..  SPDX-License-Identifier: BSD-3-Clause
    Copyright(c) 2010-2014 Intel Corporation.

Driver for VM Emulated Devices
==============================

The DPDK EM poll mode driver supports the following emulated devices:

*   qemu-kvm emulated Intel® 82540EM Gigabit Ethernet Controller (qemu e1000 device)

*   VMware emulated Intel® 82545EM Gigabit Ethernet Controller

*   VMware emulated Intel® 82574L Gigabit Ethernet Controller.

Validated Hypervisors
---------------------

The validated hypervisors are:

*   KVM (Kernel Virtual Machine) with Qemu, version 0.14.0

*   KVM (Kernel Virtual Machine) with Qemu, version 0.15.1

*   VMware ESXi 5.0, Update 1

Recommended Guest Operating System in Virtual Machine
-----------------------------------------------------

The recommended guest operating system in a virtualized environment is:

*   Fedora* 18 (64-bit)

For supported kernel versions, refer to the *DPDK Release Notes*.

Setting Up a KVM Virtual Machine
--------------------------------

The following describes a target environment:

*   Host Operating System: Fedora 14

*   Hypervisor: KVM (Kernel Virtual Machine) with Qemu version, 0.14.0

*   Guest Operating System: Fedora 14

*   Linux Kernel Version: Refer to the DPDK Getting Started Guide

*   Target Applications: testpmd

The setup procedure is as follows:

#.  Download qemu-kvm-0.14.0 from
    `http://sourceforge.net/projects/kvm/files/qemu-kvm/ <http://sourceforge.net/projects/kvm/files/qemu-kvm/>`_
    and install it in the Host OS using the following steps:

    When using a recent kernel (2.6.25+) with kvm modules included:

    .. code-block:: console

        tar xzf qemu-kvm-release.tar.gz cd qemu-kvm-release
        ./configure --prefix=/usr/local/kvm
        make
        sudo make install
        sudo /sbin/modprobe kvm-intel

    When using an older kernel or a kernel from a distribution without the kvm modules,
    you must download (from the same link), compile and install the modules yourself:

    .. code-block:: console

        tar xjf kvm-kmod-release.tar.bz2
        cd kvm-kmod-release
        ./configure
        make
        sudo make install
        sudo /sbin/modprobe kvm-intel

    Note that qemu-kvm installs in the /usr/local/bin directory.

    For more details about KVM configuration and usage, please refer to:
    `http://www.linux-kvm.org/page/HOWTO1 <http://www.linux-kvm.org/page/HOWTO1>`_.

#.  Create a Virtual Machine and install Fedora 14 on the Virtual Machine.
    This is referred to as the Guest Operating System (Guest OS).

#.  Start the Virtual Machine with at least one emulated e1000 device.

    .. note::

        The Qemu provides several choices for the emulated network device backend.
        Most commonly used is a TAP networking backend that uses a TAP networking device in the host.
        For more information about Qemu supported networking backends and different options for configuring networking at Qemu,
        please refer to:

        — `http://www.linux-kvm.org/page/Networking <http://www.linux-kvm.org/page/Networking>`_

        — `http://wiki.qemu.org/Documentation/Networking <http://wiki.qemu.org/Documentation/Networking>`_

        — `http://qemu.weilnetz.de/qemu-doc.html <http://qemu.weilnetz.de/qemu-doc.html>`_

        For example, to start a VM with two emulated e1000 devices, issue the following command:

        .. code-block:: console

            /usr/local/kvm/bin/qemu-system-x86_64 -cpu host -smp 4 -hda qemu1.raw -m 1024
            -net nic,model=e1000,vlan=1,macaddr=DE:AD:1E:00:00:01
            -net tap,vlan=1,ifname=tapvm01,script=no,downscript=no
            -net nic,model=e1000,vlan=2,macaddr=DE:AD:1E:00:00:02
            -net tap,vlan=2,ifname=tapvm02,script=no,downscript=no

        where:

        — -m = memory to assign

        — -smp = number of smp cores

        — -hda = virtual disk image

        This command starts a new virtual machine with two emulated 82540EM devices,
        backed up with two TAP networking host interfaces, tapvm01 and tapvm02.

        .. code-block:: console

            # ip tuntap show
            tapvm01: tap
            tapvm02: tap

#.  Configure your TAP networking interfaces using ip/ifconfig tools.

#.  Log in to the guest OS and check that the expected emulated devices exist:

    .. code-block:: console

        # lspci -d 8086:100e
        00:04.0 Ethernet controller: Intel Corporation 82540EM Gigabit Ethernet Controller (rev 03)
        00:05.0 Ethernet controller: Intel Corporation 82540EM Gigabit Ethernet Controller (rev 03)

#.  Install the DPDK and run testpmd.

Known Limitations of Emulated Devices
-------------------------------------

The following are known limitations:

#.  The Qemu e1000 RX path does not support multiple descriptors/buffers per packet.
    Therefore, rte_mbuf should be big enough to hold the whole packet.
    For example, to allow testpmd to receive jumbo frames, use the following:

    dpdk-testpmd [options] -- --mbuf-size=<your-max-packet-size>

#.  Qemu e1000 does not validate the checksum of incoming packets.

#.  Qemu e1000 only supports one interrupt source, so link and Rx interrupt should be exclusive.

#.  Qemu e1000 does not support interrupt auto-clear, application should disable interrupt immediately when woken up.
