On Thu, Nov 16, 2023 at 10:44 PM Markus Armbruster <arm...@redhat.com>
wrote:
> Hyman Huang <yong.hu...@smartx.com> writes:
>
> > This patch allows to display feature and status bits in virtio-status.
> >
> > An optional argument is introduced: show-bits. For example:
> > {"execute": "x-query-virtio-status",
> > "arguments": {"path":
> "/machine/peripheral-anon/device[1]/virtio-backend",
> > "show-bits": true}
> >
> > Features and status bits could be helpful for applications to compare
> > directly. For instance, when an upper application aims to ensure the
> > virtio negotiation correctness between guest, QEMU, and OVS-DPDK, it use
> > the "ovs-vsctl list interface" command to retrieve interface features
> > (in number format) and the QMP command x-query-virtio-status to retrieve
> > vhost-user net device features. If "show-bits" is added, the application
> > can compare the two features directly; No need to encoding the features
> > returned by the QMP command.
> >
> > This patch also serves as a preparation for the next one, which
> implements
> > a vhost-user test case about acked features of vhost-user protocol.
> >
> > Note that since the matching HMP command is typically used for human,
> > leave it unchanged.
> >
> > Signed-off-by: Hyman Huang <yong.hu...@smartx.com>
> > ---
> > hw/virtio/virtio-hmp-cmds.c | 2 +-
> > hw/virtio/virtio-qmp.c | 21 +++++++++++++++-
> > qapi/virtio.json | 49 ++++++++++++++++++++++++++++++++++---
> > 3 files changed, 67 insertions(+), 5 deletions(-)
> >
> > diff --git a/hw/virtio/virtio-hmp-cmds.c b/hw/virtio/virtio-hmp-cmds.c
> > index 477c97dea2..3774f3d4bf 100644
> > --- a/hw/virtio/virtio-hmp-cmds.c
> > +++ b/hw/virtio/virtio-hmp-cmds.c
> > @@ -108,7 +108,7 @@ void hmp_virtio_status(Monitor *mon, const QDict
> *qdict)
> > {
> > Error *err = NULL;
> > const char *path = qdict_get_try_str(qdict, "path");
> > - VirtioStatus *s = qmp_x_query_virtio_status(path, &err);
> > + VirtioStatus *s = qmp_x_query_virtio_status(path, false, false,
> &err);
> >
> > if (err != NULL) {
> > hmp_handle_error(mon, err);
> > diff --git a/hw/virtio/virtio-qmp.c b/hw/virtio/virtio-qmp.c
> > index 1dd96ed20f..2e92bf28ac 100644
> > --- a/hw/virtio/virtio-qmp.c
> > +++ b/hw/virtio/virtio-qmp.c
> > @@ -718,10 +718,15 @@ VirtIODevice *qmp_find_virtio_device(const char
> *path)
> > return VIRTIO_DEVICE(dev);
> > }
> >
> > -VirtioStatus *qmp_x_query_virtio_status(const char *path, Error **errp)
> > +VirtioStatus *qmp_x_query_virtio_status(const char *path,
> > + bool has_show_bits,
> > + bool show_bits,
> > + Error **errp)
> > {
> > VirtIODevice *vdev;
> > VirtioStatus *status;
> > + bool display_bits =
> > + has_show_bits ? show_bits : false;
>
> Since !has_show_bits implies !show_bits, you can simply use
> if (show_bits).
>
Ok
>
> >
> > vdev = qmp_find_virtio_device(path);
> > if (vdev == NULL) {
> > @@ -733,6 +738,11 @@ VirtioStatus *qmp_x_query_virtio_status(const char
> *path, Error **errp)
> > status->name = g_strdup(vdev->name);
> > status->device_id = vdev->device_id;
> > status->vhost_started = vdev->vhost_started;
> > + if (display_bits) {
> > + status->guest_features_bits = vdev->guest_features;
> > + status->host_features_bits = vdev->host_features;
> > + status->backend_features_bits = vdev->backend_features;
> > + }
> > status->guest_features = qmp_decode_features(vdev->device_id,
> > vdev->guest_features);
> > status->host_features = qmp_decode_features(vdev->device_id,
> > @@ -753,6 +763,9 @@ VirtioStatus *qmp_x_query_virtio_status(const char
> *path, Error **errp)
> > }
> >
> > status->num_vqs = virtio_get_num_queues(vdev);
> > + if (display_bits) {
> > + status->status_bits = vdev->status;
> > + }
> > status->status = qmp_decode_status(vdev->status);
> > status->isr = vdev->isr;
> > status->queue_sel = vdev->queue_sel;
> > @@ -775,6 +788,12 @@ VirtioStatus *qmp_x_query_virtio_status(const char
> *path, Error **errp)
> > status->vhost_dev->n_tmp_sections = hdev->n_tmp_sections;
> > status->vhost_dev->nvqs = hdev->nvqs;
> > status->vhost_dev->vq_index = hdev->vq_index;
> > + if (display_bits) {
> > + status->vhost_dev->features_bits = hdev->features;
> > + status->vhost_dev->acked_features_bits =
> hdev->acked_features;
> > + status->vhost_dev->backend_features_bits =
> hdev->backend_features;
> > + status->vhost_dev->protocol_features_bits =
> hdev->protocol_features;
> > + }
> > status->vhost_dev->features =
> > qmp_decode_features(vdev->device_id, hdev->features);
> > status->vhost_dev->acked_features =
> > diff --git a/qapi/virtio.json b/qapi/virtio.json
> > index e6dcee7b83..608b841a89 100644
> > --- a/qapi/virtio.json
> > +++ b/qapi/virtio.json
> > @@ -79,12 +79,20 @@
> > #
> > # @vq-index: vhost_dev vq_index
> > #
> > +# @features-bits: vhost_dev features in decimal format
>
> Say "encoded as a number". The number is decimal just because the
> transport is JSON. We could have another transport some day. Or
> language bindings wrapping around the JSON transport.
>
> > +#
> > # @features: vhost_dev features
>
> Double-checking... @feature-bits provides the exact same information as
> @features, only in another encoding. Correct?
> Same for all the other new -bits. Correct?
Yes, all the new fields are only about providing another encoding.
>
> > #
> > +# @acked-features-bits: vhost_dev acked_features in decimal format
> > +#
> > # @acked-features: vhost_dev acked_features
> > #
> > +# @backend-features-bits: vhost_dev backend_features in decimal format
> > +#
> > # @backend-features: vhost_dev backend_features
> > #
> > +# @protocol-features-bits: vhost_dev protocol_features in decimal format
> > +#
> > # @protocol-features: vhost_dev protocol_features
> > #
> > # @max-queues: vhost_dev max_queues
> > @@ -102,9 +110,13 @@
> > 'n-tmp-sections': 'int',
> > 'nvqs': 'uint32',
> > 'vq-index': 'int',
> > + 'features-bits': 'uint64',
> > 'features': 'VirtioDeviceFeatures',
> > + 'acked-features-bits': 'uint64',
> > 'acked-features': 'VirtioDeviceFeatures',
> > + 'backend-features-bits': 'uint64',
> > 'backend-features': 'VirtioDeviceFeatures',
> > + 'protocol-features-bits': 'uint64',
> > 'protocol-features': 'VhostDeviceProtocols',
> > 'max-queues': 'uint64',
> > 'backend-cap': 'uint64',
> > @@ -124,10 +136,16 @@
> > #
> > # @vhost-started: VirtIODevice vhost_started flag
> > #
> > +# @guest-features-bits: VirtIODevice guest_features in decimal format
> > +#
> > # @guest-features: VirtIODevice guest_features
> > #
> > +# @host-features-bits: VirtIODevice host_features in decimal format
> > +#
> > # @host-features: VirtIODevice host_features
> > #
> > +# @backend-features-bits: VirtIODevice backend_features in decimal
> format
> > +#
> > # @backend-features: VirtIODevice backend_features
> > #
> > # @device-endian: VirtIODevice device_endian
> > @@ -135,6 +153,9 @@
> > # @num-vqs: VirtIODevice virtqueue count. This is the number of
> > # active virtqueues being used by the VirtIODevice.
> > #
> > +# @status-bits: VirtIODevice configuration status in decimal format
> > +# (VirtioDeviceStatus)
> > +#
> > # @status: VirtIODevice configuration status (VirtioDeviceStatus)
> > #
> > # @isr: VirtIODevice ISR
> > @@ -170,10 +191,14 @@
> > 'device-id': 'uint16',
> > 'vhost-started': 'bool',
> > 'device-endian': 'str',
> > + 'guest-features-bits': 'uint64',
> > 'guest-features': 'VirtioDeviceFeatures',
> > + 'host-features-bits': 'uint64',
> > 'host-features': 'VirtioDeviceFeatures',
> > + 'backend-features-bits': 'uint64',
> > 'backend-features': 'VirtioDeviceFeatures',
> > 'num-vqs': 'int',
> > + 'status-bits': 'uint8',
> > 'status': 'VirtioDeviceStatus',
> > 'isr': 'uint8',
> > 'queue-sel': 'uint16',
> > @@ -195,6 +220,9 @@
> > #
> > # @path: Canonical QOM path of the VirtIODevice
> > #
> > +# @show-bits: Whether to display the feature & status bits.
> > +# Default is disabled. (Since 8.2)
>
> This makes the new members opt-in. Why not include them always?
>
Agree, this makes things simple.
>
> > +#
> > # Features:
> > #
> > # @unstable: This command is meant for debugging.
> > @@ -208,7 +236,8 @@
> > # 1. Poll for the status of virtio-crypto (no vhost-crypto active)
> > #
> > # -> { "execute": "x-query-virtio-status",
> > -# "arguments": { "path":
> "/machine/peripheral/crypto0/virtio-backend" }
> > +# "arguments": { "path":
> "/machine/peripheral/crypto0/virtio-backend",
> > +# "show-bits": true }
> > # }
> > # <- { "return": {
> > # "device-endian": "little",
> > @@ -216,6 +245,7 @@
> > # "disable-legacy-check": false,
> > # "name": "virtio-crypto",
> > # "started": true,
> > +# "guest-features-bits": 5100273664,
> > # "device-id": 20,
> > # "backend-features": {
> > # "transports": [],
> > @@ -241,6 +271,7 @@
> > # "VIRTIO_F_VERSION_1: Device compliant for v1 spec
> (legacy)"
> > # ]
> > # },
> > +# "host-features-bits": 6325010432,
> > # "host-features": {
> > # "unknown-dev-features": 1073741824,
> > # "dev-features": [],
> > @@ -252,9 +283,11 @@
> > # "VIRTIO_F_NOTIFY_ON_EMPTY: Notify when device runs
> out of avail. descs. on VQ"
> > # ]
> > # },
> > +# "backend-features-bits": 0,
> > # "use-guest-notifier-mask": true,
> > # "vm-running": true,
> > # "queue-sel": 1,
> > +# "status-bits": 15,
> > # "disabled": false,
> > # "vhost-started": false,
> > # "use-started": true
> > @@ -264,7 +297,8 @@
> > # 2. Poll for the status of virtio-net (vhost-net is active)
> > #
> > # -> { "execute": "x-query-virtio-status",
> > -# "arguments": { "path":
> "/machine/peripheral-anon/device[1]/virtio-backend" }
> > +# "arguments": { "path":
> "/machine/peripheral-anon/device[1]/virtio-backend",
> > +# "show-bits": true }
> > # }
> > # <- { "return": {
> > # "device-endian": "little",
> > @@ -272,11 +306,13 @@
> > # "disabled-legacy-check": false,
> > # "name": "virtio-net",
> > # "started": true,
> > +# "guest-features-bits": 5111807911,
> > # "device-id": 1,
> > # "vhost-dev": {
> > # "n-tmp-sections": 4,
> > # "n-mem-sections": 4,
> > # "max-queues": 1,
> > +# "features-bits": 13908344832
> > # "backend-cap": 2,
> > # "log-size": 0,
> > # "backend-features": {
> > @@ -284,6 +320,8 @@
> > # "transports": []
> > # },
> > # "nvqs": 2,
> > +# "acked-features-bits": 5100306432,
> > +# "backend-features-bits": 0,
> > # "protocol-features": {
> > # "protocols": []
> > # },
> > @@ -299,6 +337,7 @@
> > # "VIRTIO_F_VERSION_1: Device compliant for v1
> spec (legacy)"
> > # ]
> > # },
> > +# "protocol-features-bits": 0,
> > # "features": {
> > # "dev-features": [
> > # "VHOST_F_LOG_ALL: Logging write descriptors
> supported",
> > @@ -387,6 +426,7 @@
> > # "VIRTIO_F_VERSION_1: Device compliant for v1 spec
> (legacy)"
> > # ]
> > # },
> > +# "host-features-bits": 6337593319,
> > # "host-features": {
> > # "dev-features": [
> > # "VHOST_USER_F_PROTOCOL_FEATURES: Vhost-user protocol
> features negotiation supported",
> > @@ -420,9 +460,11 @@
> > # "VIRTIO_F_NOTIFY_ON_EMPTY: Notify when device runs
> out of avail. descs. on VQ"
> > # ]
> > # },
> > +# "backend-features-bits": 6337593319,
> > # "use-guest-notifier-mask": true,
> > # "vm-running": true,
> > # "queue-sel": 2,
> > +# "status-bits": 15,
> > # "disabled": false,
> > # "vhost-started": true,
> > # "use-started": true
> > @@ -430,7 +472,8 @@
> > # }
> > ##
> > { 'command': 'x-query-virtio-status',
> > - 'data': { 'path': 'str' },
> > + 'data': { 'path': 'str',
> > + '*show-bits': 'bool'},
> > 'returns': 'VirtioStatus',
> > 'features': [ 'unstable' ] }
>
>
Yong
--
Best regards
