Update documentation structure.

This patch is used to update documentation structure.

Change-Id: I50d4ef4256ccfc57a0434123e7532a50000582cf
Co-Authored by:Srinivas <srinivas.atmakuri@tcs.com>
Co-Authored by:RajithaY<rajithax.yerrumsetty@intel.com>
Co-Authored by:shravani paladugula <shravanix.paladugula@intel.com>
Co-Authored by:Navya Bathula <navyax.bathula@intel.com>
Signed-off-by: Gundarapu Kalyan Reddy <reddyx.gundarapu@intel.com>
(cherry picked from commit f1f3cc27f23bdde81c37d8142d4288d811bd5e45)

10 files changed, 301 insertions, 0 deletions

diff --git a/docs/development/design/Bare-metalPacketForwarding.png b/docs/development/design/Bare-metalPacketForwarding.png
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diff --git a/docs/development/design/PacketforwardingDPDK_OVS.png b/docs/development/design/PacketforwardingDPDK_OVS.png
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diff --git a/docs/development/design/index.rst b/docs/development/design/index.rst
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+.. This work is licensed under a Creative Commons Attribution 4.0 International License.
+.. http://creativecommons.org/licenses/by/4.0
+
+.. _kvmfornfv-design:
+
+================
+KVM4NFV Design
+================
+
+.. toctree::
+   :numbered:
+   :maxdepth: 3
+
+   kvmfornfv_design.rst
diff --git a/docs/development/design/kvm1.png b/docs/development/design/kvm1.png
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diff --git a/docs/development/design/kvmfornfv_design.rst b/docs/development/design/kvmfornfv_design.rst
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+.. This work is licensed under a Creative Commons Attribution 4.0 International License.
+.. http://creativecommons.org/licenses/by/4.0
+
+==========================
+KVM4NFV design description
+==========================
+
+This design focuses on the enhancement of following area for KVM Hypervisor
+
+* Minimal Interrupt latency variation for data plane VNFs:
+   * Minimal Timing Variation for Timing correctness of real-time VNFs
+   * Minimal packet latency variation for data-plane VNFs
+* Fast live migration
+
+**Minimal Interrupt latency variation for data plane VNFs**
+
+Processing performance and latency depend on a number of factors, including
+the CPUs (frequency, power management features, etc.), micro-architectural
+resources, the cache hierarchy and sizes, memory (and hierarchy, such as NUMA)
+and speed, inter-connects, I/O and I/O NUMA, devices, etc.
+
+There are two separate types of latencies to minimize:
+
+   1. Minimal Timing Variation for Timing correctness of real-time
+      VNFs – timing correctness for scheduling operations(such as Radio scheduling)
+   2. Minimal packet latency variation for data-plane VNFs – packet delay
+      variation, which applies to packet processing.
+
+For a VM, interrupt latency (time between arrival of H/W interrupt and
+invocation of the interrupt handler in the VM), for example, can be either of
+the above or both, depending on the type of the device. Interrupt latency with
+a (virtual) timer can cause timing correctness issues with real-time VNFs even
+if they only use polling for packet processing.
+
+We assume that the VNFs are implemented properly to minimize interrupt latency
+variation within the VMs, but we have additional causes of latency variation
+on KVM:
+
+    - Asynchronous (e.g. external interrupts) and synchronous(e.g. instructions)
+      VM exits and handling in KVM (and kernel routines called), which may have
+      loops and spin locks
+    - Interrupt handling in the host Linux and KVM, scheduling and virtual
+      interrupt delivery to VNFs
+    - Potential VM exit (e.g. EOI) in the interrupt service routines in VNFs
+    - Exit to the user-level (e.g. QEMU)
+
+.. Figure:: kvm1.png
+
+
+Design Considerations
+---------------------
+
+The latency variation and jitters can be minimized with the below
+steps (with some in parallel):
+
+    1. Statically and exclusively assign hardware resources
+       (CPUs, memory, caches,) to the VNFs.
+
+    2. Pre-allocate huge pages (e.g. 1 GB/2MB pages) and guest-to-host mapping,
+       e.g. EPT (Extended Page Table) page tables, to minimize or mitigate
+       latency from misses in caches,
+
+    3. Use the host Linux configured for hard real-time and packet latency,
+       Check the set of virtual devices used by the VMs to optimize or
+       eliminate virtualization overhead if applicable
+
+    4. Use advanced hardware virtualization features that can reduce or
+       eliminate VM exits, if present, and
+
+    5. Inspect the code paths in KVM and associated kernel services to
+       eliminate code that can cause latencies (e.g. loops and spin locks).
+
+    6. Measure latencies intensively. We leverage the existing testing methods.
+       OSADL, for example, defines industry tests for timing correctness.
+
+
+Goals and Guidelines
+--------------------
+
+The output of this project will provide :
+
+    1. A list of the performance goals, which will be obtained by the
+       OPNFV members (as described above)
+
+    2. A set of comprehensive instructions for the system configurations
+       (hardware features, BIOS setup, kernel parameters, VM configuration,
+       options to QEMU/KVM, etc.)
+
+    3. The above features to the upstream of Linux, the real-time patch
+       set, KVM, QEMU, libvirt, and
+
+    4. Performance and interrupt latency measurement tools
+
+
+Test plan
+---------
+
+The tests that need to be conducted to make sure that all components from OPNFV
+meet the requirement are mentioned below:
+
+**Timer test**:This test utilize the cyclictest
+(https://rt.wiki.kernel.org/index.php/Cyclictest) to test the guest timer
+latency (the latency from the time that the guest timer should be triggered
+to the time the guest timer is really triggered).
+
+.. Figure:: TimerTest.png
+
+**Device Interrupt Test**:A device on the hardware platform trigger interrupt
+every one ms and the device interrupt will be delivered to the VNF. This test
+cover the latency from the interrupt happened on the hardware to the time the
+interrupt handled in the VNF.
+
+.. Figure:: DeviceInterruptTest.png
+
+**Packet forwarding (DPDK OVS)**:A packet is sent from TG (Traffic Generator)
+to a VNF.  The VNF, after processing the packet, forwards the packet to another
+NIC and in the end the packet is received by the traffic generator. The test
+check the latency from the packet is sent out by the TC to the time the packet
+is received by the TC.
+
+.. Figure:: PacketforwardingDPDK_OVS.png
+
+**Packet Forwarding (SR-IOV)**:This test is similar to Packet Forwarding
+(DPDK OVS). However, instead of using virtio NIC devices on the guest,
+a PCI NIC or a PCI VF NIC is assigned to the guest for network acess.
+
+**Bare-metal Packet Forwarding**:This is used to compare with the above
+packet forwarding scenario.
+
+.. Figure:: Bare-metalPacketForwarding.png
+
+----------
+Reference
+----------
+
+https://wiki.opnfv.org/display/kvm/
diff --git a/docs/development/overview/kvmfornfv_overview.rst b/docs/development/overview/kvmfornfv_overview.rst
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+.. This work is licensed under a Creative Commons Attribution 4.0 International License.
+
+.. http://creativecommons.org/licenses/by/4.0
+
+========================
+KVM4NFV Project Overview
+========================
+
+Project Purpose
+---------------
+**Purpose:**
+
+  ``This document provides an overview of the areas that can be addressed to
+  enhance the KVM Hypervisor for NFV. It is intended to capture and convey the
+  significant changes which have been made on the KVM Hypervisor.``
+
+Project Description
+-------------------
+The NFV hypervisors provide crucial functionality in the NFV
+Infrastructure(NFVI).The existing hypervisors, however, are not necessarily
+designed or targeted to meet the requirements for the NFVI.
+
+This design focuses on the enhancement of following area for KVM Hypervisor
+
+* Minimal Interrupt latency variation for data plane VNFs:
+   * Minimal Timing Variation for Timing correctness of real-time VNFs
+   * Minimal packet latency variation for data-plane VNFs
+* Fast live migration
+
+The detailed understanding of this project is organized into different sections-
+
+* **installation procedure** - This will give the user instructions on how to deploy
+  available KVM4NFV build scenario.
+* **design** - This includes the parameters or design considerations taken into
+  account for achieving minimal interrupt latency for the data VNFs.
+* **requirements** - This includes the introduction of KVM4NFV project,
+  specifications of how the project should work, and constraints placed upon
+  its execution.
+* **configuration guide** - This provides guidance for configuring KVM4NFV
+  environment, even with the use of specific installer tools for deploying some
+  components, available in the Danube release of OPNFV.
+* **scenarios** - This includes the sceanrios that are currently implemented in the
+  kvm4nfv project,features of each scenario and a general guide to how to deploy them.
+* **userguide** - This provides the required technical assistance to the user, in
+  using the KVM4NFV process.
+* **release notes** - This describes a brief summary of recent changes, enhancements
+  and bug fixes in the KVM4NFV project.
+* **glossary** - It includes the definition of terms, used in the KVM4NFV project.
diff --git a/docs/development/requirements/index.rst b/docs/development/requirements/index.rst
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+.. This work is licensed under a Creative Commons Attribution 4.0 International License.
+.. http://creativecommons.org/licenses/by/4.0
+
+.. _kvmfornfv-requirements:
+
+====================
+KVM4NFV Requirements
+====================
+
+.. toctree::
+   :numbered:
+   :maxdepth: 3
+
+   kvmfornfv_requirements.rst
diff --git a/docs/development/requirements/kvmfornfv_requirements.rst b/docs/development/requirements/kvmfornfv_requirements.rst
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+.. This work is licensed under a Creative Commons Attribution 4.0 International License.
+.. http://creativecommons.org/licenses/by/4.0
+.. (c) OPNFV, Intel Corporation, AT&T and others.
+
+====================
+Kvm4nfv Requirements
+====================
+
+Introduction
+------------
+The NFV hypervisors provide crucial functionality in the NFV
+Infrastructure(NFVI).The existing hypervisors, however, are not necessarily
+designed or targeted to meet the requirements for the NFVI.
+
+This document specifies the list of requirements that need to be met as part
+of this "NFV Hypervisors-KVM" project in Danube release.
+
+As part of this project we need to make collaborative efforts towards enabling
+the NFV features.
+
+
+Scope and Purpose
+-----------------
+
+The main purpose of this project is to enhance the KVM hypervisor for NFV, by
+looking at the following areas initially:
+
+* Minimal Interrupt latency variation for data plane VNFs:
+   * Minimal Timing Variation for Timing correctness of real-time VNFs
+   * Minimal packet latency variation for data-plane VNFs
+* Inter-VM communication
+* Fast live migration
+
+The output of this project would be list of the performance goals,comprehensive
+instructions for the system configurations,tools to measure Performance and
+interrupt latency.
+
+Methods and Instrumentation
+---------------------------
+
+The above areas would require software development and/or specific hardware
+features, and some need just configurations information for the system
+(hardware, BIOS, OS, etc.).
+
+A right configuration is critical for improving the NFV performance/latency.
+Even working on the same code base, different configurations can make
+completely different performance/latency result.
+Configurations that can be made as part of this project to tune a specific
+scenario are:
+
+ 1. **Platform Configuration** : Some hardware features like Power management,
+    Hyper-Threading,Legacy USB Support/Port 60/64 Emulation,SMI can be configured.
+ 2. **Operating System Configuration** : Some configuration features like CPU
+    isolation,Memory allocation,IRQ affinity,Device assignment for VM,Tickless,
+    TSC,Idle,_RCU_NOCB_,Disable the RT throttling,NUMA can be configured.
+ 3. **Performance/Latency Tuning** : Application level configurations like
+    timers,Making vfio MSI interrupt as non-threaded,Cache Allocation
+    Technology(CAT) enabling can be tuned to improve the NFV
+    performance/latency.
+
+Features to be tested
+---------------------
+
+The tests that need to be conducted to make sure that latency is addressed are:
+ 1. Timer test
+ 2. Device Interrupt Test
+ 3. Packet forwarding (DPDK OVS)
+ 4. Packet Forwarding (SR-IOV)
+ 5. Bare-metal Packet Forwarding
+
+Dependencies
+------------
+
+1. OPNFV Project: “Characterize vSwitch Performance for Telco NFV Use Cases”
+   (VSPERF) for performance evaluation of ivshmem vs. vhost-user.
+2. OPNFV Project: “Pharos” for Test Bed Infrastructure, and possibly
+   “Yardstick” for infrastructure verification.
+3. There are currently no similar projects underway in OPNFV or in an upstream
+   project
+4. The relevant upstream project to be influenced here is QEMU/KVM and
+   libvirt.
+5. In terms of HW dependencies, the aim is to use standard IA Server hardware
+   for this project, as provided by OPNFV Pharos.
+
+
+Reference
+---------
+
+https://wiki.opnfv.org/display/kvm/