Re: [PATCH v3 01/16] nvmet: report ioccsz and iorcsz for disc ctrl

From: Hannes Reinecke
Date: Tue Dec 19 2023 - 02:25:33 EST


On 12/18/23 16:30, Daniel Wagner wrote:
The host started to verify the ioccsz and iorcsz values. I/O controllers
return valid values but not the discovery controllers. Use the same
values as for I/O controllers.

Fixes: 2fcd3ab39826 ("nvme-fabrics: check ioccsz and iorcsz")
Signed-off-by: Daniel Wagner <dwagner@xxxxxxx>
---
drivers/nvme/target/discovery.c | 13 +++++++++++++
1 file changed, 13 insertions(+)

diff --git a/drivers/nvme/target/discovery.c b/drivers/nvme/target/discovery.c
index 668d257fa986..e3c4d247dd23 100644
--- a/drivers/nvme/target/discovery.c
+++ b/drivers/nvme/target/discovery.c
@@ -249,6 +249,7 @@ static void nvmet_execute_disc_identify(struct nvmet_req *req)
{
struct nvmet_ctrl *ctrl = req->sq->ctrl;
struct nvme_id_ctrl *id;
+ u32 cmd_capsule_size;
u16 status = 0;
if (!nvmet_check_transfer_len(req, NVME_IDENTIFY_DATA_SIZE))
@@ -294,6 +295,18 @@ static void nvmet_execute_disc_identify(struct nvmet_req *req)
strscpy(id->subnqn, ctrl->subsys->subsysnqn, sizeof(id->subnqn));
+ /*
+ * Max command capsule size is sqe + in-capsule data size.

'is sqe size + in-capsule data size'

+ * Disable in-capsule data for Metadata capable controllers.
+ */
+ cmd_capsule_size = sizeof(struct nvme_command);
+ if (!ctrl->pi_support)
+ cmd_capsule_size += req->port->inline_data_size;
+ id->ioccsz = cpu_to_le32(cmd_capsule_size / 16);

Why the division by 16?

+
+ /* Max response capsule size is cqe */
'is cqe size'

+ id->iorcsz = cpu_to_le32(sizeof(struct nvme_completion) / 16);
+
status = nvmet_copy_to_sgl(req, 0, id, sizeof(*id));
kfree(id);

Otherwise looks good.

Cheers,

Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
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