq->ctrl->tbkas)
> sq->ctrl->reset_tbkas = true;
>
> return true;
> @@ -1677,6 +1677,7 @@ struct nvmet_ctrl *nvmet_alloc_ctrl(struct nvmet_alloc_ctrl_args *args)
> mutex_lock(&subsys->lock);
>
> ctrl->max_qid = subsys->max_qid;
> + ctrl->tbkas = subsys->tbkas;
>
> ctrl->sqs = kzalloc_objs(struct nvmet_sq *, ctrl->max_qid + 1);
> if (!ctrl->sqs)
> @@ -1865,6 +1866,7 @@ struct nvmet_subsys *nvmet_subsys_alloc(const char *subsysnqn,
> }
>
> subsys->ieee_oui = 0;
> + subsys->tbkas = true;
>
> subsys->firmware_rev = kstrndup(UTS_RELEASE, NVMET_FR_MAX_SIZE, GFP_KERNEL);
> if (!subsys->firmware_rev) {
> diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
> index dbda55895f4f..2bc0e87ea981 100644
> --- a/drivers/nvme/target/nvmet.h
> +++ b/drivers/nvme/target/nvmet.h
> @@ -270,6 +270,7 @@ struct nvmet_ctrl {
> u16 cntlid;
> u16 max_qid;
> u32 kato;
> + bool tbkas;
>
> struct nvmet_port *port;
>
> @@ -343,6 +344,7 @@ struct nvmet_subsys {
> bool subsys_discovered;
> char *subsysnqn;
> bool pi_support;
> + bool tbkas;
>
> struct config_group group;
>
> --
> 2.55.0
>
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2026-09-23 21:45 UTC | newest]
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