From e87b6efb11be9f5ff213461f5ecdbae47d9402b9 Mon Sep 17 00:00:00 2001 From: Matias Ezequiel Vara Larsen Date: Mon, 17 Feb 2025 14:12:55 +0100 Subject: [PATCH] vhost-user-snd: correct the calculation of config_size MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Use virtio_get_config_size() rather than sizeof(struct virtio_snd_config) for the config_size in the vhost-user-snd frontend. The frontend shall rely on device features for the size of the device configuration space. The presence of `controls` in the config space depends on VIRTIO_SND_F_CTLS according to the specification (v1.3): ` 5.14.4 Device Configuration Layout ... controls (driver-read-only) indicates a total number of all available control elements if VIRTIO_SND_F_CTLS has been negotiated. ` This fixes an issue introduced by commit ab0c7fb2 ("linux-headers: update to current kvm/next") in which the optional field `controls` is added to the virtio_snd_config structure. This breaks vhost-user-device backends that do not implement the `controls` field. Fixes: ab0c7fb22b ("linux-headers: update to current kvm/next") Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2805 Reviewed-by: Philippe Mathieu-Daudé Suggested-by: Stefano Garzarella Signed-off-by: Matias Ezequiel Vara Larsen Message-Id: <20250217131255.829892-1-mvaralar@redhat.com> Cc: qemu-stable@nongnu.org Reviewed-by: Stefano Garzarella Reviewed-by: Dorinda Bassey Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/virtio/vhost-user-snd.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/hw/virtio/vhost-user-snd.c b/hw/virtio/vhost-user-snd.c index 8610370af8..b414c75c06 100644 --- a/hw/virtio/vhost-user-snd.c +++ b/hw/virtio/vhost-user-snd.c @@ -16,6 +16,18 @@ #include "standard-headers/linux/virtio_ids.h" #include "standard-headers/linux/virtio_snd.h" +static const VirtIOFeature feature_sizes[] = { + {.flags = 1ULL << VIRTIO_SND_F_CTLS, + .end = endof(struct virtio_snd_config, controls)}, + {} +}; + +static const VirtIOConfigSizeParams cfg_size_params = { + .min_size = endof(struct virtio_snd_config, chmaps), + .max_size = sizeof(struct virtio_snd_config), + .feature_sizes = feature_sizes +}; + static const VMStateDescription vu_snd_vmstate = { .name = "vhost-user-snd", .unmigratable = 1, @@ -23,16 +35,20 @@ static const VMStateDescription vu_snd_vmstate = { static const Property vsnd_properties[] = { DEFINE_PROP_CHR("chardev", VHostUserBase, chardev), + DEFINE_PROP_BIT64("controls", VHostUserBase, + parent_obj.host_features, VIRTIO_SND_F_CTLS, false), }; static void vu_snd_base_realize(DeviceState *dev, Error **errp) { VHostUserBase *vub = VHOST_USER_BASE(dev); VHostUserBaseClass *vubs = VHOST_USER_BASE_GET_CLASS(dev); + VirtIODevice *vdev = &vub->parent_obj; vub->virtio_id = VIRTIO_ID_SOUND; vub->num_vqs = 4; - vub->config_size = sizeof(struct virtio_snd_config); + vub->config_size = virtio_get_config_size(&cfg_size_params, + vdev->host_features); vub->vq_size = 64; vubs->parent_realize(dev, errp); -- 2.30.2