NVMe specification 1.3 added a new Admin command: Doorbell buffer config,
which is used to enhance the performance of host software running in
Virtual Machine, and the Doorbell buffer config feature is only used
for emulated NVMe controllers. There are two buffers: "shadow doorbell"
and "eventidx", host software running in VM will update appropriate
entry in the Shadow doorbell buffer instead of controller's doorbell
registers.
Change-Id: I639ddb5b9a0ca0305bf84035ca2a5e215be06b46
Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-on: https://review.gerrithub.io/383042
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
7e3a11f98b