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+This document describes how to test each device, which is required when
+modifying the common I/O infrastructure.
+
+
+9P
+--
+
+ CONFIG_NET_9P_VIRTIO
+
+Without a --disk parameter, kvmtool shares part of the host filesystem
+with the guest using 9p. Otherwise, use the `--9p <directory>,<tag>`
+parameter to share a directory with the guest, and mount it in the guest
+with:
+
+ $ mount -t 9p <tag> <mountpoint>
+
+
+BALLOON
+-------
+
+ CONFIG_VIRTIO_BALLOON
+
+ $ lkvm run ... --balloon
+
+Display memory statistics:
+
+ $ lkvm stat -a -m
+ *** Guest memory statistics ***
+ ...
+
+Remove 20MB of memory from the guest:
+
+ $ lkvm balloon -n guest-$(pidof lkvm) -i 20
+
+
+BLOCK
+-----
+
+ CONFIG_VIRTIO_BLK
+
+ $ lkvm run ... --disk <raw or qcow2 image>
+
+
+CONSOLE
+-------
+
+ $ lkvm run ... --console virtio
+
+See also virtio-console.txt
+
+
+NET
+---
+
+ CONFIG_VIRTIO_NET (guest)
+ CONFIG_VHOST_NET (host)
+
+By default kvmtool instantiates a user network device. In order to test
+both tap and vhost, setup a tap interface on a local network.
+
+In the host:
+
+ # ip tuntap add tap0 mode tap user $USER
+ # ip link set tap0 up
+ # ip link add br0 type bridge
+ # ip link set tap0 master br0
+ # ip link set br0 up
+ # ip addr add 192.168.3.1/24 dev br0
+
+ $ lkvm run ... -n mode=tap,tapif=tap0,vhost=1
+
+In the guest:
+
+ # ip link set eth0 up
+ # ip addr add 192.168.3.12/24 dev eth0
+ $ ping -c 1 192.168.3.1
+ 64 bytes from 192.168.3.1: seq=0 ttl=64 time=0.303 ms
+
+
+RNG
+---
+
+ CONFIG_HW_RANDOM_VIRTIO
+
+ $ lkvm run ... --rng
+
+In the guest:
+
+ $ cat /sys/devices/virtual/misc/hw_random/rng_available
+ virtio_rng.0
+
+
+SCSI
+----
+
+ CONFIG_SCSI_VIRTIO (guest)
+ CONFIG_TCM_FILEIO (host)
+ CONFIG_VHOST_SCSI (host)
+
+In the host, create a fileio backstore and a target:
+
+ # targetcli (https://github.com/open-iscsi/targetcli-fb)
+ /> cd backstores/fileio
+ /backstores/fileio> create kvmtool_1 /srv/kvmtool_1 2M
+ Created fileio kvmtool_1 with size 2097152
+ /backstores/fileio> cd /vhost
+ /vhost> create
+ Created target naa.500140571c9308aa.
+ Created TPG 1.
+ /vhost> cd naa.500140571c9308aa/tpg1/luns
+ /vhost/naa.50...8aa/tpg1/luns> create /backstores/fileio/kvmtool_1
+ Created LUN 0.
+
+ $ lkvm run ... --disk scsi:naa.500140571c9308aa
+ [ 0.479644] scsi host0: Virtio SCSI HBA
+ [ 0.483009] scsi 0:0:1:0: Direct-Access LIO-ORG kvmtool_1 4.0 PQ: 0 ANSI: 6
+
+ [ 1.242833] sd 0:0:1:0: [sda] 4096 512-byte logical blocks: (2.10 MB/2.00 MiB)
+
+
+VSOCK
+-----
+
+ CONFIG_VSOCKETS
+ CONFIG_VIRTIO_VSOCKETS (guest)
+ CONFIG_VHOST_VSOCK (host)
+
+In the host, start a vsock server:
+
+ $ socat - VSOCK-LISTEN:1234
+
+We pick 12 as the guest ID. 0 and 1 are reserved, and the host has default
+ID 2.
+
+ $ lkvm run ... --vsock 12
+
+In the guest, send a message to the host:
+
+ $ echo Hello | socat - VSOCK-CONNECT:2:1234
+
+The host server should display "Hello".
Add a few instructions for testing the devices. Testing devices like vhost-scsi or vsock may seem daunting but is relatively easy. Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> --- Documentation/io-testing.txt | 141 +++++++++++++++++++++++++++++++++++ 1 file changed, 141 insertions(+) create mode 100644 Documentation/io-testing.txt