Linux host nvme driver processes all pending cqe's in one batch along with
completing backing blk_mq req's and later rings cq_doorbell once for all
processed cqes.
As blk_mq req's are completed there is room for more submissions
before ringing cq_doorbell.
This may race with vfio_user cq_is_full() which uses cq_doorbell to make final
decision and as host has not updated cq_doorbell we fail with cq_full error.
To mitigate this only process commands from sq which have free cq slot.
Signed-off-by: Swapnil Ingle <swapnil.ingle@nutanix.com>
Change-Id: I0cefb41df8099eb71de25923d05a9fcb28e4d124
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/16788
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Community-CI: Mellanox Build Bot
23b518a013