3 Creating the Virtual Machine
4 ----------------------------
6 We will now create the virtual machine. We use the "virsh create command".
8 It is important to note that in the XML file we specify the socket path that is used to connect to
11 This is done with a section that looks like this
13 .. code-block:: console
15 <interface type='vhostuser'>
16 <mac address='52:54:00:4c:47:f2'/>
17 <source type='unix' path='/tmp//vm00.sock' mode='server'/>
18 <driver rx_queue_size='1024' tx_queue_size='1024'/>
19 <model type='virtio'/>
21 <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
24 Notice the **interface type** and the **path** to the socket.
26 Now we create the VM. The virsh list command shows the VMs that have been created. We start with no VMs.
28 .. code-block:: console
32 ----------------------------------------------------
34 Create the VM with the virsh create command specifying our xml file.
36 .. code-block:: console
38 $ virsh create ./iperf3-vm.xml
39 Domain iperf-server3 created from ./iperf3-vm.xml
43 ----------------------------------------------------
44 65 iperf-server3 running
46 The VM is now created.
50 After a VM is created an xml file can created with "virsh dumpxml".
52 .. code-block:: console
54 $ virsh dumpxml iperf-server3
55 <domain type='kvm' id='65'>
56 <name>iperf-server3</name>
57 <uuid>e23d37c1-10c3-4a6e-ae99-f315a4165641</uuid>
58 <memory unit='KiB'>262144</memory>
61 Once the virtual machine is created notice the socket filename shows **Success** and
62 there are **Memory Regions**. At this point the VM and FD.io VPP are connected. Also
63 notice **qsz 1024**. A queue size of 256 will affect vhost throughput. The qsz should
64 be 1024. In QEMU 2.10.0 and libvirt 3.7.0 and later versions this is specified in the
65 xml file with the line **<driver rx_queue_size='1024' tx_queue_size='1024'/>** shown above
68 .. code-block:: console
71 Virtio vhost-user interfaces
73 coalesce frames 32 time 1e-3
74 number of rx virtqueues in interrupt mode: 0
75 Interface: VirtualEthernet0/0/0 (ifindex 3)
77 features mask (0xffffffffffffffff):
78 features (0x58208000):
79 VIRTIO_NET_F_MRG_RXBUF (15)
80 VIRTIO_NET_F_GUEST_ANNOUNCE (21)
81 VIRTIO_F_ANY_LAYOUT (27)
82 VIRTIO_F_INDIRECT_DESC (28)
83 VHOST_USER_F_PROTOCOL_FEATURES (30)
84 protocol features (0x3)
85 VHOST_USER_PROTOCOL_F_MQ (0)
86 VHOST_USER_PROTOCOL_F_LOG_SHMFD (1)
88 socket filename /tmp/vm00.sock type client errno "Success"
91 thread 1 on vring 1, polling
92 tx placement: spin-lock
96 Memory regions (total 2)
97 region fd guest_phys_addr memory_size userspace_addr mmap_offset mmap_addr
98 ====== ===== ================== ================== ================== ================== =============== ===
99 0 31 0x0000000000000000 0x00000000000a0000 0x00007f1db9c00000 0x0000000000000000 0x00007f7db0400 000
100 1 32 0x00000000000c0000 0x000000000ff40000 0x00007f1db9cc0000 0x00000000000c0000 0x00007f7d94ec0 000
103 qsz 1024 last_avail_idx 0 last_used_idx 0
104 avail.flags 0 avail.idx 256 used.flags 1 used.idx 0
105 kickfd 33 callfd 34 errfd -1
108 qsz 1024 last_avail_idx 8 last_used_idx 8
109 avail.flags 0 avail.idx 8 used.flags 1 used.idx 8
110 kickfd 29 callfd 35 errfd -1