From: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> This field is mostly unused and sometimes confusing. We even have a TODO-like comment to drop it, the comment is removed in this commit. The field is used to held VHOST_USER_F_PROTOCOL_FEATURES for vhost-user and/or VHOST_NET_F_VIRTIO_NET_HDR for vhost-net (which may be vhost-user-net). But we can simply recalculate these two flags in place from hdev->features, and from net-client for VHOST_NET_F_VIRTIO_NET_HDR. Note: removing field from x-query-virtio-status result is incompatible change. We can do it because the command is unstable. Cc: devel@lists.libvirt.org Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Acked-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Daniil Tatianin <d-tatianin@yandex-team.ru> Acked-by: Raphael Norwitz <raphael.s.norwitz@gmail.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Tested-by: Lei Yang <leiyang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Message-Id: <20260420200339.708640-3-vsementsov@yandex-team.ru> --- hw/block/vhost-user-blk.c | 1 - hw/net/vhost_net.c | 26 ++++++++++++++------------ hw/scsi/vhost-scsi.c | 1 - hw/scsi/vhost-user-scsi.c | 1 - hw/virtio/vdpa-dev.c | 1 - hw/virtio/vhost-user.c | 17 ++++++++--------- hw/virtio/virtio-hmp-cmds.c | 2 -- hw/virtio/virtio-qmp.c | 4 ---- include/hw/virtio/vhost.h | 7 ------- qapi/virtio.json | 3 --- 10 files changed, 22 insertions(+), 41 deletions(-) diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c index c151e83677..dc99de0263 100644 --- a/hw/block/vhost-user-blk.c +++ b/hw/block/vhost-user-blk.c @@ -348,7 +348,6 @@ static int vhost_user_blk_connect(DeviceState *dev, Error **errp) s->dev.nvqs = s->num_queues; s->dev.vqs = s->vhost_vqs; s->dev.vq_index = 0; - s->dev.backend_features = 0; vhost_dev_set_config_notifier(&s->dev, &blk_ops); diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c index 25e9f1fd24..fda90e231e 100644 --- a/hw/net/vhost_net.c +++ b/hw/net/vhost_net.c @@ -52,8 +52,14 @@ int vhost_net_set_config(struct vhost_net *net, const uint8_t *data, void vhost_net_ack_features_ex(struct vhost_net *net, const uint64_t *features) { - virtio_features_copy(net->dev.acked_features_ex, - net->dev.backend_features_ex); + virtio_features_clear(net->dev.acked_features_ex); + if (net->backend == -1) { + net->dev.acked_features = + net->dev.features & (1ULL << VHOST_USER_F_PROTOCOL_FEATURES); + } else if (!qemu_has_vnet_hdr(net->nc)) { + net->dev.acked_features = 1ULL << VHOST_NET_F_VIRTIO_NET_HDR; + } + vhost_ack_features_ex(&net->dev, net->feature_bits, features); } @@ -258,12 +264,9 @@ struct vhost_net *vhost_net_init(VhostNetOptions *options) if (r < 0) { goto fail; } - net->dev.backend_features = qemu_has_vnet_hdr(options->net_backend) - ? 0 : (1ULL << VHOST_NET_F_VIRTIO_NET_HDR); net->backend = r; net->dev.protocol_features = 0; } else { - virtio_features_clear(net->dev.backend_features_ex); net->dev.protocol_features = 0; net->backend = -1; @@ -284,13 +287,12 @@ struct vhost_net *vhost_net_init(VhostNetOptions *options) net->dev.features &= ~(1ULL << VIRTIO_NET_F_MRG_RXBUF); } - if (virtio_features_andnot(missing_features, - net->dev.backend_features_ex, - net->dev.features_ex)) { - fprintf(stderr, "vhost lacks feature mask 0x" VIRTIO_FEATURES_FMT - " for backend\n", VIRTIO_FEATURES_PR(missing_features)); - goto fail; - } + if (!qemu_has_vnet_hdr(options->net_backend) && + (~net->dev.features & (1ULL << VHOST_NET_F_VIRTIO_NET_HDR))) { + fprintf(stderr, "vhost lacks feature mask 0x%llx for backend\n", + ~net->dev.features & (1ULL << VHOST_NET_F_VIRTIO_NET_HDR)); + goto fail; + } } /* Set sane init value. Override when guest acks. */ diff --git a/hw/scsi/vhost-scsi.c b/hw/scsi/vhost-scsi.c index 699863cc10..859888fdba 100644 --- a/hw/scsi/vhost-scsi.c +++ b/hw/scsi/vhost-scsi.c @@ -275,7 +275,6 @@ static void vhost_scsi_realize(DeviceState *dev, Error **errp) vqs = g_new0(struct vhost_virtqueue, vsc->dev.nvqs); vsc->dev.vqs = vqs; vsc->dev.vq_index = 0; - vsc->dev.backend_features = 0; ret = vhost_dev_init(&vsc->dev, (void *)(uintptr_t)vhostfd, VHOST_BACKEND_TYPE_KERNEL, 0, errp); diff --git a/hw/scsi/vhost-user-scsi.c b/hw/scsi/vhost-user-scsi.c index 3612897d4b..5070178dc2 100644 --- a/hw/scsi/vhost-user-scsi.c +++ b/hw/scsi/vhost-user-scsi.c @@ -159,7 +159,6 @@ static int vhost_user_scsi_connect(DeviceState *dev, Error **errp) vsc->dev.nvqs = VIRTIO_SCSI_VQ_NUM_FIXED + vs->conf.num_queues; vsc->dev.vqs = s->vhost_vqs; vsc->dev.vq_index = 0; - vsc->dev.backend_features = 0; ret = vhost_dev_init(&vsc->dev, &s->vhost_user, VHOST_BACKEND_TYPE_USER, 0, errp); diff --git a/hw/virtio/vdpa-dev.c b/hw/virtio/vdpa-dev.c index 4532d63653..06179e402e 100644 --- a/hw/virtio/vdpa-dev.c +++ b/hw/virtio/vdpa-dev.c @@ -104,7 +104,6 @@ static void vhost_vdpa_device_realize(DeviceState *dev, Error **errp) v->dev.vqs = vqs; v->dev.vq_index = 0; v->dev.vq_index_end = v->dev.nvqs; - v->dev.backend_features = 0; v->started = false; ret = vhost_vdpa_get_iova_range(v->vhostfd, &iova_range); diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c index 13c73e7b17..7ce17c5b2d 100644 --- a/hw/virtio/vhost-user.c +++ b/hw/virtio/vhost-user.c @@ -1465,14 +1465,15 @@ static int vhost_user_set_features(struct vhost_dev *dev, int ret; /* - * We need to include any extra backend only feature bits that - * might be needed by our device. Currently this includes the - * VHOST_USER_F_PROTOCOL_FEATURES bit for enabling protocol - * features. + * Don't lose VHOST_USER_F_PROTOCOL_FEATURES, which is vhost-user + * specific. */ - ret = vhost_user_set_u64(dev, VHOST_USER_SET_FEATURES, - features | dev->backend_features, - log_enabled); + if (virtio_has_feature(dev->features, VHOST_USER_F_PROTOCOL_FEATURES)) { + features |= 1ULL << VHOST_USER_F_PROTOCOL_FEATURES; + } + + ret = vhost_user_set_u64(dev, VHOST_USER_SET_FEATURES, features, + log_enabled); if (virtio_has_feature(dev->protocol_features, VHOST_USER_PROTOCOL_F_STATUS)) { @@ -2192,8 +2193,6 @@ static int vhost_user_backend_init(struct vhost_dev *dev, void *opaque, (dev->config_ops && dev->config_ops->vhost_dev_config_notifier); uint64_t protocol_features; - dev->backend_features |= 1ULL << VHOST_USER_F_PROTOCOL_FEATURES; - err = vhost_user_get_u64(dev, VHOST_USER_GET_PROTOCOL_FEATURES, &protocol_features); if (err < 0) { diff --git a/hw/virtio/virtio-hmp-cmds.c b/hw/virtio/virtio-hmp-cmds.c index 1daae482d3..4bf9a3109d 100644 --- a/hw/virtio/virtio-hmp-cmds.c +++ b/hw/virtio/virtio-hmp-cmds.c @@ -176,8 +176,6 @@ void hmp_virtio_status(Monitor *mon, const QDict *qdict) hmp_virtio_dump_features(mon, s->vhost_dev->features); monitor_printf(mon, " Acked features:\n"); hmp_virtio_dump_features(mon, s->vhost_dev->acked_features); - monitor_printf(mon, " Backend features:\n"); - hmp_virtio_dump_features(mon, s->vhost_dev->backend_features); monitor_printf(mon, " Protocol features:\n"); hmp_virtio_dump_protocols(mon, s->vhost_dev->protocol_features); } diff --git a/hw/virtio/virtio-qmp.c b/hw/virtio/virtio-qmp.c index f9cdca50d9..71717c56a4 100644 --- a/hw/virtio/virtio-qmp.c +++ b/hw/virtio/virtio-qmp.c @@ -710,8 +710,6 @@ VirtioStatus *qmp_x_query_virtio_status(const char *path, Error **errp) vdev->guest_features_ex); status->host_features = qmp_decode_features(vdev->device_id, vdev->host_features_ex); - status->backend_features = qmp_decode_features(vdev->device_id, - vdev->backend_features_ex); switch (vdev->device_endian) { case VIRTIO_DEVICE_ENDIAN_LITTLE: @@ -752,8 +750,6 @@ VirtioStatus *qmp_x_query_virtio_status(const char *path, Error **errp) qmp_decode_features(vdev->device_id, hdev->features_ex); status->vhost_dev->acked_features = qmp_decode_features(vdev->device_id, hdev->acked_features_ex); - status->vhost_dev->backend_features = - qmp_decode_features(vdev->device_id, hdev->backend_features_ex); status->vhost_dev->protocol_features = qmp_decode_protocols(hdev->protocol_features); diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h index 3dfec5e15c..e139e05985 100644 --- a/include/hw/virtio/vhost.h +++ b/include/hw/virtio/vhost.h @@ -100,16 +100,9 @@ struct vhost_dev { * * @features: available features provided by the backend * @acked_features: final negotiated features with front-end driver - * - * @backend_features: this is used in a couple of places to either - * store VHOST_USER_F_PROTOCOL_FEATURES to apply to - * VHOST_USER_SET_FEATURES or VHOST_NET_F_VIRTIO_NET_HDR. Its - * future use should be discouraged and the variable retired as - * its easy to confuse with the VirtIO backend_features. */ VIRTIO_DECLARE_FEATURES(features); VIRTIO_DECLARE_FEATURES(acked_features); - VIRTIO_DECLARE_FEATURES(backend_features); /** * @protocol_features: is the vhost-user only feature set by diff --git a/qapi/virtio.json b/qapi/virtio.json index 09dd0e6d05..671f1ad793 100644 --- a/qapi/virtio.json +++ b/qapi/virtio.json @@ -85,8 +85,6 @@ # # @acked-features: vhost_dev acked_features # -# @backend-features: vhost_dev backend_features -# # @protocol-features: vhost_dev protocol_features # # @max-queues: vhost_dev max_queues @@ -106,7 +104,6 @@ 'vq-index': 'int', 'features': 'VirtioDeviceFeatures', 'acked-features': 'VirtioDeviceFeatures', - 'backend-features': 'VirtioDeviceFeatures', 'protocol-features': 'VhostDeviceProtocols', 'max-queues': 'uint64', 'backend-cap': 'uint64', -- MST