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+# VMD driver {#vmd}
+
+# In this document {#vmd_toc}
+
+* @ref vmd_intro
+* @ref vmd_interface
+* @ref vmd_key_functions
+* @ref vmd_config
+* @ref vmd_app_frame
+* @ref vmd_app
+* @ref vmd_led
+
+# Introduction {#vmd_intro}
+
+Intel Volume Management Device is a hardware logic inside processor's Root Complex
+responsible for management of PCIe NVMe SSDs. It provides robust Hot Plug support
+and Status LED management.
+
+The driver is responsible for enumeration and hooking NVMe devices behind VMD
+into SPDK PCIe subsystem. It also provides API for LED management and hot plug.
+
+# Public Interface {#vmd_interface}
+
+- spdk/vmd.h
+
+# Key Functions {#vmd_key_functions}
+
+Function                                | Description
+--------------------------------------- | -----------
+spdk_vmd_init()                         | @copybrief spdk_vmd_init()
+spdk_vmd_pci_device_list()              | @copybrief spdk_vmd_pci_device_list()
+spdk_vmd_set_led_state()                | @copybrief spdk_vmd_set_led_state()
+spdk_vmd_get_led_state()                | @copybrief spdk_vmd_get_led_state()
+spdk_vmd_hotplug_monitor()              | @copybrief spdk_vmd_hotplug_monitor()
+
+# Configuration {#vmd_config}
+
+To enable VMD driver enumeration, the following steps are required:
+
+Check for available VMD devices (VMD needs to be properly set up in BIOS first).
+
+Example:
+```
+$ lspci | grep 201d
+
+$ 5d:05.5 RAID bus controller: Intel Corporation Device 201d (rev 04)
+$ d7:05.5 RAID bus controller: Intel Corporation Device 201d (rev 04)
+```
+
+Run setup.sh script with VMD devices set in PCI_WHITELIST.
+
+Example:
+```
+$ PCI_WHITELIST="0000:5d:05.5 0000:d7:05.5" scripts/setup.sh
+```
+
+Check for available devices behind the VMD with spdk_lspci.
+
+Example:
+```
+$ ./build/bin/spdk_lspci
+
+ 5d0505:01:00.0 (8086 a54) (NVMe disk behind VMD)
+ 5d0505:03:00.0 (8086 a54) (NVMe disk behind VMD)
+ d70505:01:00.0 (8086 a54) (NVMe disk behind VMD)
+ d70505:03:00.0 (8086 a54) (NVMe disk behind VMD)
+ 0000:5d:05.5 (8086 201d) (VMD)
+ 0000:d7:05.5 (8086 201d) (VMD)
+```
+
+VMD NVMe BDF could be used as regular NVMe BDF.
+
+Example:
+```
+$ ./scripts/rpc.py bdev_nvme_attach_controller -b NVMe1 -t PCIe -a 5d0505:01:00.0
+```
+
+# Application framework {#vmd_app_frame}
+
+When application framework is used, VMD section needs to be added to the configuration file:
+
+Text config:
+```
+[VMD]
+  Enable True
+```
+
+JSON config:
+```
+{
+    "subsystem": "vmd",
+    "config": [
+      {
+        "method": "enable_vmd",
+        "params": {}
+      }
+    ]
+}
+```
+
+or use RPC call before framework starts e.g.
+```
+$ ./build/bin/spdk_tgt --wait_for_rpc
+$ ./scripts/rpc.py enable_vmd
+$ ./scripts/rpc.py framework_start_init
+```
+# Applications w/o application framework {#vmd_app}
+
+To enable VMD enumeration in SPDK application that are not using application framework
+e.g nvme/perf, nvme/identify -V flag is required - please refer to app help if it supports VMD.
+
+Applications need to call spdk_vmd_init() to enumerate NVMe devices behind the VMD prior to calling
+spdk_nvme_(probe|connect).
+To support hot plugs spdk_vmd_hotplug_monitor() needs to be called periodically.
+
+# LED management {#vmd_led}
+
+VMD LED utility in the [examples/vmd/led](https://github.com/spdk/spdk/tree/master/examples/vmd/led)
+could be used to set LED states.
+
+In order to verify that a platform is correctly configured to support LED management, ledctl(8) can
+be utilized.  For instructions on how to use it, consult the manual page of this utility.