diff mbox series

[RFC,v5,1/2] virtio: introduce `query-virtio' QMP command

Message ID 1508867404-18046-2-git-send-email-jan.dakinevich@virtuozzo.com
State New
Headers show
Series virtio: introduce `info virtio' hmp command | expand

Commit Message

Jan Dakinevich Oct. 24, 2017, 5:50 p.m. UTC 
The command is intended for gathering virtio information such as status,
feature bits, negotiation status. It is convenient and useful for debug
purpose.

The commands returns generic virtio information for virtio such as
common feature names and status bits names and information for all
attached to current machine devices.

Cc: Denis V. Lunev <den@virtuozzo.com>
Signed-off-by: Jan Dakinevich <jan.dakinevich@virtuozzo.com>
---
 hw/virtio/Makefile.objs |   3 +
 hw/virtio/virtio-qmp.c  | 223 +++++++++++++++++++++++
 hw/virtio/virtio-stub.c |   9 +
 qapi-schema.json        | 466 ++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 701 insertions(+)
 create mode 100644 hw/virtio/virtio-qmp.c
 create mode 100644 hw/virtio/virtio-stub.c

Comments

Eric Blake Nov. 2, 2017, 6:52 p.m. UTC | #1 
On 10/24/2017 12:50 PM, Jan Dakinevich wrote:
> The command is intended for gathering virtio information such as status,
> feature bits, negotiation status. It is convenient and useful for debug
> purpose.
> 
> The commands returns generic virtio information for virtio such as
> common feature names and status bits names and information for all
> attached to current machine devices.
> 
> Cc: Denis V. Lunev <den@virtuozzo.com>
> Signed-off-by: Jan Dakinevich <jan.dakinevich@virtuozzo.com>
> ---

> +++ b/qapi-schema.json
> @@ -3200,3 +3200,469 @@
>  # Since: 2.11
>  ##
>  { 'command': 'watchdog-set-action', 'data' : {'action': 'WatchdogAction'} }
> +
> +##
> +# @VirtioStatus:
> +#
> +# Virtio device status bits
> +#
> +# Since: 2.11

We've entered soft freeze, and this is a new feature, so it may be
better to propose this for 2.12 rather than trying to rush it in now.

> +#
> +##
> +{
> +    'enum': 'VirtioStatus',
> +    'data': [
> +        'acknowledge',
> +        'driver',
> +        'driver-ok',
> +        'features-ok',
> +        'status-reserved-4',
> +        'status-reserved-5',

Are we ever going to report a '*-reserved-NNN' enum value to the end
user?  I hope not, in which case, we don't need to expose it in the QAPI
enums.  Yes, that means you have to do some mapping between named bits
and enum strings (you would no longer have the property that
'status-reserved-4' is value 4, but would instead have to map that bit 6
translates to 'needs-reset' with enum value 4), but a clean
public-facing interface may be worth the hassle.  What's more, as newer
qemu learns new bit names down the road, then expanding the enums to
cover those new names is introspectible; whereas you can't rename an
existing enum value while still retaining back-compat.


> +##
> +# @VirtioFeatureName:
> +#
> +# Since: 2.11
> +#
> +##
> +{
> +    'union': 'VirtioFeatureName',
> +    'data': {
> +        'common': 'VirtioFeatureCommon',
> +        'net': 'VirtioFeatureNet',
> +        'blk': 'VirtioFeatureBlk',

Do we really need to abbreviate this one?

> +        'serial': 'VirtioFeatureSerial',
> +        'balloon': 'VirtioFeatureBalloon',
> +        'scsi': 'VirtioFeatureScsi',
> +        'virtfs': 'VirtioFeatureVirtfs',
> +        'gpu': 'VirtioFeatureGpu',
> +        'other': 'VirtioFeatureOther'
> +    }
> +}

This is a so-called "simple union" - but we do not want any more of
these in our code.  In fact, Markus and I are toying with the idea of
renaming it to "legacy union", and/or making the syntax more painful,
because we WANT to use "flat unions" in all new code (and make their
syntax easier to type).

So, a comparable flat union would be something like:

{ 'enum': 'VirtioFeatureCategory',
  'data': [ 'common', 'net', 'block', 'serial', 'balloon', 'scsi',
'virtfs', 'gpu', 'other' ] }
{ 'union': 'VirtioFeatureName',
  'base': { 'category': 'VirtioFeatureCategory' },
  'discriminator': 'category',
  'data': { 'common': 'VirtioFeatureCommon', ... } }

except that flat unions don't permit enum types (they require a struct
type).  Hmm.

> +
> +##
> +# @VirtioFeature:
> +#
> +# Feature bit with negotiation status
> +#
> +# @host: true if host exposes the feature
> +#
> +# @guest: true if guest acknowledges the feature
> +#
> +# Since: 2.11
> +#
> +##
> +{
> +    'struct': 'VirtioFeature',
> +    'data': {
> +        'host': 'bool',
> +        'guest': 'bool',
> +        'name': 'VirtioFeatureName'
> +    }
> +}

With your proposal, an example on the wire might be:

"feature": { "host": true, "guest": false, "name": { "type": "common",
"data": "notify-on-empty" } }

> +
> +##
> +# @VirtioInfo:
> +#
> +# Information about virtio device
> +#
> +# @qom-path: QOM path of the device
> +#
> +# @status: status bitmask
> +#
> +# @status-names: names of checked bits in status bitmask
> +#
> +# @host-features: bitmask of features, exposed by device
> +#
> +# @guest-features: bitmask of features, acknowledged by guest
> +#
> +# @features: negotiation status and names of device features
> +#
> +##
> +{
> +    'struct': 'VirtioInfo',
> +    'data': {
> +        'qom-path': 'str',
> +        'status': 'uint8',
> +        'status-names': ['VirtioStatus'],

Umm, isn't it better to just have 'status': 'VirtioStatus' (as we can
only ever have a single status value, so we don't really need an array
to tell us what all the other status values are named).

> +        'host-features': 'uint64',
> +        'guest-features': 'uint64',
> +        'features': ['VirtioFeature']

Do we really want to expose both a 64-bit number and an array of feature
names, where the array repeats the information on whether host and guest
support the bit?

I guess we first want to figure out WHAT we want to send over the wire.
Maybe:

"info": { "qom-path": "...", "status": "driver-ok",
          "host": [ { "common": "notify-on-empty" },
                    { "common": "any-layout" },
                    { "net": "csum" } ],
          "guest": [ { "common": "notify-on-empty" },
                     { "net": "csum" } ] }

or

"info": { "qom-path": "...", "status": "driver-ok",
          "host": [ { "type": "common", "value": "notify-on-empty" },
                    { "type": "common", "value": "any-layout" },
                    { "type": "net", "value": "csum" } ],
          "guest": [ { "type": "common", "value": "notify-on-empty" },
                     { "type": "net", "value": "csum" } ] }

or

"info": { "qom-path": "...", "status": "driver-ok",
          "host": { "common": [ "notify-on-empty", "any-layout" ],
                    "net": [ "csum" ] },
          "guest": { "common": [ "notify-on-empty" ] },
                     "net": [ "csum" ] } }

(some of those forms may be easier than others to express in our current
QAPI language; if we need to modify the qapi language to get our ideal
form supported, then that may be worth the effort).

> +
> +##
> +# @query-virtio:
> +#
> +# Returns virtio information such as device status and features
> +#
> +# Since: 2.11
> +#
> +##
> +{
> +    'command': 'query-virtio',
> +    'data': { '*path': 'str' },

Do we need filterable queries, or is it better to just have the command
return info on all virtio devices at once and let the client filter the
results as desired?

> +    'returns': ['VirtioInfo']
> +}
>
diff mbox series

Patch

diff --git a/hw/virtio/Makefile.objs b/hw/virtio/Makefile.objs
index 765d363..3524aa7 100644
--- a/hw/virtio/Makefile.objs
+++ b/hw/virtio/Makefile.objs
@@ -3,12 +3,15 @@  common-obj-y += virtio-rng.o
 common-obj-$(CONFIG_VIRTIO_PCI) += virtio-pci.o
 common-obj-y += virtio-bus.o
 common-obj-y += virtio-mmio.o
+common-obj-y += virtio-qmp.o
 
 obj-y += virtio.o virtio-balloon.o 
 obj-$(CONFIG_LINUX) += vhost.o vhost-backend.o vhost-user.o
 obj-$(CONFIG_VHOST_VSOCK) += vhost-vsock.o
 obj-y += virtio-crypto.o
 obj-$(CONFIG_VIRTIO_PCI) += virtio-crypto-pci.o
+else
+obj-y += virtio-stub.o
 endif
 
 common-obj-$(call lnot,$(CONFIG_LINUX)) += vhost-stub.o
diff --git a/hw/virtio/virtio-qmp.c b/hw/virtio/virtio-qmp.c
new file mode 100644
index 0000000..8192c33
--- /dev/null
+++ b/hw/virtio/virtio-qmp.c
@@ -0,0 +1,223 @@ 
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+#include "qmp-commands.h"
+
+#include "hw/virtio/virtio.h"
+#include "hw/virtio/virtio-net.h"
+#include "hw/virtio/virtio-blk.h"
+#include "hw/virtio/virtio-serial.h"
+#include "hw/virtio/virtio-balloon.h"
+#include "hw/virtio/virtio-scsi.h"
+#ifdef CONFIG_VIRTFS
+#include "hw/9pfs/virtio-9p.h"
+#endif
+#include "hw/virtio/virtio-gpu.h"
+
+#define qmp_query_virtio_features(__vdev, __info, __offset, __count,\
+                                  __name_kind, __name_type, __name_field) ({ \
+    unsigned __idx; \
+    for (__idx = (__count); __idx--; ) { \
+        unsigned int __fbit = __idx + (__offset); \
+        bool __host = virtio_host_has_feature(__vdev, __fbit); \
+        bool __guest = virtio_vdev_has_feature(__vdev, __fbit); \
+        VirtioFeatureList *__feature; \
+ \
+        if (!__host && !__guest) { \
+            continue; \
+        } \
+ \
+        __feature = g_new0(VirtioFeatureList, 1); \
+        __feature->value = g_new0(VirtioFeature, 1); \
+        __feature->value->name = g_new0(VirtioFeatureName, 1); \
+ \
+        __feature->value->host = __host; \
+        __feature->value->guest = __guest; \
+ \
+        __feature->value->name->type = (__name_kind); \
+        __feature->value->name->u.__name_field.data = (__name_type)__idx; \
+ \
+        __feature->next = (__info)->features; \
+        (__info)->features = __feature; \
+    } \
+})
+
+#define qmp_query_virtio_features_common(__vdev, __info) \
+    qmp_query_virtio_features((__vdev), (__info), VIRTIO_FEATURE_OTHER__MAX, \
+        VIRTIO_FEATURE_COMMON__MAX, VIRTIO_FEATURE_NAME_KIND_COMMON, \
+        VirtioFeatureCommon, common)
+
+#define qmp_query_virtio_features_net(__vdev, __info) \
+    qmp_query_virtio_features((__vdev), (__info), 0, \
+        VIRTIO_FEATURE_NET__MAX, VIRTIO_FEATURE_NAME_KIND_NET, \
+        VirtioFeatureNet, net)
+
+#define qmp_query_virtio_features_blk(__vdev, __info) \
+    qmp_query_virtio_features((__vdev), (__info), 0, \
+        VIRTIO_FEATURE_BLK__MAX, VIRTIO_FEATURE_NAME_KIND_BLK, \
+        VirtioFeatureBlk, blk)
+
+#define qmp_query_virtio_features_serial(__vdev, __info) \
+    qmp_query_virtio_features((__vdev), (__info), 0, \
+        VIRTIO_FEATURE_SERIAL__MAX, VIRTIO_FEATURE_NAME_KIND_SERIAL, \
+        VirtioFeatureSerial, serial)
+
+#define qmp_query_virtio_features_balloon(__vdev, __info) \
+    qmp_query_virtio_features((__vdev), (__info), 0, \
+        VIRTIO_FEATURE_BALLOON__MAX, VIRTIO_FEATURE_NAME_KIND_BALLOON, \
+        VirtioFeatureBalloon, balloon)
+
+#define qmp_query_virtio_features_scsi(__vdev, __info) \
+    qmp_query_virtio_features((__vdev), (__info), 0, \
+        VIRTIO_FEATURE_SCSI__MAX, VIRTIO_FEATURE_NAME_KIND_SCSI, \
+        VirtioFeatureScsi, scsi)
+
+#ifdef CONFIG_VIRTFS
+#define qmp_query_virtio_features_virtfs(__vdev, __info) \
+    qmp_query_virtio_features((__vdev), (__info), 0, \
+        VIRTIO_FEATURE_VIRTFS__MAX, VIRTIO_FEATURE_NAME_KIND_VIRTFS, \
+        VirtioFeatureVirtfs, virtfs)
+#endif
+
+#define qmp_query_virtio_features_gpu(__vdev, __info) \
+    qmp_query_virtio_features((__vdev), (__info), 0, \
+        VIRTIO_FEATURE_GPU__MAX, VIRTIO_FEATURE_NAME_KIND_GPU, \
+        VirtioFeatureGpu, gpu)
+
+#define qmp_query_virtio_features_other(__vdev, __info) \
+    qmp_query_virtio_features((__vdev), (__info), 0, \
+        VIRTIO_FEATURE_OTHER__MAX, VIRTIO_FEATURE_NAME_KIND_OTHER, \
+        VirtioFeatureOther, other)
+
+
+static VirtioInfoList *qmp_query_virtio_one(VirtIODevice *vdev)
+{
+    VirtioInfoList *list;
+    VirtioInfo *info;
+    unsigned int idx;
+
+    QEMU_BUILD_BUG_ON(VIRTIO_FEATURE_COMMON__MAX != 40);
+    QEMU_BUILD_BUG_ON(VIRTIO_FEATURE_NET__MAX != 24);
+    QEMU_BUILD_BUG_ON(VIRTIO_FEATURE_BLK__MAX != 24);
+    QEMU_BUILD_BUG_ON(VIRTIO_FEATURE_SCSI__MAX != 24);
+    QEMU_BUILD_BUG_ON(VIRTIO_FEATURE_BALLOON__MAX != 24);
+    QEMU_BUILD_BUG_ON(VIRTIO_FEATURE_SERIAL__MAX != 24);
+    QEMU_BUILD_BUG_ON(VIRTIO_FEATURE_GPU__MAX != 24);
+    QEMU_BUILD_BUG_ON(VIRTIO_FEATURE_OTHER__MAX != 24);
+
+    list = g_new0(VirtioInfoList, 1);
+    list->value = g_new0(VirtioInfo, 1);
+
+    info = list->value;
+    info->qom_path = object_get_canonical_path(OBJECT(vdev));
+    info->status = vdev->status;
+    info->host_features = vdev->host_features;
+    info->guest_features = vdev->guest_features;
+
+    /* device status */
+    for (idx = VIRTIO_STATUS__MAX; idx--; ) {
+        VirtioStatusList *status;
+
+        if (!(vdev->status & (1 << idx))) {
+            continue;
+        }
+
+        status = g_new0(VirtioStatusList, 1);
+        status->value = (VirtioStatus)idx;
+
+        status->next = info->status_names;
+        info->status_names = status;
+    }
+
+    /* device-specific features */
+    if (object_dynamic_cast(OBJECT(vdev), TYPE_VIRTIO_NET)) {
+        qmp_query_virtio_features_net(vdev, info);
+    } else if (object_dynamic_cast(OBJECT(vdev), TYPE_VIRTIO_BLK)) {
+        qmp_query_virtio_features_blk(vdev, info);
+    } else if (object_dynamic_cast(OBJECT(vdev), TYPE_VIRTIO_SERIAL)) {
+        qmp_query_virtio_features_serial(vdev, info);
+    } else if (object_dynamic_cast(OBJECT(vdev), TYPE_VIRTIO_BALLOON)) {
+        qmp_query_virtio_features_balloon(vdev, info);
+    } else if (object_dynamic_cast(OBJECT(vdev), TYPE_VIRTIO_SCSI)) {
+        qmp_query_virtio_features_scsi(vdev, info);
+#ifdef CONFIG_VIRTFS
+    } else if (object_dynamic_cast(OBJECT(vdev), TYPE_VIRTIO_9P)) {
+        qmp_query_virtio_features_virtfs(vdev, info);
+#endif
+    } else if (object_dynamic_cast(OBJECT(vdev), TYPE_VIRTIO_GPU)) {
+        qmp_query_virtio_features_gpu(vdev, info);
+    } else {
+        qmp_query_virtio_features_other(vdev, info);
+    }
+
+    /* common features */
+    qmp_query_virtio_features_common(vdev, info);
+
+    return list;
+}
+
+typedef struct QueryVirtioEntry {
+    VirtIODevice *vdev;
+    QTAILQ_ENTRY(QueryVirtioEntry) link;
+} QueryVirtioEntry;
+
+typedef QTAILQ_HEAD(, QueryVirtioEntry) QueryVirtioHead;
+
+static void qmp_query_virtio_recursive(QueryVirtioHead *head, BusState *bus)
+{
+    BusChild *kid;
+
+    QTAILQ_FOREACH(kid, &bus->children, sibling) {
+        DeviceState *dev = kid->child;
+        BusState *child;
+
+        if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_DEVICE)) {
+            QueryVirtioEntry *entry = g_new0(QueryVirtioEntry, 1);
+
+            entry->vdev = VIRTIO_DEVICE(dev);
+            QTAILQ_INSERT_TAIL(head, entry, link);
+        }
+        QLIST_FOREACH(child, &dev->child_bus, sibling) {
+            qmp_query_virtio_recursive(head, child);
+        }
+    }
+}
+
+VirtioInfoList *qmp_query_virtio(bool has_path, const char *path, Error **errp)
+{
+    BusState *bus = sysbus_get_default();
+    VirtioInfoList *list = NULL;
+
+    if (!bus) {
+        return NULL;
+    }
+
+    if (has_path) {
+        Object *obj = object_resolve_path(path, NULL);
+        if (!obj) {
+            return NULL;
+        }
+        if (!object_dynamic_cast(OBJECT(obj), TYPE_VIRTIO_DEVICE)) {
+            return NULL;
+        }
+
+        list = qmp_query_virtio_one(VIRTIO_DEVICE(obj));
+    } else {
+        QueryVirtioHead head;
+        QueryVirtioEntry *query, *tmp;
+
+        QTAILQ_INIT(&head);
+        qmp_query_virtio_recursive(&head, bus);
+
+        QTAILQ_FOREACH_SAFE(query, &head, link, tmp) {
+            VirtioInfoList *entry = qmp_query_virtio_one(query->vdev);
+
+            QTAILQ_REMOVE(&head, query, link);
+            g_free(query);
+
+            entry->next = list;
+            list = entry;
+        }
+    }
+
+    return list;
+}
diff --git a/hw/virtio/virtio-stub.c b/hw/virtio/virtio-stub.c
new file mode 100644
index 0000000..185d4bd
--- /dev/null
+++ b/hw/virtio/virtio-stub.c
@@ -0,0 +1,9 @@ 
+#include "qemu/osdep.h"
+#include "qmp-commands.h"
+#include "qapi/qmp/qerror.h"
+
+VirtioInfoList *qmp_query_virtio(bool has_path, const char *path, Error **errp)
+{
+    error_setg(errp, QERR_UNSUPPORTED);
+    return NULL;
+}
diff --git a/qapi-schema.json b/qapi-schema.json
index a9dd043..b1645f3 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -3200,3 +3200,469 @@ 
 # Since: 2.11
 ##
 { 'command': 'watchdog-set-action', 'data' : {'action': 'WatchdogAction'} }
+
+##
+# @VirtioStatus:
+#
+# Virtio device status bits
+#
+# Since: 2.11
+#
+##
+{
+    'enum': 'VirtioStatus',
+    'data': [
+        'acknowledge',
+        'driver',
+        'driver-ok',
+        'features-ok',
+        'status-reserved-4',
+        'status-reserved-5',
+        'needs-reset',
+        'failed'
+    ]
+}
+
+##
+# @VirtioFeatureCommon:
+#
+# Virtio feature bits common to all devices
+#
+# Since: 2.11
+#
+##
+{
+    'enum': 'VirtioFeatureCommon',
+    'data': [
+        'notify-on-empty',
+        'common-reserved-25',
+        'common-reserved-26',
+        'any-layout',
+        'indirect-desc',
+        'event-idx',
+        'bad-feature',
+        'common-reserved-31',
+        'version-1',
+        'iommu-platform',
+        'common-reserved-34',
+        'common-reserved-35',
+        'common-reserved-36',
+        'common-reserved-37',
+        'common-reserved-38',
+        'common-reserved-39',
+        'common-reserved-40',
+        'common-reserved-41',
+        'common-reserved-42',
+        'common-reserved-43',
+        'common-reserved-44',
+        'common-reserved-45',
+        'common-reserved-46',
+        'common-reserved-47',
+        'common-reserved-48',
+        'common-reserved-49',
+        'common-reserved-50',
+        'common-reserved-51',
+        'common-reserved-52',
+        'common-reserved-53',
+        'common-reserved-54',
+        'common-reserved-55',
+        'common-reserved-56',
+        'common-reserved-57',
+        'common-reserved-58',
+        'common-reserved-59',
+        'common-reserved-60',
+        'common-reserved-61',
+        'common-reserved-62',
+        'common-reserved-63'
+    ]
+}
+
+##
+# @VirtioFeatureNet:
+#
+# Virtio network device feature bits
+#
+# Since: 2.11
+#
+##
+{
+    'enum': 'VirtioFeatureNet',
+    'data': [
+        'csum',
+        'guest-csum',
+        'ctrl-guest-offloads',
+        'mtu',
+        'net-reserved-4',
+        'mac',
+        'gso',
+        'guest-tso4',
+        'guest-tso6',
+        'guest-ecn',
+        'guest-ufo',
+        'host-tso4',
+        'host-tso6',
+        'host-ecn',
+        'host-ufo',
+        'mrg-rxbuf',
+        'status',
+        'ctrl-vq',
+        'ctrl-rx',
+        'ctrl-vlan',
+        'ctrl-rx-extra',
+        'guest-announce',
+        'mq',
+        'ctrl-mac-addr'
+    ]
+}
+
+##
+# @VirtioFeatureBlk:
+#
+# Virtio block device feature bits
+#
+# Since: 2.11
+#
+##
+{
+    'enum': 'VirtioFeatureBlk',
+    'data': [
+        'barrier',
+        'size-max',
+        'seg-max',
+        'blk-reserved-3',
+        'geometry',
+        'ro',
+        'blk-size',
+        'scsi',
+        'blk-reserved-8',
+        'flush',
+        'topology',
+        'config-wce',
+        'mq',
+        'blk-reserved-13',
+        'blk-reserved-14',
+        'blk-reserved-15',
+        'blk-reserved-16',
+        'blk-reserved-17',
+        'blk-reserved-18',
+        'blk-reserved-19',
+        'blk-reserved-20',
+        'blk-reserved-21',
+        'blk-reserved-22',
+        'blk-reserved-23'
+    ]
+}
+
+##
+# @VirtioFeatureSerial:
+#
+# Virtio serial device (console) feature bits
+#
+# Since: 2.11
+#
+##
+{
+    'enum': 'VirtioFeatureSerial',
+    'data': [
+        'size',
+        'multiport',
+        'emerg-write',
+        'serial-reserved-3',
+        'serial-reserved-4',
+        'serial-reserved-5',
+        'serial-reserved-6',
+        'serial-reserved-7',
+        'serial-reserved-8',
+        'serial-reserved-9',
+        'serial-reserved-10',
+        'serial-reserved-11',
+        'serial-reserved-12',
+        'serial-reserved-13',
+        'serial-reserved-14',
+        'serial-reserved-15',
+        'serial-reserved-16',
+        'serial-reserved-17',
+        'serial-reserved-18',
+        'serial-reserved-19',
+        'serial-reserved-20',
+        'serial-reserved-21',
+        'serial-reserved-22',
+        'serial-reserved-23'
+    ]
+}
+
+##
+# @VirtioFeatureBalloon:
+#
+# Virtio balloon feature bits
+#
+# Since: 2.11
+#
+##
+{
+    'enum': 'VirtioFeatureBalloon',
+    'data': [
+        'must-tell-host',
+        'stats-vq',
+        'deflate-on-oom',
+        'balloon-reserved-3',
+        'balloon-reserved-4',
+        'balloon-reserved-5',
+        'balloon-reserved-6',
+        'balloon-reserved-7',
+        'balloon-reserved-8',
+        'balloon-reserved-9',
+        'balloon-reserved-10',
+        'balloon-reserved-11',
+        'balloon-reserved-12',
+        'balloon-reserved-13',
+        'balloon-reserved-14',
+        'balloon-reserved-15',
+        'balloon-reserved-16',
+        'balloon-reserved-17',
+        'balloon-reserved-18',
+        'balloon-reserved-19',
+        'balloon-reserved-20',
+        'balloon-reserved-21',
+        'balloon-reserved-22',
+        'balloon-reserved-23'
+    ]
+}
+
+##
+# @VirtioFeatureScsi:
+#
+# Virtio scsi controller feature bits
+#
+# Since: 2.11
+#
+##
+{
+    'enum': 'VirtioFeatureScsi',
+    'data': [
+        'inout',
+        'hotplug',
+        'change',
+        't10-pi',
+        'scsi-reserved-4',
+        'scsi-reserved-5',
+        'scsi-reserved-6',
+        'scsi-reserved-7',
+        'scsi-reserved-8',
+        'scsi-reserved-9',
+        'scsi-reserved-10',
+        'scsi-reserved-11',
+        'scsi-reserved-12',
+        'scsi-reserved-13',
+        'scsi-reserved-14',
+        'scsi-reserved-15',
+        'scsi-reserved-16',
+        'scsi-reserved-17',
+        'scsi-reserved-18',
+        'scsi-reserved-19',
+        'scsi-reserved-20',
+        'scsi-reserved-21',
+        'scsi-reserved-22',
+        'scsi-reserved-23'
+    ]
+}
+
+##
+# @VirtioFeatureVirtfs:
+#
+# Virtio virtfs (9p) feature bits
+#
+# Since: 2.11
+#
+##
+{
+    'enum': 'VirtioFeatureVirtfs',
+    'data': [
+        'mount-tag',
+        'virtfs-reserved-1',
+        'virtfs-reserved-2',
+        'virtfs-reserved-3',
+        'virtfs-reserved-4',
+        'virtfs-reserved-5',
+        'virtfs-reserved-6',
+        'virtfs-reserved-7',
+        'virtfs-reserved-8',
+        'virtfs-reserved-9',
+        'virtfs-reserved-10',
+        'virtfs-reserved-11',
+        'virtfs-reserved-12',
+        'virtfs-reserved-13',
+        'virtfs-reserved-14',
+        'virtfs-reserved-15',
+        'virtfs-reserved-16',
+        'virtfs-reserved-17',
+        'virtfs-reserved-18',
+        'virtfs-reserved-19',
+        'virtfs-reserved-20',
+        'virtfs-reserved-21',
+        'virtfs-reserved-22',
+        'virtfs-reserved-23'
+    ]
+}
+
+##
+# @VirtioFeatureGpu:
+#
+# Virtio GPU device feature bits
+#
+# Since: 2.11
+#
+##
+{
+    'enum': 'VirtioFeatureGpu',
+    'data': [
+        'virgl',
+        'gpu-reserved-1',
+        'gpu-reserved-2',
+        'gpu-reserved-3',
+        'gpu-reserved-4',
+        'gpu-reserved-5',
+        'gpu-reserved-6',
+        'gpu-reserved-7',
+        'gpu-reserved-8',
+        'gpu-reserved-9',
+        'gpu-reserved-10',
+        'gpu-reserved-11',
+        'gpu-reserved-12',
+        'gpu-reserved-13',
+        'gpu-reserved-14',
+        'gpu-reserved-15',
+        'gpu-reserved-16',
+        'gpu-reserved-17',
+        'gpu-reserved-18',
+        'gpu-reserved-19',
+        'gpu-reserved-20',
+        'gpu-reserved-21',
+        'gpu-reserved-22',
+        'gpu-reserved-23'
+    ]
+}
+
+##
+# @VirtioFeatureOther:
+#
+# Feature bits of other virtio devices
+#
+# Since: 2.11
+#
+##
+{
+    'enum': 'VirtioFeatureOther',
+    'data': [
+        'other-reserved-0',
+        'other-reserved-1',
+        'other-reserved-2',
+        'other-reserved-3',
+        'other-reserved-4',
+        'other-reserved-5',
+        'other-reserved-6',
+        'other-reserved-7',
+        'other-reserved-8',
+        'other-reserved-9',
+        'other-reserved-10',
+        'other-reserved-11',
+        'other-reserved-12',
+        'other-reserved-13',
+        'other-reserved-14',
+        'other-reserved-15',
+        'other-reserved-16',
+        'other-reserved-17',
+        'other-reserved-18',
+        'other-reserved-19',
+        'other-reserved-20',
+        'other-reserved-21',
+        'other-reserved-22',
+        'other-reserved-23'
+    ]
+}
+
+##
+# @VirtioFeatureName:
+#
+# Since: 2.11
+#
+##
+{
+    'union': 'VirtioFeatureName',
+    'data': {
+        'common': 'VirtioFeatureCommon',
+        'net': 'VirtioFeatureNet',
+        'blk': 'VirtioFeatureBlk',
+        'serial': 'VirtioFeatureSerial',
+        'balloon': 'VirtioFeatureBalloon',
+        'scsi': 'VirtioFeatureScsi',
+        'virtfs': 'VirtioFeatureVirtfs',
+        'gpu': 'VirtioFeatureGpu',
+        'other': 'VirtioFeatureOther'
+    }
+}
+
+##
+# @VirtioFeature:
+#
+# Feature bit with negotiation status
+#
+# @host: true if host exposes the feature
+#
+# @guest: true if guest acknowledges the feature
+#
+# Since: 2.11
+#
+##
+{
+    'struct': 'VirtioFeature',
+    'data': {
+        'host': 'bool',
+        'guest': 'bool',
+        'name': 'VirtioFeatureName'
+    }
+}
+
+##
+# @VirtioInfo:
+#
+# Information about virtio device
+#
+# @qom-path: QOM path of the device
+#
+# @status: status bitmask
+#
+# @status-names: names of checked bits in status bitmask
+#
+# @host-features: bitmask of features, exposed by device
+#
+# @guest-features: bitmask of features, acknowledged by guest
+#
+# @features: negotiation status and names of device features
+#
+##
+{
+    'struct': 'VirtioInfo',
+    'data': {
+        'qom-path': 'str',
+        'status': 'uint8',
+        'status-names': ['VirtioStatus'],
+        'host-features': 'uint64',
+        'guest-features': 'uint64',
+        'features': ['VirtioFeature']
+    }
+}
+
+##
+# @query-virtio:
+#
+# Returns virtio information such as device status and features
+#
+# Since: 2.11
+#
+##
+{
+    'command': 'query-virtio',
+    'data': { '*path': 'str' },
+    'returns': ['VirtioInfo']
+}