SPDK can submit more commands to remote NVMf target than allowed by
negotiated queue size. SPDK submits up to SQSIZE commands, but only
SQSIZE-1 are allowed.
Here is a relevant quote from NVMe over Fabrics rev.1.1a ch.2.4.1
“Submission Queue Flow Control Negotiation”:
If SQ flow control is disabled, then the host should limit the number
of outstanding commands for a queue pair to be less than the size of
the Submission Queue. If the controller detects that the number of
outstanding commands for a queue pair is greater than or equal to the
size of the Submission Queue, then the controller shall:
a) stop processing commands and set the Controller Fatal
Status (CSTS.CFS) bit to ‘1’ (refer to section 10.5 in the NVMe Base
specification); and
b) terminate the NVMe Transport connection and end the association
between the host and the controller.
Signed-off-by: Evgeniy Kochetov <evgeniik@nvidia.com>
Change-Id: Ifbcf5d51911fc4ddcea1f7cde3135571648606f3
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/11413
Community-CI: Broadcom CI <spdk-ci.pdl@broadcom.com>
Community-CI: Mellanox Build Bot
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Shuhei Matsumoto <smatsumoto@nvidia.com>
Reviewed-by: Aleksey Marchuk <alexeymar@mellanox.com>
834e3c5a0e