This series introduces new QMP/HMP commands to dump the status
of a a virtio device at different levels.
1. Main command
HMP Only:
virtio [subcommand]
Example:
List all sub-commands:
(qemu) virtio
virtio query -- List all available virtio devices
virtio status path -- Display status of a given virtio device
virtio queue-status path queue -- Display status of a given virtio queue
virtio queue-element path queue [index] -- Display element of a given
virtio queue
2. List available virtio devices in the machine
HMP Form:
virtio query
Example:
(qemu) virtio query
/machine/peripheral-anon/device[3]/virtio-backend [virtio-net]
/machine/peripheral-anon/device[1]/virtio-backend [virtio-serial]
/machine/peripheral-anon/device[0]/virtio-backend [virtio-blk]
QMP Form:
{ 'command': 'query-virtio', 'returns': ['VirtioInfo'] }
Example:
-> { "execute": "query-virtio" }
<- { "return": [
{
"path": "/machine/peripheral-anon/device[3]/virtio-backend",
"type": "virtio-net"
},
{
"path": "/machine/peripheral-anon/device[1]/virtio-backend",
"type": "virtio-serial"
},
{
"path": "/machine/peripheral-anon/device[0]/virtio-backend",
"type": "virtio-blk"
}
]
}
3. Display status of a given virtio device
HMP Form:
virtio status <path>
Example:
(qemu) virtio status /machine/peripheral-anon/device[3]/virtio-backend
/machine/peripheral-anon/device[3]/virtio-backend:
Device Id: 1
Guest features: 0x0000000130afffa7
Host features: 0x0000000179bfffe7
Backend features: 0x0000000000000000
Endianness: little
VirtQueues: 3
QMP Form:
{ 'command': 'virtio-status',
'data': { 'path': 'str' },
'returns': 'VirtioStatus'
}
Example:
-> { "execute": "virtio-status",
"arguments": {
"path": "/machine/peripheral-anon/device[3]/virtio-backend"
}
}
<- { "return": {
"backend_features": 0,
"guest_features": 5111807911,
"num_vqs": 3,
"host_features": 6337593319,
"device_endian": "little",
"device_id": 1
}
}
4. Display status of a given virtio queue
HMP Form:
virtio queue-status <path> <queue>
Example:
(qemu) virtio queue-status
/machine/peripheral-anon/device[3]/virtio-backend 0
/machine/peripheral-anon/device[3]/virtio-backend:
index: 0
inuse: 0
last_avail_idx: 61
shadow_avail_idx: 292
signalled_used: 61
signalled_used_valid: 1
VRing:
num: 256
num_default: 256
align: 4096
desc: 0x000000006c352000
avail: 0x000000006c353000
used: 0x000000006c353240
QMP Form:
{ 'command': 'virtio-queue-status',
'data': { 'path': 'str', 'queue': 'uint16' },
'returns': 'VirtQueueStatus'
}
Example:
-> { "execute": "virtio-queue-status",
"arguments": {
"path": "/machine/peripheral-anon/device[3]/virtio-backend",
"queue": 0
}
}
<- { "return": {
"signalled_used": 373,
"inuse": 0,
"vring_desc": 864411648,
"vring_num_default": 256,
"signalled_used_valid": 1,
"vring_avail": 864415744,
"last_avail_idx": 373,
"queue_index": 0,
"vring_used": 864416320,
"shadow_avail_idx": 619,
"used_idx": 373,
"vring_num": 256,
"vring_align": 4096
}
}
5. Display element of a given virtio queue
HMP Form:
virtio queue-element <path> <queue> [index]
Example:
Dump the information of the head element of the first queue of
the first virtio device::
(qemu) virtio
queue-element/machine/peripheral-anon/device[3]/virtio-backend 0
index: 67
ndescs: 1
descs: addr 0x6fe69800 len 1536 (write-only)
(qemu) xp/128bx 0x6fe69800
000000006fe69800: 0x02 0x00 0x00 0x00 0x00 0x00 0x00 0x00
000000006fe69808: 0x00 0x00 0x01 0x00 0x52 0x54 0x00 0x12
000000006fe69810: 0x34 0x56 0x52 0x54 0x00 0x09 0x51 0xde
000000006fe69818: 0x08 0x00 0x45 0x00 0x00 0x4c 0x8f 0x32
device[3] is a virtio-net device and we can see in the element buffer the
MAC address of the card::
[root@localhost ~]# ip link show ens4
2: ens4: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state
UP m0
link/ether 52:54:00:12:34:56 brd ff:ff:ff:ff:ff:ff
and the MAC address of the gateway::
[root@localhost ~]# arp -a
_gateway (192.168.122.1) at 52:54:00:09:51:de [ether] on ens4
QMP Form:
{ 'command': 'virtio-queue-element',
'data': { 'path': 'str', 'queue': 'uint16', '*index': 'uint16' },
'returns': 'VirtioQueueElement'
}
Example:
-> { "execute": "virtio-queue-element",
"arguments": {
"path": "/machine/peripheral-anon/device[3]/virtio-backend",
"queue": 0
}
}
-> { "return": {
"index": 109,
"len": 0,
"ndescs": 1,
"descs": [
{ "flags": 2, "len": 2048, "addr": 853145600 }
]
}
}
Laurent Vivier (5):
qmp: add QMP command query-virtio
qmp: add QMP command virtio-status
qmp: add QMP command virtio-queue-status
qmp: add QMP command virtio-queue-element
hmp: add virtio commands
Makefile | 2 +-
Makefile.target | 7 +-
docs/system/monitor.rst | 2 +
hmp-commands-virtio.hx | 148 ++++++++++++++++++
hmp-commands.hx | 10 ++
hw/virtio/Makefile.objs | 2 +
hw/virtio/virtio-stub.c | 32 ++++
hw/virtio/virtio.c | 313 +++++++++++++++++++++++++++++++++++++
include/hw/virtio/virtio.h | 1 +
include/monitor/hmp.h | 4 +
monitor/misc.c | 17 ++
qapi/Makefile.objs | 2 +-
qapi/qapi-schema.json | 1 +
qapi/virtio.json | 302 +++++++++++++++++++++++++++++++++++
tests/qtest/qmp-cmd-test.c | 1 +
15 files changed, 840 insertions(+), 4 deletions(-)
create mode 100644 hmp-commands-virtio.hx
create mode 100644 hw/virtio/virtio-stub.c
create mode 100644 qapi/virtio.json
--
2.25.1
